A new method to measure necrotic core and calcium content in coronary plaques using intravascular ultrasound radiofrequency-based analysis

NARCIS (Netherlands)

E.S. Shin (Eun-Seok); H.M. Garcia-Garcia (Hector); P.W.J.C. Serruys (Patrick)

2010-01-01

textabstractAlthough previous intravascular ultrasound (IVUS) radiofrequency-based analysis data showed acceptable reproducibility for plaque composition, measurements are not easily obtained, particularly that of lumen contour, because of the limited IVUS resolution. The purpose of this study was

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

DEFF Research Database (Denmark)

Huisman, Jennifer; Egede, Rasmus; Rdzanek, Adam

2012-01-01

To assess in a multicenter design the between-center reproducibility of volumetric virtual histology intravascular ultrasound (VH-IVUS) measurements with a semi-automated, computer-assisted contour detection system in coronary lesions that were consecutively stented. To evaluate the reproducibility...... of volumetric VH-IVUS measurements, experienced analysts of 4 European IVUS centers performed independent analyses (in total 8,052 cross-sectional analyses) to obtain volumetric data of 40 coronary segments (length 20.0 ± 0.3 mm) from target lesions prior to percutaneous intervention that were performed...... in the setting of stable (65%) or unstable angina pectoris (35%). Geometric and compositional VH-IVUS measurements were highly correlated for the different comparisons. Overall intraclass correlation for vessel, lumen, plaque volume and plaque burden was 0.99, 0.92, 0.96, and 0.83, respectively; for fibrous...

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

Directory of Open Access Journals (Sweden)

Sridhar Kasturi, MD, DM, FACC

2015-12-01

Full Text Available 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.

Comparison of angiography and intravascular ultrasound before and after balloon angioplasty of the femoropopliteal artery

International Nuclear Information System (INIS)

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

1998-01-01

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.

Impact of statin therapy on coronary plaque composition: A systematic review and meta-analysis of virtual histology intravascular ultrasound studies

NARCIS (Netherlands)

M. Banach (Maciej); C. Serban (Corina); A. Sahebkar (Amirhossein); D.P. Mikhailidis (Dimitri P.); S. Ursoniu (Sorin); K.K. Ray (Kausik K.); J. Rysz (Jacek); P.P. Toth (Peter); P. Muntner (Paul); S. Mosteoru (Svetlana); H.M. Garcia-Garcia (Hector); G.K. Hovingh (Kees); J.J.P. Kastelein (John); P.W.J.C. Serruys (Patrick)

2015-01-01

textabstractBackground: Virtual histology intravascular ultrasound (VH-IVUS) imaging is an innovative tool for the morphological evaluation of coronary atherosclerosis. Evidence for the effects of statin therapy on VH-IVUS parameters have been inconclusive. Consequently, we performed a systematic

Efficacy And Safety Of IVUS-Guided Percutaneous Coronary Interventions

Directory of Open Access Journals (Sweden)

Popovic Marija

2015-06-01

Full Text Available The inclusion of IVUS-guided PCI has yet to become a routine approach in invasive cardiology due to the relatively high cost of the procedure, equivocal positive results in important studies and the steep learning curve. As an additional diagnostic tool, IVUS seems to be irreplaceable in stent apposition research, edge dissections and the determination of plaque composition.

Impact of statin therapy on coronary plaque composition: a systematic review and meta-analysis of virtual histology intravascular ultrasound studies

NARCIS (Netherlands)

Banach, Maciej; Serban, Corina; Sahebkar, Amirhossein; Mikhailidis, Dimitri P.; Ursoniu, Sorin; Ray, Kausik K.; Rysz, Jacek; Toth, Peter P.; Muntner, Paul; Mosteoru, Svetlana; García-García, Hector M.; Hovingh, G. Kees; Kastelein, John J. P.; Serruys, Patrick W.

2015-01-01

Virtual histology intravascular ultrasound (VH-IVUS) imaging is an innovative tool for the morphological evaluation of coronary atherosclerosis. Evidence for the effects of statin therapy on VH-IVUS parameters have been inconclusive. Consequently, we performed a systematic review and meta-analysis

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

NARCIS (Netherlands)

Huisman, Jeroen; Egede, R.; Rdzanek, A.; Böse, D.; Erbel, R.; van der Palen, Jacobus Adrianus Maria; von Birgelen, Clemens

2012-01-01

To assess in a multicenter design the between-center reproducibility of volumetric virtual histology intravascular ultrasound (VH-IVUS) measurements with a semi-automated, computer-assisted contour detection system in coronary lesions that were consecutively stented. To evaluate the reproducibility

Association of insulin resistance and coronary artery remodeling: an intravascular ultrasound study

OpenAIRE

Kim, Sang-Hoon; Moon, Jae-Youn; Lim, Yeong Min; Kim, Kyung Ho; Yang, Woo-In; Sung, Jung-Hoon; Yoo, Seung Min; Kim, In Jai; Lim, Sang-Wook; Cha, Dong-Hun; Cho, Seung-Yun

2015-01-01

Background There are few studies that investigated the correlation between insulin resistance (IR) and the coronary artery remodeling. The aim of the study is to investigate the association of IR measured by homeostasis model assessment of insulin resistance (HOMA-IR) and coronary artery remodeling evaluated by intravascular ultrasound (IVUS). Methods A total of 298 consecutive patients who received percutaneous coronary interventions under IVUS guidance were retrospectively enrolled. The val...

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

Directory of Open Access Journals (Sweden)

Jinwon Son

2017-01-01

Full Text Available 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.

Intravascular ultrasound based dose assessment in endovascular brachytherapy

International Nuclear Information System (INIS)

Catalano, Gianpiero; Tamburini, Vittorio; Colombo, Antonio; Nishida, Takahiro; Parisi, Giovanni; Mazzetta, Chiara; Orecchia, Roberto

2003-01-01

Background: the role of endovascular brachytherapy in restenosis prevention is well documented. Dose is usually prescribed at a fixed distance from the source axis by angiographic quantification of vessel diameter. Recently, intravascular ultrasound (IVUS) was introduced in dose prescription, allowing a better evaluation of the vessel anatomy. This study retrospectively explores the difference between prescription following angiographic vessel sizing and delivered dose calculated with IVUS. Methods and results: Seventeen lesions were studied with IVUS, identifying on irradiated segment, three sections on which measuring minimal and maximal distance from the centre of IVUS catheter to the adventitia; using dedicated software, corresponding doses were calculated. The dose ranged widely, with maximal and minimal values of 71.6 and 4.9 Gy; furthermore, heterogeneity in dose among different sections was observed. In the central section, the maximal dose was 206% of the one prescribed with the QCA model at 2 mm from the source axis, while the minimal dose was 96%. In proximal and distal sections, respective values were 182, 45, 243, and 122%. Conclusions: Our analysis confirmed the dose inhomogeneity delivered with an angiographic fixed-dose prescription strategy. A dose variation was found along the irradiated segment due to the differences in vessel thickness. IVUS emerged as an important tool in endovascular brachytherapy, especially for irregular-shaped vessels

The clinical importance and prediction of steal following femoro-femoral cross-over bypass: study of the donor iliac artery by intravascular ultrasound, arteriography, duplex scanning and pressure measurements

DEFF Research Database (Denmark)

Vogt, K C; Rasmussen, J G; Schroeder, T V

2000-01-01

to evaluate the clinical significance of the steal phenomenon following femoro-femoral bypass, and whether the addition of intravascular ultrasound (IVUS) to the established examinations of the donor iliac artery can improve the prediction of patients who will develop steal.......to evaluate the clinical significance of the steal phenomenon following femoro-femoral bypass, and whether the addition of intravascular ultrasound (IVUS) to the established examinations of the donor iliac artery can improve the prediction of patients who will develop steal....

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

International Nuclear Information System (INIS)

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

1998-01-01

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

Anatomical and Physiological Changes after Paclitaxel-Coated Balloon for Atherosclerotic De Novo Coronary Lesions: Serial IVUS-VH and FFR Study.

Directory of Open Access Journals (Sweden)

Soe Hee Ann

Full Text Available 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.

Comparison of intravascular ultrasound and angiographic assessement of coronary reference segment size in patients with type 2 diabetes mellitus

DEFF Research Database (Denmark)

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

2008-01-01

During percutaneous coronary intervention, the reference segment is assessed angiographically. This report described the discrepancy between angiographic and intravascular ultrasound (IVUS) assessment of reference segment size in patients with type 2 diabetes mellitus. Preintervention IVUS was used...... to study 62 de novo lesions in 41 patients with type 2 diabetes mellitus. The lesion site was the image slice with the smallest lumen cross-sectional area (CSA). The proximal and distal reference segments were the most normal-looking segments within 5 mm proximal and distal to the lesion. Plaque burden...... was measured as plaque CSA/external elastic membrane (EEM) CSA. Using IVUS, the reference lumen diameter was 2.80 +/- 0.42 mm and the reference EEM diameter was 4.17 +/- 0.56 mm. The angiographic reference diameter was 2.63 +/- 0.36 mm. Mean difference between the IVUS EEM diameter and angiographic reference...

Focus on the research utility of intravascular ultrasound - comparison with other invasive modalities

Directory of Open Access Journals (Sweden)

Hoye Angela

2011-01-01

Full Text Available Abstract Intravascular ultrasound (IVUS is an invasive modality which provides cross-sectional images of a coronary artery. In these images both the lumen and outer vessel wall can be identified and accurate estimations of their dimensions and of the plaque burden can be obtained. In addition, further processing of the IVUS backscatter signal helps in the characterization of the type of the plaque and thus it has been used to study the natural history of the atherosclerotic evolution. On the other hand its indigenous limitations do not allow IVUS to assess accurately stent struts coverage, existence of thrombus or exact site of plaque rupture and to identify some of the features associated with increased plaque vulnerability. In order this information to be obtained, other modalities such as optical coherence tomography, angioscopy, near infrared spectroscopy and intravascular magnetic resonance imaging have either been utilized or are under evaluation. The aim of this review article is to present the current utilities of IVUS in research and to discuss its advantages and disadvantages over the other imaging techniques.

Association between increased epicardial adipose tissue volume and coronary plaque composition

OpenAIRE

Yamashita, Kennosuke; Yamamoto, Myong Hwa; Ebara, Seitarou; Okabe, Toshitaka; Saito, Shigeo; Hoshimoto, Koichi; Yakushiji, Tadayuki; Isomura, Naoei; Araki, Hiroshi; Obara, Chiaki; Ochiai, Masahiko

2013-01-01

To assess the relationship between epicardial adipose tissue volume (EATV) and plaque vulnerability in significant coronary stenosis using a 40-MHz intravascular ultrasound (IVUS) imaging system (iMap-IVUS), we analyzed 130 consecutive patients with coronary stenosis who underwent dual-source computed tomography (CT) and cardiac catheterization. Culprit lesions were imaged by iMap-IVUS before stenting. The iMAP-IVUS system classified coronary plaque components as fibrous, lipid, necrotic, or ...

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-09-15

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

Intravascular ultrasound guided directional atherectomy versus directional atherectomy guided by angiography for the treatment of femoropopliteal in-stent restenosis

Science.gov (United States)

Krishnan, Prakash; Tarricone, Arthur; K-Raman, Purushothaman; Majeed, Farhan; Kapur, Vishal; Gujja, Karthik; Wiley, Jose; Vasquez, Miguel; Lascano, Rheoneil A.; Quiles, Katherine G.; Distin, Tashanne; Fontenelle, Ran; Atallah-Lajam, Farah; Kini, Annapoorna; Sharma, Samin

2017-01-01

Background: The aim of this study was to compare 1-year outcomes for patients with femoropopliteal in-stent restenosis using directional atherectomy guided by intravascular ultrasound (IVUS) versus directional atherectomy guided by angiography. Methods and results: This was a retrospective analysis for patients with femoropopliteal in-stent restenosis treated with IVUS-guided directional atherectomy versus directional atherectomy guided by angiography from a single center between March 2012 and February 2016. Clinically driven target lesion revascularization was the primary endpoint and was evaluated through medical chart review as well as phone call follow up. Conclusions: Directional atherectomy guided by IVUS reduces clinically driven target lesion revascularization for patients with femoropopliteal in-stent restenosis. PMID:29265002

Heterogeneous Intravascular Ultrasound Findings of Stent Thrombosis

OpenAIRE

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 d...

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

Science.gov (United States)

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.

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

DEFF Research Database (Denmark)

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

2012-01-01

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

Development of an intravascular ultrasound elastography based on a dual-element transducer

Science.gov (United States)

Shih, Cho-Chiang; Chen, Pei-Yu; Ma, Teng; Zhou, Qifa; Shung, K. Kirk; Huang, Chih-Chung

2018-04-01

The ability to measure the elastic properties of plaques and vessels would be useful in clinical diagnoses, particularly for detecting a vulnerable plaque. This study demonstrates the feasibility of the combination of intravascular ultrasound (IVUS) and acoustic radiation force elasticity imaging for detecting the distribution of stiffness within atherosclerotic arteries ex vivo. A dual-frequency IVUS transducer with two elements was used to induce the propagation of the shear wave (by the 8.5 MHz pushing element) which could be simultaneously monitored by the 31 MHz imaging element. The wave-amplitude image and the wave-velocity image were reconstructed by measuring the peak displacement and wave velocity of shear wave propagation, respectively. System performance was verified using gelatin phantoms. The phantom results demonstrate that the stiffness differences of shear modulus of 1.6 kPa can be distinguished through the wave-amplitude and wave-velocity images. The stiffness distributions of the atherosclerotic aorta from a rabbit were obtained, for which the values of peak displacement and the shear wave velocity were 3.7 ± 1.2 µm and 0.38 ± 0.19 m s-1 for the lipid-rich plaques, and 1.0 ± 0.2 µm and 3.45 ± 0.45 m s-1 for the arterial walls, respectively. These results indicate that IVUS elasticity imaging can be used to distinguish the elastic properties of plaques and vessels.

Application of intravascular ultrasound in percutaneous coronary interventional therapy

International Nuclear Information System (INIS)

Wang Jingping; Li Bao; An Jian; Yang Bin; Wang Zhongchao; Wang Rijun; Zhang Wutang; Lei Xinyu; Wang Huixian; Lu Lifang; Gao Yongli

2009-01-01

Objective: To evaluate intravascular ultrasound (IVUS)in demonstrating the characteristics of coronary plaque and in implanting the coronary stent. Methods: Before stent implantation, IVUS was used to observe the plaque character/sties(soft, fibrotic, calcified or mixed) as well as the eccentric degree in 28 patients with angiographically-proved single coronary branch lesion. The minimal luminal diameter, minimal cross-sectional area and plaque area were measured. After stent deployment the above measurements were repeated, and the location, symmetrical index and expansion of the stent were observed. Results: A total of 36 stents was implanted in 28 patients with coronary disease. After the procedure the minimal luminal diameter and the minimal cross-sectional area was increased, while the plaque area was decreased. The difference between the values before and after the stent implantation was statistically significant (P<0.01). IVUS after stent deployment found that in all cases the stent had a nice location and covered the lesion completely with no interlayer at its both ends. Excellent expansion of the stent was seen in 30 cases (83.3%). Insufficient expansion occurred in 3 cases and undesirable contact of the stent to the arterial wall was found in 3 cases (16.7%). In such circumstances, one size bigger low-compliance balloon dilatation was adopted, or the original balloon was used again with higher pressure (18-22 atm), in order to expand the stent once more, and good results accord with IVUS optimal criteria were obtained. Conclusions: IVUS can clearly demonstrate the pathological features of the coronary lesions, such as plaque type, eccentric degree, luminal diameter, cross-sectional area and plaque area, which are very helpful in guiding the selection of the proper stent before the procedure, and are also very useful in evaluating the location, expansion of the stent as well as the stent-to-wall contact condition after the procedure. (authors)

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-08-15

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

Variability and accuracy of coronary CT angiography including use of iterative reconstruction algorithms for plaque burden assessment as compared with intravascular ultrasound - an ex vivo study

Energy Technology Data Exchange (ETDEWEB)

Stolzmann, Paul [Massachusetts General Hospital and Harvard Medical School, Cardiac MR PET CT Program, Boston, MA (United States); University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Schlett, Christopher L.; Maurovich-Horvat, Pal; Scheffel, Hans; Engel, Leif-Christopher; Karolyi, Mihaly; Hoffmann, Udo [Massachusetts General Hospital and Harvard Medical School, Cardiac MR PET CT Program, Boston, MA (United States); Maehara, Akiko; Ma, Shixin; Mintz, Gary S. [Columbia University Medical Center, Cardiovascular Research Foundation, New York, NY (United States)

2012-10-15

To systematically assess inter-technique and inter-/intra-reader variability of coronary CT angiography (CTA) to measure plaque burden compared with intravascular ultrasound (IVUS) and to determine whether iterative reconstruction algorithms affect variability. IVUS and CTA data were acquired from nine human coronary arteries ex vivo. CT images were reconstructed using filtered back projection (FBPR) and iterative reconstruction algorithms: adaptive-statistical (ASIR) and model-based (MBIR). After co-registration of 284 cross-sections between IVUS and CTA, two readers manually delineated the cross-sectional plaque area in all images presented in random order. Average plaque burden by IVUS was 63.7 {+-} 10.7% and correlated significantly with all CTA measurements (r = 0.45-0.52; P < 0.001), while CTA overestimated the burden by 10 {+-} 10%. There were no significant differences among FBPR, ASIR and MBIR (P > 0.05). Increased overestimation was associated with smaller plaques, eccentricity and calcification (P < 0.001). Reproducibility of plaque burden by CTA and IVUS datasets was excellent with a low mean intra-/inter-reader variability of <1/<4% for CTA and <0.5/<1% for IVUS respectively (P < 0.05) with no significant difference between CT reconstruction algorithms (P > 0.05). In ex vivo coronary arteries, plaque burden by coronary CTA had extremely low inter-/intra-reader variability and correlated significantly with IVUS measurements. Accuracy as well as reader reliability were independent of CT image reconstruction algorithm. (orig.)

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

Directory of Open Access Journals (Sweden)

Varga Albert

2011-06-01

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

Intravascular ultrasound evaluation of JETSTREAM atherectomy removal of superficial calcium in peripheral arteries.

Science.gov (United States)

Maehara, Akiko; Mintz, Gary S; Shimshak, Thomas M; Ricotta, Joseph J; Ramaiah, Venkatesh; Foster, Malcolm T; Davis, Thomas P; Gray, William A

2015-05-01

Endovascular treatment of calcified femoral-popliteal disease is challenging. We sought to evaluate the mechanism of lumen gain when using the JETSTREAM Atherectomy System to treat calcified peripheral artery lesions. The JETSTREAM Calcium Study was a prospective, single-arm, multicentre study to evaluate the JETSTREAM Atherectomy System for severely calcified femoral-popliteal artery lesions, i.e., patients with claudication and lesions with superficial calcium >90° and >5 mm in length as determined by intravascular ultrasound (IVUS). The 2.1 mm catheter was used in this study without distal protection. Fifty-five patients underwent angiographic screening: 26 (45%) met IVUS inclusion criteria. Angiographic calcium was moderate in eight cases and severe in 14, with no available data for four cases. Visual diameter stenosis was 86±9% pre-treatment, 37±13% post atherectomy, and 10±6% post adjunctive treatment (adjunctive PTA+stenting in eight and adjunct PTA alone in 16). IVUS showed lumen area increased from 6.6±3.7 mm2 to 10.0±3.6 mm2 (p=0.001): calcium reduction was responsible for 86±23% of the lumen increase. Although the superficial calcium arc did not change (151±70° to 146±71°, p=0.83), the arc of reverberation increased (23±20° to 65±40°, p=0.006), indicating device-related modification of calcium. Adjunctive balloon angioplasty was performed in 62% of the lesions, and stent implantation in 31%. In 11 cases with adjunctive balloon dilation, the MLA increased from 7.1 (6.4, 7.8) mm2 post atherectomy to 11.9 (10.3, 13.5) mm2 post balloon (pAtherectomy System increased lumen dimensions in moderately or severely calcified femoral-popliteal lesions by removing superficial calcium without major complications.

Accuracy of multidetector row computed tomography for the detection of transplant vasculopathy: comparison with invasive coronary angiography and intravascular ultrasound

International Nuclear Information System (INIS)

Carrascosa, P.; Capunay, C.; Carrascosa, J.; Perrone, S.; Deviggiano, A.; Lopez, E.M.; Lev, G.; Garcia, M.J.

2009-01-01

Objective: To evaluate the diagnostic accuracy of multidetector computed tomography (MDCT) for detection of luminal stenosis and cardiac allograft vasculopathy in comparison with coronary angiography (CA) and intravascular ultrasound (IVUS) respectively. Material and methods: Nineteen cardiac transplant patients scheduled for follow-up CA were included. MDCT coronary angiography was performed using a 16-row CT scanner within 7-14 days after CA and IVUS. Studies were analyzed by independent readers; two observers evaluated the CT datasets for the presence of coronary artery stenosis > 50% and allograft vasculopathy. Results: The sensitivity for detecting > 50% luminal stenosis was 80-88% and specificity, 98-99% and for detection of cardiac allograft vasculopathy, the sensitivity was 91-96% and specificity, 88-91%. Conclusion: In this preliminary series, our results indicate that MDCT coronary angiography was capable of detecting both significant coronary stenosis as well as diffuse intimal proliferation. This non-invasive procedure could be an alternative to CA and IVUS in the surveillance of heart transplant patients. (authors) [es

Lumen and calcium characteristics within calcified coronary lesions. Comparison of computed tomography coronary angiography versus intravascular ultrasound.

Science.gov (United States)

Noll, Dariusz; Kruk, Mariusz; Pręgowski, Jerzy; Kaczmarska, Edyta; Kryczka, Karolina; Pracoń, Radosław; Skwarek, Mirosław; Dzielińska, Zofia; Petryka, Joanna; Spiewak, Mateusz; Lubiszewska, Barbara; Norwa-Otto, Bożena; Opolski, Maksymilian; Witkowski, Adam; Demkow, Marcin; Rużyłło, Witold; Kępka, Cezary

2013-01-01

Computed tomography coronary angiography (CTCA) is a diagnostic method used for exclusion of coronary artery disease. However, lower accuracy of CTCA in assessment of calcified lesions is a significant factor impeding applicability of CTCA for assessment of coronary atherosclerosis. To provide insight into lumen and calcium characteristics assessed with CTCA, we compared these parameters to the reference of intravascular ultrasound (IVUS). Two hundred and fifty-two calcified lesions within 97 arteries of 60 patients (19 women, age 63 ±10 years) underwent assessment with both 2 × 64 slice CT (Somatom Definition, Siemens) and IVUS (s5, Volcano Corp.). Coronary lumen and calcium dimensions within calcified lesions were assessed with CTCA and compared to the reference measurements made with IVUS. On average CTCA underestimated mean lumen diameter (2.8 ±0.7 mm vs. 2.9 ±0.8 mm for IVUS), lumen area (6.4 ±3.4 mm(2) vs. 7.0 ±3.7 mm(2) for IVUS, p < 0.001) and total calcium arc (52 ±35° vs. 83 ±54°). However, analysis of tertiles of the examined parameters revealed that the mean lumen diameter, lumen area and calcium arc did not significantly differ between CTCA and IVUS within the smallest lumens (1(st) tertile of mean lumen diameter at 2.1 mm, and 1(st) tertile of lumen area at 3.7 mm(2)) and lowest calcium arc (mean of 40°). Although, on average, CTCA underestimates lumen diameter and area as well as calcium arc within calcified lesions, the differences are not significant within the smallest vessels and calcium arcs. The low diagnostic accuracy of CTCA within calcified lesions may be attributed to high variance and not to systematic error of measurements.

Impact of analyzing fewer image frames per segment during offline volumetric radiofrequency based intravascular ultrasound measurements of target lesions prior to percutaneous coronary interventions

NARCIS (Netherlands)

Huisman, J.; Hartmann, M.; Hartmann, M.; Mintz, G.S.; van Houwelingen, G.K.; Stoel, M.G.; de Man, F.H.; Louwerenburg, H.; von Birgelen, Clemens

2012-01-01

In the present study, we evaluated the impact of a 50% reduction in number of image frames (every second frame) on the analysis time and variability of offline volumetric radiofrequency-based intravascular ultrasound (RF-IVUS) measurements in target lesions prior to percutaneous coronary

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

International Nuclear Information System (INIS)

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

2010-01-01

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.

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

Science.gov (United States)

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.

Serial Assessment of Tissue Precursors and Progression of Coronary Calcification Analyzed by Fusion of IVUS and OCT

DEFF Research Database (Denmark)

Zeng, Yaping; Tateishi, Hiroki; Cavalcante, Rafael

2017-01-01

have individual strengths in assessing plaque composition and volume. Fusion of images obtained using these methods could potentially aid in coronary plaque assessment. METHODS: Anatomic landmarks and endoluminal radiopaque markers were used to fuse OCT and IVUS images and match baseline and follow......-up. RESULTS: 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...... 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%. CONCLUSIONS: 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...

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

Energy Technology Data Exchange (ETDEWEB)

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

2007-10-15

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

Prospective implementation of an algorithm for bedside intravascular ultrasound-guided filter placement in critically ill patients.

Science.gov (United States)

Killingsworth, Christopher D; Taylor, Steven M; Patterson, Mark A; Weinberg, Jordan A; McGwin, Gerald; Melton, Sherry M; Reiff, Donald A; Kerby, Jeffrey D; Rue, Loring W; Jordan, William D; Passman, Marc A

2010-05-01

Although contrast venography is the standard imaging method for inferior vena cava (IVC) filter insertion, intravascular ultrasound (IVUS) imaging is a safe and effective option that allows for bedside filter placement and is especially advantageous for immobilized critically ill patients by limiting resource use, risk of transportation, and cost. This study reviewed the effectiveness of a prospectively implemented algorithm for IVUS-guided IVC filter placement in this high-risk population. Current evidence-based guidelines were used to create a clinical decision algorithm for IVUS-guided IVC filter placement in critically ill patients. After a defined lead-in phase to allow dissemination of techniques, the algorithm was prospectively implemented on January 1, 2008. Data were collected for 1 year using accepted reporting standards and a quality assurance review performed based on intent-to-treat at 6, 12, and 18 months. As defined in the prospectively implemented algorithm, 109 patients met criteria for IVUS-directed bedside IVC filter placement. Technical feasibility was 98.1%. Only 2 patients had inadequate IVUS visualization for bedside filter placement and required subsequent placement in the endovascular suite. Technical success, defined as proper deployment in an infrarenal position, was achieved in 104 of the remaining 107 patients (97.2%). The filter was permanent in 21 (19.6%) and retrievable in 86 (80.3%). The single-puncture technique was used in 101 (94.4%), with additional dual access required in 6 (5.6%). Periprocedural complications were rare but included malpositioning requiring retrieval and repositioning in three patients, filter tilt >/=15 degrees in two, and arteriovenous fistula in one. The 30-day mortality rate for the bedside group was 5.5%, with no filter-related deaths. Successful placement of IVC filters using IVUS-guided imaging at the bedside in critically ill patients can be established through an evidence-based prospectively

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

DEFF Research Database (Denmark)

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

2007-01-01

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

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

International Nuclear Information System (INIS)

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

1997-01-01

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 2 to 8.1 ± 2.7 mm 2 (p= 0.0004). Additional DA increased FLA to 9.3 ± 2.3 mm 2 (p= 0.002) after the second passage and to 9.8 ± 2.4 mm 2 (p= 0.09) after the final DA run. The plaque area (PLA) before DA decreased from 18.1 ± 4.2 mm 2 to 15.4 ± 4.8 mm 2 (p= 0.002) after the first passage, and to 13.5 ± 5.0 mm 2 (p= 0.004) and 12.8 ± 4.4 mm 2 (p= 0.07) after the second and final DA runs, respectively. PLA of the reference segment (9.5 ± 5.7 mm 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 2 to 23.0 ± 4.7 mm 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%. Conclusion: Lumen enlargement following DA is predominantly due to plaque

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

Energy Technology Data Exchange (ETDEWEB)

Danilouchkine, M G; Mastik, F; Steen, A F W van der [Department of Biomedical Engineering, Erasmus Medical Center, Ee2302, PO Box 2040, 3000 CA, Rotterdam (Netherlands)], E-mail: m.danilouchkine@ErasmusMC.nl, E-mail: f.mastik@ErasmusMC.nl, E-mail: a.vandersteen@ErasmusMC.nl

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{sup 0} 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.

Optical coherence tomography compared with intravascular ultrasound and with angiography to guide coronary stent implantation (ILUMIEN III: OPTIMIZE PCI): a randomised controlled trial.

Science.gov (United States)

Ali, Ziad A; Maehara, Akiko; Généreux, Philippe; Shlofmitz, Richard A; Fabbiocchi, Franco; Nazif, Tamim M; Guagliumi, Giulio; Meraj, Perwaiz M; Alfonso, Fernando; Samady, Habib; Akasaka, Takashi; Carlson, Eric B; Leesar, Massoud A; Matsumura, Mitsuaki; Ozan, Melek Ozgu; Mintz, Gary S; Ben-Yehuda, Ori; Stone, Gregg W

2016-11-26

Percutaneous coronary intervention (PCI) is most commonly guided by angiography alone. Intravascular ultrasound (IVUS) guidance has been shown to reduce major adverse cardiovascular events (MACE) after PCI, principally by resulting in a larger postprocedure lumen than with angiographic guidance. Optical coherence tomography (OCT) provides higher resolution imaging than does IVUS, although findings from some studies suggest that it might lead to smaller luminal diameters after stent implantation. We sought to establish whether or not a novel OCT-based stent sizing strategy would result in a minimum stent area similar to or better than that achieved with IVUS guidance and better than that achieved with angiography guidance alone. In this randomised controlled trial, we recruited patients aged 18 years or older undergoing PCI from 29 hospitals in eight countries. Eligible patients had one or more target lesions located in a native coronary artery with a visually estimated reference vessel diameter of 2·25-3·50 mm and a length of less than 40 mm. We excluded patients with left main or ostial right coronary artery stenoses, bypass graft stenoses, chronic total occlusions, planned two-stent bifurcations, and in-stent restenosis. Participants were randomly assigned (1:1:1; with use of an interactive web-based system in block sizes of three, stratified by site) to OCT guidance, IVUS guidance, or angiography-guided stent implantation. We did OCT-guided PCI using a specific protocol to establish stent length, diameter, and expansion according to reference segment external elastic lamina measurements. All patients underwent final OCT imaging (operators in the IVUS and angiography groups were masked to the OCT images). The primary efficacy endpoint was post-PCI minimum stent area, measured by OCT at a masked independent core laboratory at completion of enrolment, in all randomly allocated participants who had primary outcome data. The primary safety endpoint was procedural

Lumen and calcium characteristics within calcified coronary lesions. Comparison of computed tomography coronary angiography versus intravascular ultrasound

OpenAIRE

Noll, Dariusz; Kruk, Mariusz; Pręgowski, Jerzy; Kaczmarska, Edyta; Kryczka, Karolina; Pracoń, Radosław; Skwarek, Mirosław; Dzielińska, Zofia; Petryka, Joanna; Śpiewak, Mateusz; Lubiszewska, Barbara; Norwa-Otto, Bożena; Opolski, Maksymilian; Witkowski, Adam; Demkow, Marcin

2013-01-01

Introduction Computed tomography coronary angiography (CTCA) is a diagnostic method used for exclusion of coronary artery disease. However, lower accuracy of CTCA in assessment of calcified lesions is a significant factor impeding applicability of CTCA for assessment of coronary atherosclerosis. Aim To provide insight into lumen and calcium characteristics assessed with CTCA, we compared these parameters to the reference of intravascular ultrasound (IVUS). Material and methods Two hundred and...

Detection of attenuated plaque in stable angina with 64-multidetector computed tomography: a comparison with intravascular ultrasound.

Science.gov (United States)

Jinzaki, Masahiro; Okabe, Teruo; Endo, Ayaka; Kawamura, Akio; Koga, Seiko; Yamada, Minoru; Fukuda, Keiichi; Kuribayashi, Sachio

2012-01-01

To clarify multidetector computed tomography (MDCT) findings of attenuated plaque detected by intravascular ultrasound (IVUS). One hundred and fifty-four patients with stable angina underwent MDCT before IVUS. The attenuated plaque was identified in the targeted artery with IVUS, and the same artery was analyzed with MDCT for the presence of a high density area (HDA) >130 Hounsfield units (HU), and a low density area (LDA) HDA in attenuated plaque was compared with that in calcified plaque. Ten attenuated plaques and 15 calcified plaques were identified in 9 of 154 patients (males=9, 66.2 ± 9.5 years). Eight of the 10 attenuated plaques and all 15 calcified plaques were accompanied with a HDA on MDCT. The HDA ranged from 174 to 667 HU (mean 389.0 ± 148.3 HU) in the 8 attenuated plaques, and from 545 to 1,205 HU (mean 920.9 ± 215.9 HU) in 15 calcified plaques. There was a significant difference in CT density of the HDA between the attenuated and calcified plaque (PHDA. MDCT has the ability to demonstrate attenuated plaque as the combination of HDA (approximately 400 HU on average) and LDA HDA can be differentiated from calcified plaque by its lower CT density value.

Análisis in vivo de la vasculopatía arterial pulmonar mediante ultrasonido intravascular (IVUS) en pacientes con insuficiencia respiratoria crónica evaluados para trasplante pulmonar

OpenAIRE

Acosta Vélez, Juan Gabriel

2013-01-01

El objetivo del estudio es evaluar el remodelado estructural y funcional de las arterias pulmonares asociado a insuficiencia respiratoria crónica severa, mediante ecografía intravascular (IVUS). Se incluyeron 80 pacientes en estudio pretrasplante pulmonar a los que se les realizó cateterismo cardiaco derecho e IVUS de una arteria pulmonar de mediano calibre. A través del IVUS se determinó el módulo elástico, pulsatilidad y porcentaje de fibrosis arterial. La insuficiencia respiratoria crónica...

Bioresorbable Scaffold for Treatment of Coronary Artery Lesions: Intravascular Ultrasound Results From the ABSORB Japan Trial.

Science.gov (United States)

Okada, Kozo; Honda, Yasuhiro; Kitahara, Hideki; Otagiri, Kyuhachi; Tanaka, Shigemitsu; Hollak, M Brooke; Yock, Paul G; Popma, Jeffrey J; Kusano, Hajime; Cheong, Wai-Fung; Sudhir, Krishnankutty; Fitzgerald, Peter J; Kimura, Takeshi

2018-04-09

The aim of this study was to characterize post-procedural intravascular ultrasound (IVUS) findings in the ABSORB Japan trial, specifically stratified by the size of target coronary arteries. Despite overall noninferiority confirmed in recent randomized trials comparing bioresorbable vascular scaffolds (BVS) (Absorb BVS) and cobalt-chromium everolimus-eluting metallic stents (CoCr-EES), higher event rates of Absorb BVS have been reported with suboptimal deployment, especially in small coronary arteries. In the ABSORB Japan trial, 150 patients (2:1 randomization) were scheduled in the IVUS cohort. Small vessel was defined as mean reference lumen diameter strategy, possibly different between polymeric and metallic devices, needs to be established for bioresorbable scaffold technology. (AVJ-301 Clinical Trial: A Clinical Evaluation of AVJ-301 Absorb™ BVS) in Japanese Population [ABSORB JAPAN]; NCT01844284). Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

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

Science.gov (United States)

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

Effect of cilostazol on in-stent neointimal hyperplasia after coronary artery stenting. A quantitative coronary angiography and volumetric intravascular ultrasound study

International Nuclear Information System (INIS)

Min, Pil-Ki; Jung, Jae-Hun; Ko, Young-Guk; Choi, Donghoon; Jang, Yangsoo; Shim, Won-Heum

2007-01-01

This study was designed to investigate the efficacy of cilostazol on the prevention of in-stent neointimal hyperplasia as measured by both quantitative coronary angiography (CAG) and volumetric intravascular ultrasound (IVUS). Fifty-nine patients (39 men, age 62 years) undergoing elective coronary stenting were randomly assigned to receive aspirin plus clopidogrel or ticlopidine (Group I, n=28, 30 lesions) or aspirin plus clopidogrel or ticlopidine plus cilostazol (Group II, n=31, 35 lesions). CAG and IVUS were performed and repeated at 6 months to assess the primary endpoints of minimal luminal diameter (MLD) and in-stent neointimal hyperplasia volume. Follow-up CAG was performed on all patients and follow-up IVUS study was available for 50 lesions in 48 patients (24 lesions in Group I, 26 in Group II). There were no significant differences in the baseline angiographic data between the 2 groups. At 6 months follow-up, in-stent MLD was 1.90±0.76 mm in Group I and 2.41±0.85 mm in Group II (p=0.006). Volumetric IVUS at 6 months demonstrated that in-stent intimal hyperplasia volume per stent length was 2.2±1.4 mm 3 /mm in Group I and 1.0±0.5 mm 3 /mm in Group II (p=0.001). Triple antiplatelet therapy including cilostazol seems to be more effective at preventing in-stent neointimal hyperplasia than a dual antiplatelet regimen. (author)

Accurate and reproducible reconstruction of coronary arteries and endothelial shear stress calculation using 3D OCT: comparative study to 3D IVUS and 3D QCA.

Science.gov (United States)

Toutouzas, Konstantinos; Chatzizisis, Yiannis S; Riga, Maria; Giannopoulos, Andreas; Antoniadis, Antonios P; Tu, Shengxian; Fujino, Yusuke; Mitsouras, Dimitrios; Doulaverakis, Charalampos; Tsampoulatidis, Ioannis; Koutkias, Vassilis G; Bouki, Konstantina; Li, Yingguang; Chouvarda, Ioanna; Cheimariotis, Grigorios; Maglaveras, Nicos; Kompatsiaris, Ioannis; Nakamura, Sunao; Reiber, Johan H C; Rybicki, Frank; Karvounis, Haralambos; Stefanadis, Christodoulos; Tousoulis, Dimitris; Giannoglou, George D

2015-06-01

Geometrically-correct 3D OCT is a new imaging modality with the potential to investigate the association of local hemodynamic microenvironment with OCT-derived high-risk features. We aimed to describe the methodology of 3D OCT and investigate the accuracy, inter- and intra-observer agreement of 3D OCT in reconstructing coronary arteries and calculating ESS, using 3D IVUS and 3D QCA as references. 35 coronary artery segments derived from 30 patients were reconstructed in 3D space using 3D OCT. 3D OCT was validated against 3D IVUS and 3D QCA. The agreement in artery reconstruction among 3D OCT, 3D IVUS and 3D QCA was assessed in 3-mm-long subsegments using lumen morphometry and ESS parameters. The inter- and intra-observer agreement of 3D OCT, 3D IVUS and 3D QCA were assessed in a representative sample of 61 subsegments (n = 5 arteries). The data processing times for each reconstruction methodology were also calculated. There was a very high agreement between 3D OCT vs. 3D IVUS and 3D OCT vs. 3D QCA in terms of total reconstructed artery length and volume, as well as in terms of segmental morphometric and ESS metrics with mean differences close to zero and narrow limits of agreement (Bland-Altman analysis). 3D OCT exhibited excellent inter- and intra-observer agreement. The analysis time with 3D OCT was significantly lower compared to 3D IVUS. Geometrically-correct 3D OCT is a feasible, accurate and reproducible 3D reconstruction technique that can perform reliable ESS calculations in coronary arteries. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

An ultrasound system for simultaneous ultrasound hyperthermia and photon beam irradiation

International Nuclear Information System (INIS)

Straube, William L.; Moros, Eduardo G.; Low, Daniel A.; Klein, Eric E.; Willcut, Virgil M.; Myerson, Robert J.

1996-01-01

Purpose: An existing ultrasound system has been adapted for simultaneous use with external photon beam irradiation. The system is being used to investigate the potential for increased biological benefit of simultaneously combined hyperthermia and external beam irradiation with currently achievable temperature distributions. Methods and Materials: An existing clinical ultrasound system has been modified for simultaneous operation with a 60 Co teletherapy machine. The generator, thermometry system, computer, and applicators are located inside the treatment room, while the monitor and system control are located at the control console. Two approaches have been used clinically to combine the two modalities. In the first approach, an en-face setup is used in which the ultrasound beam and the photon beam travel through the same window of entry to the tumor. This is achieved by a reflecting system designed to deflect the ultrasound to the tumor while positioning the ultrasound transducer outside the radiation beam. The reflecting system consists of water and water-equivalent materials except for a 1 mm sheet of polished brass that is used as the reflector. The relative pressure fields were measured in water at the same distance from the ultrasound source using a scanning hydrophone with and without the reflector at the two operating frequencies of the device (1.0 and 3.4 MHz) for two applicators. Radiation dosimetry measurements were performed to determine the relationship between 60 Co irradiation through the reflector and absorbed dose. In the second approach the ultrasound and the radiation beam travel into the tumor from different windows of entry such that the radiation beam passes through no portion of the water bolus prior to entering the patient. We have termed this approach the orthogonal approach. For both approaches, the radiation fraction is given in the middle of an uninterrupted 60-min hyperthermia treatment. Results: The system modifications did not impair

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

Science.gov (United States)

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.

A Diagnostic Ultrasound Imaging System

International Nuclear Information System (INIS)

Lee, Seong Woo

1999-01-01

The ability to see the internal organs of the human body in a noninvasive way is a powerful diagnostic tool of modern medicine. Among these imaging modalities such as X-ray, MRI, and ultrasound. MRI and ultrasound are presenting much less risk of undesirable damage of both patient and examiner. In fact, no deleterious effects have been reported as a result of clinical examination by using MRI and ultrasound diagnostic equipment. As a result, their market volume has been rapidly increased. MRI has a good resolution. but there are a few disadvantages such as high price. non-real-time imaging capability. and expensive diagnostic cost. On the other hand, the ultrasound imaging system has inherently poor resolution as compared with X-ray and MRI. In spite of its poor resolution, the ultrasound diagnostic equipment is lower in price and has an ability of real-time imaging as compared with the others. As a result, the ultrasound imaging system has become general and essential modality for imaging the internal organs of human body. In this review various researches and developments to enhance the resolution of the ultrasound images are explained and future trends of the ultrasound imaging technology are described

IVUS and OCT guided primary percutaneous coronary intervention for spontaneous coronary artery dissection with bioresorbable vascular scaffolds

Energy Technology Data Exchange (ETDEWEB)

Mahmood, Muhammad Muzaffar; Austin, David, E-mail: david.austin@stees.nhs.uk

2017-01-15

Summary: Spontaneous coronary artery dissection (SCAD) is an uncommon but important cause of acute coronary syndrome. The diagnosis of SCAD by an angiogram alone can be challenging and the increasing use of intracoronary imaging has proven an invaluable diagnostic adjunct in this regard. The appropriate initial management of SCAD has been a matter of significant debate. Owing to frequent spontaneous healing of coronary dissection and a higher risk of complications with percutaneous coronary intervention (PCI) in the setting of SCAD, a default approach of mechanical revascularization is not recommended. However in the presence of vessel occlusion and on-going myocardial infarction PCI is mandated. Bioresorbable vascular scaffolds (BVS) offer potential advantages over the conventional stents in the setting of SCAD. We describe a state-of-the-art approach to the acute treatment of SCAD causing STEMI, utilizing intravascular ultrasound (IVUS), optical coherence tomography (OCT) and BVS and discuss management strategies for the modern era. - Highlights: • SCAD is an infrequent but important cause of acute coronary syndrome. • Intracoronary imaging is a useful adjunct in the diagnosis of SCAD. • Revascularization is recommended in the presence on-going myocardial infarction. • BVS may be considered preferable to conventional stents in the setting of SCAD.

IVUS and OCT guided primary percutaneous coronary intervention for spontaneous coronary artery dissection with bioresorbable vascular scaffolds

International Nuclear Information System (INIS)

Mahmood, Muhammad Muzaffar; Austin, David

2017-01-01

Summary: Spontaneous coronary artery dissection (SCAD) is an uncommon but important cause of acute coronary syndrome. The diagnosis of SCAD by an angiogram alone can be challenging and the increasing use of intracoronary imaging has proven an invaluable diagnostic adjunct in this regard. The appropriate initial management of SCAD has been a matter of significant debate. Owing to frequent spontaneous healing of coronary dissection and a higher risk of complications with percutaneous coronary intervention (PCI) in the setting of SCAD, a default approach of mechanical revascularization is not recommended. However in the presence of vessel occlusion and on-going myocardial infarction PCI is mandated. Bioresorbable vascular scaffolds (BVS) offer potential advantages over the conventional stents in the setting of SCAD. We describe a state-of-the-art approach to the acute treatment of SCAD causing STEMI, utilizing intravascular ultrasound (IVUS), optical coherence tomography (OCT) and BVS and discuss management strategies for the modern era. - Highlights: • SCAD is an infrequent but important cause of acute coronary syndrome. • Intracoronary imaging is a useful adjunct in the diagnosis of SCAD. • Revascularization is recommended in the presence on-going myocardial infarction. • BVS may be considered preferable to conventional stents in the setting of SCAD.

A comparison between plaque-based and vessel-based measurement for plaque component using volumetric intravascular ultrasound radiofrequency data analysis.

Science.gov (United States)

Shin, Eun-Seok; Garcia-Garcia, Hector M; Garg, Scot; Serruys, Patrick W

2011-04-01

Although percent plaque components on plaque-based measurement have been used traditionally in previous studies, the impact of vessel-based measurement for percent plaque components have yet to be studied. The purpose of this study was therefore to correlate percent plaque components derived by plaque- and vessel-based measurement using intravascular ultrasound virtual histology (IVUS-VH). The patient cohort comprised of 206 patients with de novo coronary artery lesions who were imaged with IVUS-VH. Age ranged from 35 to 88 years old, and 124 patients were male. Whole pullback analysis was used to calculate plaque volume, vessel volume, and absolute and percent volumes of fibrous, fibrofatty, necrotic core, and dense calcium. The plaque and vessel volumes were well correlated (r = 0.893, P measurement was also highly correlated with vessel-based measurement. Therefore, the percent plaque component volume calculated by vessel volume could be used instead of the conventional percent plaque component volume calculated by plaque volume.

Intravascular Young's modulus reconstruction using a parametric finite element model

NARCIS (Netherlands)

Baldewsing, R.A.; Oomens, C.W.J.; Steen, van der A.F.W.; Yuhas, D.; Schneider, S.C.

2003-01-01

IntraVascular UltraSound (IVUS) elastography may be used to detect vulnerable, rupture prone plaques, which are held responsible for the majority of acute coronary syndromes. IVUS elastography accomplishes this by visualising local incremental radial strain of arteries, in so-called elastograms.

StentBoost Visualization for the Evaluation of Coronary Stent Expansion During Percutaneous Coronary Interventions

OpenAIRE

Cura, Fernando; Albertal, Mariano; Candiello, Alfonsina; Nau, Gerardo; Bonvini, Victor; Tricherri, Hernan; Padilla, Lucio T.; Belardi, Jorge A.

2013-01-01

Introduction Inadequate stent implantation is associated with stent thrombosis and restenosis. StentBoost can enhance stent visualization and evaluate stent expansion. Currently, there are limited comparison studies between StentBoost and intravascular ultrasound (IVUS). We aimed to test the correlation and agreement between IVUS and StentBoost measurements. Methods From December 2010 to December 2011, 38 patients (54 stents) were analyzed using IVUS and StentBoost. Minimal stent diameter and...

Automatic media-adventitia IVUS image segmentation based on sparse representation framework and dynamic directional active contour model.

Science.gov (United States)

Zakeri, Fahimeh Sadat; Setarehdan, Seyed Kamaledin; Norouzi, Somayye

2017-10-01

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.

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

DEFF Research Database (Denmark)

Antonsen, Lisbeth; Maeng, Michael; Thayssen, Per

2013-01-01

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

Association between increased epicardial adipose tissue volume and coronary plaque composition.

Science.gov (United States)

Yamashita, Kennosuke; Yamamoto, Myong Hwa; Ebara, Seitarou; Okabe, Toshitaka; Saito, Shigeo; Hoshimoto, Koichi; Yakushiji, Tadayuki; Isomura, Naoei; Araki, Hiroshi; Obara, Chiaki; Ochiai, Masahiko

2014-09-01

To assess the relationship between epicardial adipose tissue volume (EATV) and plaque vulnerability in significant coronary stenosis using a 40-MHz intravascular ultrasound (IVUS) imaging system (iMap-IVUS), we analyzed 130 consecutive patients with coronary stenosis who underwent dual-source computed tomography (CT) and cardiac catheterization. Culprit lesions were imaged by iMap-IVUS before stenting. The iMAP-IVUS system classified coronary plaque components as fibrous, lipid, necrotic, or calcified tissue, based on the radiofrequency spectrum. Epicardial adipose tissue was measured as the tissue ranging from -190 to -30 Hounsfield units. EATV, calculated as the sum of the fat areas on short-axis images, was 85.0 ± 34.0 cm(3). There was a positive correlation between EATV and the percentage of necrotic plaque tissue (R (2) = 0.34, P EATV and the percentage of fibrous tissue (R (2) = 0.24, P EATV (β = 0.14, P = 0.02) were independently associated with the percentage of necrotic plaque tissue. An increase in EATV was associated with the development of coronary atherosclerosis and, potentially, with the most dangerous type of plaque.

Machine Learning in Ultrasound Computer-Aided Diagnostic Systems: A Survey.

Science.gov (United States)

Huang, Qinghua; Zhang, Fan; Li, Xuelong

2018-01-01

The ultrasound imaging is one of the most common schemes to detect diseases in the clinical practice. There are many advantages of ultrasound imaging such as safety, convenience, and low cost. However, reading ultrasound imaging is not easy. To support the diagnosis of clinicians and reduce the load of doctors, many ultrasound computer-aided diagnosis (CAD) systems are proposed. In recent years, the success of deep learning in the image classification and segmentation led to more and more scholars realizing the potential of performance improvement brought by utilizing the deep learning in the ultrasound CAD system. This paper summarized the research which focuses on the ultrasound CAD system utilizing machine learning technology in recent years. This study divided the ultrasound CAD system into two categories. One is the traditional ultrasound CAD system which employed the manmade feature and the other is the deep learning ultrasound CAD system. The major feature and the classifier employed by the traditional ultrasound CAD system are introduced. As for the deep learning ultrasound CAD, newest applications are summarized. This paper will be useful for researchers who focus on the ultrasound CAD system.

Machine Learning in Ultrasound Computer-Aided Diagnostic Systems: A Survey

Directory of Open Access Journals (Sweden)

Qinghua Huang

2018-01-01

Full Text Available The ultrasound imaging is one of the most common schemes to detect diseases in the clinical practice. There are many advantages of ultrasound imaging such as safety, convenience, and low cost. However, reading ultrasound imaging is not easy. To support the diagnosis of clinicians and reduce the load of doctors, many ultrasound computer-aided diagnosis (CAD systems are proposed. In recent years, the success of deep learning in the image classification and segmentation led to more and more scholars realizing the potential of performance improvement brought by utilizing the deep learning in the ultrasound CAD system. This paper summarized the research which focuses on the ultrasound CAD system utilizing machine learning technology in recent years. This study divided the ultrasound CAD system into two categories. One is the traditional ultrasound CAD system which employed the manmade feature and the other is the deep learning ultrasound CAD system. The major feature and the classifier employed by the traditional ultrasound CAD system are introduced. As for the deep learning ultrasound CAD, newest applications are summarized. This paper will be useful for researchers who focus on the ultrasound CAD system.

[Ultrasound of the urinary system].

Science.gov (United States)

Segura-Grau, A; Herzog, R; Díaz-Rodriguez, N; Segura-Cabral, J M

2016-09-01

Ultrasound techniques are able to provide a fairly complete examination of the urinary system, achieving a high sensitivity in relevant-pathology detection, especially in the kidney, bladder and prostate. Early detection of pathologies such as tumors or urinary tract obstructions, sometimes even before their clinical manifestation, has improved their management and prognosis in many cases. This, added to its low cost and harmlessness, makes ultrasound ideal for early approaches and follow-up of a wide number of urinary system pathologies. In this article, the ultrasound characteristics of the main urinary system pathologies that can be diagnosed by this technique, are reviewed. Copyright © 2014 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España, S.L.U. All rights reserved.

OSPACS: Ultrasound image management system

Directory of Open Access Journals (Sweden)

Bessant Conrad

2008-06-01

Full Text Available Abstract Background Ultrasound scanning uses the medical imaging format, DICOM, for electronically storing the images and data associated with a particular scan. Large health care facilities typically use a picture archiving and communication system (PACS for storing and retrieving such images. However, these systems are usually not suitable for managing large collections of anonymized ultrasound images gathered during a clinical screening trial. Results We have developed a system enabling the accurate archiving and management of ultrasound images gathered during a clinical screening trial. It is based upon a Windows application utilizing an open-source DICOM image viewer and a relational database. The system automates the bulk import of DICOM files from removable media by cross-validating the patient information against an external database, anonymizing the data as well as the image, and then storing the contents of the file as a field in a database record. These image records may then be retrieved from the database and presented in a tree-view control so that the user can select particular images for display in a DICOM viewer or export them to external media. Conclusion This system provides error-free automation of ultrasound image archiving and management, suitable for use in a clinical trial. An open-source project has been established to promote continued development of the system.

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

DEFF Research Database (Denmark)

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

2011-01-01

Patients with diabetes mellitus have increased risk of in-stent restenosis after coronary stent implantation due to neointimal hyperplasia (NIH). The aim of this study was to use quantitative coronary angiography (QCA) and volumetric intravascular ultrasound (IVUS) to evaluate the effects...... of the sirolimus-eluting Cypher® stent (SES) and the zotarolimus-eluting Endeavor® stent (ZES) on angiographic late lumen loss and intima hyperplasia in diabetic patients....

A nonimaging catheter for measurement of coronary artery lumen area: a first in man pilot study.

Science.gov (United States)

Hermiller, James; Choy, Jenny S; Svendsen, Mark; Bigelow, Brian; Fouts, Andrew M; Hall, Jack; Parr, Kirk; Ball, Michael; Sinha, Anjan; Bhatt, Deepak L; Kassab, Ghassan S

2011-08-01

The objective of this human pilot study was to determine the safety and the level of agreement between a novel nonimaging 2.7 Fr. catheter-based system (LumenRECON, LR) that uses electrical conductance for measurement of lumen cross-sectional area (CSA) with intravascular ultrasound (IVUS) and quantitative coronary angiography (QCA). Based on previous animal studies, we hypothesized the level of agreement between LR and IVUS to be 13%. Accurate and reproducible vessel sizing is essential for optimal percutaneous coronary intervention (PCI). A total of 12 patients were studied to evaluate the safety, accuracy, and reproducibility of the system in comparison with IVUS and QCA. The CSA of coronary arteries was determined by IVUS, QCA, and LR in the distal, proximal, and center of a lesion during standard PCI. A Bland-Altman plot of the LR versus IVUS and QCA show a nonsignificant mean difference between the two measurements of 0.04 and 0.07 mm in diameter, respectively. The root mean square error of LR versus IVUS and QCA was 14.3 and 25.8% of the mean IVUS or QCA diameter, respectively. The mean of the difference between two LR duplicate measurements was nearly zero (0.03 mm) and the repeatability coefficient was within 8.7% of the mean of the two measurements. There were no procedural complications nor were any device-related MACE reported within 30 days of the procedure. This proof of concept pilot study establishes the safety and accuracy of the conductance technology for a pivotal trial of coronary sizing. Copyright © 2011 Wiley-Liss, Inc.

Automatic segmentation and 3D reconstruction of intravascular ultrasound images for a fast preliminar evaluation of vessel pathologies.

Science.gov (United States)

Sanz-Requena, Roberto; Moratal, David; García-Sánchez, Diego Ramón; Bodí, Vicente; Rieta, José Joaquín; Sanchis, Juan Manuel

2007-03-01

Intravascular ultrasound (IVUS) imaging is used along with X-ray coronary angiography to detect vessel pathologies. Manual analysis of IVUS images is slow and time-consuming and it is not feasible for clinical purposes. A semi-automated method is proposed to generate 3D reconstructions from IVUS video sequences, so that a fast diagnose can be easily done, quantifying plaque length and severity as well as plaque volume of the vessels under study. The methodology described in this work has four steps: a pre-processing of IVUS images, a segmentation of media-adventitia contour, a detection of intima and plaque and a 3D reconstruction of the vessel. Preprocessing is intended to remove noise from the images without blurring the edges. Segmentation of media-adventitia contour is achieved using active contours (snakes). In particular, we use the gradient vector flow (GVF) as external force for the snakes. The detection of lumen border is obtained taking into account gray-level information of the inner part of the previously detected contours. A knowledge-based approach is used to determine which level of gray corresponds statistically to the different regions of interest: intima, plaque and lumen. The catheter region is automatically discarded. An estimate of plaque type is also given. Finally, 3D reconstruction of all detected regions is made. The suitability of this methodology has been verified for the analysis and visualization of plaque length, stenosis severity, automatic detection of the most problematic regions, calculus of plaque volumes and a preliminary estimation of plaque type obtaining for automatic measures of lumen and vessel area an average error smaller than 1mm(2) (equivalent aproximately to 10% of the average measure), for calculus of plaque and lumen volume errors smaller than 0.5mm(3) (equivalent approximately to 20% of the average measure) and for plaque type estimates a mismatch of less than 8% in the analysed frames.

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

Directory of Open Access Journals (Sweden)

Edmund M T Lau

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

Negative remodeling at the ostium of the left circumflex artery.

Science.gov (United States)

Kobayashi, Y; Mehran, R; Moussa, I; Reyes, A; Moses, J W

2001-12-01

We report an ostial lesion with negative remodeling. Coronary angiography revealed a 60% stenosis at the ostium of the left circumflex artery (LCX). Intravascular ultrasound (IVUS)-guided directional atherectomy followed by stenting was planned. However, IVUS images revealed no significant stenosis and negative remodeling at the ostium of the LCX. The lesion did not undergo intervention.

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

International Nuclear Information System (INIS)

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

2006-01-01

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

Security of patient data when decommissioning ultrasound systems.

Science.gov (United States)

Moggridge, James

2017-02-01

Although ultrasound systems generally archive to Picture Archiving and Communication Systems (PACS), their archiving workflow typically involves storage to an internal hard disk before data are transferred onwards. Deleting records from the local system will delete entries in the database and from the file allocation table or equivalent but, as with a PC, files can be recovered. Great care is taken with disposal of media from a healthcare organisation to prevent data breaches, but ultrasound systems are routinely returned to lease companies, sold on or donated to third parties without such controls. In this project, five methods of hard disk erasure were tested on nine ultrasound systems being decommissioned: the system's own delete function; full reinstallation of system software; the manufacturer's own disk wiping service; open source disk wiping software for full and just blank space erasure. Attempts were then made to recover data using open source recovery tools. All methods deleted patient data as viewable from the ultrasound system and from browsing the disk from a PC. However, patient identifiable data (PID) could be recovered following the system's own deletion and the reinstallation methods. No PID could be recovered after using the manufacturer's wiping service or the open source wiping software. The typical method of reinstalling an ultrasound system's software may not prevent PID from being recovered. When transferring ownership, care should be taken that an ultrasound system's hard disk has been wiped to a sufficient level, particularly if the scanner is to be returned with approved parts and in a fully working state.

A passive wireless ultrasound pitch–catch system

International Nuclear Information System (INIS)

Zahedi, F; Yao, J; Huang, H

2015-01-01

This paper exploits amplitude modulation and demodulation to achieve a passive wireless ultrasound pitch–catch system consisting of a wireless interrogator and a combination of a wireless actuator and a sensor mounted on a structure. The wireless interrogator operates in two modes, i.e. the generation and sensing modes. At the generation mode, the interrogator transmits two microwave signals; one is amplitude modulated with the ultrasound excitation signal while the other is a continuous-wave carrier signal. Once received by the wireless actuator, the amplitude modulated signal is demodulated using the carrier signal to recover the ultrasound excitation signal, which is then supplied to a piezoelectric wafer actuator for ultrasound generation. Subsequently, the interrogator is switched to the sensing mode by transmitting a carrier signal with a different frequency. Once received by the wireless sensor, this carrier signal is modulated with the ultrasound sensing signal acquired by the piezoelectric wafer sensor to produce an amplitude modulated microwave signal, which can then be wirelessly transmitted and demodulated by the interrogator to recover the original ultrasound sensing signal. The principle and implementation of the wireless ultrasound pitch–catch system as well as the data processing of the wirelessly received sensing signal are described. Experiment results validating wireless ultrasound generation and sensing from a distance of 0.5 m are presented. (paper)

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-06-15

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

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

International Nuclear Information System (INIS)

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

2014-01-01

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

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

Science.gov (United States)

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.

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

Directory of Open Access Journals (Sweden)

Liang Wang

2015-12-01

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

PLUS: open-source toolkit for ultrasound-guided intervention systems.

Science.gov (United States)

Lasso, Andras; Heffter, Tamas; Rankin, Adam; Pinter, Csaba; Ungi, Tamas; Fichtinger, Gabor

2014-10-01

A variety of advanced image analysis methods have been under the development for ultrasound-guided interventions. Unfortunately, the transition from an image analysis algorithm to clinical feasibility trials as part of an intervention system requires integration of many components, such as imaging and tracking devices, data processing algorithms, and visualization software. The objective of our paper is to provide a freely available open-source software platform-PLUS: Public software Library for Ultrasound-to facilitate rapid prototyping of ultrasound-guided intervention systems for translational clinical research. PLUS provides a variety of methods for interventional tool pose and ultrasound image acquisition from a wide range of tracking and imaging devices, spatial and temporal calibration, volume reconstruction, simulated image generation, and recording and live streaming of the acquired data. This paper introduces PLUS, explains its functionality and architecture, and presents typical uses and performance in ultrasound-guided intervention systems. PLUS fulfills the essential requirements for the development of ultrasound-guided intervention systems and it aspires to become a widely used translational research prototyping platform. PLUS is freely available as open source software under BSD license and can be downloaded from http://www.plustoolkit.org.

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

Science.gov (United States)

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

2014-06-01

We present a new clinically practical method for online co-registration of 3D quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS) or optical coherence tomography (OCT). The workflow is based on two modified commercially available software packages. Reconstruction steps are explained and compared to previously available methods. The feasibility for different clinical scenarios is illustrated. The co-registration appears accurate, robust and induced a minimal delay on the normal cath lab activities. This new method is based on the 3D angiographic reconstruction of the catheter path and does not require operator's identification of landmarks to establish the image synchronization. Copyright © 2014 Elsevier Inc. All rights reserved.

Ultrasound findings in biliary system

International Nuclear Information System (INIS)

Park, Won Sik; Lee, Yong Woo; Cheung, Hwan

1986-01-01

In the liver and biliary system ultrasound has emerged as one of the most useful imaging techniques. It is usually the first radiological procedure selected and is often sufficient alone to enable a clinical decision to be made. Good result with ultrasound depend critically on expert scanning technique coupled with an understanding of tomographic anatomy and, of course, an appreciation of the clinical significance of any findings. In addition to we'd like to stress on the ultrasonical anatomy and for the technologist and also discuss about pathological part

In vivo evaluation of axial integrity of coronary stents using intravascular ultrasound: Insights on longitudinal stent deformation.

Science.gov (United States)

Dvir, Danny; Kitabata, Hironori; Barbash, Israel M; Minha, Sa'ar; Badr, Salem; Loh, Joshua P; Chen, Fang; Torguson, Rebecca; Waksman, Ron

2014-09-01

To evaluate the axial integrity of different coronary stents using intravascular ultrasound (IVUS). Longitudinal stent deformation was recently reported. Consecutive patients who underwent IVUS analysis after drug-eluting stent (DES) implantation for de novo coronary lesions were evaluated. Stent length was compared with label length for calculation of absolute change and relative difference (absolute change divided by label length). A total of 233 DES utilizing five different platforms were included. The median absolute change in stent length was 0.90 mm (interquartile range [IQR] 0.48-1.39) and the relative difference was 5.24% (IQR 2.55-8.29). There was no significant difference among the groups in median absolute or relative change: Cypher 0.89 mm/3.89%, Taxus 0.88 mm/5.39%, Endeavor 1.16 mm/6.77%, Xience V 0.86 mm/5.80%, and PROMUS Element 0.79 mm/5.34% (P = 0.085, P = 0.072, respectively). Multivariate logistic regression revealed that the Cypher stent was independently correlated with a lower change in length, whereas stent label length and deployment pressure were correlated with higher absolute change. The axial integrity of DES platforms examined in vivo was high, with only mild changes in stent length after implantation. While there are differences between first- and second-generation DES, axial integrity among second-generation DES was similar. © 2013 Wiley Periodicals, Inc.

Robot-assisted ultrasound imaging: overview and development of a parallel telerobotic system.

Science.gov (United States)

Monfaredi, Reza; Wilson, Emmanuel; Azizi Koutenaei, Bamshad; Labrecque, Brendan; Leroy, Kristen; Goldie, James; Louis, Eric; Swerdlow, Daniel; Cleary, Kevin

2015-02-01

Ultrasound imaging is frequently used in medicine. The quality of ultrasound images is often dependent on the skill of the sonographer. Several researchers have proposed robotic systems to aid in ultrasound image acquisition. In this paper we first provide a short overview of robot-assisted ultrasound imaging (US). We categorize robot-assisted US imaging systems into three approaches: autonomous US imaging, teleoperated US imaging, and human-robot cooperation. For each approach several systems are introduced and briefly discussed. We then describe a compact six degree of freedom parallel mechanism telerobotic system for ultrasound imaging developed by our research team. The long-term goal of this work is to enable remote ultrasound scanning through teleoperation. This parallel mechanism allows for both translation and rotation of an ultrasound probe mounted on the top plate along with force control. Our experimental results confirmed good mechanical system performance with a positioning error of < 1 mm. Phantom experiments by a radiologist showed promising results with good image quality.

A 3D computer graphics approach to brachytherapy planning.

Science.gov (United States)

Weichert, Frank; Wawro, Martin; Wilke, Carsten

2004-06-01

Intravascular brachytherapy (IVB) can significantly reduce the risk of restenosis after interventional treatment of stenotic arteries, if planned and applied correctly. In order to facilitate computer-based IVB planning, a three-dimensional reconstruction of the stenotic artery based on intravascular ultrasound (IVUS) sequences is desirable. For this purpose, the frames of the IVUS sequence are properly aligned in space, possible gaps inbetween the IVUS frames are filled by interpolation with radial basis functions known from scattered data interpolation. The alignment procedure uses additional information which is obtained from biplane X-ray angiography performed simultaneously during the capturing of the IVUS sequence. After IVUS images and biplane angiography data are acquired from the patient, the vessel-wall borders and the IVUS catheter are detected by an active contour algorithm. Next, the twist (relative orientation) between adjacent IVUS frames is determined by a sequential triangulation method. The absolute orientation of each frame is established by a stochastic analysis based on anatomical landmarks. Finally, the reconstructed 3D vessel model is visualized by methods of combined volume and polygon rendering. The reconstruction is then used for the computation of the radiation-distribution within the tissue, emitted from a beta-radiation source. All these steps are performed during the percutaneous intervention.

Perspectives on Imaging the Left Main Coronary Artery Using Intravascular Ultrasound and Optical Coherence Tomography

Directory of Open Access Journals (Sweden)

Harry C Lowe

2015-01-01

Full Text Available Percutaneous Coronary Intervention (PCI for significant left main coronary artery (LMCA stenosis is increasingly being viewed as a viable alternative to Coronary Artery Bypass Grafting (CABG (1. This is leading to an expectation of increasing numbers of such procedures, with a consequent focus on both the ability to image both lesion severity, and assess more accurately the results of PCI. While there have been advances in physiologic assessment of left main severity using fractional flow reserve (FFR, imaging of the LMCA using Intravascular Ultrasound (IVUS and more recently Optical Coherence Tomography (OCT has the specific advantage of being able to provide detailed anatomical information both pre and post PCI, such that it is timely to review briefly the current status of these two imaging technologies in the context of LMCA intervention.

Active ultrasound pattern injection system (AUSPIS for interventional tool guidance.

Directory of Open Access Journals (Sweden)

Xiaoyu Guo

Full Text Available Accurate tool tracking is a crucial task that directly affects the safety and effectiveness of many interventional medical procedures. Compared to CT and MRI, ultrasound-based tool tracking has many advantages, including low cost, safety, mobility and ease of use. However, surgical tools are poorly visualized in conventional ultrasound images, thus preventing effective tool tracking and guidance. Existing tracking methods have not yet provided a solution that effectively solves the tool visualization and mid-plane localization accuracy problem and fully meets the clinical requirements. In this paper, we present an active ultrasound tracking and guiding system for interventional tools. The main principle of this system is to establish a bi-directional ultrasound communication between the interventional tool and US imaging machine within the tissue. This method enables the interventional tool to generate an active ultrasound field over the original imaging ultrasound signals. By controlling the timing and amplitude of the active ultrasound field, a virtual pattern can be directly injected into the US machine B mode display. In this work, we introduce the time and frequency modulation, mid-plane detection, and arbitrary pattern injection methods. The implementation of these methods further improves the target visualization and guiding accuracy, and expands the system application beyond simple tool tracking. We performed ex vitro and in vivo experiments, showing significant improvements of tool visualization and accurate localization using different US imaging platforms. An ultrasound image mid-plane detection accuracy of ±0.3 mm and a detectable tissue depth over 8.5 cm was achieved in the experiment. The system performance is tested under different configurations and system parameters. We also report the first experiment of arbitrary pattern injection to the B mode image and its application in accurate tool tracking.

Characteristics of virtual histology-intravascular unltrasound of infarction-related artery atheromatous plaque and pregnancy-associated plasma protein A level: a correlation study

International Nuclear Information System (INIS)

Chen Shaobo; Jiang Tiemin; Liang Guoqing; Zhao Jihong; Li Yuming

2011-01-01

Objective: To observe the characteristics of virtual histology-intravascular ultrasound (VH-IVUS) in 70 patients with acute ST segment elevated type myocardial infarction (AMI), the findings were compared with that in 70 patients with stable angina (control group), and to analyze the correlation between VH-IVUS characteristics and pregnancy-associated plasma protein A (PAPPA) level. Methods: Seventy patients with ST segment elevated AMI and 70 patients with stable angina, who received percutaneous coronary artery intervention and were encountered from Jan. 2008 to Dec. 2009, were involved in this study. After coronary angiography was completed,the plasma was aspirated from culprit coronary artery with ZEEK catheter. Then, IVUS examination to culprit lesion was carried out and grayscale and VH data were stored. The characteristics of VH-IVUS of culprit atheromatous plaque were observed and its correlation with PAPPA was analyzed. Results: The difference in age,gender, hypertension, smoking, diabetes mellitus and hyperlipidemia between two groups was of no statistical significance, but statistically significant difference in VH-IVUS characteristics of the atheromatous plaque existed between two groups, more fibro-fatty tissue and necrotic tissue with less dense calcium were seen in AMI group. The ratio of necrotic tissue area to calcified tissue area was (3.62±1.46) in AMI group and(7.18±2.53) in control group (P<0.01). PAPPA in AMI group was significantly higher than that in control group (P<0.01). Parameters of VH-IVUS in AMI group were highly correlated with PAPPA (P<0.05 or P<0.01). Conclusion: The characteristics of virtual histology-intravascular ultrasound of infarction-related artery atheromatous plaque include more necrotic tissue, higher ratio of necrotic tissue area to calcified tissue area and a closer correlation with PAPPA. (authors)

Bedside intravascular ultrasound-guided inferior vena cava filter placement in medical-surgical intensive care critically-ill patients

Directory of Open Access Journals (Sweden)

Mohammad A. Abusedera

2015-09-01

Conclusions: Bedside IVUS-guided filter placement in medical-surgical critically ill patient in intensive care unit is a feasible, safe and reliable technique for IVC interruption. IVUS may be the most appropriate tool to guide filter insertion in obese patient.

A single FPGA-based portable ultrasound imaging system for point-of-care applications.

Science.gov (United States)

Kim, Gi-Duck; Yoon, Changhan; Kye, Sang-Bum; Lee, Youngbae; Kang, Jeeun; Yoo, Yangmo; Song, Tai-kyong

2012-07-01

We present a cost-effective portable ultrasound system based on a single field-programmable gate array (FPGA) for point-of-care applications. In the portable ultrasound system developed, all the ultrasound signal and image processing modules, including an effective 32-channel receive beamformer with pseudo-dynamic focusing, are embedded in an FPGA chip. For overall system control, a mobile processor running Linux at 667 MHz is used. The scan-converted ultrasound image data from the FPGA are directly transferred to the system controller via external direct memory access without a video processing unit. The potable ultrasound system developed can provide real-time B-mode imaging with a maximum frame rate of 30, and it has a battery life of approximately 1.5 h. These results indicate that the single FPGA-based portable ultrasound system developed is able to meet the processing requirements in medical ultrasound imaging while providing improved flexibility for adapting to emerging POC applications.

Modification of Food Systems by Ultrasound

Directory of Open Access Journals (Sweden)

L. M. Carrillo-Lopez

2017-01-01

Full Text Available This review describes the mechanism, operation, and recent potential applications of ultrasound in various food systems, as well as the physical and chemical effects of ultrasound treatments on the conservation and modification of different groups of food. Acoustic energy has been recognized as an emerging technology with great potential for applications in the food industry. The phenomenon of acoustic cavitation, which modifies the physical, chemical, and functional properties of food, can be used to improve existing processes and to develop new ones. The combination of ultrasonic energy with a sanitizing agent can improve the effect of microbial reduction in foods and, thereby, their quality. Finally, it is concluded that the use of ultrasound in food is a very promising area of research; however, more research is still needed before applying this technology in a wider range of industrial sectors.

Stent underexpansion in angiographic guided percutaneous coronary intervention, despite adjunctive balloon post-dilatation, in drug eluting stent era

Directory of Open Access Journals (Sweden)

Mehrdad Taherioun

2014-01-01

Full Text Available BACKGROUND: Stent underexpansion is the most powerful predictor of long-term stent patency and clinical outcome. The purpose of this study was to evaluate the incidence and predictors of stent underexpansion despite adjunctive post-dilatation with non-compliant balloon. METHODS: After elective coronary stent implantation and adjunctive post-dilatation with non-compliant balloon and optimal angiographic result confirmed by the operator, intravascular ultrasound (IVUS was performed for all the treated lesions. If the treated lesions fulfilled the IVUS criteria, they are considered as the optimal stent group; if not, they are considered as the suboptimal group. RESULTS: From 50 patients enrolled in this study 39 (78% had optimal stent deployment and 11 (22% had suboptimal stent deployment. In the suboptimal group 7 (14% had underexpansion, 2 (4% malposition, and 2 (4% had asymmetry. There were no stent edge dissections detected by IVUS. We did not find any correlation between lesion calcification, ostial lesions, stent length, and stent underexpansion. Stent diameter ≤ 2.75 mm had a strong correlation with stent underexpansion. CONCLUSION: Despite adjunctive post-dilatation with noncompliant balloon, using a relatively small stent diameter was a strong predictor for underexpansion. IVUS guided percutaneous coronary intervention (PCI may be considered for drug eluting stent (DES implantation in relatively small vessels.   Keywords: Stent, Percutaneous Coronary Intervention, Ultrasound, Post-dilatation 

Myocardial Infarction in a Young Female with Palindromic Rheumatism: A Consequence of Negative Remodeling

Directory of Open Access Journals (Sweden)

Timothy R. Larsen

2012-01-01

Full Text Available Palindromic rheumatism is a rare disease associated with systemic inflammation. Negative or constrictive coronary artery remodeling is typically not seen until the 7th or 8th decade of life. We report a case of a young female with palindromic rheumatism who suffered a non-ST segment elevation myocardial infarction secondary to a flow-limiting lesion that demonstrated negative remodeling by intravascular ultrasound (IVUS.

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

Science.gov (United States)

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

2016-12-15

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.

Impact of Medical Therapy on Atheroma Volume Measured by Different Cardiovascular Imaging Modalities

Directory of Open Access Journals (Sweden)

Mohamad C. N. Sinno

2010-01-01

Full Text Available Atherosclerosis is a systemic disease that affects most vascular beds. The gold standard of atherosclerosis imaging has been invasive intravascular ultrasound (IVUS. Newer noninvasive imaging modalities like B-mode ultrasound, cardiac computed tomography (CT, positron emission tomography (PET, and magnetic resonance imaging (MRI have been used to assess these vascular territories with high accuracy and reproducibility. These imaging modalities have lately been used for the assessment of the atherosclerotic plaque and the response of its volume to several medical therapies used in the treatment of patients with cardiovascular disease. To study the impact of these medications on atheroma volume progression or regression, imaging modalities have been used on a serial basis providing a unique opportunity to monitor the effect these antiatherosclerotic strategies exert on plaque burden. As a result, studies incorporating serial IVUS imaging, quantitative coronary angiography (QCA, B-mode ultrasound, electron beam computed tomography (EBCT, and dynamic contrast-enhanced magnetic resonance imaging have all been used to evaluate the impact of therapeutic strategies that modify cholesterol and blood pressure on the progression/regression of atherosclerotic plaque. In this review, we intend to summarize the impact of different therapies aimed at halting the progression or even result in regression of atherosclerotic cardiovascular disease evaluated by different imaging modalities.

Ultrasound Vector Flow Imaging: Part II: Parallel Systems

DEFF Research Database (Denmark)

Jensen, Jørgen Arendt; Nikolov, Svetoslav Ivanov; Yu, Alfred C. H.

2016-01-01

The paper gives a review of the current state-of-theart in ultrasound parallel acquisition systems for flow imaging using spherical and plane waves emissions. The imaging methods are explained along with the advantages of using these very fast and sensitive velocity estimators. These experimental...... ultrasound imaging for studying brain function in animals. The paper explains the underlying acquisition and estimation methods for fast 2-D and 3-D velocity imaging and gives a number of examples. Future challenges and the potentials of parallel acquisition systems for flow imaging are also discussed....

Dependence of the frequency spectrum of small amplitude vibrations superimposed on finite deformations of a nonlinear, cylindrical elastic body on residual stress

KAUST Repository

Gorb, Yuliya; Walton, Jay R.

2010-01-01

We model and analyze the response of nonlinear, residually stressed elastic bodies subjected to small amplitude vibrations superimposed upon large deformations. The problem derives from modeling the use of intravascular ultrasound (IVUS) imaging

Design and development of an ultrasound calibration phantom and system

Science.gov (United States)

Cheng, Alexis; Ackerman, Martin K.; Chirikjian, Gregory S.; Boctor, Emad M.

2014-03-01

Image-guided surgery systems are often used to provide surgeons with informational support. Due to several unique advantages such as ease of use, real-time image acquisition, and no ionizing radiation, ultrasound is a common medical imaging modality used in image-guided surgery systems. To perform advanced forms of guidance with ultrasound, such as virtual image overlays or automated robotic actuation, an ultrasound calibration process must be performed. This process recovers the rigid body transformation between a tracked marker attached to the ultrasound transducer and the ultrasound image. A phantom or model with known geometry is also required. In this work, we design and test an ultrasound calibration phantom and software. The two main considerations in this work are utilizing our knowledge of ultrasound physics to design the phantom and delivering an easy to use calibration process to the user. We explore the use of a three-dimensional printer to create the phantom in its entirety without need for user assembly. We have also developed software to automatically segment the three-dimensional printed rods from the ultrasound image by leveraging knowledge about the shape and scale of the phantom. In this work, we present preliminary results from using this phantom to perform ultrasound calibration. To test the efficacy of our method, we match the projection of the points segmented from the image to the known model and calculate a sum squared difference between each point for several combinations of motion generation and filtering methods. The best performing combination of motion and filtering techniques had an error of 1.56 mm and a standard deviation of 1.02 mm.

Verification and compensation of respiratory motion using an ultrasound imaging system

International Nuclear Information System (INIS)

Chuang, Ho-Chiao; Hsu, Hsiao-Yu; Chiu, Wei-Hung; Tien, Der-Chi; Wu, Ren-Hong; Hsu, Chung-Hsien

2015-01-01

Purpose: The purpose of this study was to determine if it is feasible to use ultrasound imaging as an aid for moving the treatment couch during diagnosis and treatment procedures associated with radiation therapy, in order to offset organ displacement caused by respiratory motion. A noninvasive ultrasound system was used to replace the C-arm device during diagnosis and treatment with the aims of reducing the x-ray radiation dose on the human body while simultaneously being able to monitor organ displacements. Methods: This study used a proposed respiratory compensating system combined with an ultrasound imaging system to monitor the compensation effect of respiratory motion. The accuracy of the compensation effect was verified by fluoroscopy, which means that fluoroscopy could be replaced so as to reduce unnecessary radiation dose on patients. A respiratory simulation system was used to simulate the respiratory motion of the human abdomen and a strain gauge (respiratory signal acquisition device) was used to capture the simulated respiratory signals. The target displacements could be detected by an ultrasound probe and used as a reference for adjusting the gain value of the respiratory signal used by the respiratory compensating system. This ensured that the amplitude of the respiratory compensation signal was a faithful representation of the target displacement. Results: The results show that performing respiratory compensation with the assistance of the ultrasound images reduced the compensation error of the respiratory compensating system to 0.81–2.92 mm, both for sine-wave input signals with amplitudes of 5, 10, and 15 mm, and human respiratory signals; this represented compensation of the respiratory motion by up to 92.48%. In addition, the respiratory signals of 10 patients were captured in clinical trials, while their diaphragm displacements were observed simultaneously using ultrasound. Using the respiratory compensating system to offset, the diaphragm

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

Science.gov (United States)

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

2016-05-01

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

Low-cost Volumetric Ultrasound by Augmentation of 2D Systems: Design and Prototype.

Science.gov (United States)

Herickhoff, Carl D; Morgan, Matthew R; Broder, Joshua S; Dahl, Jeremy J

2018-01-01

Conventional two-dimensional (2D) ultrasound imaging is a powerful diagnostic tool in the hands of an experienced user, yet 2D ultrasound remains clinically underutilized and inherently incomplete, with output being very operator dependent. Volumetric ultrasound systems can more fully capture a three-dimensional (3D) region of interest, but current 3D systems require specialized transducers, are prohibitively expensive for many clinical departments, and do not register image orientation with respect to the patient; these systems are designed to provide improved workflow rather than operator independence. This work investigates whether it is possible to add volumetric 3D imaging capability to existing 2D ultrasound systems at minimal cost, providing a practical means of reducing operator dependence in ultrasound. In this paper, we present a low-cost method to make 2D ultrasound systems capable of quality volumetric image acquisition: we present the general system design and image acquisition method, including the use of a probe-mounted orientation sensor, a simple probe fixture prototype, and an offline volume reconstruction technique. We demonstrate initial results of the method, implemented using a Verasonics Vantage research scanner.

Performance Evaluation of a Synthetic Aperture Real-Time Ultrasound System

DEFF Research Database (Denmark)

Stuart, Matthias Bo; Tomov, Borislav Gueorguiev; Jensen, Jørgen Arendt

2011-01-01

This paper evaluates the signal-to-noise ratio, the time stability, and the phase difference of the sampling in the experimental ultrasound scanner SARUS: A synthetic aperture, real-time ultrasound system. SARUS has 1024 independent transmit and receive channels and is capable of handling 2D probes...... arrays (FPGAs) making it very flexible and allowing implementation of other real-time ultrasound processing methods in the future. For conventional B-mode imaging, a penetration depth around 7 cm for a 7 MHz transducer is obtained (signal-tonoise ratio of 0 dB), which is comparable to commercial...... for 3D ultrasound imaging. It samples at 12 bits per sample and has a sampling rate of 70 MHz with the possibility of decimating the sampling frequency at the input. SARUS is capable of advanced real-time computations such as synthetic aperture imaging. The system is built using fieldprogrammable gate...

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

Directory of Open Access Journals (Sweden)

Luiz Eduardo Mastrocolla

2006-01-01

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

Real-Time Implementation of Medical Ultrasound Strain Imaging System

International Nuclear Information System (INIS)

Jeong, Mok Kun; Kwon, Sung Jae; Bae, Moo Ho

2008-01-01

Strain imaging in a medical ultrasound imaging system can differentiate the cancer or tumor in a lesion that is stiffer than the surrounding tissue. In this paper, a strain imaging technique using quasistatic compression is implemented that estimates the displacement between pre- and postcompression ultrasound echoes and obtains strain by differentiating it in the spatial direction. Displacements are computed from the phase difference of complex baseband signals obtained using their autocorrelation, and errors associated with converting the phase difference into time or distance are compensated for by taking into the center frequency variation. Also, to reduce the effect of operator's hand motion, the displacements of all scanlines are normalized with the result that satisfactory strain image quality has been obtained. These techniques have been incorporated into implementing a medical ultrasound strain imaging system that operates in real time.

Ultrasound systems for blood velocity estimation

DEFF Research Database (Denmark)

Jensen, Jørgen Arendt

1998-01-01

Medical ultrasound scanners can be used both for displayinggray-scale images of the anatomy and for visualizing theblood flow dynamically in the body.The systems can interrogate the flow at a single position in the bodyand there find the velocity distribution over time. They can also show adynamic...

A Flexible Stent with Small Intestinal Submucosa Covering for Direct Intrahepatic Portocaval Shunt: Experimental Pilot Study in Swine

International Nuclear Information System (INIS)

Niyyati, Mahtab; Petersen, Bryan D.; Pavcnik, Dusan; Uchida, Barry T.; Timmermans, Hans A.; Hiraki, Takao; Wu Renghong; Brountzos, Elias; Keller, Frederick S.; Roesch, Josef

2005-01-01

The suitability of the flexible sandwich Zilver stent-graft (SZSG) with a biologically active tissue layer (small intestinal submucosa) for creation of the intravascular ultrasound (IVUS)-guided direct intrahepatic portocaval shunt (DIPS) was explored in six young swine in a search for a flexible system to replace the rigid polytetrafluoroethylene (PTFE) stent originally used by this group with limited success. The portal vein was punctured from the inferior vena cava through the caudate lobe of the liver using IVUS guidance. After balloon dilation of the puncture tract, DIPS was successfully created in all animals with use of an SZSG 9 mm in diameter and 6 cm or 8 cm long. Only one DIPS remained well patent at 14 days when the animal had to be killed because of encephalopathy. DIPS in the other five animals were found to be either severely stenosed (3 animals) or occluded (2 animals) at 4 weeks due to accelerated formation of neointimal hyperplasia (NIH) in the liver parenchymal portion of the shunt and superimposed thrombosis. The lack of high pressure in the portal system contributed to early endograft closure. The flexible stent and the covering fail badly. The reason for this could be due to either component. More work is required to find a reliable flexible system with long-term patency. Exploration of the IVUS-guided direct extrahepatic portocaval shunt is suggested

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

Science.gov (United States)

Kitabata, Hironori; Loh, Joshua P; Pendyala, Lakshmana K; Omar, Alfazir; Ota, Hideaki; Minha, Sa'ar; Magalhaes, Marco A; Torguson, Rebecca; Chen, Fang; Satler, Lowell F; Pichard, Augusto D; Waksman, Ron

2014-04-01

We aimed to compare neointimal tissue characteristics between bare-metal stents (BMS) and drug-eluting stents (DES) at long-term follow-up using optical coherence tomography (OCT) and virtual histology intravascular ultrasound (VH-IVUS). Neoatherosclerosis in neointima has been reported in BMS and in DES. Thirty patients with 36 stented lesions [BMS (n=17) or DES (n=19)] >3years after implantation were prospectively enrolled. OCT and VH-IVUS were performed and analyzed independently. Stents with ≥70% diameter stenosis were excluded. The median duration from implantation was 126.0months in the BMS group and 60.0months in the DES group (p 3years to stents had evidence of intimal disruption. The percentage volume of necrotic core (16.1% [9.7, 20.3] vs. 9.7% [7.0, 16.5], p=0.062) and dense calcium (9.5% [3.8, 13.6] vs. 2.7% [0.4, 4.9], p=0.080) in neointima tended to be greater in BMS-treated lesions. Intra-stent VH-TCFA (BMS vs. DES 45.5% vs. 18.2%, p=0.361) did not differ significantly. At long-term follow-up beyond 3 years after implantation, the intra-stent neointimal tissue characteristics appeared similar for both BMS and DES. Copyright © 2014 Elsevier Inc. All rights reserved.

Development and implementation of ultrasound picture archiving and communication system

Science.gov (United States)

Weinberg, Wolfram S.; Tessler, Franklin N.; Grant, Edward G.; Kangarloo, Hooshang; Huang, H. K.

1990-08-01

The Department of Radiological Sciences at the UCLA School of Medicine is developing an archiving and communication system (PACS) for digitized ultrasound images. In its final stage the system will involve the acquisition and archiving of ultrasound studies from four different locations including the Center for Health Sciences, the Department for Mental Health and the Outpatient Radiology and Endoscopy Departments with a total of 200-250 patient studies per week. The concept comprises two stages of image manipulation for each ultrasound work area. The first station is located close to the examination site and accomodates the acquisition of digital images from up to five ultrasound devices and provides for instantaneous display and primary viewing and image selection. Completed patient studies are transferred to a main workstation for secondary review, further analysis and comparison studies. The review station has an on-line storage capacity of 10,000 images with a resolution of 512x512 8 bit data to allow for immediate retrieval of active patient studies of up to two weeks. The main work stations are connected through the general network and use one central archive for long term storage and a film printer for hardcopy output. First phase development efforts concentrate on the implementation and testing of a system at one location consisting of a number of ultrasound units with video digitizer and network interfaces and a microcomputer workstation as host for the display station with two color monitors, each allowing simultaneous display of four 512x512 images. The discussion emphasizes functionality, performance and acceptance of the system in the clinical environment.

In-Vivo Assessment of Coronary Atherosclerosis

NARCIS (Netherlands)

G.A. Rodriguez-Granillo

2006-01-01

textabstractIntravascular ultrasound (IVUS) has emerged as a highly accurate tool for the serial assessment of the natural history of coronary atherosclerosis and to evaluate the effect of different conventional and emerging drug therapies on the progression of atherosclerosis. The

System Architecture of an Experimental Synthetic Aperture Real-Time Ultrasound System

DEFF Research Database (Denmark)

Jensen, Jørgen Arendt; Hansen, Martin; Tomov, Borislav Gueorguiev

2007-01-01

is done using a parametric beam former. Code synthesized for a Xilinx V4FX100 speed grade 11 FPGA can operate at a maximum clock frequency of 167.8 MHz producing 1 billion I and Q samples/second sufficient for real time SA imaging. The system is currently in production, and all boards have been laid out......Synthetic Aperture (SA) ultrasound imaging has many advantages in terms of flexibility and accuracy. One of the major drawbacks is, however, that no system exists, which can implement SA imaging in real time due to the very high number of calculations amounting to roughly 1 billion complex focused...... samples per second per receive channel. Real time imaging is a key aspect in ultrasound, and to truly demonstrate the many advantages of SA imaging, a system usable in the clinic should be made. The paper describes a system capable of real time SA B-mode and vector flow imaging. The Synthetic Aperture...

Evaluation of Chest Ultrasound Integrated Teaching of Respiratory System Physiology to Medical Students

Science.gov (United States)

Paganini, Matteo; Bondì, Michela; Rubini, Alessandro

2017-01-01

Ultrasound imaging is a widely used diagnostic technique, whose integration in medical education is constantly growing. The aim of this study was to evaluate chest ultrasound usefulness in teaching respiratory system physiology, students' perception of chest ultrasound integration into a traditional lecture in human physiology, and short-term…

Preliminary Clinical Experience with a Combined Automated Breast Ultrasound and Digital Breast Tomosynthesis System.

Science.gov (United States)

Larson, Eric D; Lee, Won-Mean; Roubidoux, Marilyn A; Goodsitt, Mitchell M; Lashbrook, Chris; Davis, Cynthia E; Kripfgans, Oliver D; Carson, Paul L

2018-03-01

We analyzed the performance of a mammographically configured, automated breast ultrasound (McABUS) scanner combined with a digital breast tomosynthesis (DBT) system. The GE Invenia ultrasound system was modified for integration with GE DBT systems. Ultrasound and DBT imaging were performed in the same mammographic compression. Our small preliminary study included 13 cases, six of whom had contained invasive cancers. From analysis of these cases, current limitations and corresponding potential improvements of the system were determined. A registration analysis was performed to compare the ease of McABUS to DBT registration for this system with that of two systems designed previously. It was observed that in comparison to data from an earlier study, the McABUS-to-DBT registration alignment errors for both this system and a previously built combined system were smaller than those for a previously built standalone McABUS system. Copyright © 2018 World Federation for Ultrasound in Medicine and Biology. Published by Elsevier Inc. All rights reserved.

ROLE OF PRE- AND POST-TRANSPLANT FACTORS IN THE DEVELOPMENT OF CORONARY DISEASE OF THE TRANSPLANT HEART

Directory of Open Access Journals (Sweden)

E. K. Kurlianskaya

2015-01-01

Full Text Available Aim: to assess the relationship between preand post-transplantation factors and degree of coronary artery lesion, reported by intravascular ultrasound study (IVUS in patients who underwent orthotopic heart transplantation (OHT surgery. Materials and methods. The study comprised of 27 patients who underwent OHT more than 2 years before. The age of patients was 46,8 ± 10,4 years old. All of them were preoperatively classified by HLA system. All patients received transthoracic echocardiography at terms of 1, 6, 12 and 24 months after OHT. Coronary angiography (CAG and IVUS were performed at 24 ± 6 months. Results. In CAG none of the patients showed angiographic signs of CA stenosis, but changes of various degrees were detected by IVUS. Results obtained by IVUS were clustered to select two groups with different degree of coronary artery lesion. The donor’s age in Group 2 was evidently higher compared to Group 1 (34,77 ± 1,03 and 40,00 ± 2,04 years, respectively, p = 0,043. Donor-recipient coincidence frequency was lower in group with significant CA lesion (by 2,36, р = 0,003. The number of cardiac surgeries performed prior to OHT was higher in Group 2 (by 2,8, р = 0,008. Post-transplant factor analysis showed that the number of diabetes mellitus (DM cases revealed after transplantation was more frequent in Group 2 (by 3,2 vs Group 1, р = 0,021. Conclusion. The degree of CA lesion according to IVUS at 24-month period after OTH was associated with several post-transplant factors, which were the presence of cardiac surgical interventions before transplantation, low HLA donor-recipient coincidence frequency, and donor’s age. The more significant CA lesion is, the more cases of DM after OHT occur. 

Relationship between thin cap fibroatheroma identified by virtual histology and angioscopic yellow plaque in quantitative analysis with colorimetry.

Science.gov (United States)

Yamamoto, Masanori; Takano, Masamichi; Okamatsu, Kentaro; Murakami, Daisuke; Inami, Shigenobu; Xie, Yong; Seimiya, Koji; Ohba, Takayoshi; Seino, Yoshihiko; Mizuno, Kyoichi

2009-03-01

Thin cap fibroatheroma (TCFA) is considered to be a vulnerable plaque. Virtual Histology-intravascular ultrasound (VH-IVUS) can precisely identify TCFA in vivo. Intense yellow plaque on angioscopy determined by quantitative colorimetry with L a b color space corresponds with histological TCFA; in particular, a plaque of color b value >23 indicates an atheroma with a fibrous cap thickness colorimetry was investigated. Fifty-seven culprit plaques in 57 patients were evaluated by VH-IVUS and angioscopy. VH-TCFA was defined as a plaque with a necrotic core >10% of plaque area without overlying fibrous tissue, and angioscopic TCFA was a plaque with b value >23. The frequency of angioscopic TCFA was higher in the VH-TCFA group than in the VH-non-TCFA group (74% vs 23%, P=0.0002). Moreover, yellow color intensity (b value) significantly correlated with plaque classification on VH-IVUS. When TCFA detected with angioscopy was used as the gold standard, the sensitivity, specificity, and accuracy for TCFA with VH-IVUS was 68%, 81%, and 75%, respectively. VH-TCFA strongly correlated with angioscopic TCFA determined by a quantitative analysis with colorimetry.

Intravascular ultrasound for iliac artery imaging. Clinical review

DEFF Research Database (Denmark)

Vogt, K G; Schroeder, T V

2001-01-01

IVUS is able to produce trans-sectional images of the iliac arteries at a high resolution. The three layered appearance of the arterial wall can be visualized. In the atherosclerotic diseased artery calcified plaques can be discerned from non-calcified plaques, and the distribution of the plaque...

Evolution of Robot-assisted ultrasound-guided breast biopsy systems

Directory of Open Access Journals (Sweden)

Mustafa Z. Mahmoud

2018-01-01

Full Text Available Robot-assisted ultrasound-guided breast biopsy combines ultrasound (US imaging with a robotic system for medical interventions. This study was designed to provide a literature review of a robotic US-guided breast biopsy system to delineate its efficacious impact on current medical practice. In addition, the strengths and limitations of this approach were also addressed. Articles published in the English language between 2000 and 2016 were appraised in this review. A wide range of systems that bind robotics with US imaging and guided breast biopsy were examined in this article. The fundamental safety and real-time imaging capabilities of US, together with the accuracy and maneuverability of robotic devices, is clearly an effective association with unmatched capabilities. Numerous experimental systems have obvious benefits over old-fashioned techniques, and the future of robot-assisted US-guided breast biopsy will be characterized by increasing levels of automation, and they hold tremendous possibility to impact doctor achievement, patient recovery, and clinical management.

Obstetrical ultrasound data-base management system by using personal computer

International Nuclear Information System (INIS)

Jeon, Hae Jeong; Park, Jeong Hee; Kim, Soo Nyung

1993-01-01

A computer program which performs obstetric calculations on Clipper Language using the data from ultrasonography was developed for personal computer. It was designed for fast assessment of fetal development, prediction of gestational age, and weight from ultrasonographic measurements which included biparietal diameter, femur length, gestational sac, occipito-frontal diameter, abdominal diameter, and etc. The Obstetrical-Ultrasound Data-Base Management System was tested for its performance. The Obstetrical-Ultrasound Data-Base Management System was very useful in patient management with its convenient data filing, easy retrieval of previous report, prompt but accurate estimation of fetal growth and skeletal anomaly and production of equation and growth curve for pregnant women

High-intensity ultrasound production of Maillard reaction flavor compounds in a cysteine-xylose model system.

Science.gov (United States)

Ong, Olivia X H; Seow, Yi-Xin; Ong, Peter K C; Zhou, Weibiao

2015-09-01

Application of high intensity ultrasound has shown potential in the production of Maillard reaction odor-active flavor compounds in model systems. The impact of initial pH, sonication duration, and ultrasound intensity on the production of Maillard reaction products (MRPs) by ultrasound processing in a cysteine-xylose model system were evaluated using Response Surface Methodology (RSM) with a modified mathematical model. Generation of selected MRPs, 2-methylthiophene and tetramethyl pyrazine, was optimal at an initial pH of 6.00, accompanied with 78.1 min of processing at an ultrasound intensity of 19.8 W cm(-2). However, identification of volatiles using gas chromatography-mass spectrometry (GC/MS) revealed that ultrasound-assisted Maillard reactions generated fewer sulfur-containing volatile flavor compounds as compared to conventional heat treatment of the model system. Likely reasons for this difference in flavor profile include the expulsion of H2S due to ultrasonic degassing and inefficient transmission of ultrasonic energy. Copyright © 2015 Elsevier B.V. All rights reserved.

Toward a real-time system for temporal enhanced ultrasound-guided prostate biopsy.

Science.gov (United States)

Azizi, Shekoofeh; Van Woudenberg, Nathan; Sojoudi, Samira; Li, Ming; Xu, Sheng; Abu Anas, Emran M; Yan, Pingkun; Tahmasebi, Amir; Kwak, Jin Tae; Turkbey, Baris; Choyke, Peter; Pinto, Peter; Wood, Bradford; Mousavi, Parvin; Abolmaesumi, Purang

2018-03-27

We have previously proposed temporal enhanced ultrasound (TeUS) as a new paradigm for tissue characterization. TeUS is based on analyzing a sequence of ultrasound data with deep learning and has been demonstrated to be successful for detection of cancer in ultrasound-guided prostate biopsy. Our aim is to enable the dissemination of this technology to the community for large-scale clinical validation. In this paper, we present a unified software framework demonstrating near-real-time analysis of ultrasound data stream using a deep learning solution. The system integrates ultrasound imaging hardware, visualization and a deep learning back-end to build an accessible, flexible and robust platform. A client-server approach is used in order to run computationally expensive algorithms in parallel. We demonstrate the efficacy of the framework using two applications as case studies. First, we show that prostate cancer detection using near-real-time analysis of RF and B-mode TeUS data and deep learning is feasible. Second, we present real-time segmentation of ultrasound prostate data using an integrated deep learning solution. The system is evaluated for cancer detection accuracy on ultrasound data obtained from a large clinical study with 255 biopsy cores from 157 subjects. It is further assessed with an independent dataset with 21 biopsy targets from six subjects. In the first study, we achieve area under the curve, sensitivity, specificity and accuracy of 0.94, 0.77, 0.94 and 0.92, respectively, for the detection of prostate cancer. In the second study, we achieve an AUC of 0.85. Our results suggest that TeUS-guided biopsy can be potentially effective for the detection of prostate cancer.

Clinical diagnostic ultrasound

International Nuclear Information System (INIS)

Barnett, E.; Morley, P.

1986-01-01

This textbook on diagnostic ultrasound covers the main systems, with emphasis being placed on the clinical application of diagnostic ultrasound in everyday practice. It provides not only a textbook for postgraduates (particularly FRCR candidates), but also a reference work for practitioners of clinical ultrasound and clinicians generally

A novel fluoride anion modified gelatin nanogel system for ultrasound-triggered drug release.

Science.gov (United States)

Wu, Daocheng; Wan, Mingxi

2008-01-01

Controlled drug release, especially tumor-targeted drug release, remains a great challenge. Here, we prepare a novel fluoride anion-modified gelatin nanogel system and investigate its characteristics of ultrasound-triggered drug release. Adriamycin gelatin nanogel modified with fluoride anion (ADM-GNMF) was prepared by a modified co-precipitation method with fluoride anion and sodium sulfate. The loading and encapsulation efficiency of the anti-neoplastic agent adriamycin (ADM) were measured by high performance liquid chromatography (HPLC). The size and shape of ADM-GNMF were determined by electron microscopy and photo-correlation spectroscopy. The size distribution and drug release efficiency of ADM-GNMF, before and after sonication, were measured by two designed measuring devices that consisted of either a submicron particle size analyzer and an ultrasound generator as well as an ultrasound generator, automatic sampler, and HPLC. The ADM-GNMF was stable in solution with an average diameter of 46+/-12 nm; the encapsulation and loading efficiency of adriamycin were 87.2% and 6.38%, respectively. The ultrasound-triggered drug release and size change were most efficient at a frequency of 20 kHz, power density of 0.4w/cm2, and a 1~2 min duration. Under this ultrasound-triggered condition, 51.5% of drug in ADM-GNMF was released within 1~2 min, while the size of ADM-GNMF changed from 46 +/- 12 nm to 1212 +/- 35 nm within 1~2 min of sonication and restored to its previous size in 2~3 min after the ultrasound stopped. In contrast, 8.2% of drug in ADM-GNMF was released within 2~3 min without sonication, and only negligible size changes were found. The ADM-GNMF system efficiently released the encompassed drug in response to ultrasound, offering a novel and promising controlled drug release system for targeted therapy for cancer or other diseases.

A Portable Ultrasound System for Non-Invasive Ultrasonic Neuro-Stimulation.

Science.gov (United States)

Qiu, Weibao; Zhou, Juan; Chen, Yan; Su, Min; Li, Guofeng; Zhao, Huixia; Gu, Xianyi; Meng, De; Wang, Congzhi; Xiao, Yang; Lam, Kwok Ho; Dai, Jiyan; Zheng, Hairong

2017-12-01

Fundamental insights into the function of the neural circuits often follows from the advances in methodologies and tools for neuroscience. Electrode- and optical- based stimulation methods have been used widely for neuro-modulation with high resolution. However, they are suffering from inherent invasive surgical procedure. Ultrasound has been proved as a promising technology for neuro-stimulation in a non-invasive manner. However, no portable ultrasound system has been developed particularly for neuro-stimulation. The utilities used currently are assembled by traditional functional generator, power amplifier, and general transducer, therefore, resulting in lack of flexibility. This paper presents a portable system to achieve ultrasonic neuro-stimulation to satisfy various studies. The system incorporated a high voltage waveform generator and a matching circuit that were optimized for neuro-stimulation. A new switching mode power amplifier was designed and fabricated. The noise generated by the power amplifier was reduced (about 30 dB), and the size and weight were smaller in contrast with commercial equipment. In addition, a miniaturized ultrasound transducer was fabricated using Pb(Mg 1/3 Nb 2/3 )O 3 -PbTiO 3 (PMN-PT) 1-3 composite single crystal for the improved ultrasonic performance. The spatial peak temporal average pressure was higher than 250 kPa in the range of 0.5-5 MHz. In vitro and in vivo studies were conducted to show the performance of the system.

Use of Ultrasound Elastography in the Assessment of the Musculoskeletal System

International Nuclear Information System (INIS)

Paluch, Łukasz; Nawrocka-Laskus, Ewa; Wieczorek, Janusz; Mruk, Bartosz; Frel, Małgorzata; Walecki, Jerzy

2016-01-01

This article presents possible applications of ultrasound elastography in musculoskeletal imaging based on the available literature, as well as the possibility of extending indications for the use of elastography in the future. Ultrasound elastography (EUS) is a new method that shows structural changes in tissues following application of physical stress. Elastography techniques have been widely used to assess muscles and tendons in vitro since the early parts of the twentieth century. Only recently with the advent of new technology and creation of highly specialized ultrasound devices, has elastography gained widespread use in numerous applications. The authors performed a search of the Medline/PubMed databases for original research and reviewed publications on the application of ultrasound elastography for musculoskeletal imaging. All publications demonstrate possible uses of ultrasound elastography in examinations of the musculoskeletal system. The most widely studied areas include the muscles, tendons and rheumatic diseases. There are also reports on the employment in vessel imaging. The main limitation of elastography as a technique is above all the variability of applied pressure during imaging, which is operator-dependent. It would therefore be reasonable to provide clear guidelines on the technique applied, as well as clear indications for performing the test. It is important to develop methods for creating artifact-free, closed-loop, compression-decompression cycles. The main advantages include cost-effectiveness, short duration of the study, non-invasive nature of the procedure, as well as a potentially broader clinical availability. There are no clear guidelines with regard to indications as well as examination techniques. Ultrasound elastography is a new and still poorly researched method. We conclude, however, that it can be widely used in the examinations of musculoskeletal system. Therefore, it is necessary to conduct large, multi-center studies to

Accuracy and safety of ward based pleural ultrasound in the Australian healthcare system.

Science.gov (United States)

Hammerschlag, Gary; Denton, Matthew; Wallbridge, Peter; Irving, Louis; Hew, Mark; Steinfort, Daniel

2017-04-01

Ultrasound has been shown to improve the accuracy and safety of pleural procedures. Studies to date have been performed in large, specialized units, where pleural procedures are performed by a small number of highly specialized physicians. There are no studies examining the safety and accuracy of ultrasound in the Australian healthcare system where procedures are performed by junior doctors with a high staff turnover. We performed a retrospective review of the ultrasound database in the Respiratory Department at the Royal Melbourne Hospital to determine accuracy and complications associated pleural procedures. A total of 357 ultrasounds were performed between October 2010 and June 2013. Accuracy of pleural procedures was 350 of 356 (98.3%). Aspiration of pleural fluid was successful in 121 of 126 (96%) of patients. Two (0.9%) patients required chest tube insertion for management of pneumothorax. There were no recorded pleural infections, haemorrhage or viscera puncture. Ward-based ultrasound for pleural procedures is safe and accurate when performed by appropriately trained and supported junior medical officers. Our findings support this model of pleural service care in the Australian healthcare system. © 2016 Asian Pacific Society of Respirology.

A new method for measuring coronary artery diameters with CT spatial profile curves

International Nuclear Information System (INIS)

Shimamoto, Ryoichi; Suzuki, Jun-ichi; Yamazaki, Tadashi; Tsuji, Taeko; Ohmoto, Yuki; Morita, Toshihiro; Yamashita, Hiroshi; Honye, Junko; Nagai, Ryozo; Akahane, Masaaki; Ohtomo, Kuni

2007-01-01

Purpose: Coronary artery vascular edge recognition on computed tomography (CT) angiograms is influenced by window parameters. A noninvasive method for vascular edge recognition independent of window setting with use of multi-detector row CT was contrived and its feasibility and accuracy were estimated by intravascular ultrasound (IVUS). Methods: Multi-detector row CT was performed to obtain 29 CT spatial profile curves by setting a line cursor across short-axis coronary angiograms processed by multi-planar reconstruction. IVUS was also performed to determine the reference coronary diameter. IVUS diameter was fitted horizontally between two points on the upward and downward slopes of the profile curves and Hounsfield number was measured at the fitted level to test seven candidate indexes for definition of intravascular coronary diameter. The best index from the curves should show the best agreement with IVUS diameter. Results: Of the seven candidates the agreement was the best (agreement: 16 ± 11%) when the two ratios of Hounsfield number at the level of IVUS diameter over that at the peak on the profile curves were used with water and with fat as the background tissue. These edge definitions were achieved by cutting the horizontal distance by the curves at the level defined by the ratio of 0.41 for water background and 0.57 for fat background. Conclusions: Vascular edge recognition of the coronary artery with CT spatial profile curves was feasible and the contrived method could define the coronary diameter with reasonable agreement

Assessment of substantia nigra echogenicity in German and Filipino populations using a portable ultrasound system.

Science.gov (United States)

Go, Criscely L; Frenzel, Antonia; Rosales, Raymond L; Lee, Lillian V; Benecke, Reiner; Dressler, Dirk; Walter, Uwe

2012-02-01

Transcranial sonography of the substantia nigra for diagnosing premotor stages of Parkinson disease has been attracting increasing interest. Standard reference values defining an abnormal increased echogenic size (hyperechogenicity) of the substantia nigra have been established in several populations using high-end stationary ultrasound systems. It is unknown whether a portable ultrasound system can be appropriately used and how the Filipino population would compare with the well-studied white population. We prospectively studied substantia nigra echogenic sizes and third ventricle widths in 71 healthy adult German participants and 30 age- and sex-matched Filipino participants using both a well-established stationary ultrasound system (in the German cohort) and a recently distributed portable ultrasound system (in both ethnic cohorts). Mean substantia nigra echogenic sizes, cutoff values defining abnormal hyperechogenicity, and intra-rater reliability were similar with both systems and in both ethnic cohorts studied. The Filipino and German participants did not differ with respect to the frequency of insufficient insonation conditions (each 3%) and substantia nigra hyperechogenicity (10% versus 9%; P = .80). However, third ventricle widths were smaller in the Filipino than the German participants (mean ± SD, 1.6 ± 1.1 versus 2.4 ± 1.0 mm; P = .004). The frequency of substantia nigra hyperechogenicity appears to be homogeneous in white and Asian populations. Screening for this feature may well be performed with a present-day portable ultrasound system.

Evaluation of coronary artery remodeling in patients with acute coronary syndrome and stable angina by multislice computed tomography

International Nuclear Information System (INIS)

Imazeki, Takako; Sato, Yuichi; Inoue, Fumio; Anazawa, Takeo; Tani, Shigemasa; Matsumoto, Naoya; Takayama, Tadateru; Uchiyama, Takahisa; Saito, Satoshi

2004-01-01

Multislice computed tomography (MSCT) was used to evaluate coronary artery remodeling in patients with acute coronary syndrome (ACS) and stable angina (SA). MSCT was performed in 31 patients with ACS and 26 patients with SA and intravascular ultrasound (IVUS) was performed in 28 of these 57 patients. In both the MSCT and IVUS analyses, coronary artery remodeling was assessed by the remodeling index (RI): RI>1.10 was defined as positive coronary artery remodeling (PCAR) and RI<0.95 was defined as negative coronary artery remodeling (NCAR). The RI assessed by MSCT closely correlated with that of IVUS (r=0.86, n=28). The vessel area at the region of maximum luminal narrowing was also comparable between the MSCT and IVUS measurements (r=0.92). PCAR was present in 19 patients (61.3%) with ACS, but in none of the patients with SA (p<0.0001). However, NCAR was present in only 1 patient with ACS (3.2%), but was present in 18 patients (62.9%) with SA. The RI was significantly larger in patients with ACS (1.19±0.18) than in those with SA (0.89±0.10, p<0.0001). MSCT accurately assesses coronary artery remodeling. (author)

Compensated Row-Column Ultrasound Imaging System Using Multilayered Edge Guided Stochastically Fully Connected Random Fields.

Science.gov (United States)

Ben Daya, Ibrahim; Chen, Albert I H; Shafiee, Mohammad Javad; Wong, Alexander; Yeow, John T W

2017-09-06

The row-column method received a lot of attention for 3-D ultrasound imaging. By reducing the number of connections required to address the 2-D array and therefore reducing the amount of data to handle, this addressing method allows for real time 3-D imaging. Row-column still has its limitations: the issues of sparsity, speckle noise inherent to ultrasound, the spatially varying point spread function, and the ghosting artifacts inherent to the row-column method must all be taken into account when building a reconstruction framework. In this research, we build on a previously published system and propose an edge-guided, compensated row-column ultrasound imaging system that incorporates multilayered edge-guided stochastically fully connected conditional random fields to address the limitations of the row-column method. Tests carried out on simulated and real row-column ultrasound images show the effectiveness of our proposed system over other published systems. Visual assessment show our proposed system's potential at preserving edges and reducing speckle. Quantitative analysis shows that our proposed system outperforms previously published systems when evaluated with metrics such as Peak Signal-to-Noise Ratio, Coefficient of Correlation, and Effective Number of Looks. These results show the potential of our proposed system as an effective tool for enhancing 3-D row-column imaging.

A multipoint feedback control system for scanned focussed ultrasound hyperthermia

International Nuclear Information System (INIS)

Johnson, C.; Kress, R.; Roemer, R.; Hynynen, K.

1987-01-01

A multipoint feedback control system has been developed and tested for use with a scanned focussed ultrasound hyperthermia system. Extensive in-vivo tests (using a perfused organ model) have been made to evaluate the basic performance characteristics of the feedback control scheme for control of temperature in perfused media. The results of these tests are presented and compared with the predictions of a simulation routine. The control scheme was also tested in vivo using dogs' thighs and kidneys. Thigh experiments show the control scheme responds well to the affects of vasodilation and is able to maintain the targeted temperatures. In kidney experiments, where the rate of perfusion was controllable, the power adjusting algorithm successfully maintained uniform temperature distributions across regions of varying rates of perfusion. As a conclusion, the results show that this multipoint feedback controller scheme induces uniform temperature distributions when used with scanned focussed ultrasound systems

Unpowered wireless transmission of ultrasound signals

International Nuclear Information System (INIS)

Huang, H; Paramo, D; Deshmukh, S

2011-01-01

This paper presents a wireless ultrasound sensing system that uses frequency conversion to convert the ultrasound signal to a microwave signal and transmit it directly without digitization. Constructed from a few passive microwave components, the sensor is able to sense, modulate, and transmit the full waveform of ultrasound signals wirelessly without requiring any local power source. The principle of operation of the unpowered wireless ultrasound sensor is described first, and this is followed by a detailed description of the implementation of the sensor and the sensor interrogation unit using commercially available antennas and microwave components. Validation of the sensing system using an ultrasound pitch–catch system and the power analysis model of the system are also presented

Dissimilar trend of nonlinearity in ultrasound transducers and systems at resonance and non-resonance frequencies

DEFF Research Database (Denmark)

Ghasemi, Negareh; Zare, Firuz; Davari, Pooya

2017-01-01

Several factors can affect performance of an ultrasound system such as quality of excitation signal and ultrasound transducer behaviour. Nonlinearity of piezoelectric ultrasound transducers is a key determinant in designing a proper driving power supply. Although, the nonlinearity of piezoelectric...... was excited at different frequencies. Different excitation signals were generated using a linear power amplifier and a multilevel converter within a range of 30–200 V. Empirical relation was developed to express the resistance of the piezoelectric transducer as a nonlinear function of both excitation voltage...... and resonance frequency. The impedance measurements revealed that at higher voltage ranges, the piezoelectric transducer can be easily saturated. Also, it was shown that for the developed ultrasound system composed of two transducers (one transmitter and one receiver), the output voltage measured across...

The Effects of Ultrasound on Biological Systems: Site

Science.gov (United States)

El-Karmi, Anan M.

Earlier studies (Dinno et al., Ultrasound Med. Biol. 15:461 -470; 1989) demonstrated that ultrasound at therapeutic intensities causes large increases in total conductance (G_{rm t}) of frog skin. These changes were attributed to non-thermal mechanisms, primarily, cavitation. In this study, the site(s) and mechanism(s) of action of ultrasound for the increase in G_{rm t} were examined. The reversible changes in G_{rm t } and sodium current were monitored in real time as a function of ultrasound exposure. Amiloride, a sodium channel blocker, was used to differentiate between cellular (G_{rm c}) and paracellular (G_{rm s}) pathways in the presence and absence of ultrasound. No significant changes were detected in G_ {rm c}. However, changes in G _{rm s} were significant. These results demonstrate that most of the increase in G _{rm t} due to ultrasound is taking place in the paracellular pathways. Sodium channels were not significantly affected by ultrasound. Thus, the changes in G_{rm c} are not specific. The effects of ultrasound were examined in the presence of radical scavengers and antioxidants. The increase in G_{rm t} due to ultrasound was significantly minimized in the presence of cystamine, cysteamine, and sodium ascorbate. This demonstrates that free radicals and other reactive species generated by cavitation are causing the increase in G_ {rm t}, possibly by acting from inside the cells. Radical scavengers and antioxidants are providing protection from oxidative damage but are not involved in the recovery of G_{ rm t} towards steady state values after sonication. The role of Ca^{2+} in the effects of ultrasound was examined since many of the cellular reactions involved in tissue recovery are dependent on the intracellular availability of free Ca^{2+}. The percentage increase in G_{rm t} in the presence of Ca^{2+} was larger than in its absence (140% vs. 27%). The time constant for G_{rm t} to return to steady state was longer in calcium-free solutions (122

A review of the recommendations governing quality assurance of ultrasound systems used for guidance in prostate brachytherapy.

Science.gov (United States)

Doyle, Andrea Jane; King, Deirdre M; Browne, Jacinta E

2017-12-01

Ultrasound guided brachytherapy for the treatment of prostate cancer has become a routine treatment option, due to many benefits including patient recovery and dose localisation [1]; however it is not clear whether the standards which govern the image quality for these systems are adequate. Upon review of the recommended standards for ultrasound systems used in prostate brachytherapy procedures, the recommended tests do not appear to be specific to the clinical application of ultrasound guided prostate brachytherapy. Rather they are generic and similar to those recommended for other clinical applications such as general abdominal scanning [2]. Furthermore, there is growing evidence that these tests should be specific to the clinical application [3,4] in order to gain meaningful data about the performance of the system for the application, and also to detect clinically relevant changes in quality control results. An additional problem is that there are no clinically relevant test phantom recommended for the quality assurance of ultrasound systems used in prostate brachytherapy. The image quality for this application of ultrasound needs to be monitored to ensure consistent levels of confidence in the procedure. This paper reviews the currently recommended test guidelines and test phantoms for ultrasound systems used in prostate brachytherapy from the different standard bodies and professional organisations. A critical analysis of those tests which are most reflective of the imaging and guidance tasks undertaken in an ultrasound guided prostate brachytherapy procedure will also be presented to inform the design of a TRUS quality assurance protocol. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Long-term safety and feasibility of three-vessel multimodality intravascular imaging in patients with ST-elevation myocardial infarction

DEFF Research Database (Denmark)

Taniwaki, Masanori; Radu, Maria D; Garcia-Garcia, Hector M

2015-01-01

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 s......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...

MO-AB-210-00: Diagnostic Ultrasound Imaging Quality Control and High Intensity Focused Ultrasound Therapy Hands-On Workshop

International Nuclear Information System (INIS)

2015-01-01

The goal of this ultrasound hands-on workshop is to demonstrate advancements in high intensity focused ultrasound (HIFU) and to demonstrate quality control (QC) testing in diagnostic ultrasound. HIFU is a therapeutic modality that uses ultrasound waves as carriers of energy. HIFU is used to focus a beam of ultrasound energy into a small volume at specific target locations within the body. The focused beam causes localized high temperatures and produces a well-defined regions of necrosis. This completely non-invasive technology has great potential for tumor ablation and targeted drug delivery. At the workshop, attendees will see configurations, applications, and hands-on demonstrations with on-site instructors at separate stations. The involvement of medical physicists in diagnostic ultrasound imaging service is increasing due to QC and accreditation requirements. At the workshop, an array of ultrasound testing phantoms and ultrasound scanners will be provided for attendees to learn diagnostic ultrasound QC in a hands-on environment with live demonstrations of the techniques. Target audience: Medical physicists and other medical professionals in diagnostic imaging and radiation oncology with interest in high-intensity focused ultrasound and in diagnostic ultrasound QC. Learning Objectives: Learn ultrasound physics and safety for HIFU applications through live demonstrations Get an overview of the state-of-the art in HIFU technologies and equipment Gain familiarity with common elements of a quality control program for diagnostic ultrasound imaging Identify QC tools available for testing diagnostic ultrasound systems and learn how to use these tools List of supporting vendors for HIFU and diagnostic ultrasound QC hands-on workshop: Philips Healthcare Alpinion Medical Systems Verasonics, Inc Zonare Medical Systems, Inc Computerized Imaging Reference Systems (CIRS), Inc. GAMMEX, Inc., Cablon Medical BV Steffen Sammet: NIH/NCI grant 5R25CA132822, NIH/NINDS grant 5R25NS

MO-AB-210-00: Diagnostic Ultrasound Imaging Quality Control and High Intensity Focused Ultrasound Therapy Hands-On Workshop

Energy Technology Data Exchange (ETDEWEB)

NONE

2015-06-15

The goal of this ultrasound hands-on workshop is to demonstrate advancements in high intensity focused ultrasound (HIFU) and to demonstrate quality control (QC) testing in diagnostic ultrasound. HIFU is a therapeutic modality that uses ultrasound waves as carriers of energy. HIFU is used to focus a beam of ultrasound energy into a small volume at specific target locations within the body. The focused beam causes localized high temperatures and produces a well-defined regions of necrosis. This completely non-invasive technology has great potential for tumor ablation and targeted drug delivery. At the workshop, attendees will see configurations, applications, and hands-on demonstrations with on-site instructors at separate stations. The involvement of medical physicists in diagnostic ultrasound imaging service is increasing due to QC and accreditation requirements. At the workshop, an array of ultrasound testing phantoms and ultrasound scanners will be provided for attendees to learn diagnostic ultrasound QC in a hands-on environment with live demonstrations of the techniques. Target audience: Medical physicists and other medical professionals in diagnostic imaging and radiation oncology with interest in high-intensity focused ultrasound and in diagnostic ultrasound QC. Learning Objectives: Learn ultrasound physics and safety for HIFU applications through live demonstrations Get an overview of the state-of-the art in HIFU technologies and equipment Gain familiarity with common elements of a quality control program for diagnostic ultrasound imaging Identify QC tools available for testing diagnostic ultrasound systems and learn how to use these tools List of supporting vendors for HIFU and diagnostic ultrasound QC hands-on workshop: Philips Healthcare Alpinion Medical Systems Verasonics, Inc Zonare Medical Systems, Inc Computerized Imaging Reference Systems (CIRS), Inc. GAMMEX, Inc., Cablon Medical BV Steffen Sammet: NIH/NCI grant 5R25CA132822, NIH/NINDS grant 5R25NS

Ultrasound assisted combustion synthesis of TiC in Al-Ti-C system.

Science.gov (United States)

Liu, Zhiwei; Rakita, Milan; Xu, Wilson; Wang, Xiaoming; Han, Qingyou

2015-11-01

This research investigated the effects of high-intensity ultrasound on the combustion synthesis of TiC particles in Al-Ti-C system. The process involved that high-intensity ultrasound was applied on the surface of a compacted Al-Ti-C pellet directly through a Nb probe during the thermal explosion reaction. By comparing with the sample without ultrasonic treatment, it was found that the thermal explosion reaction for synthesizing TiC phase could take place thoroughly in the ultrasonically treated sample. During the process of synthesizing TiC phase, the dissolution of solid graphite particles into the Al-Ti melt, as well as the nucleation and growth of TiC particles could be promoted effectively due to the effects of ultrasound, leading to an enhancement of the formation of TiC particles. Ultrasound assisted combustion synthesis as a simple and effective approach was proposed for synthesizing materials in this research. Copyright © 2015 Elsevier B.V. All rights reserved.

Potential and problems in ultrasound-responsive drug delivery systems

Directory of Open Access Journals (Sweden)

Zhao YZ

2013-04-01

Full Text Available Ying-Zheng Zhao,1,3 Li-Na Du,2 Cui-Tao Lu,1 Yi-Guang Jin,2 Shu-Ping Ge3 1Wenzhou Medical College, Wenzhou City, Zhejiang Province, 2Department of Pharmaceutical Sciences, Beijing Institute of Radiation Medicine, Beijing, People’s Republic of China; 3St Christopher’s Hospital for Children/Drexel University College of Medicine, Philadelphia, PA, USA Abstract: Ultrasound is an important local stimulus for triggering drug release at the target tissue. Ultrasound-responsive drug delivery systems (URDDS have become an important research focus in targeted therapy. URDDS include many different formulations, such as microbubbles, nanobubbles, nanodroplets, liposomes, emulsions, and micelles. Drugs that can be loaded into URDDS include small molecules, biomacromolecules, and inorganic substances. Fields of clinical application include anticancer therapy, treatment of ischemic myocardium, induction of an immune response, cartilage tissue engineering, transdermal drug delivery, treatment of Huntington’s disease, thrombolysis, and disruption of the blood–brain barrier. This review focuses on recent advances in URDDS, and discusses their formulations, clinical application, and problems, as well as a perspective on their potential use in the future. Keywords: ultrasound, targeted therapy, clinical application

Portable Ultrasound Imaging

DEFF Research Database (Denmark)

di Ianni, Tommaso

This PhD project investigates hardware strategies and imaging methods for hand-held ultrasound systems. The overall idea is to use a wireless ultrasound probe linked to general-purpose mobile devices for the processing and visualization. The approach has the potential to reduce the upfront costs...... beamforming strategies are simulated from a system-level perspective. The quality of the B-mode image is evaluated and the minimum specifications are derived for the design of a portable probe with integrated electronics in-handle. The system is based on a synthetic aperture sequential beamforming approach...... that allows to significantly reduce the data rate between the probe and processing unit. The second part investigates the feasibility of vector flow imaging in a hand-held ultrasound system. Vector flow imaging overcomes the limitations of conventional imaging methods in terms of flow angle compensation...

Mesh three-dimensional arm orthosis with built-in ultrasound physiotherapy system

Science.gov (United States)

Kashapova, R. M.; Kashapov, R. N.; Kashapova, R. S.

2017-09-01

The possibility of using the built-in ultrasound physiotherapy system of the hand orthosis is explored in the work. The individual mesh orthosis from nylon 12 was manufactured by the 3D prototyping method on the installation of selective laser sintering SLS SPro 60HD. The applied technology of three-dimensional scanning made it possible to obtain a model of the patient’s hand and on the basis of it to build a virtual model of the mesh frame. In the course of the research, the developed system of ultrasound exposure was installed on the orthosis and its tests were carried out. As a result, the acceleration of the healing process and the reduction in the time of wearing orthosis were found.

Breast Ultrasound Examination with Video Monitor System: A Satisfaction Survey among Patients

International Nuclear Information System (INIS)

Ryu, Jung Kyu; Kim, Hyun Cheol; Yang, Dal Mo

2010-01-01

The purpose of this study is to assess the patients satisfaction with a newly established video-monitor system and the associated basic items for performing breast ultrasound exams by conducting a survey among the patients. 349 patients were invited to take the survey and they had undergone breast ultrasound examination once during the 3 months after the monitor system has been introduced. The questionnaire was composed of 8 questions, 4 of which were about the basic items such as age, gender and the reason of their taking the breast ultrasound exam, their preference for the gender of the examiner and the desired length of time for the examination. The other 4 question were about their satisfaction with the video monitor. The patients were divided into two groups according to the purposes of taking the exams, which were screening or diagnostic purposes. The results were compared between these 2 groups. The satisfaction with the video monitor system was assessed by using a scoring system that ranged from 1 to 5. For the total patients, the screening group was composed of 124 patients and the diagnostic group was composed of 225. The reasons why the patients wanted to take the examinations in the diagnostic group varied. The questionnaire about the preference of the gender of the examiner showed that 81.5% in the screening group and 79.1% in the diagnostic group preferred a woman doctor. The required, suitable time for the breast ultrasound examination was 5 to 10 minutes or 10 to 15 minutes for about 70% of the patients. The mean satisfaction score for the video monitor system was as high as 3.95 point. The portion of patients in each group who answered over 3 points for their satisfaction with the monitor system was 88.7% and 94.2%, respectively. Our study showed that patients preferred 5-15 minutes for the length of the examination time and a female examiner. We also confirmed high patient satisfaction with the video monitor system

Breast Ultrasound Examination with Video Monitor System: A Satisfaction Survey among Patients

Energy Technology Data Exchange (ETDEWEB)

Ryu, Jung Kyu; Kim, Hyun Cheol; Yang, Dal Mo [East-West Neo Medical Center, Kyung-Hee University, Seoul (Korea, Republic of)

2010-03-15

The purpose of this study is to assess the patients satisfaction with a newly established video-monitor system and the associated basic items for performing breast ultrasound exams by conducting a survey among the patients. 349 patients were invited to take the survey and they had undergone breast ultrasound examination once during the 3 months after the monitor system has been introduced. The questionnaire was composed of 8 questions, 4 of which were about the basic items such as age, gender and the reason of their taking the breast ultrasound exam, their preference for the gender of the examiner and the desired length of time for the examination. The other 4 question were about their satisfaction with the video monitor. The patients were divided into two groups according to the purposes of taking the exams, which were screening or diagnostic purposes. The results were compared between these 2 groups. The satisfaction with the video monitor system was assessed by using a scoring system that ranged from 1 to 5. For the total patients, the screening group was composed of 124 patients and the diagnostic group was composed of 225. The reasons why the patients wanted to take the examinations in the diagnostic group varied. The questionnaire about the preference of the gender of the examiner showed that 81.5% in the screening group and 79.1% in the diagnostic group preferred a woman doctor. The required, suitable time for the breast ultrasound examination was 5 to 10 minutes or 10 to 15 minutes for about 70% of the patients. The mean satisfaction score for the video monitor system was as high as 3.95 point. The portion of patients in each group who answered over 3 points for their satisfaction with the monitor system was 88.7% and 94.2%, respectively. Our study showed that patients preferred 5-15 minutes for the length of the examination time and a female examiner. We also confirmed high patient satisfaction with the video monitor system

Ultrasound skin tightening.

Science.gov (United States)

Minkis, Kira; Alam, Murad

2014-01-01

Ultrasound skin tightening is a noninvasive, nonablative method that allows for energy deposition into the deep dermal and subcutaneous tissue while avoiding epidermal heating. Ultrasound coagulation is confined to arrays of 1-mm(3) zones that include the superficial musculoaponeurotic system and connective tissue. This technology gained approval from the Food and Drug Administration as the first energy-based skin "lifting" device, specifically for lifting lax tissue on the neck, submentum, and eyebrows. Ultrasound has the unique advantage of direct visualization of treated structures during treatment. Ultrasound is a safe and efficacious treatment for mild skin tightening and lifting. Copyright © 2014 Elsevier Inc. All rights reserved.

Medical ultrasound imaging

DEFF Research Database (Denmark)

Jensen, Jørgen Arendt

2007-01-01

The paper gives an introduction to current medical ultrasound imaging systems. The basics of anatomic and blood flow imaging are described. The properties of medical ultrasound and its focusing are described, and the various methods for two- and three-dimensional imaging of the human anatomy...

Advanced Imaging of Intracranial Atherosclerosis: Lessons from Interventional Cardiology

Directory of Open Access Journals (Sweden)

Davor Pavlin-Premrl

2017-08-01

Full Text Available Intracranial atherosclerosis is a major cause of ischemic stroke. Patients with a high degree of stenosis have a significant rate of stroke despite medical therapy. Two randomized trials of stenting have failed to show benefit. Improving periprocedural complication rates and patient selection may improve stenting outcomes. Fractional flow reserve (FFR, intravascular ultrasound (IVUS, and optical coherence tomography (OCT are intravascular imaging techniques employed to improve patient selection and stent placement in interventional cardiology. FFR has been shown to improve cardiovascular outcomes when used in patient selection for intervention. Studies of FFR in intracranial atherosclerosis show that the measure may predict which plaques lead to stroke. IVUS is used in cardiology to quantify stenosis and assist with stent placement. Comparisons with histology show that it can reliably characterize plaques. Several case reports of IVUS in intracranial arteries show the technique to be feasible and indicate it may improve stent placement. Plaque characteristics on IVUS may help identify vulnerable plaques. In interventional cardiology, OCT provides excellent visualization of vessel geometry and is useful periprocedurally. Images reliably identify thin-capped fibroatheromas and other plaque features. Case reports indicate that OCT is safe for use in intracranial arteries. OCT can be used to identify perforator vessels and so may be useful in avoiding perforator strokes, a common complication of stenting. Plaque characteristics on OCT may be useful in patient selection.

CT and Ultrasound Guided Stereotactic High Intensity Focused Ultrasound (HIFU)

Science.gov (United States)

Wood, Bradford J.; Yanof, J.; Frenkel, V.; Viswanathan, A.; Dromi, S.; Oh, K.; Kruecker, J.; Bauer, C.; Seip, R.; Kam, A.; Li, K. C. P.

2006-05-01

To demonstrate the feasibility of CT and B-mode Ultrasound (US) targeted HIFU, a prototype coaxial focused ultrasound transducer was registered and integrated to a CT scanner. CT and diagnostic ultrasound were used for HIFU targeting and monitoring, with the goals of both thermal ablation and non-thermal enhanced drug delivery. A 1 megahertz coaxial ultrasound transducer was custom fabricated and attached to a passive position-sensing arm and an active six degree-of-freedom robotic arm via a CT stereotactic frame. The outer therapeutic transducer with a 10 cm fixed focal zone was coaxially mounted to an inner diagnostic US transducer (2-4 megahertz, Philips Medical Systems). This coaxial US transducer was connected to a modified commercial focused ultrasound generator (Focus Surgery, Indianapolis, IN) with a maximum total acoustic power of 100 watts. This pre-clinical paradigm was tested for ability to heat tissue in phantoms with monitoring and navigation from CT and live US. The feasibility of navigation via image fusion of CT with other modalities such as PET and MRI was demonstrated. Heated water phantoms were tested for correlation between CT numbers and temperature (for ablation monitoring). The prototype transducer and integrated CT/US imaging system enabled simultaneous multimodality imaging and therapy. Pre-clinical phantom models validated the treatment paradigm and demonstrated integrated multimodality guidance and treatment monitoring. Temperature changes during phantom cooling corresponded to CT number changes. Contrast enhanced or non-enhanced CT numbers may potentially be used to monitor thermal ablation with HIFU. Integrated CT, diagnostic US, and therapeutic focused ultrasound bridges a gap between diagnosis and therapy. Preliminary results show that the multimodality system may represent a relatively inexpensive, accessible, and simple method of both targeting and monitoring HIFU effects. Small animal pre-clinical models may be translated to large

Therapeutic ultrasound

International Nuclear Information System (INIS)

Crum, Lawrence A

2004-01-01

The use of ultrasound in medicine is now quite commonplace, especially with the recent introduction of small, portable and relatively inexpensive, hand-held diagnostic imaging devices. Moreover, ultrasound has expanded beyond the imaging realm, with methods and applications extending to novel therapeutic and surgical uses. These applications broadly include: tissue ablation, acoustocautery, lipoplasty, site-specific and ultrasound mediated drug activity, extracorporeal lithotripsy, and the enhancement of natural physiological functions such as wound healing and tissue regeneration. A particularly attractive aspect of this technology is that diagnostic and therapeutic systems can be combined to produce totally non-invasive, imageguided therapy. This general lecture will review a number of these exciting new applications of ultrasound and address some of the basic scientific questions and future challenges in developing these methods and technologies for general use in our society. We shall particularly emphasize the use of High Intensity Focused Ultrasound (HIFU) in the treatment of benign and malignant tumors as well as the introduction of acoustic hemostasis, especially in organs which are difficult to treat using conventional medical and surgical techniques. (amum lecture)

Sampling system for in vivo ultrasound images

DEFF Research Database (Denmark)

Jensen, Jorgen Arendt; Mathorne, Jan

1991-01-01

Newly developed algorithms for processing medical ultrasound images use the high frequency sampled transducer signal. This paper describes demands imposed on a sampling system suitable for acquiring such data and gives details about a prototype constructed. It acquires full clinical images...... at a sampling frequency of 20 MHz with a resolution of 12 bits. The prototype can be used for real time image processing. An example of a clinical in vivo image is shown and various aspects of the data acquisition process are discussed....

Molecular ultrasound imaging: current status and future directions

International Nuclear Information System (INIS)

Deshpande, N.; Needles, A.; Willmann, J.K.

2010-01-01

Targeted contrast-enhanced ultrasound (molecular ultrasound) is an emerging imaging strategy that combines ultrasound technology with novel molecularly-targeted ultrasound contrast agents for assessing biological processes at the molecular level. Molecular ultrasound contrast agents are nano- or micro-sized particles that are targeted to specific molecular markers by adding high-affinity binding ligands onto the surface of the particles. Following intravenous administration, these targeted ultrasound contrast agents accumulate at tissue sites overexpressing specific molecular markers, thereby enhancing the ultrasound imaging signal. High spatial and temporal resolution, real-time imaging, non-invasiveness, relatively low costs, lack of ionising irradiation and wide availability of ultrasound systems are advantages compared to other molecular imaging modalities. In this article we review current concepts and future directions of molecular ultrasound imaging, including different classes of molecular ultrasound contrast agents, ongoing technical developments of pre-clinical and clinical ultrasound systems, the potential of molecular ultrasound for imaging different diseases at the molecular level, and the translation of molecular ultrasound into the clinic.

Five-dimensional ultrasound system for soft tissue visualization.

Science.gov (United States)

Deshmukh, Nishikant P; Caban, Jesus J; Taylor, Russell H; Hager, Gregory D; Boctor, Emad M

2015-12-01

A five-dimensional ultrasound (US) system is proposed as a real-time pipeline involving fusion of 3D B-mode data with the 3D ultrasound elastography (USE) data as well as visualization of these fused data and a real-time update capability over time for each consecutive scan. 3D B-mode data assist in visualizing the anatomy of the target organ, and 3D elastography data adds strain information. We investigate the feasibility of such a system and show that an end-to-end real-time system, from acquisition to visualization, can be developed. We present a system that consists of (a) a real-time 3D elastography algorithm based on a normalized cross-correlation (NCC) computation on a GPU; (b) real-time 3D B-mode acquisition and network transfer; (c) scan conversion of 3D elastography and B-mode volumes (if acquired by 4D wobbler probe); and (d) visualization software that fuses, visualizes, and updates 3D B-mode and 3D elastography data in real time. We achieved a speed improvement of 4.45-fold for the threaded version of the NCC-based 3D USE versus the non-threaded version. The maximum speed was 79 volumes/s for 3D scan conversion. In a phantom, we validated the dimensions of a 2.2-cm-diameter sphere scan-converted to B-mode volume. Also, we validated the 5D US system visualization transfer function and detected 1- and 2-cm spherical objects (phantom lesion). Finally, we applied the system to a phantom consisting of three lesions to delineate the lesions from the surrounding background regions of the phantom. A 5D US system is achievable with real-time performance. We can distinguish between hard and soft areas in a phantom using the transfer functions.

Actuator-Assisted Calibration of Freehand 3D Ultrasound System.

Science.gov (United States)

Koo, Terry K; Silvia, Nathaniel

2018-01-01

Freehand three-dimensional (3D) ultrasound has been used independently of other technologies to analyze complex geometries or registered with other imaging modalities to aid surgical and radiotherapy planning. A fundamental requirement for all freehand 3D ultrasound systems is probe calibration. The purpose of this study was to develop an actuator-assisted approach to facilitate freehand 3D ultrasound calibration using point-based phantoms. We modified the mathematical formulation of the calibration problem to eliminate the need of imaging the point targets at different viewing angles and developed an actuator-assisted approach/setup to facilitate quick and consistent collection of point targets spanning the entire image field of view. The actuator-assisted approach was applied to a commonly used cross wire phantom as well as two custom-made point-based phantoms (original and modified), each containing 7 collinear point targets, and compared the results with the traditional freehand cross wire phantom calibration in terms of calibration reproducibility, point reconstruction precision, point reconstruction accuracy, distance reconstruction accuracy, and data acquisition time. Results demonstrated that the actuator-assisted single cross wire phantom calibration significantly improved the calibration reproducibility and offered similar point reconstruction precision, point reconstruction accuracy, distance reconstruction accuracy, and data acquisition time with respect to the freehand cross wire phantom calibration. On the other hand, the actuator-assisted modified "collinear point target" phantom calibration offered similar precision and accuracy when compared to the freehand cross wire phantom calibration, but it reduced the data acquisition time by 57%. It appears that both actuator-assisted cross wire phantom and modified collinear point target phantom calibration approaches are viable options for freehand 3D ultrasound calibration.

Implementation of a versatile research data acquisition system using a commercially available medical ultrasound scanner

DEFF Research Database (Denmark)

Hemmsen, Martin Christian; Nikolov, Svetoslav Ivanov; Pedersen, Mads Møller

2012-01-01

to the clinic. The system consists of a standard PC equipped with a camera link and an ultrasound scanner equipped with a research interface. The ultrasound scanner is an easy-to-use imaging device that is capable of generating high-quality images. In addition to supporting the acquisition of multiple data...

Field: A Program for Simulating Ultrasound Systems

DEFF Research Database (Denmark)

Jensen, Jørgen Arendt

1997-01-01

A program for the simulation of ultrasound systems is presented.It is based on the Tupholme-Stepanishen method, and is fastbecause of the use of a far-field approximation. Any kind oftransducer geometry and excitation can be simulated, and bothpulse-echo and continuous wave fields can be calculated...... for bothtransmit and pulse-echo. Dynamic apodization and focusing arehandled through time lines, and different focusingschemes can be simulated. The versatility of the program isensured by interfacing it to Matlab. All routines are calleddirectly from Matlab, and all Matlab features can be used. Thismakes...

Three-Year Major Clinical Outcomes of Angiography-Guided Single Stenting Technique in Non-Complex Left Main Coronary Artery Diseases.

Science.gov (United States)

Kim, Yong Hoon; Her, Ae-Young; Rha, Seung-Woon; Choi, Byoung Geol; Shim, Minsuk; Choi, Se Yeon; Byun, Jae Kyeong; Li, Hu; Kim, Woohyeun; Kang, Jun Hyuk; Choi, Jah Yeon; Park, Eun Jin; Park, Sung Hun; Lee, Sunki; Na, Jin Oh; Choi, Cheol Ung; Lim, Hong Euy; Kim, Eung Ju; Park, Chang Gyu; Seo, Hong Seog; Oh, Dong Joo

2017-10-12

There is limited long-term comparative clinical outcome data concerning angiography- versus intravascular ultrasound (IVUS)-guided percutaneous coronary intervention (PCI) in non-complex left main coronary artery (LMCA) disease treated with the single stenting technique in the drug-eluting stent (DES) era.The aim of this study was to investigate whether angiography-guided stenting is comparable to IVUS-guided stenting during 3-year clinical follow-up periods in patients with non-complex LM disease treated with the single stenting technique.A total of 196 patients treated with either angiography-guided (n = 74) or IVUS-guided (n = 122) PCI were included. The primary outcome was the occurrence of major adverse cardiac events (MACE) defined as total death, non-fatal myocardial infarction (MI), target lesion revascularization (TLR), target vessel revascularization (TVR), and non-target vessel revascularization (Non-TVR). To adjust for any potential confounders, propensity score (PS) adjusted analysis was performed.During 3-year follow-up, the PS adjusted Cox-proportional hazard ratio (HR) was not significantly different between the two groups for total death, cardiac death, and MI. Also, TLR and the combined rates of TVR and non-TVR were not significantly different. Finally, MACE was not significantly different between the two groups (HR: 0.63, 95% Confidence interval (CI): 0.33-1.17; P = 0.149).Angiography-guided PCI for non-complex LMCA diseases treated with the single stenting technique showed comparable results compared with IVUS-guided PCI in reducing clinical events during 3-year clinical follow-up in the DES era. Although IVUS guided PCI is the ideal strategy, angiography-guided PCI can be an option for LMCA PCI in some selected cases.

Virtual histology study of atherosclerotic plaque composition in patients with stable angina and acute phase of acute coronary syndromes without ST segment elevation

Directory of Open Access Journals (Sweden)

Ivanović Miloš

2013-01-01

Full Text Available Introduction. Rupture of vulnerable atherosclerotic plaques is the cause of most acute coronary syndromes (ACS. Postmortem studies which compared stable coronary lesions and atherosclerotic plaques in patients who have died because of ACS indicated high lipid-core content as one of the major determinants of plaque vulnerability. Objective. Our primary goal was to assess the potential relations of plaque composition determined by IVUS-VH (Intravascular Ultrasound - Virtual Histology in patients with stable angina and subjects in acute phase of ACS without ST segment elevation. Methods. The study comprised of 40 patients who underwent preintervention IVUS examination. Tissue maps were reconstructed from radio frequency data using IVUS-VH software. Results. We analyzed 53 lesions in 40 patients. Stable angina was diagnosed in 24 patients (29 lesions, while acute phase of ACS without ST elevation was diagnosed in 16 patients (24 lesions. In the patients in acute phase of ACS without ST segment elevation IVUS-VH examination showed a significantly larger area of the necrotic core at the site of minimal lumen area and a larger mean of the necrotic core volume in the entire lesion comparing to stable angina subjects (1.84±0.90 mm2 vs. 0.96±0.69 mm2; p<0.001 and 20.94±15.79 mm3 vs. 11.54±14.15 mm3; p<0.05 respectively. Conclusion. IVUS-VH detected that the necrotic core was significantly larger in atherosclerotic lesions in patients in acute phase of ACS without ST elevation comparing to the stable angina subjects and that it could be considered as a marker of plaque vulnerability.

Improved vessel morphology measurements in contrast-enhanced multi-detector computed tomography coronary angiography with non-linear post-processing

International Nuclear Information System (INIS)

Ferencik, Maros; Lisauskas, Jennifer B.; Cury, Ricardo C.; Hoffmann, Udo; Abbara, Suhny; Achenbach, Stephan; Karl, W. Clem; Brady, Thomas J.; Chan, Raymond C.

2006-01-01

Multi-detector computed tomography (MDCT) permits detection of coronary plaque. However, noise and blurring impair accuracy and precision of plaque measurements. The aim of the study was to evaluate MDCT post-processing based on non-linear image deblurring and edge-preserving noise suppression for measurements of plaque size. Contrast-enhanced MDCT coronary angiography was performed in four subjects (mean age 55 ± 5 years, mean heart rate 54 ± 5 bpm) using a 16-slice scanner (Siemens Sensation 16, collimation 16 x 0.75 mm, gantry rotation 420 ms, tube voltage 120 kV, tube current 550 mAs, 80 mL of contrast). Intravascular ultrasound (IVUS; 40 MHz probe) was performed in one vessel in each patient and served as a reference standard. MDCT vessel cross-sectional images (1 mm thickness) were created perpendicular to centerline and aligned with corresponding IVUS images. MDCT images were processed using a deblurring and edge-preserving noise suppression algorithm. Then, three independent blinded observers segmented lumen and outer vessel boundaries in each modality to obtain vessel cross-sectional area and wall area in the unprocessed MDCT cross-sections, post-processed MDCT cross-sections and corresponding IVUS. The wall area measurement difference for unprocessed and post-processed MDCT images relative to IVUS was 0.4 ± 3.8 mm 2 and -0.2 ± 2.2 mm 2 (p 2 , respectively. In conclusion, MDCT permitted accurate in vivo measurement of wall area and vessel cross-sectional area as compared to IVUS. Post-processing to reduce blurring and noise reduced variability of wall area measurements and reduced measurement bias for both wall area and vessel cross-sectional area

A novel fusion imaging system for endoscopic ultrasound

DEFF Research Database (Denmark)

Gruionu, Lucian Gheorghe; Saftoiu, Adrian; Gruionu, Gabriel

2016-01-01

BACKGROUND AND OBJECTIVE: Navigation of a flexible endoscopic ultrasound (EUS) probe inside the gastrointestinal (GI) tract is problematic due to the small window size and complex anatomy. The goal of the present study was to test the feasibility of a novel fusion imaging (FI) system which uses...... time was 24.6 ± 6.6 min, while the time to reach the clinical target was 8.7 ± 4.2 min. CONCLUSIONS: The FI system is feasible for clinical use, and can reduce the learning curve for EUS procedures and improve navigation and targeting in difficult anatomic locations....

TH-A-207B-02: QIBA Ultrasound Elasticity Imaging System Biomarker Qualification and User Testing of Systems

International Nuclear Information System (INIS)

Garra, B.

2016-01-01

Imaging of tissue elastic properties is a relatively new and powerful approach to one of the oldest and most important diagnostic tools. Imaging of shear wave speed with ultrasound is has been added to most high-end ultrasound systems. Understanding this exciting imaging mode aiding its most effective use in medicine can be a rewarding effort for medical physicists and other medical imaging and treatment professionals. Assuring consistent, quantitative measurements across the many ultrasound systems in a typical imaging department will constitute a major step toward realizing the great potential of this technique and other quantitative imaging. This session will target these two goals with two presentations. A. Basics and Current Implementations of Ultrasound Imaging of Shear Wave Speed and Elasticity - Shigao Chen, Ph.D. Learning objectives-To understand: Introduction: Importance of tissue elasticity measurement Strain vs. shear wave elastography (SWE), beneficial features of SWE The link between shear wave speed and material properties, influence of viscosity Generation of shear waves External vibration (Fibroscan) ultrasound radiation force Point push Supersonic push (Aixplorer) Comb push (GE Logiq E9) Detection of shear waves Motion detection from pulse-echo ultrasound Importance of frame rate for shear wave imaging Plane wave imaging detection How to achieve high effective frame rate using line-by-line scanners Shear wave speed calculation Time to peak Random sample consensus (RANSAC) Cross correlation Sources of bias and variation in SWE Tissue viscosity Transducer compression or internal pressure of organ Reflection of shear waves at boundaries B. Elasticity Imaging System Biomarker Qualification and User Testing of Systems – Brian Garra, M.D. Learning objectives-To understand: Goals Review the need for quantitative medical imaging Provide examples of quantitative imaging biomarkers Acquaint the participant with the purpose of the RSNA Quantitative Imaging

TH-A-207B-02: QIBA Ultrasound Elasticity Imaging System Biomarker Qualification and User Testing of Systems

Energy Technology Data Exchange (ETDEWEB)

Garra, B. [FDA, Silver Spring, MD (United States)

2016-06-15

Imaging of tissue elastic properties is a relatively new and powerful approach to one of the oldest and most important diagnostic tools. Imaging of shear wave speed with ultrasound is has been added to most high-end ultrasound systems. Understanding this exciting imaging mode aiding its most effective use in medicine can be a rewarding effort for medical physicists and other medical imaging and treatment professionals. Assuring consistent, quantitative measurements across the many ultrasound systems in a typical imaging department will constitute a major step toward realizing the great potential of this technique and other quantitative imaging. This session will target these two goals with two presentations. A. Basics and Current Implementations of Ultrasound Imaging of Shear Wave Speed and Elasticity - Shigao Chen, Ph.D. Learning objectives-To understand: Introduction: Importance of tissue elasticity measurement Strain vs. shear wave elastography (SWE), beneficial features of SWE The link between shear wave speed and material properties, influence of viscosity Generation of shear waves External vibration (Fibroscan) ultrasound radiation force Point push Supersonic push (Aixplorer) Comb push (GE Logiq E9) Detection of shear waves Motion detection from pulse-echo ultrasound Importance of frame rate for shear wave imaging Plane wave imaging detection How to achieve high effective frame rate using line-by-line scanners Shear wave speed calculation Time to peak Random sample consensus (RANSAC) Cross correlation Sources of bias and variation in SWE Tissue viscosity Transducer compression or internal pressure of organ Reflection of shear waves at boundaries B. Elasticity Imaging System Biomarker Qualification and User Testing of Systems – Brian Garra, M.D. Learning objectives-To understand: Goals Review the need for quantitative medical imaging Provide examples of quantitative imaging biomarkers Acquaint the participant with the purpose of the RSNA Quantitative Imaging

An experimental system for the study of ultrasound exposure of isolated blood vessels

International Nuclear Information System (INIS)

Tokarczyk, Anna; Rivens, Ian; Symonds-Tayler, Richard; Ter Haar, Gail; Van Bavel, E

2013-01-01

An experimental system designed for the study of the effects of diagnostic or therapeutic ultrasound exposure on isolated blood vessels in the presence or absence of intraluminal contrast agent is described. The system comprised several components. A microscope was used to monitor vessel size (and thus vessel functionality), and potential leakage of intraluminal 70 kDa FITC-dextran fluorescence marker. A vessel chamber allowed the mounting of an isolated vessel whilst maintaining its viability, with pressure regulation for the control of intraluminal pressure and induction of flow for the infusion of contrast microbubbles. A fibre-optic hydrophone sensor mounted on the vessel chamber using a micromanipulator allowed pre-exposure targeting of the vessel to within 150 µm, and monitoring of acoustic cavitation emissions during exposures. Acoustic cavitation was also detected using changes in the ultrasound drive voltage and by detection of audible emissions using a submerged microphone. The suitability of this system for studying effects in the isolated vessel model has been demonstrated using a pilot study of 6 sham exposed and 18 high intensity focused ultrasound exposed vessels, with or without intraluminal contrast agent (SonoVue) within the vessels. (paper)

SU-G-JeP3-08: Robotic System for Ultrasound Tracking in Radiation Therapy

Energy Technology Data Exchange (ETDEWEB)

Kuhlemann, I [University of Luebeck, Luebeck (Germany); Graduate School for Computing in Medicine and Life Sciences, University of Luebeck (Germany); Jauer, P; Schweikard, A; Ernst, F [University of Luebeck, Luebeck (Germany)

2016-06-15

Purpose: For safe and accurate real-time tracking of tumors for IGRT using 4D ultrasound, it is necessary to make use of novel, high-end force-sensitive lightweight robots designed for human-machine interaction. Such a robot will be integrated into an existing robotized ultrasound system for non-invasive 4D live tracking, using a newly developed real-time control and communication framework. Methods: The new KUKA LWR iiwa robot is used for robotized ultrasound real-time tumor tracking. Besides more precise probe contact pressure detection, this robot provides an additional 7th link, enhancing the dexterity of the kinematic and the mounted transducer. Several integrated, certified safety features create a safe environment for the patients during treatment. However, to remotely control the robot for the ultrasound application, a real-time control and communication framework has to be developed. Based on a client/server concept, client-side control commands are received and processed by a central server unit and are implemented by a client module running directly on the robot’s controller. Several special functionalities for robotized ultrasound applications are integrated and the robot can now be used for real-time control of the image quality by adjusting the transducer position, and contact pressure. The framework was evaluated looking at overall real-time capability for communication and processing of three different standard commands. Results: Due to inherent, certified safety modules, the new robot ensures a safe environment for patients during tumor tracking. Furthermore, the developed framework shows overall real-time capability with a maximum average latency of 3.6 ms (Minimum 2.5 ms; 5000 trials). Conclusion: The novel KUKA LBR iiwa robot will advance the current robotized ultrasound tracking system with important features. With the developed framework, it is now possible to remotely control this robot and use it for robotized ultrasound tracking

SU-G-JeP3-08: Robotic System for Ultrasound Tracking in Radiation Therapy

International Nuclear Information System (INIS)

Kuhlemann, I; Jauer, P; Schweikard, A; Ernst, F

2016-01-01

Purpose: For safe and accurate real-time tracking of tumors for IGRT using 4D ultrasound, it is necessary to make use of novel, high-end force-sensitive lightweight robots designed for human-machine interaction. Such a robot will be integrated into an existing robotized ultrasound system for non-invasive 4D live tracking, using a newly developed real-time control and communication framework. Methods: The new KUKA LWR iiwa robot is used for robotized ultrasound real-time tumor tracking. Besides more precise probe contact pressure detection, this robot provides an additional 7th link, enhancing the dexterity of the kinematic and the mounted transducer. Several integrated, certified safety features create a safe environment for the patients during treatment. However, to remotely control the robot for the ultrasound application, a real-time control and communication framework has to be developed. Based on a client/server concept, client-side control commands are received and processed by a central server unit and are implemented by a client module running directly on the robot’s controller. Several special functionalities for robotized ultrasound applications are integrated and the robot can now be used for real-time control of the image quality by adjusting the transducer position, and contact pressure. The framework was evaluated looking at overall real-time capability for communication and processing of three different standard commands. Results: Due to inherent, certified safety modules, the new robot ensures a safe environment for patients during tumor tracking. Furthermore, the developed framework shows overall real-time capability with a maximum average latency of 3.6 ms (Minimum 2.5 ms; 5000 trials). Conclusion: The novel KUKA LBR iiwa robot will advance the current robotized ultrasound tracking system with important features. With the developed framework, it is now possible to remotely control this robot and use it for robotized ultrasound tracking

Bipolar-power-transistor-based limiter for high frequency ultrasound imaging systems.

Science.gov (United States)

Choi, Hojong; Yang, Hao-Chung; Shung, K Kirk

2014-03-01

High performance limiters are described in this paper for applications in high frequency ultrasound imaging systems. Limiters protect the ultrasound receiver from the high voltage (HV) spikes produced by the transmitter. We present a new bipolar power transistor (BPT) configuration and compare its design and performance to a diode limiter used in traditional ultrasound research and one commercially available limiter. Limiter performance depends greatly on the insertion loss (IL), total harmonic distortion (THD) and response time (RT), each of which will be evaluated in all the limiters. The results indicated that, compared with commercial limiter, BPT-based limiter had less IL (-7.7 dB), THD (-74.6 dB) and lower RT (43 ns) at 100 MHz. To evaluate the capability of these limiters, they were connected to a 100 MHz single element transducer and a two-way pulse-echo test was performed. It was found that the -6 dB bandwidth and sensitivity of the transducer using BPT-based limiter were better than those of the commercial limiter by 22% and 140%, respectively. Compared to the commercial limiter, BPT-based limiter is shown to be capable of minimizing signal attenuation, RT and THD at high frequencies and is thus suited for high frequency ultrasound applications. Copyright © 2013 Elsevier B.V. All rights reserved.

Effect of Prior Aspirin Treatment on Patients With Acute Coronary Syndromes: Insights From the PROSPECT Study.

Science.gov (United States)

Brener, Sorin J; Maehara, Akiko; Mintz, Gary S; Weisz, Giora; de Bruyne, Bernard; Serruys, Patrick W; Stone, Gregg W

2015-12-01

Prior aspirin treatment is considered a risk factor for adverse outcomes in acute coronary syndrome (ACS) patients. The relationships between aspirin pretreatment and findings on quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS), as well as clinical outcomes, are not well understood. In the PROSPECT trial, QCA and triple-vessel IVUS imaging were performed after successful percutaneous coronary intervention (PCI) of the culprit lesion(s) in ACS patients. We compared patients receiving aspirin within 7 days of enrollment to those naive to aspirin. Propensity score matching was performed to adjust for differences in baseline characteristics. Aspirin-pretreated patients (n = 236; 35%) were older and more likely to have known coronary disease than those without pretreatment (P≤.01 for all). Pretreated patients had more untreated non-culprit lesions with angiographic and IVUS characteristics predictive of future events (53.1% vs 38.6%; PPROSPECT trial, aspirin pretreatment identifies an older population with more advanced coronary disease. Aspirin pretreatment was not an independent predictor of MACE in ACS patients treated with an early invasive strategy. The extent to which aspirin pretreatment is a risk factor for adverse events after PCI in ACS should be revisited.

Clinical use of intracoronary imaging. Part 1: guidance and optimization of coronary interventions. An expert consensus document of the European Association of Percutaneous Cardiovascular Interventions: Endorsed by the Chinese Society of Cardiology.

Science.gov (United States)

Räber, Lorenz; Mintz, Gary S; Koskinas, Konstantinos C; Johnson, Thomas W; Holm, Niels R; Onuma, Yoshinubo; Radu, Maria D; Joner, Michael; Yu, Bo; Jia, Haibo; Menevau, Nicolas; de la Torre Hernandez, Jose M; Escaned, Javier; Hill, Jonathan; Prati, Francesco; Colombo, Antonio; di Mario, Carlo; Regar, Evelyn; Capodanno, Davide; Wijns, William; Byrne, Robert A; Guagliumi, Giulio

2018-05-22

This Consensus Document is the first of two reports summarizing the views of an expert panel organized by the European Association of Percutaneous Cardiovascular Interventions (EAPCI) on the clinical use of intracoronary imaging including intravascular ultrasound (IVUS) and optical coherence tomography (OCT). The first document appraises the role of intracoronary imaging to guide percutaneous coronary interventions (PCIs) in clinical practice. Current evidence regarding the impact of intracoronary imaging guidance on cardiovascular outcomes is summarized, and patients or lesions most likely to derive clinical benefit from an imaging-guided intervention are identified. The relevance of the use of IVUS or OCT prior to PCI for optimizing stent sizing (stent length and diameter) and planning the procedural strategy is discussed. Regarding post-implantation imaging, the consensus group recommends key parameters that characterize an optimal PCI result and provides cut-offs to guide corrective measures and optimize the stenting result. Moreover, routine performance of intracoronary imaging in patients with stent failure (restenosis or stent thrombosis) is recommended. Finally, strengths and limitations of IVUS and OCT for guiding PCI and assessing stent failures and areas that warrant further research are critically discussed.

Design of low noise transimpedance amplifier for intravascular ultrasound

KAUST Repository

Reda, Dina

2009-11-01

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

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... frequently used to evaluate the reproductive and urinary systems. Ultrasound is safe, noninvasive and does not use ... and evaluate a variety of urinary and reproductive system disorders in both sexes without x-ray exposure. ...

Combined ultrasound and MR imaging to guide focused ultrasound therapies in the brain

Science.gov (United States)

Arvanitis, Costas D.; Livingstone, Margaret S.; McDannold, Nathan

2013-07-01

Several emerging therapies with potential for use in the brain, harness effects produced by acoustic cavitation—the interaction between ultrasound and microbubbles either generated during sonication or introduced into the vasculature. Systems developed for transcranial MRI-guided focused ultrasound (MRgFUS) thermal ablation can enable their clinical translation, but methods for real-time monitoring and control are currently lacking. Acoustic emissions produced during sonication can provide information about the location, strength and type of the microbubble oscillations within the ultrasound field, and they can be mapped in real-time using passive imaging approaches. Here, we tested whether such mapping can be achieved transcranially within a clinical brain MRgFUS system. We integrated an ultrasound imaging array into the hemisphere transducer of the MRgFUS device. Passive cavitation maps were obtained during sonications combined with a circulating microbubble agent at 20 targets in the cingulate cortex in three macaques. The maps were compared with MRI-evident tissue effects. The system successfully mapped microbubble activity during both stable and inertial cavitation, which was correlated with MRI-evident transient blood-brain barrier disruption and vascular damage, respectively. The location of this activity was coincident with the resulting tissue changes within the expected resolution limits of the system. While preliminary, these data clearly demonstrate, for the first time, that it is possible to construct maps of stable and inertial cavitation transcranially, in a large animal model, and under clinically relevant conditions. Further, these results suggest that this hybrid ultrasound/MRI approach can provide comprehensive guidance for targeted drug delivery via blood-brain barrier disruption and other emerging ultrasound treatments, facilitating their clinical translation. We anticipate that it will also prove to be an important research tool that will

Combined ultrasound and MR imaging to guide focused ultrasound therapies in the brain

International Nuclear Information System (INIS)

Arvanitis, Costas D; McDannold, Nathan; Livingstone, Margaret S

2013-01-01

Several emerging therapies with potential for use in the brain, harness effects produced by acoustic cavitation—the interaction between ultrasound and microbubbles either generated during sonication or introduced into the vasculature. Systems developed for transcranial MRI-guided focused ultrasound (MRgFUS) thermal ablation can enable their clinical translation, but methods for real-time monitoring and control are currently lacking. Acoustic emissions produced during sonication can provide information about the location, strength and type of the microbubble oscillations within the ultrasound field, and they can be mapped in real-time using passive imaging approaches. Here, we tested whether such mapping can be achieved transcranially within a clinical brain MRgFUS system. We integrated an ultrasound imaging array into the hemisphere transducer of the MRgFUS device. Passive cavitation maps were obtained during sonications combined with a circulating microbubble agent at 20 targets in the cingulate cortex in three macaques. The maps were compared with MRI-evident tissue effects. The system successfully mapped microbubble activity during both stable and inertial cavitation, which was correlated with MRI-evident transient blood–brain barrier disruption and vascular damage, respectively. The location of this activity was coincident with the resulting tissue changes within the expected resolution limits of the system. While preliminary, these data clearly demonstrate, for the first time, that it is possible to construct maps of stable and inertial cavitation transcranially, in a large animal model, and under clinically relevant conditions. Further, these results suggest that this hybrid ultrasound/MRI approach can provide comprehensive guidance for targeted drug delivery via blood–brain barrier disruption and other emerging ultrasound treatments, facilitating their clinical translation. We anticipate that it will also prove to be an important research tool that

Potential use of an ultrasound antifouling technology as a ballast water treatment system

Science.gov (United States)

Estévez-Calvar, Noelia; Gambardella, Chiara; Miraglia, Francesco; Pavanello, Giovanni; Greco, Giuliano; Faimali, Marco; Garaventa, Francesca

2018-03-01

The aim of this study was to investigate, at a laboratory scale, the potentialities of an ultrasound-based treatment initially designed to eliminate fouling, as a ballast water treatment system. Therefore, early life stages of three different zooplanktonic species (Amphibalanus amphitrite, Brachionus plicatilis and Artemia salina) were exposed to ultrasound waves (20-22 kHz). The experimental set up included static assays with variations of time exposure (30 s, 60 s and 30 s on/60 s off/30 s on), material of tanks (stainless steel, galvanized steel and plastic) and position of the ultrasound source. Results showed that the treatment efficacy increased from 30 to 60 s and no differences were registered between 60 s-continuous exposure and pulse exposure. The highest efficacy was observed in Experiment I (metal-to-metal contact assay) with a mortality value of 93-95% for B. plicatilis and A. salina. It consisted of organisms located inside stainless steel tubes that were located in direct contact with the ultrasound source and treated for 60 s. Further, we found that, generally, A. amphitrite and B. plicatilis were the most resistant species to the ultrasound treatment whereas A. salina was the most sensitive. We further discuss that US may unlikely be used for commercial vessels, but may be used to treat ballast water in smaller ballast tanks as on board of mega yachts.

An experimental system for the study of ultrasound exposure of isolated blood vessels

NARCIS (Netherlands)

Tokarczyk, Anna; Rivens, Ian; van Bavel, E.; Symonds-Tayler, Richard; ter Haar, Gail

2013-01-01

An experimental system designed for the study of the effects of diagnostic or therapeutic ultrasound exposure on isolated blood vessels in the presence or absence of intraluminal contrast agent is described. The system comprised several components. A microscope was used to monitor vessel size (and

Ultrasound pregnancy

Science.gov (United States)

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

MATLAB/Simulink Pulse-Echo Ultrasound System Simulator Based on Experimentally Validated Models.

Science.gov (United States)

Kim, Taehoon; Shin, Sangmin; Lee, Hyongmin; Lee, Hyunsook; Kim, Heewon; Shin, Eunhee; Kim, Suhwan

2016-02-01

A flexible clinical ultrasound system must operate with different transducers, which have characteristic impulse responses and widely varying impedances. The impulse response determines the shape of the high-voltage pulse that is transmitted and the specifications of the front-end electronics that receive the echo; the impedance determines the specification of the matching network through which the transducer is connected. System-level optimization of these subsystems requires accurate modeling of pulse-echo (two-way) response, which in turn demands a unified simulation of the ultrasonics and electronics. In this paper, this is realized by combining MATLAB/Simulink models of the high-voltage transmitter, the transmission interface, the acoustic subsystem which includes wave propagation and reflection, the receiving interface, and the front-end receiver. To demonstrate the effectiveness of our simulator, the models are experimentally validated by comparing the simulation results with the measured data from a commercial ultrasound system. This simulator could be used to quickly provide system-level feedback for an optimized tuning of electronic design parameters.

Signal Processing in Medical Ultrasound B-mode Imaging

International Nuclear Information System (INIS)

Song, Tai Kyong

2000-01-01

Ultrasonic imaging is the most widely used modality among modern imaging device for medical diagnosis and the system performance has been improved dramatically since early 90's due to the rapid advances in DSP performance and VLSI technology that made it possible to employ more sophisticated algorithms. This paper describes 'main stream' digital signal processing functions along with the associated implementation considerations in modern medical ultrasound imaging systems. Topics covered include signal processing methods for resolution improvement, ultrasound imaging system architectures, roles and necessity of the applications of DSP and VLSI technology in the development of the medical ultrasound imaging systems, and array signal processing techniques for ultrasound focusing

Ultrasound imaging with a micromotor; Micromotor ni yoru choonpa imaging

Energy Technology Data Exchange (ETDEWEB)

Oshiro, O.; Salimuzzaman, M.; Matani, A.; Chihara, K. [Nara Institute of Science and Technology, Nara (Japan); Asao, M. [Osaka National Hospital, Osaka (Japan)

1998-03-01

This paper describes a new ultrasound intravascular imaging system. In this system, an ultrasound probe consists of a micromotor, an ultrasound reflecting mirror attached with the micromotor and an ultrasound transducer. Ultrasound is scanned radially by a micromotor instead of a rotation transmitting wire and the rotation of the micromotor is performed and controlled by an external magnetic field. This ultrasound imaging system with a micromotor was applied to observe the inside of blood vessels through in vitro experiments. The preliminary results suggest that this system has the sufficient ability to define the blood vessel morphology and that the simple image processing enhances signal-to-noise ratio of the reconstructed image. 12 refs., 5 figs.

Superficial Ultrasound Shear Wave Speed Measurements in Soft and Hard Elasticity Phantoms: Repeatability and Reproducibility Using Two Different Ultrasound Systems

Science.gov (United States)

Dillman, Jonathan R.; Chen, Shigao; Davenport, Matthew S.; Zhao, Heng; Urban, Matthew W.; Song, Pengfei; Watcharotone, Kuanwong; Carson, Paul L.

2014-01-01

Background There is a paucity of data available regarding the repeatability and reproducibility of superficial shear wave speed (SWS) measurements at imaging depths relevant to the pediatric population. Purpose To assess the repeatability and reproducibility of superficial shear wave speed (SWS) measurements acquired from elasticity phantoms at varying imaging depths using three different imaging methods, two different ultrasound systems, and multiple operators. Methods and Materials Soft and hard elasticity phantoms manufactured by Computerized Imaging Reference Systems, Inc. (Norfolk, VA) were utilized for our investigation. Institution #1 used an Acuson S3000 ultrasound system (Siemens Medical Solutions USA, Inc.) and three different shear wave imaging method/transducer combinations, while institution #2 used an Aixplorer ultrasound system (Supersonic Imagine) and two different transducers. Ten stiffness measurements were acquired from each phantom at three depths (1.0, 2.5, and 4.0 cm) by four operators at each institution. Student’s t-test was used to compare SWS measurements between imaging techniques, while SWS measurement agreement was assessed with two-way random effects single measure intra-class correlation coefficients and coefficients of variation. Mixed model regression analysis determined the effect of predictor variables on SWS measurements. Results For the soft phantom, the average of mean SWS measurements across the various imaging methods and depths was 0.84 ± 0.04 m/s (mean ± standard deviation) for the Acuson S3000 system and 0.90 ± 0.02 m/s for the Aixplorer system (p=0.003). For the hard phantom, the average of mean SWS measurements across the various imaging methods and depths was 2.14 ± 0.08 m/s for the Acuson S3000 system and 2.07 ± 0.03 m/s Aixplorer system (p>0.05). The coefficients of variation were low (0.5–6.8%), and inter-operator agreement was near-perfect (ICCs ≥0.99). Shear wave imaging method and imaging depth

New ultrasound stone locking system in extracorporeal lithotripsy: Decreased duration of fluoroscopy and radiation doses

International Nuclear Information System (INIS)

Abid, N.; Ravier, E.; Codas, R.; Crouzet, S.; Martin, X.

2013-01-01

Extracorporeal shock wave lithotripsy is the most common method of treatment for kidney stones. Both fluoroscopy and ultrasound imaging can be used to locate stones, but fluoroscopy is more frequently employed. Evaluation of a new stereotaxic navigational system: the stone was located using an ultrasound probe, and its 3D location was saved. The table automatically moved to position the stone at the focal point. A real-time follow-up was possible during treatment. Our objective was to demonstrate a decrease in the use of fluoroscopy to locate kidney stones for extracorporeal shock wave lithotripsy through the use of a 3D ultrasound stone locking system. Prospective analysis of the case records of the 20 patients preceding and the 20 patients succeeding the arrival of the ultrasound stone locking system Visio-Track (EDAP-TMS). We used a Student test to compare age, BMI, kidney stone size, number of shock waves and administered energy. Patient characteristics were comparable. The average age was 55 years old and the average kidney stone size was 10.7 mm. Radiation duration was 174.8 seconds in the group without Visio-Track versus 57.1 seconds in the group with it (P < 0.0001). A similar result was observed for radiation doses: 5197.25 mGy.cm 2 for the group without versus 1987.6 mGy.cm 2 for the group with Visio-Track (P ≡ 0.0033). The stone locking system Visio-Track reduced fluoroscopy in our first group of patients, which decreased the patient's individual absorbed irradiation dose. (authors)

Transverse vs torsional ultrasound: prospective randomized contralaterally controlled study comparing two phacoemulsification-system handpieces.

Science.gov (United States)

Assil, Kerry K; Harris, Lindsay; Cecka, Jeannie

2015-01-01

To compare surgical efficiency and multiple early clinical outcome variables in eyes undergoing phacoemulsification using either transversal or torsional ultrasound systems. Assil Eye Institute, Beverly Hills, CA, USA. Prospective, randomized, clinician-masked, contralaterally controlled single-center evaluation. Patients seeking cataract removal in both eyes with implantation of multifocal intraocular lenses were randomly assigned to one of two treatment rooms for phacoemulsification with either a transverse ultrasound system or torsional handpiece system. The contralateral eye was treated at a later date with the alternate device. A total of 54 eyes of 27 patients having similar degrees of cataract, astigmatism, and visual potential were included. All operative data were collected for analysis, and patients were followed for 3 months after surgery. Similar visual acuity was reported at all postoperative visits between the two groups. Mean phacoemulsification time and total power required were both significantly lower with the transverse system than with the torsional technique (Ptransverse system vs torsional (Ptransverse vs torsional. Macular swelling was less at 1 week, 1 month, and 3 months with transverse vs torsional, although the difference did not achieve significance (P=0.1) at any single time point. Clinically detectable corneal edema was reported less frequently at all postoperative time points with the transverse system. The transverse ultrasound system was found to be possibly associated with less balanced salt-solution use, less phacoemulsification time, and less power required than the torsional phaco system. Postoperative data suggested that improved phaco efficiency may translate to a better overall safety profile for the patient.

A thermocouple thermometry system for ultrasound hyperthermia

International Nuclear Information System (INIS)

Ozarka, M.; Gharakhani, A.; Magin, R.; Cain, C.

1984-01-01

A thermometry system designed to be used in the treatment of cancer by ultrasound hyperthermia is described. The system monitors tumor temperatures using 16 type T (copper-constantan) thermocouples and is controlled by a 12 MHz Intel 8031 microcomputer. An analog circuit board contains the thermocouple amplifiers, an analog multiplexer, scaling circuitry, and an analog to digital converter. A digital board contains the Intel 8031, program memory, data memory, as well as circuitry for control and data communications. Communication with the hyperthermia system control computer is serially by RS-232 with selectable baud rate. Since the thermocouple amplifiers may have slight differences in gain and offset, a calibrated offset is added to a lookup table value to obtain the proper display temperature to within +- 0.1 0 C. The calibration routine, implemented in software, loads a nonvolatile random access memory chip with the proper offset values based on the outputs of each thermocouple channel at known temperatures which bracket a range of interest

Implementation and utility of a daily ultrasound-based localization system with intensity-modulated radiotherapy for prostate cancer

International Nuclear Information System (INIS)

Morr, Jody; DiPetrillo, Thomas; Tsai, J.-S.; Engler, Mark; Wazer, David E. MD.

2002-01-01

Purpose: To evaluate the clinical feasibility of daily computer-assisted transabdominal ultrasonography for target position verification in the setting of intensity-modulated radiotherapy (IMRT) for prostate cancer. Methods and Materials: Twenty-three patients with clinically localized prostate cancer were treated using a sequential tomotherapy IMRT technique (Peacock) and daily computer-assisted transabdominal ultrasonography (BAT) for target localization. Patients were instructed to maintain a full bladder and were placed in the supine position using triangulation tattoos and a leg immobilizer to minimize pelvic rotation. The BAT ultrasound system is docked to the treatment collimator and electronically imports the CT simulation target contours and isocenter. The system is able to use the machine isocenter as a reference point to overlay the corresponding CT contours onto the ultrasound images captured in the transverse and sagittal planes. A touch screen menu is used to maneuver the CT contours in three dimensions such that they match the ultrasound images. The system then displays the three-dimensional couch shifts required to produce field alignment. Data were prospectively collected to measure the frequency by which useful ultrasound images were obtained, the amount of time required for localization/setup, and the direction/magnitude of the positional adjustments. Results: Of the 23 patients, the BAT ultrasound system produced images of sufficient quality to perform the overlay of the CT contours in 19 patients such that positional verification could be reliably performed. Poor image quality was associated with patient inability to maintain a full bladder, large body habitus, or other anatomic constraints. Of the 19 assessable patients, a total of 185 treatment alignments were performed (mean 8.8/patient). For all cases, the average time required for the daily ultrasound imaging and positional adjustments was 11.9 min. After the initial 5 cases, the user

High definition ultrasound imaging for battlefield medical applications

Energy Technology Data Exchange (ETDEWEB)

Kwok, K.S.; Morimoto, A.K.; Kozlowski, D.M.; Krumm, J.C.; Dickey, F.M. [Sandia National Labs., Albuquerque, NM (United States); Rogers, B; Walsh, N. [Texas Univ. Health Science Center, San Antonio, TX (United States)

1996-06-23

A team has developed an improved resolution ultrasound system for low cost diagnostics. This paper describes the development of an ultrasound based imaging system capable of generating 3D images showing surface and subsurface tissue and bone structures. We include results of a comparative study between images obtained from X-Ray Computed Tomography (CT) and ultrasound. We found that the quality of ultrasound images compares favorably with those from CT. Volumetric and surface data extracted from these images were within 7% of the range between ultrasound and CT scans. We also include images of porcine abdominal scans from two different sets of animal trials.

Ultrasound-controlled neuronavigator-guided brain surgery.

Science.gov (United States)

Koivukangas, J; Louhisalmi, Y; Alakuijala, J; Oikarinen, J

1993-07-01

The development of a unique neurosurgical navigator is described and a preliminary series of seven cases of intracerebral lesions approached with the assistance of this neuronavigation system under ultrasound control is presented. The clinical series included five low-grade astrocytomas, one chronic intracerebral hematoma, and one porencephalic cyst. Management procedures included biopsy in all cases, drainage of the hematoma, and endoscopy and fenestration for the cyst. The features of the neuronavigation system are interactive reconstructions of preoperative computerized tomography and magnetic resonance imaging data, corresponding intraoperative ultrasound images, versatility of the interchangeable end-effector instruments, graphic presentation of instruments on the reconstructed images, and voice control of the system. The principle of a common axis in the reconstructed images served to align the navigational pointer, biopsy guide, endoscope guide, ultrasound transducer, and surgical microscope to the brain anatomy. Intraoperative ultrasound imaging helped to verify the accuracy of the neuronavigator and check the results of the procedures. The arm of the neuronavigation system served as a holder for instruments, such as the biopsy guide, endoscope guide, and ultrasound transducer, in addition to functioning as a navigational pointer. Also, the surgical microscope was aligned with the neuronavigator for inspection and biopsy of the hematoma capsule to rule out tumor etiology. Voice control freed the neurosurgeon from manual exercises during start-up and calibration of the system.

Round Robin Test for Performance Demonstration System of Ultrasound Examination Personnel in Nuclear Power Plants

International Nuclear Information System (INIS)

Kim, Young Ho; Yang, Seung Han; Kim, Yong Sik; Yoon, Byung Sik; Lee, Hee Jong

2005-01-01

Ultrasound testing performance during in-service inspection for the main components of NPPs is strongly affected by each examination person. Therefore, ASME established a more strict qualification requirement in Sec. XI Appendix VIII for the ultrasound testing personnel in nuclear power plants. The Korean Performance Demonstration (KPD) System according to the ASME code for the ultrasonic testing personnel, equipments, and procedures to apply to the Class 1 and 2 piping ultrasound examination of nuclear power plants in Korea was established. And a round robin test was conducted in order to verify the effectiveness of PD method by comparing the examination results from the method of Performance Demonstration (PD) and a traditional ASME code dB-drop method. The round robin test shows that the reliability of the PD method is better than that of the dB-drop method. As a result, application of the PD method to the in-service inspection of the nuclear power plants will improve the performance of ultrasound testing

[Mobile hospital -real time mobile telehealthcare system with ultrasound and CT van using high-speed satellite communication-].

Science.gov (United States)

Takizawa, Masaomi; Miyashita, Toyohisa; Murase, Sumio; Kanda, Hirohito; Karaki, Yoshiaki; Yagi, Kazuo; Ohue, Toru

2003-01-01

A real-time telescreening system is developed to detect early diseases for rural area residents using two types of mobile vans with a portable satellite station. The system consists of a satellite communication system with 1.5Mbps of the JCSAT-1B satellite, a spiral CT van, an ultrasound imaging van with two video conference system, a DICOM server and a multicast communication unit. The video image and examination image data are transmitted from the van to hospitals and the university simultaneously. Physician in the hospital observes and interprets exam images from the van and watches the video images of the position of ultrasound transducer on screenee in the van. After the observation images, physician explains a results of the examination by the video conference system. Seventy lung CT screening and 203 ultrasound screening were done from March to June 2002. The trial of this real time screening suggested that rural residents are given better healthcare without visit to the hospital. And it will open the gateway to reduce the medical cost and medical divide between city area and rural area.

Prostate Ultrasound

Medline Plus

Full Text Available ... Physician Resources Professions Site Index A-Z Ultrasound - Prostate Ultrasound of the prostate uses sound waves to ... Ultrasound Imaging? What is Ultrasound Imaging of the Prostate? Ultrasound is safe and painless, and produces pictures ...

Ultrasound -- Pelvis

Medline Plus

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

Integrated ultrasound and magnetic resonance imaging for simultaneous temperature and cavitation monitoring during focused ultrasound therapies.

Science.gov (United States)

Arvanitis, Costas D; McDannold, Nathan

2013-11-01

Ultrasound can be used to noninvasively produce different bioeffects via viscous heating, acoustic cavitation, or their combination, and these effects can be exploited to develop a wide range of therapies for cancer and other disorders. In order to accurately localize and control these different effects, imaging methods are desired that can map both temperature changes and cavitation activity. To address these needs, the authors integrated an ultrasound imaging array into an MRI-guided focused ultrasound (MRgFUS) system to simultaneously visualize thermal and mechanical effects via passive acoustic mapping (PAM) and MR temperature imaging (MRTI), respectively. The system was tested with an MRgFUS system developed for transcranial sonication for brain tumor ablation in experiments with a tissue mimicking phantom and a phantom-filled ex vivo macaque skull. In experiments on cavitation-enhanced heating, 10 s continuous wave sonications were applied at increasing power levels (30-110 W) until broadband acoustic emissions (a signature for inertial cavitation) were evident. The presence or lack of signal in the PAM, as well as its magnitude and location, were compared to the focal heating in the MRTI. Additional experiments compared PAM with standard B-mode ultrasound imaging and tested the feasibility of the system to map cavitation activity produced during low-power (5 W) burst sonications in a channel filled with a microbubble ultrasound contrast agent. When inertial cavitation was evident, localized activity was present in PAM and a marked increase in heating was observed in MRTI. The location of the cavitation activity and heating agreed on average after registration of the two imaging modalities; the distance between the maximum cavitation activity and focal heating was -3.4 ± 2.1 mm and -0.1 ± 3.3 mm in the axial and transverse ultrasound array directions, respectively. Distortions and other MRI issues introduced small uncertainties in the PAM�

High-frequency Doppler ultrasound transducer for the peripheral circulatory system

Energy Technology Data Exchange (ETDEWEB)

Bae, Youngmin; Yang, Jeongwon; Kang, Uk; Kim, Guanghoon [Korea Electrotechnology Research Institute, Ansan (Korea, Republic of)

2011-12-15

A Doppler ultrasound transducer was designed and implemented to measure the blood flow velocity in tiny vessels near the skin of hands or feet. The geometric parameters of the transducer for defining the observation volume were derived and implemented with an acoustic window made of polystyrene. The observation volume designed in this study was located 6.5 mm from the transducer, which was comparable to the value predicted geometrically. The two-way insertion loss of the transducer was -11.3 dB on ultrasound frequency of 20 MHz, and the 3-dB bandwidth was approximately 2 MHz. In addition, the Doppler shift in the frequency measured by using a Doppler device composed of the transducer and a Doppler signal processing unit was proportional to the flow velocity generated by a homemade flowing system. Finally, we concluded that the transducer could be applied to measure the blood flow velocity in hands or feet.

High-frequency Doppler ultrasound transducer for the peripheral circulatory system

International Nuclear Information System (INIS)

Bae, Youngmin; Yang, Jeongwon; Kang, Uk; Kim, Guanghoon

2011-01-01

A Doppler ultrasound transducer was designed and implemented to measure the blood flow velocity in tiny vessels near the skin of hands or feet. The geometric parameters of the transducer for defining the observation volume were derived and implemented with an acoustic window made of polystyrene. The observation volume designed in this study was located 6.5 mm from the transducer, which was comparable to the value predicted geometrically. The two-way insertion loss of the transducer was -11.3 dB on ultrasound frequency of 20 MHz, and the 3-dB bandwidth was approximately 2 MHz. In addition, the Doppler shift in the frequency measured by using a Doppler device composed of the transducer and a Doppler signal processing unit was proportional to the flow velocity generated by a homemade flowing system. Finally, we concluded that the transducer could be applied to measure the blood flow velocity in hands or feet.

Automated flow quantification in valvular heart disease based on backscattered Doppler power analysis: implementation on matrix-array ultrasound imaging systems.

Science.gov (United States)

Buck, Thomas; Hwang, Shawn M; Plicht, Björn; Mucci, Ronald A; Hunold, Peter; Erbel, Raimund; Levine, Robert A

2008-06-01

Cardiac ultrasound imaging systems are limited in the noninvasive quantification of valvular regurgitation due to indirect measurements and inaccurate hemodynamic assumptions. We recently demonstrated that the principle of integration of backscattered acoustic Doppler power times velocity can be used for flow quantification in valvular regurgitation directly at the vena contracta of a regurgitant flow jet. We now aimed to accomplish implementation of automated Doppler power flow analysis software on a standard cardiac ultrasound system utilizing novel matrix-array transducer technology with detailed description of system requirements, components and software contributing to the system. This system based on a 3.5 MHz, matrix-array cardiac ultrasound scanner (Sonos 5500, Philips Medical Systems) was validated by means of comprehensive experimental signal generator trials, in vitro flow phantom trials and in vivo testing in 48 patients with mitral regurgitation of different severity and etiology using magnetic resonance imaging (MRI) for reference. All measurements displayed good correlation to the reference values, indicating successful implementation of automated Doppler power flow analysis on a matrix-array ultrasound imaging system. Systematic underestimation of effective regurgitant orifice areas >0.65 cm(2) and volumes >40 ml was found due to currently limited Doppler beam width that could be readily overcome by the use of new generation 2D matrix-array technology. Automated flow quantification in valvular heart disease based on backscattered Doppler power can be fully implemented on board a routinely used matrix-array ultrasound imaging systems. Such automated Doppler power flow analysis of valvular regurgitant flow directly, noninvasively, and user independent overcomes the practical limitations of current techniques.

Ultrasound-Assisted Hot Air Drying of Foods

Science.gov (United States)

Mulet, Antonio; Cárcel, Juan Andrés; García-Pérez, José Vicente; Riera, Enrique

This chapter deals with the application of power ultrasound, also named high-intensity ultrasound, in the hot air drying of foods. The aim of ultrasound-assisted drying is to overcome some of the limitations of traditional convective drying systems, especially by increasing drying rate without reducing quality attributes. The effects of ultrasound on drying rate are responsible for some of the phenomena produced in the internal and/or external resistance to mass transfer.

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... Ultrasound - Abdomen Obstetric Ultrasound Ultrasound - Prostate Kidney and Bladder Stones Abnormal Vaginal Bleeding Ovarian Cancer Images related to Ultrasound - Pelvis Sponsored by Please ...

[System design of small intellectualized ultrasound hyperthermia instrument in the LabVIEW environment].

Science.gov (United States)

Jiang, Feng; Bai, Jingfeng; Chen, Yazhu

2005-08-01

Small-scale intellectualized medical instrument has attracted great attention in the field of biomedical engineering, and LabVIEW (Laboratory Virtual Instrument Engineering Workbench) provides a convenient environment for this application due to its inherent advantages. The principle and system structure of the hyperthermia instrument are presented. Type T thermocouples are employed as thermotransducers, whose amplifier consists of two stages, providing built-in ice point compensation and thus improving work stability over temperature. Control signals produced by specially designed circuit drive the programmable counter/timer 8254 chip to generate PWM (Pulse width modulation) wave, which is used as ultrasound radiation energy control signal. Subroutine design topics such as inner-tissue real time feedback temperature control algorithm, water temperature control in the ultrasound applicator are also described. In the cancer tissue temperature control subroutine, the authors exert new improvments to PID (Proportional Integral Differential) algorithm according to the specific demands of the system and achieve strict temperature control to the target tissue region. The system design and PID algorithm improvement have experimentally proved to be reliable and excellent, meeting the requirements of the hyperthermia system.

Diagnostic efficacy for coronary in-stent patency with parameters defined on Hounsfield CT value-spatial profile curves

International Nuclear Information System (INIS)

Yamazaki, Tadashi; Suzuki, Jun-ichi; Shimamoto, Ryoichi; Tsuji, Taeko; Ohmoto-Sekine, Yuki; Morita, Toshihiro; Yamashita, Hiroshi; Honye, Junko; Nagai, Ryozo; Komatsu, Shuhei; Akahane, Masaaki; Ohtomo, Kuni

2008-01-01

Purpose: Hounsfield CT values across coronary CT angiograms constitute CT value-spatial profile curves. These CT profile curves are independent of window settings, and therefore, parameters derived from the curves can be used for objective anatomic analyses. Applicability of parameters derived from the curves to quantification of coronary in-stent patency has not yet been evaluated. Methods: Twenty-five CT value-spatial profile curves were delineated from 10 consecutive coronary stents to test correlation between the curve derived parameter (i.e., the minimum extreme value normalized by dividing by the maximum value of the curves obtained at neighboring outside of stents) and three intravascular ultrasound (IVUS) parameters. Results: Correlation coefficients between normalized minimum extreme value of CT value-spatial profile curves and three IVUS parameters (such as patent cross-sectional in-stent area, the percentage of patent cross-sectional in-stent area, and coronary artery intra-stent diameter) were 0.65 (p < 0.01), 0.44 (p < 0.05) and 0.51 (p < 0.05), respectively. Conclusions: CT parameters defined on Hounsfield CT value-spatial profile curves correlated significantly with IVUS parameters for quantitative coronary in-stent patency. A new approach with CT coronary angiography is therefore indicated for the noninvasive assessment of in-stent re-stenosis

Targeting the adventitia with intracoronary beta-radiation: comparison of two dose prescriptions and the role of centering coronary arteries

International Nuclear Information System (INIS)

Kaluza, Grzegorz L.; Jenkins, Todd P.; Mourtada, Firas A.; Ali, Nadir M.; Lee, David P.; Okura, Hiroyuki; Fitzgerald, Peter J.; Raizner, Albert E.

2002-01-01

Purpose: To compare by intravascular ultrasound (IVUS) the efficacy of delivering the prescribed dose to the adventitia between two commonly used dose prescriptions for intracoronary radiotherapy. Methods and Materials: In 59 human postangioplasty coronary vessels, one IVUS cross-section (1 mm thick) with the highest plaque burden was used for creating dose-volume histograms with different hypothetical positions of the source. Results: On average, prescription to 1 mm beyond lumen surface resulted in delivery of the prescribed dose (20 Gy ± 20%) to a higher fraction of adventitial volume than with the prescription to 2 mm from the source, with source placed in vessel center, lumen center, or in the IVUS catheter position. Source placement in the lumen center resulted in a low dose heterogeneity to the adventitia and the least dose heterogeneity to the intima. Conclusions: Prescription to 1 mm beyond lumen surface appeared more effective in delivering the prescribed dose to the adventitia than the American Association of Physicists in Medicine (AAPM) recommended prescription to 2 mm from the source center. Moreover, centering the source in the lumen provides the better balance of effective adventitial targeting and intimal dose homogeneity. Modification of the current AAPM recommendation for dose prescription for intracoronary radiotherapy should be considered

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... Children's (Pediatric) Ultrasound - Abdomen Obstetric Ultrasound Ultrasound - Prostate Kidney and Bladder Stones Abnormal Vaginal Bleeding Ovarian Cancer Images related to Ultrasound - Pelvis Sponsored by Please ...

Integrated low power ultrasound sensor interfaces

OpenAIRE

Gustafsson, Martin

2005-01-01

Imagine that the technical development can take the ultrasound measurement systems from the large piece of machinery today, to a coin size system tomorrow. The factor that has reduced the size of electronic systems over time is integration and integrated circuits. In this thesis circuit simulator models of complete ultrasound systems are used to design custom integrated circuits. These circuits are optimized for low power consumption and small size. The models that are used predict the acoust...

Computer-aided diagnostic system for detection of Hashimoto thyroiditis on ultrasound images from a Polish population.

Science.gov (United States)

Acharya, U Rajendra; Sree, S Vinitha; Krishnan, M Muthu Rama; Molinari, Filippo; Zieleźnik, Witold; Bardales, Ricardo H; Witkowska, Agnieszka; Suri, Jasjit S

2014-02-01

Computer-aided diagnostic (CAD) techniques aid physicians in better diagnosis of diseases by extracting objective and accurate diagnostic information from medical data. Hashimoto thyroiditis is the most common type of inflammation of the thyroid gland. The inflammation changes the structure of the thyroid tissue, and these changes are reflected as echogenic changes on ultrasound images. In this work, we propose a novel CAD system (a class of systems called ThyroScan) that extracts textural features from a thyroid sonogram and uses them to aid in the detection of Hashimoto thyroiditis. In this paradigm, we extracted grayscale features based on stationary wavelet transform from 232 normal and 294 Hashimoto thyroiditis-affected thyroid ultrasound images obtained from a Polish population. Significant features were selected using a Student t test. The resulting feature vectors were used to build and evaluate the following 4 classifiers using a 10-fold stratified cross-validation technique: support vector machine, decision tree, fuzzy classifier, and K-nearest neighbor. Using 7 significant features that characterized the textural changes in the images, the fuzzy classifier had the highest classification accuracy of 84.6%, sensitivity of 82.8%, specificity of 87.0%, and a positive predictive value of 88.9%. The proposed ThyroScan CAD system uses novel features to noninvasively detect the presence of Hashimoto thyroiditis on ultrasound images. Compared to manual interpretations of ultrasound images, the CAD system offers a more objective interpretation of the nature of the thyroid. The preliminary results presented in this work indicate the possibility of using such a CAD system in a clinical setting after evaluating it with larger databases in multicenter clinical trials.

Virtual Ultrasound Guidance for Inexperienced Operators

Science.gov (United States)

Caine, Timothy; Martin, David

2012-01-01

Medical ultrasound or echocardiographic studies are highly operator-dependent and generally require lengthy training and internship to perfect. To obtain quality echocardiographic images in remote environments, such as on-orbit, remote guidance of studies has been employed. This technique involves minimal training for the user, coupled with remote guidance from an expert. When real-time communication or expert guidance is not available, a more autonomous system of guiding an inexperienced operator through an ultrasound study is needed. One example would be missions beyond low Earth orbit in which the time delay inherent with communication will make remote guidance impractical. The Virtual Ultrasound Guidance system is a combination of hardware and software. The hardware portion includes, but is not limited to, video glasses that allow hands-free, full-screen viewing. The glasses also allow the operator a substantial field of view below the glasses to view and operate the ultrasound system. The software is a comprehensive video program designed to guide an inexperienced operator through a detailed ultrasound or echocardiographic study without extensive training or guidance from the ground. The program contains a detailed description using video and audio to demonstrate equipment controls, ergonomics of scanning, study protocol, and scanning guidance, including recovery from sub-optimal images. The components used in the initial validation of the system include an Apple iPod Classic third-generation as the video source, and Myvue video glasses. Initially, the program prompts the operator to power-up the ultrasound and position the patient. The operator would put on the video glasses and attach them to the video source. After turning on both devices and the ultrasound system, the audio-video guidance would then instruct on patient positioning and scanning techniques. A detailed scanning protocol follows with descriptions and reference video of each view along with

Effect of high intensity ultrasound on the fermentation profile of Lactobacillus sakei in a meat model system.

Science.gov (United States)

Ojha, Kumari Shikha; Kerry, Joseph P; Alvarez, Carlos; Walsh, Des; Tiwari, Brijesh K

2016-07-01

The objective of this study was to investigate the efficacy of high intensity ultrasound on the fermentation profile of Lactobacillus sakei in a meat model system. Ultrasound power level (0-68.5 W) and sonication time (0-9 min) at 20 °C were assessed against the growth of L. sakei using a Microplate reader over a period of 24h. The L. sakei growth data showed a good fit with the Gompertz model (R(2)>0.90; SEfunctional food products can be tailored by selection of ultrasound processing parameters. Copyright © 2016 Elsevier B.V. All rights reserved.

Relative ultrasound energy measurement circuit

OpenAIRE

Gustafsson, E.Martin I.; Johansson, Jonny; Delsing, Jerker

2005-01-01

A relative ultrasound energy estimation circuit has been designed in a standard 0.35-μm CMOS process, to be a part of a thumb size internet connected wireless ultrasound measurement system. This circuit measures the relative energy between received ultrasound pulses, and presents an output signal that is linear to the received energy. Post-layout simulations indicate 7 bit linearity for 500 mV input signals, 5 μsec startup and stop times, 2.6 mW power consumption during active state. The acti...

Multi-Channel RF System for MRI-Guided Transurethral Ultrasound Thermal Therapy

Science.gov (United States)

Yak, Nicolas; Asselin, Matthew; Chopra, Rajiv; Bronskill, Michael

2009-04-01

MRI-guided transurethral ultrasound thermal therapy is an approach to treating localized prostate cancer which targets precise deposition of thermal energy within a confined region of the gland. This treatment requires a system incorporating a heating applicator with multiple planar ultrasound transducers and associated RF electronics to control individual elements independently in order to achieve accurate 3D treatment. We report the design, construction, and characterization of a prototype multi-channel system capable of controlling 16 independent RF signals for a 16-element heating applicator. The main components are a control computer, microcontroller, and a 16-channel signal generator with 16 amplifiers, each incorporating a low-pass filter and transmitted/reflected power detection circuit. Each channel can deliver from 0.5 to 10 W of electrical power and good linearity from 3 to 12 MHz. Harmonic RF signals near the Larmor frequency of a 1.5 T MRI were measured to be below -30 dBm and heating experiments within the 1.5 T MR system showed no significant decrease in SNR of the temperature images. The frequency and power for all 16 channels could be changed in less than 250 ms, which was sufficiently rapid for proper performance of the control algorithms. A common backplane design was chosen which enabled an inexpensive, modular approach for each channel resulting in an overall system with minimal footprint.

Electrical impedance tomography imaging using a priori ultrasound data

Directory of Open Access Journals (Sweden)

Soleimani Manuchehr

2006-02-01

Full Text Available Abstract Background Different imaging systems (e.g. electrical, magnetic, and ultrasound rely on a wide variety of physical properties, and the datasets obtained from such systems provide only partial information about the unknown true state. One approach is to choose complementary imaging systems, and to combine the information to achieve a better representation. Methods This paper discusses the combination of ultrasound and electrical impedance tomography (EIT information. Ultrasound reflection signals are good at locating sharp acoustic density changes associated with the boundaries of objects. Some boundaries, however, may be indeterminable due to masking from intermediate boundaries or because they are outside the ultrasound beam. Conversely, the EIT data contains relatively low-quality information, but it includes the whole region enclosed by the electrodes. Results Results are shown from a narrowband level-set method applied to 2D and 3D EIT incorporating limited angle ultrasound time of flight data. Conclusion The EIT reconstruction is shown to be faster and more accurate using the additional edge information from both one and four transducer ultrasound systems.

Impact of ultrasound video transfer on the practice of ultrasound

Science.gov (United States)

Duerinckx, Andre J.; Hayrapetian, Alek S.; Grant, Edward G.; Valentino, Daniel J.; Rahbar, Darius; Kiszonas, Mike; Franco, Ricky; Melany, Michelle; Narin, Sherelle L.; Ragavendra, Nagesh

1996-05-01

Sonography can be highly dependent on real-time imaging and as such is highly physician intensive. Such situations arise mostly during complicated ultrasound radiology studies or echocardiology examinations. Under those circumstances it would be of benefit to transmit real-time images beyond the immediate area of the ultrasound laboratory when a physician is not on location. We undertook this study to determine if both static and dynamic image transfer to remote locations might be accomplished using an ultrafast ATM network and PACS. Image management of the local image files was performed by a commercial PACS from AGFA corporation. The local network was Ethernet based, and the global network was based on Asynchronous Transfer Mode (ATM, rates up to 100 Mbits/sec). Real-time image transfer involved two teaching hospitals, one of which had 2 separate ultrasound facilities. Radiologists consulted with technologists via telephone while the examinations were being performed. The applications of ATM network providing real time video for ultrasound imaging in a clinical environment and its potential impact on health delivery and clinical teaching. This technology increased technologist and physician productivity due to the elimination of commute time for physicians and waiting time for technologists and patients. Physician confidence in diagnosis increased compared to reviewing static images alone. This system provided instant access for radiologists to real-time scans from remote sites. Image quality and frame rate were equivalent to the original. The system increased productivity by allowing physicians to monitor studies at multiple sites simultaneously.

Prehospital Ultrasound

Directory of Open Access Journals (Sweden)

Jen-Tang Sun

2014-06-01

Full Text Available Ultrasound is a commonly used diagnostic tool in clinical conditions. With recent developments in technology, use of portable ultrasound devices has become feasible in prehospital settings. Many studies also proved the feasibility and accuracy of prehospital ultrasound. In this article, we focus on the use of prehospital ultrasound, with emphasis on trauma and chest ultrasound.

Dependence of the frequency spectrum of small amplitude vibrations superimposed on finite deformations of a nonlinear, cylindrical elastic body on residual stress

KAUST Repository

Gorb, Yuliya

2010-11-01

We model and analyze the response of nonlinear, residually stressed elastic bodies subjected to small amplitude vibrations superimposed upon large deformations. The problem derives from modeling the use of intravascular ultrasound (IVUS) imaging to interrogate atherosclerotic plaques in vivo in large arteries. The goal of this investigation is twofold: (i) introduce a modeling framework for residual stress that unlike traditional Fung type classical opening angle models may be used for a diseased artery, and (ii) investigate the sensitivity of the spectra of small amplitude high frequency time harmonic vibrations superimposed on a large deformation to the details of the residual stress stored in arteries through a numerical simulation using physiologic parameter values under both low and high blood pressure loadings. The modeling framework also points the way towards an inverse problem using IVUS techniques to estimate residual stress in healthy and diseased arteries. © 2010 Elsevier Ltd. All rights reserved.

Poster - 09: A MATLAB-based Program for Automated Quality Assurance of a Prostate Brachytherapy Ultrasound System

Energy Technology Data Exchange (ETDEWEB)

Poon, Justin; Sabondjian, Eric; Sankreacha, Raxa [University of British Columbia, Dept. of Physics and Astronomy, Vancouver, BC (Canada); Trillium Health Partners – Credit Valley Hospital, Peel Regional Cancer Centre, Mississauga, ON, Trillium Health Partners – Credit Valley Hospital, Peel Regional Cancer Centre, Mississauga, ON, Trillium Health Partners – Credit Valley Hospital, Peel Regional Cancer Centre, Mississauga, ON (Canada); University of Toronto, Dept. of Radiation Oncology, Toronto, ON (Canada)

2016-08-15

Purpose: A robust Quality Assurance (QA) program is essential for prostate brachytherapy ultrasound systems due to the importance of imaging accuracy during treatment and planning. Task Group 128 of the American Association of Physicists in Medicine has recommended a set of QA tests covering grayscale visibility, depth of penetration, axial and lateral resolution, distance measurement, area measurement, volume measurement, and template/electronic grid alignment. Making manual measurements on the ultrasound system can be slow and inaccurate, so a MATLAB program was developed for automation of the described tests. Methods: Test images were acquired using a BK Medical Flex Focus 400 ultrasound scanner and 8848 transducer with the CIRS Brachytherapy QA Phantom – Model 045A. For each test, the program automatically segments the inputted image(s), makes the appropriate measurements, and indicates if the test passed or failed. The program was tested by analyzing two sets of images, where the measurements from the first set were used as baseline values. Results: The program successfully analyzed the images for each test and determined if any action limits were exceeded. All tests passed – the measurements made by the program were consistent and met the requirements outlined by Task Group 128. Conclusions: The MATLAB program we have developed can be used for automated QA of an ultrasound system for prostate brachytherapy. The GUI provides a user-friendly way to analyze images without the need for any manual measurement, potentially removing intra- and inter-user variability for more consistent results.

Poster - 09: A MATLAB-based Program for Automated Quality Assurance of a Prostate Brachytherapy Ultrasound System

International Nuclear Information System (INIS)

Poon, Justin; Sabondjian, Eric; Sankreacha, Raxa

2016-01-01

Purpose: A robust Quality Assurance (QA) program is essential for prostate brachytherapy ultrasound systems due to the importance of imaging accuracy during treatment and planning. Task Group 128 of the American Association of Physicists in Medicine has recommended a set of QA tests covering grayscale visibility, depth of penetration, axial and lateral resolution, distance measurement, area measurement, volume measurement, and template/electronic grid alignment. Making manual measurements on the ultrasound system can be slow and inaccurate, so a MATLAB program was developed for automation of the described tests. Methods: Test images were acquired using a BK Medical Flex Focus 400 ultrasound scanner and 8848 transducer with the CIRS Brachytherapy QA Phantom – Model 045A. For each test, the program automatically segments the inputted image(s), makes the appropriate measurements, and indicates if the test passed or failed. The program was tested by analyzing two sets of images, where the measurements from the first set were used as baseline values. Results: The program successfully analyzed the images for each test and determined if any action limits were exceeded. All tests passed – the measurements made by the program were consistent and met the requirements outlined by Task Group 128. Conclusions: The MATLAB program we have developed can be used for automated QA of an ultrasound system for prostate brachytherapy. The GUI provides a user-friendly way to analyze images without the need for any manual measurement, potentially removing intra- and inter-user variability for more consistent results.

Multiparametric ultrasound in the detection of prostate cancer: a systematic review.

Science.gov (United States)

Postema, Arnoud; Mischi, Massimo; de la Rosette, Jean; Wijkstra, Hessel

2015-11-01

To investigate the advances and clinical results of the different ultrasound modalities and the progress in combining them into multiparametric UltraSound (mpUS). A systematic literature search on mpUS and the different ultrasound modalities included: greyscale ultrasound, computerized transrectal ultrasound, Doppler and power Doppler techniques, dynamic contrast-enhanced ultrasound and (shear wave) elastography. Limited research available on combining ultrasound modalities has presented improvement in diagnostic performance. The data of two studies suggest that even adding a lower performing ultrasound modality to a better performing modality using crude methods can already improve the sensitivity by 13-51 %. The different modalities detect different tumours. No study has tried to combine ultrasound modalities employing a system similar to the PIRADS system used for mpMRI or more advanced classifying algorithms. Available evidence confirms that combining different ultrasound modalities significantly improves diagnostic performance.

Evaluation of a Novel Wireless Transmission System for Trauma Ultrasound Examinations From Moving Ambulances.

Science.gov (United States)

Morchel, Herman; Ogedegbe, Chinwe; Chaplin, William; Cheney, Brianna; Zakharchenko, Svetlana; Misch, David; Schwartz, Matthew; Feldman, Joseph; Kaul, Sanjeev

2018-03-01

To determine if physicians trained in ultrasound interpretation perceive a difference in image quality and usefulness between Extended Focused Assessment with Sonography ultrasound examinations performed at bedside in a hospital vs. by emergency medical technicians minimally trained in medical ultrasound on a moving ambulance and transmitted to the hospital via a novel wireless system. In particular, we sought to demonstrate that useful images could be obtained from patients in less than optimal imaging conditions; that is, while they were in transport. Emergency medical technicians performed the examinations during transport of blunt trauma patients. Upon patient arrival at the hospital, a bedside Extended Focused Assessment with Sonography examination was performed by a physician. Both examinations were recorded and later reviewed by physicians trained in ultrasound interpretation. Data were collected on 20 blunt trauma patients over a period of 13 mo. Twenty ultrasound-trained physicians blindly compared transmitted vs. bedside images using 11 Questionnaire for User Interaction Satisfaction scales. Four paired samples t-tests were conducted to assess mean differences between ratings for ambulatory and base images. Although there is a slight tendency for the average rating across all subjects and raters to be slightly higher in the base than in the ambulatory condition, none of these differences are statistically significant. These results suggest that the quality of the ambulatory images was viewed as essentially as good as the quality of the base images.

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... the ovaries. Transvaginal ultrasound also evaluates the myometrium (muscular walls of the uterus). Sonohysterography allows for a ... and evaluate a variety of urinary and reproductive system disorders in both sexes without x-ray exposure. ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... Ultrasound - Pelvis Ultrasound imaging of the pelvis uses sound waves to produce pictures of the structures and ... pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or ...

Prostate Ultrasound

Medline Plus

Full Text Available ... ultrasound or with a rectal examination, an ultrasound-guided biopsy can be performed. This procedure involves advancing ... of the Prostate) Prostate Cancer Ultrasound- and MRI-Guided Prostate Biopsy Images related to Ultrasound - Prostate Sponsored ...

MO-AB-210-02: Ultrasound Imaging and Therapy-Hands On Workshop

International Nuclear Information System (INIS)

Sammet, S.

2015-01-01

The goal of this ultrasound hands-on workshop is to demonstrate advancements in high intensity focused ultrasound (HIFU) and to demonstrate quality control (QC) testing in diagnostic ultrasound. HIFU is a therapeutic modality that uses ultrasound waves as carriers of energy. HIFU is used to focus a beam of ultrasound energy into a small volume at specific target locations within the body. The focused beam causes localized high temperatures and produces a well-defined regions of necrosis. This completely non-invasive technology has great potential for tumor ablation and targeted drug delivery. At the workshop, attendees will see configurations, applications, and hands-on demonstrations with on-site instructors at separate stations. The involvement of medical physicists in diagnostic ultrasound imaging service is increasing due to QC and accreditation requirements. At the workshop, an array of ultrasound testing phantoms and ultrasound scanners will be provided for attendees to learn diagnostic ultrasound QC in a hands-on environment with live demonstrations of the techniques. Target audience: Medical physicists and other medical professionals in diagnostic imaging and radiation oncology with interest in high-intensity focused ultrasound and in diagnostic ultrasound QC. Learning Objectives: Learn ultrasound physics and safety for HIFU applications through live demonstrations Get an overview of the state-of-the art in HIFU technologies and equipment Gain familiarity with common elements of a quality control program for diagnostic ultrasound imaging Identify QC tools available for testing diagnostic ultrasound systems and learn how to use these tools List of supporting vendors for HIFU and diagnostic ultrasound QC hands-on workshop: Philips Healthcare Alpinion Medical Systems Verasonics, Inc Zonare Medical Systems, Inc Computerized Imaging Reference Systems (CIRS), Inc. GAMMEX, Inc., Cablon Medical BV Steffen Sammet: NIH/NCI grant 5R25CA132822, NIH/NINDS grant 5R25NS

MO-AB-210-01: Ultrasound Imaging and Therapy-Hands On Workshop

International Nuclear Information System (INIS)

Lu, Z.

2015-01-01

The goal of this ultrasound hands-on workshop is to demonstrate advancements in high intensity focused ultrasound (HIFU) and to demonstrate quality control (QC) testing in diagnostic ultrasound. HIFU is a therapeutic modality that uses ultrasound waves as carriers of energy. HIFU is used to focus a beam of ultrasound energy into a small volume at specific target locations within the body. The focused beam causes localized high temperatures and produces a well-defined regions of necrosis. This completely non-invasive technology has great potential for tumor ablation and targeted drug delivery. At the workshop, attendees will see configurations, applications, and hands-on demonstrations with on-site instructors at separate stations. The involvement of medical physicists in diagnostic ultrasound imaging service is increasing due to QC and accreditation requirements. At the workshop, an array of ultrasound testing phantoms and ultrasound scanners will be provided for attendees to learn diagnostic ultrasound QC in a hands-on environment with live demonstrations of the techniques. Target audience: Medical physicists and other medical professionals in diagnostic imaging and radiation oncology with interest in high-intensity focused ultrasound and in diagnostic ultrasound QC. Learning Objectives: Learn ultrasound physics and safety for HIFU applications through live demonstrations Get an overview of the state-of-the art in HIFU technologies and equipment Gain familiarity with common elements of a quality control program for diagnostic ultrasound imaging Identify QC tools available for testing diagnostic ultrasound systems and learn how to use these tools List of supporting vendors for HIFU and diagnostic ultrasound QC hands-on workshop: Philips Healthcare Alpinion Medical Systems Verasonics, Inc Zonare Medical Systems, Inc Computerized Imaging Reference Systems (CIRS), Inc. GAMMEX, Inc., Cablon Medical BV Steffen Sammet: NIH/NCI grant 5R25CA132822, NIH/NINDS grant 5R25NS

MO-AB-210-02: Ultrasound Imaging and Therapy-Hands On Workshop

Energy Technology Data Exchange (ETDEWEB)

Sammet, S. [University of Chicago Medical Center (United States)

2015-06-15

The goal of this ultrasound hands-on workshop is to demonstrate advancements in high intensity focused ultrasound (HIFU) and to demonstrate quality control (QC) testing in diagnostic ultrasound. HIFU is a therapeutic modality that uses ultrasound waves as carriers of energy. HIFU is used to focus a beam of ultrasound energy into a small volume at specific target locations within the body. The focused beam causes localized high temperatures and produces a well-defined regions of necrosis. This completely non-invasive technology has great potential for tumor ablation and targeted drug delivery. At the workshop, attendees will see configurations, applications, and hands-on demonstrations with on-site instructors at separate stations. The involvement of medical physicists in diagnostic ultrasound imaging service is increasing due to QC and accreditation requirements. At the workshop, an array of ultrasound testing phantoms and ultrasound scanners will be provided for attendees to learn diagnostic ultrasound QC in a hands-on environment with live demonstrations of the techniques. Target audience: Medical physicists and other medical professionals in diagnostic imaging and radiation oncology with interest in high-intensity focused ultrasound and in diagnostic ultrasound QC. Learning Objectives: Learn ultrasound physics and safety for HIFU applications through live demonstrations Get an overview of the state-of-the art in HIFU technologies and equipment Gain familiarity with common elements of a quality control program for diagnostic ultrasound imaging Identify QC tools available for testing diagnostic ultrasound systems and learn how to use these tools List of supporting vendors for HIFU and diagnostic ultrasound QC hands-on workshop: Philips Healthcare Alpinion Medical Systems Verasonics, Inc Zonare Medical Systems, Inc Computerized Imaging Reference Systems (CIRS), Inc. GAMMEX, Inc., Cablon Medical BV Steffen Sammet: NIH/NCI grant 5R25CA132822, NIH/NINDS grant 5R25NS

MO-AB-210-01: Ultrasound Imaging and Therapy-Hands On Workshop

Energy Technology Data Exchange (ETDEWEB)

Lu, Z. [University of Chicago (United States)

2015-06-15

The goal of this ultrasound hands-on workshop is to demonstrate advancements in high intensity focused ultrasound (HIFU) and to demonstrate quality control (QC) testing in diagnostic ultrasound. HIFU is a therapeutic modality that uses ultrasound waves as carriers of energy. HIFU is used to focus a beam of ultrasound energy into a small volume at specific target locations within the body. The focused beam causes localized high temperatures and produces a well-defined regions of necrosis. This completely non-invasive technology has great potential for tumor ablation and targeted drug delivery. At the workshop, attendees will see configurations, applications, and hands-on demonstrations with on-site instructors at separate stations. The involvement of medical physicists in diagnostic ultrasound imaging service is increasing due to QC and accreditation requirements. At the workshop, an array of ultrasound testing phantoms and ultrasound scanners will be provided for attendees to learn diagnostic ultrasound QC in a hands-on environment with live demonstrations of the techniques. Target audience: Medical physicists and other medical professionals in diagnostic imaging and radiation oncology with interest in high-intensity focused ultrasound and in diagnostic ultrasound QC. Learning Objectives: Learn ultrasound physics and safety for HIFU applications through live demonstrations Get an overview of the state-of-the art in HIFU technologies and equipment Gain familiarity with common elements of a quality control program for diagnostic ultrasound imaging Identify QC tools available for testing diagnostic ultrasound systems and learn how to use these tools List of supporting vendors for HIFU and diagnostic ultrasound QC hands-on workshop: Philips Healthcare Alpinion Medical Systems Verasonics, Inc Zonare Medical Systems, Inc Computerized Imaging Reference Systems (CIRS), Inc. GAMMEX, Inc., Cablon Medical BV Steffen Sammet: NIH/NCI grant 5R25CA132822, NIH/NINDS grant 5R25NS

Prostate Ultrasound

Medline Plus

Full Text Available ... Z Ultrasound - Prostate Ultrasound of the prostate uses sound waves to produce pictures of a man’s prostate ... pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or ...

Ultrasound -- Pelvis

Science.gov (United States)

... endometrial polyps fibroids cancer, especially in patients with abnormal uterine bleeding Some physicians also use 3-D ultrasound or ... Obstetric Ultrasound Ultrasound - Prostate Kidney and Bladder Stones Abnormal Vaginal Bleeding Ovarian Cancer Images related to Ultrasound - Pelvis Sponsored ...

Error analysis for determination of accuracy of an ultrasound navigation system for head and neck surgery.

Science.gov (United States)

Kozak, J; Krysztoforski, K; Kroll, T; Helbig, S; Helbig, M

2009-01-01

The use of conventional CT- or MRI-based navigation systems for head and neck surgery is unsatisfactory due to tissue shift. Moreover, changes occurring during surgical procedures cannot be visualized. To overcome these drawbacks, we developed a novel ultrasound-guided navigation system for head and neck surgery. A comprehensive error analysis was undertaken to determine the accuracy of this new system. The evaluation of the system accuracy was essentially based on the method of error definition for well-established fiducial marker registration methods (point-pair matching) as used in, for example, CT- or MRI-based navigation. This method was modified in accordance with the specific requirements of ultrasound-guided navigation. The Fiducial Localization Error (FLE), Fiducial Registration Error (FRE) and Target Registration Error (TRE) were determined. In our navigation system, the real error (the TRE actually measured) did not exceed a volume of 1.58 mm(3) with a probability of 0.9. A mean value of 0.8 mm (standard deviation: 0.25 mm) was found for the FRE. The quality of the coordinate tracking system (Polaris localizer) could be defined with an FLE of 0.4 +/- 0.11 mm (mean +/- standard deviation). The quality of the coordinates of the crosshairs of the phantom was determined with a deviation of 0.5 mm (standard deviation: 0.07 mm). The results demonstrate that our newly developed ultrasound-guided navigation system shows only very small system deviations and therefore provides very accurate data for practical applications.

Evaluation of an automated breast 3D-ultrasound system by comparing it with hand-held ultrasound (HHUS) and mammography.

Science.gov (United States)

Golatta, Michael; Baggs, Christina; Schweitzer-Martin, Mirjam; Domschke, Christoph; Schott, Sarah; Harcos, Aba; Scharf, Alexander; Junkermann, Hans; Rauch, Geraldine; Rom, Joachim; Sohn, Christof; Heil, Joerg

2015-04-01

Automated three-dimensional (3D) breast ultrasound (US) systems are meant to overcome the shortcomings of hand-held ultrasound (HHUS). The aim of this study is to analyze and compare clinical performance of an automated 3D-US system by comparing it with HHUS, mammography and the clinical gold standard (defined as the combination of HHUS, mammography and-if indicated-histology). Nine hundred and eighty three patients (=1,966 breasts) were enrolled in this monocentric, explorative and prospective cohort study. All examinations were analyzed blinded to the patients´ history and to the results of the routine imaging. The agreement of automated 3D-US with HHUS, mammography and the gold standard was assessed with kappa statistics. Sensitivity, specificity and positive and negative predictive value were calculated to assess the test performance. Blinded to the results of the gold standard the agreement between automated 3D-US and HHUS or mammography was fair, given by a Kappa coefficient of 0.31 (95% CI [0.26;0.36], p automated 3D-US the sensitivity improved to 84% (NPV = 99%, specificity = 85%). The results of this study let us suggest, that automated 3D-US might be a helpful new tool in breast imaging, especially in screening.

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... endometrial polyps fibroids cancer, especially in patients with abnormal uterine bleeding Some physicians also use 3-D ultrasound or ... Obstetric Ultrasound Ultrasound - Prostate Kidney and Bladder Stones Abnormal Vaginal Bleeding Ovarian Cancer Images related to Ultrasound - Pelvis Sponsored ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... Radiation Therapy for Gynecologic Cancers Radiation Therapy for Prostate Cancer top of page This page was reviewed on ... Abdomen Children's (Pediatric) Ultrasound - Abdomen Obstetric Ultrasound Ultrasound - Prostate Kidney and Bladder Stones Abnormal Vaginal Bleeding ... Images related to Ultrasound - Pelvis Sponsored by Please ...

Enhanced ultrasound for advanced diagnostics, ultrasound tomography for volume limb imaging and prosthetic fitting

Science.gov (United States)

Anthony, Brian W.

2016-04-01

Ultrasound imaging methods hold the potential to deliver low-cost, high-resolution, operator-independent and nonionizing imaging systems - such systems couple appropriate algorithms with imaging devices and techniques. The increasing demands on general practitioners motivate us to develop more usable and productive diagnostic imaging equipment. Ultrasound, specifically freehand ultrasound, is a low cost and safe medical imaging technique. It doesn't expose a patient to ionizing radiation. Its safety and versatility make it very well suited for the increasing demands on general practitioners, or for providing improved medical care in rural regions or the developing world. However it typically suffers from sonographer variability; we will discuss techniques to address user variability. We also discuss our work to combine cylindrical scanning systems with state of the art inversion algorithms to deliver ultrasound systems for imaging and quantifying limbs in 3-D in vivo. Such systems have the potential to track the progression of limb health at a low cost and without radiation exposure, as well as, improve prosthetic socket fitting. Current methods of prosthetic socket fabrication remain subjective and ineffective at creating an interface to the human body that is both comfortable and functional. Though there has been recent success using methods like magnetic resonance imaging and biomechanical modeling, a low-cost, streamlined, and quantitative process for prosthetic cup design and fabrication has not been fully demonstrated. Medical ultrasonography may inform the design process of prosthetic sockets in a more objective manner. This keynote talk presents the results of progress in this area.

Interobserver variability of ultrasound elastography and the ultrasound BI-RADS lexicon of breast lesions.

Science.gov (United States)

Park, Chang Suk; Kim, Sung Hun; Jung, Na Young; Choi, Jae Jung; Kang, Bong Joo; Jung, Hyun Seouk

2015-03-01

Elastographpy is a newly developed noninvasive imaging technique that uses ultrasound (US) to evaluate tissue stiffness. The interpretation of the same elastographic images may be variable according to reviewers. Because breast lesions are usually reported according to American College of Radiology Breast Imaging and Data System (ACR BI-RADS) lexicons and final category, we tried to compare observer variability between lexicons and final categorization of US BI-RADS and the elasticity score of US elastography. From April 2009 to February 2010, 1356 breast lesions in 1330 patients underwent ultrasound-guided core biopsy. Among them, 63 breast lesions in 55 patients (mean age, 45.7 years; range, 21-79 years) underwent both conventional ultrasound and elastography and were included in this study. Two radiologists independently performed conventional ultrasound and elastography, and another three observers reviewed conventional ultrasound images and elastography videos. Observers independently recorded the elasticity score for a 5-point scoring system proposed by Itoh et al., BI-RADS lexicons and final category using ultrasound BI-RADS. The histopathologic results were obtained and used as the reference standard. Interobserver variability was evaluated. Of the 63 lesions, 42 (66.7 %) were benign, and 21 (33.3 %) were malignant. The highest value of concordance among all variables was achieved for the elasticity score (k = 0.59), followed by shape (k = 0.54), final category (k = 0.48), posterior acoustic features (k = 0.44), echogenecity and orientation (k = 0.43). The least concordances were margin (k = 0.26), lesion boundary (k = 0.29) and calcification (k = 0.3). Elasticity score showed a higher level of interobserver agreement for the diagnosis of breast lesions than BI-RADS lexicons and final category.

The fluoro-less and contrast-less peripheral endovascular intervention: Halfway there

Energy Technology Data Exchange (ETDEWEB)

Ephrem, Georges, E-mail: g.ephrem@gmail.com; Garikipati, Sireesha; Hanson, Ivan D.

2016-09-15

Introduction: Percutaneous endovascular revascularization requires the use of fluoroscopic guidance and radiopaque contrast. We present a successful intervention without the use of iodinated contrast. Case: A 92-year-old man with dry gangrene involving the second and fourth left toes had acute on chronic kidney injury. Arterial duplex showed severe stenosis in bilateral superficial femoral arteries (SFAs). Fluoroscopic and ultrasound guidance and intravascular imaging were used to avoid iodinated contrast. After right to left femoral crossover, the entire left SFA was imaged with ultrasound. The lesion was delineated with radiopaque measuring tapes then wired. Near-infrared spectroscopy and intravascular ultrasound (NIRS-IVUS) imaging were performed. Points of interest were correlated with corresponding radiopaque markings on the ruler. Stenting and post-dilation resulted in complete stent expansion and no evidence of dissection by IVUS. The total procedure time was 113 min and the total radiation dose 813 mGy. The day after the procedure, there was a palpable dorsalis pedis pulse. He was discharged to inpatient rehabilitation on dual antiplatelet therapy. Discussion: Contrast and radiation continue to limit the feasibility of endovascular angiography and intervention. Carbon dioxide (CO2) digital subtraction angiography is an alternative for these patients but has several disadvantages. Previously proposed projects demonstrated the real potential of performing endovascular peripheral intervention without fluoroscopy or contrast. Conclusion: This case is a clear demonstration of a successful use of a combination of fluoroscopy, ultrasonography and intravascular imaging to achieve a successful endovascular intervention to treat critical limb ischemia, without the use of iodinated contrast.

Novel power MOSFET-based expander for high frequency ultrasound systems.

Science.gov (United States)

Choi, Hojong; Shung, K Kirk

2014-01-01

The function of an expander is to obstruct the noise signal transmitted by the pulser so that it does not pass into the transducer or receive electronics, where it can produce undesirable ring-down in an ultrasound imaging application. The most common type is a diode-based expander, which is essentially a simple diode-pair, is widely used in pulse-echo measurements and imaging applications because of its simple architecture. However, diode-based expanders may degrade the performance of ultrasonic transducers and electronic components on the receiving and transmitting sides of the ultrasound systems, respectively. Since they are non-linear devices, they cause excessive signal attenuation and noise at higher frequencies and voltages. In this paper, a new type of expander that utilizes power MOSFET components, which we call a power MOSFET-based expander, is introduced and evaluated for use in high frequency ultrasound imaging systems. The performance of a power MOSFET-based expander was evaluated relative to a diode-based expander by comparing the noise figure (NF), insertion loss (IL), total harmonic distortion (THD), response time (RT), electrical impedance (EI) and dynamic power consumption (DPC). The results showed that the power MOSFET-based expander provided better NF (0.76 dB), IL (-0.3 dB) and THD (-62.9 dB), and faster RT (82 ns) than did the diode-based expander (NF (2.6 dB), IL (-1.4 dB), THD (-56.0 dB) and RT (119 ns)) at 70 MHz. The -6 dB bandwidth and the peak-to-peak voltage of the echo signal received by the transducer using the power MOSFET-based expander improved by 17.4% and 240% compared to the diode-based expander, respectively. The new power MOSFET-based expander was shown to yield lower NF, IL and THD, faster RT and lower ring down than the diode-based expander at the expense of higher dynamic power consumption. Copyright © 2013 Elsevier B.V. All rights reserved.

Application of a drug delivery system using ultrasound and nano/microbubbles for anti-angiogenic therapy

International Nuclear Information System (INIS)

Horie, Sachiko; Kodama, Tetsuya; Sato, Yasushi

2017-01-01

The drug delivery system using ultrasound and nano/microbubbles is a molecular delivery approach using the mechanism of sonoporation. With sonoporation, an endothelium-derived negative-feedback regulator of angiogenesis, Vasohibin-1 (VASH1), was introduced specifically into tumor vessels. We found VASH1 in tumor vessels induce normalization of tumor vessels and inhibited tumor growth. A recent topic regarding tumor angiogenesis is vascular normalization. Tumor vessels are abnormal or immature that cause hyperpermeability and impaired blood flow. Tumor vascular normalization improves blood flow and tissue hypoxia, which increase the effectiveness of chemotherapy and radiotherapy and reduce tumor cell malignancy. In this review, application of drug delivery system using ultrasound for an anti-angiogenic therapy, a tumor vessel normalization therapy to treat cancer, is summarized. (author)

System Level Design of a Continuous-Time Delta-Sigma Modulator for Portable Ultrasound Scanners

DEFF Research Database (Denmark)

Llimos Muntal, Pere; Færch, Kjartan; Jørgensen, Ivan Harald Holger

2015-01-01

In this paper the system level design of a continuous-time ∆Σ modulator for portable ultrasound scanners is presented. The overall required signal-to-noise ratio (SNR) is derived to be 42 dB and the sampling frequency used is 320 MHz for an oversampling ratio of 16. In order to match these requir......, based on high-level VerilogA simulations, the performance of the ∆Σ modulator versus various block performance parameters is presented as trade-off curves. Based on these results, the block specifications are derived.......In this paper the system level design of a continuous-time ∆Σ modulator for portable ultrasound scanners is presented. The overall required signal-to-noise ratio (SNR) is derived to be 42 dB and the sampling frequency used is 320 MHz for an oversampling ratio of 16. In order to match...

General Ultrasound Imaging

Medline Plus

Full Text Available ... inserted into a man's rectum to view the prostate. Transvaginal ultrasound. The transducer is inserted into a ... Stenting Ultrasound-Guided Breast Biopsy Obstetric Ultrasound Ultrasound - Prostate Biopsies - Overview Images related to General Ultrasound Videos ...

General Ultrasound Imaging

Medline Plus

Full Text Available ... News Physician Resources Professions Site Index A-Z General Ultrasound Ultrasound imaging uses sound waves to produce ... the limitations of General Ultrasound Imaging? What is General Ultrasound Imaging? Ultrasound is safe and painless, and ...

Intraluminal laser atherectomy with ultrasound and electromagnetic guidance

Science.gov (United States)

Gregory, Kenton W.; Aretz, H. Thomas; Martinelli, Michael A.; LeDet, Earl G.; Hatch, G. F.; Gregg, Richard E.; Sedlacek, Tomas; Haase, Wayne C.

1991-05-01

The MagellanTM coronary laser atherectomy system is described. It uses high- resolution ultrasound imaging and electromagnetic sensing to provide real-time guidance and control of laser therapy in the coronary arteries. The system consists of a flexible catheter, an electromagnetic navigation antenna, a sensor signal processor and a computer for image processing and display. The small, flexible catheter combines an ultrasound transducer and laser delivery optics, aimed at the artery wall, and an electromagnetic receiving sensor. An extra-corporeal electromagnetic transmit antenna, in combination with catheter sensors, locates the position of the ultrasound and laser beams in the artery. Navigation and ultrasound data are processed electronically to produce real-time, transverse, and axial cross-section images of the artery wall at selected locations. By exploiting the ability of ultrasound to image beneath the surface of artery walls, it is possible to identify candidate treatment sites and perform safe radial laser debulking of atherosclerotic plaque with reduced danger of perforation. The utility of the system in plaque identification and ablation is demonstrated with imaging and experimental results.

WE-AB-206-01: Diagnostic Ultrasound Imaging Quality Assurance

Energy Technology Data Exchange (ETDEWEB)

Zagzebski, J. [University of Wisconsin (United States)

2016-06-15

The involvement of medical physicists in diagnostic ultrasound imaging service is increasing due to QC and accreditation requirements. The goal of this ultrasound hands-on workshop is to demonstrate quality control (QC) testing in diagnostic ultrasound and to provide updates in ACR ultrasound accreditation requirements. The first half of this workshop will include two presentations reviewing diagnostic ultrasound QA/QC and ACR ultrasound accreditation requirements. The second half of the workshop will include live demonstrations of basic QC tests. An array of ultrasound testing phantoms and ultrasound scanners will be available for attendees to learn diagnostic ultrasound QC in a hands-on environment with live demonstrations and on-site instructors. The targeted attendees are medical physicists in diagnostic imaging. Learning Objectives: Gain familiarity with common elements of a QA/QC program for diagnostic ultrasound imaging dentify QC tools available for testing diagnostic ultrasound systems and learn how to use these tools Learn ACR ultrasound accreditation requirements Jennifer Walter is an employee of American College of Radiology on Ultrasound Accreditation.

WE-AB-206-01: Diagnostic Ultrasound Imaging Quality Assurance

International Nuclear Information System (INIS)

Zagzebski, J.

2016-01-01

The involvement of medical physicists in diagnostic ultrasound imaging service is increasing due to QC and accreditation requirements. The goal of this ultrasound hands-on workshop is to demonstrate quality control (QC) testing in diagnostic ultrasound and to provide updates in ACR ultrasound accreditation requirements. The first half of this workshop will include two presentations reviewing diagnostic ultrasound QA/QC and ACR ultrasound accreditation requirements. The second half of the workshop will include live demonstrations of basic QC tests. An array of ultrasound testing phantoms and ultrasound scanners will be available for attendees to learn diagnostic ultrasound QC in a hands-on environment with live demonstrations and on-site instructors. The targeted attendees are medical physicists in diagnostic imaging. Learning Objectives: Gain familiarity with common elements of a QA/QC program for diagnostic ultrasound imaging dentify QC tools available for testing diagnostic ultrasound systems and learn how to use these tools Learn ACR ultrasound accreditation requirements Jennifer Walter is an employee of American College of Radiology on Ultrasound Accreditation.

Dose-volume histograms based on serial intravascular ultrasound: a calculation model for radioactive stents

International Nuclear Information System (INIS)

Kirisits, Christian; Wexberg, Paul; Gottsauner-Wolf, Michael; Pokrajac, Boris; Ortmann, Elisabeth; Aiginger, Hannes; Glogar, Dietmar; Poetter, Richard

2001-01-01

Background and purpose: Radioactive stents are under investigation for reduction of coronary restenosis. However, the actual dose delivered to specific parts of the coronary artery wall based on the individual vessel anatomy has not been determined so far. Dose-volume histograms (DVHs) permit an estimation of the actual dose absorbed by the target volume. We present a method to calculate DVHs based on intravascular ultrasound (IVUS) measurements to determine the dose distribution within the vessel wall. Materials and methods: Ten patients were studied by intravascular ultrasound after radioactive stenting (BX Stent, P-32, 15-mm length) to obtain tomographic cross-sections of the treated segments. We developed a computer algorithm using the actual dose distribution of the stent to calculate differential and cumulative DVHs. The minimal target dose, the mean target dose, the minimal doses delivered to 10 and 90% of the adventitia (DV10, DV90), and the percentage of volume receiving a reference dose at 0.5 mm from the stent surface cumulated over 28 days were derived from the DVH plots. Results were expressed as mean±SD. Results: The mean activity of the stents was 438±140 kBq at implantation. The mean reference dose was 111±35 Gy, whereas the calculated mean target dose within the adventitia along the stent was 68±20 Gy. On average, DV90 and DV10 were 33±9 Gy and 117±41 Gy, respectively. Expanding the target volume to include 2.5-mm-long segments at the proximal and distal ends of the stent, the calculated mean target dose decreased to 55±17 Gy, and DV 90 and DV 10 were 6.4±2.4 Gy and 107±36 Gy, respectively. Conclusions: The assessment of DVHs seems in principle to be a valuable tool for both prospective and retrospective analysis of dose-distribution of radioactive stents. It may provide the basis to adapt treatment planning in coronary brachytherapy to the common standards of radiotherapy

Compensatory enlargement of Ossabaw miniature swine coronary arteries in diffuse atherosclerosis

Directory of Open Access Journals (Sweden)

Jenny S. Choy

2015-03-01

Full Text Available Studies in human and non-human primates have confirmed the compensatory enlargement or positive remodeling (Glagov phenomenon of coronary vessels in the presence of focal stenosis. To our knowledge, this is the first study to document arterial enlargement in a metabolic syndrome animal model with diffuse coronary artery disease (DCAD in the absence of severe focal stenosis. Two different groups of Ossabaw miniature pigs were fed a high fat atherogenic diet for 4 months (Group I and 12 months (Group II, respectively. Group I (6 pigs underwent contrast enhanced computed tomographic angiography (CCTA and intravascular ultrasound (IVUS at baseline and after 4 months of high fat diet, whereas Group II (7 pigs underwent only IVUS at 12 months of high fat diet. IVUS measurements of the left anterior descending (LAD, left circumflex (LCX and right coronary (RCA arteries in Group I showed an average increase in their lumen cross-sectional areas (CSA of 25.8%, 11.4%, and 43.4%, respectively, as compared to baseline. The lumen CSA values of LAD in Group II were found to be between the baseline and 4 month values in Group I. IVUS and CCTA measurements showed a similar trend and positive correlation. Fractional flow reserve (FFR was 0.91 ± 0.07 at baseline and 0.93 ± 0.05 at 4 months with only 2.2%, 1.6% and 1% stenosis in the LAD, LCX and RCA, respectively. The relation between percent stenosis and lumen CSA shows a classical Glagov phenomenon in this animal model of DCAD.

MO-AB-210-03: Workshop [Advancements in high intensity focused ultrasound

Energy Technology Data Exchange (ETDEWEB)

Lu, Z. [University of Chicago (United States)

2015-06-15

The goal of this ultrasound hands-on workshop is to demonstrate advancements in high intensity focused ultrasound (HIFU) and to demonstrate quality control (QC) testing in diagnostic ultrasound. HIFU is a therapeutic modality that uses ultrasound waves as carriers of energy. HIFU is used to focus a beam of ultrasound energy into a small volume at specific target locations within the body. The focused beam causes localized high temperatures and produces a well-defined regions of necrosis. This completely non-invasive technology has great potential for tumor ablation and targeted drug delivery. At the workshop, attendees will see configurations, applications, and hands-on demonstrations with on-site instructors at separate stations. The involvement of medical physicists in diagnostic ultrasound imaging service is increasing due to QC and accreditation requirements. At the workshop, an array of ultrasound testing phantoms and ultrasound scanners will be provided for attendees to learn diagnostic ultrasound QC in a hands-on environment with live demonstrations of the techniques. Target audience: Medical physicists and other medical professionals in diagnostic imaging and radiation oncology with interest in high-intensity focused ultrasound and in diagnostic ultrasound QC. Learning Objectives: Learn ultrasound physics and safety for HIFU applications through live demonstrations Get an overview of the state-of-the art in HIFU technologies and equipment Gain familiarity with common elements of a quality control program for diagnostic ultrasound imaging Identify QC tools available for testing diagnostic ultrasound systems and learn how to use these tools List of supporting vendors for HIFU and diagnostic ultrasound QC hands-on workshop: Philips Healthcare Alpinion Medical Systems Verasonics, Inc Zonare Medical Systems, Inc Computerized Imaging Reference Systems (CIRS), Inc. GAMMEX, Inc., Cablon Medical BV Steffen Sammet: NIH/NCI grant 5R25CA132822, NIH/NINDS grant 5R25NS

Interference-free ultrasound imaging during HIFU therapy, using software tools

Science.gov (United States)

Vaezy, Shahram (Inventor); Held, Robert (Inventor); Sikdar, Siddhartha (Inventor); Managuli, Ravi (Inventor); Zderic, Vesna (Inventor)

2010-01-01

Disclosed herein is a method for obtaining a composite interference-free ultrasound image when non-imaging ultrasound waves would otherwise interfere with ultrasound imaging. A conventional ultrasound imaging system is used to collect frames of ultrasound image data in the presence of non-imaging ultrasound waves, such as high-intensity focused ultrasound (HIFU). The frames are directed to a processor that analyzes the frames to identify portions of the frame that are interference-free. Interference-free portions of a plurality of different ultrasound image frames are combined to generate a single composite interference-free ultrasound image that is displayed to a user. In this approach, a frequency of the non-imaging ultrasound waves is offset relative to a frequency of the ultrasound imaging waves, such that the interference introduced by the non-imaging ultrasound waves appears in a different portion of the frames.

Development of ClearPEM-Sonic, a multimodal mammography system for PET and Ultrasound

Science.gov (United States)

Cucciati, G.; Auffray, E.; Bugalho, R.; Cao, L.; Di Vara, N.; Farina, F.; Felix, N.; Frisch, B.; Ghezzi, A.; Juhan, V.; Jun, D.; Lasaygues, P.; Lecoq, P.; Mensah, S.; Mundler, O.; Neves, J.; Paganoni, M.; Peter, J.; Pizzichemi, M.; Siles, P.; Silva, J. C.; Silva, R.; Tavernier, S.; Tessonnier, L.; Varela, J.

2014-03-01

ClearPEM-Sonic is an innovative imaging device specifically developed for breast cancer. The possibility to work in PEM-Ultrasound multimodality allows to obtain metabolic and morphological information increasing the specificity of the exam. The ClearPEM detector is developed to maximize the sensitivity and the spatial resolution as compared to Whole-Body PET scanners. It is coupled with a 3D ultrasound system, the SuperSonic Imagine Aixplorer that improves the specificity of the exam by providing a tissue elasticity map. This work describes the ClearPEM-Sonic project focusing on the technological developments it has required, the technical merits (and limits) and the first multimodal images acquired on a dedicated phantom. It finally presents selected clinical case studies that confirm the value of PEM information.

Development of ClearPEM-Sonic, a multimodal mammography system for PET and Ultrasound

International Nuclear Information System (INIS)

Cucciati, G; Vara, N Di; Ghezzi, A; Paganoni, M; Pizzichemi, M; Auffray, E; Frisch, B; Lecoq, P; Bugalho, R; Neves, J; Cao, L; Peter, J; Farina, F; Felix, N; Juhan, V; Mundler, O; Siles, P; Jun, D; Lasaygues, P; Mensah, S

2014-01-01

ClearPEM-Sonic is an innovative imaging device specifically developed for breast cancer. The possibility to work in PEM-Ultrasound multimodality allows to obtain metabolic and morphological information increasing the specificity of the exam. The ClearPEM detector is developed to maximize the sensitivity and the spatial resolution as compared to Whole-Body PET scanners. It is coupled with a 3D ultrasound system, the SuperSonic Imagine Aixplorer that improves the specificity of the exam by providing a tissue elasticity map. This work describes the ClearPEM-Sonic project focusing on the technological developments it has required, the technical merits (and limits) and the first multimodal images acquired on a dedicated phantom. It finally presents selected clinical case studies that confirm the value of PEM information

Ultrasound mediated nanoparticle drug delivery

Science.gov (United States)

Mullin, Lee B.

Ultrasound is not only a powerful diagnostic tool, but also a promising therapeutic technology that can be used to improve localized drug delivery. Microbubble contrast agents are micron sized encapsulated gas filled bubbles that are administered intravenously. Originally developed to enhance ultrasound images, microbubbles are highly echogenic due to the gas core that provides a detectable impedance difference from the surrounding medium. The core also allows for controlled response of the microbubbles to ultrasound pulses. Microbubbles can be pushed using acoustic radiation force and ruptured using high pressures. Destruction of microbubbles can increase permeability at the cellular and vascular level, which can be advantageous for drug delivery. Advances in drug delivery methods have been seen with the introduction of nanoparticles, nanometer sized objects often carrying a drug payload. In chemotherapy, nanoparticles can deliver drugs to tumors while limiting systemic exposure due to abnormalities in tumor vasculature such large gaps between endothelial cells that allow nanoparticles to enter into the interstitial space; this is referred to as the enhanced permeability and retention (EPR) effect. However, this effect may be overestimated in many tumors. Additionally, only a small percentage of the injected dose accumulates in the tumor, which most the nanoparticles accumulating in the liver and spleen. It is hypothesized that combining the acoustic activity of an ultrasound contrast agent with the high payload and extravasation ability of a nanoparticle, localized delivery to the tumor with reduced systemic toxicity can be achieved. This method can be accomplished by either loading nanoparticles onto the shell of the microbubble or through a coadministration method of both nanoparticles and microbubbles. The work presented in this dissertation utilizes novel and commercial nanoparticle formulations, combined with microbubbles and a variety of ultrasound systems

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... ultrasound exams are also used to monitor the health and development of an embryo or fetus during pregnancy. See the ... can help to identify and evaluate a variety of urinary and reproductive system disorders in both sexes without x-ray exposure. ...

Prostate Ultrasound

Medline Plus

Full Text Available ... through blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. Prostate ultrasound, also called transrectal ultrasound, provides ...

SU-E-P-10: Imaging in the Cardiac Catheterization Lab - Technologies and Clinical Applications

International Nuclear Information System (INIS)

Fetterly, K

2014-01-01

Purpose: Diagnosis and treatment of cardiovascular disease in the cardiac catheterization laboratory is often aided by a multitude of imaging technologies. The purpose of this work is to highlight the contributions to patient care offered by the various imaging systems used during cardiovascular interventional procedures. Methods: Imaging technologies used in the cardiac catheterization lab were characterized by their fundamental technology and by the clinical applications for which they are used. Whether the modality is external to the patient, intravascular, or intracavity was specified. Specific clinical procedures for which multiple modalities are routinely used will be highlighted. Results: X-ray imaging modalities include fluoroscopy/angiography and angiography CT. Ultrasound imaging is performed with external, trans-esophageal echocardiography (TEE), and intravascular (IVUS) transducers. Intravascular infrared optical coherence tomography (IVOCT) is used to assess vessel endothelium. Relatively large (>0.5 mm) anatomical structures are imaged with x-ray and ultrasound. IVUS and IVOCT provide high resolution images of vessel walls. Cardiac CT and MRI images are used to plan complex cardiovascular interventions. Advanced applications are used to spatially and temporally merge images from different technologies. Diagnosis and treatment of coronary artery disease frequently utilizes angiography and intra-vascular imaging, and treatment of complex structural heart conditions routinely includes use of multiple imaging modalities. Conclusion: There are several imaging modalities which are routinely used in the cardiac catheterization laboratory to diagnose and treat both coronary artery and structural heart disease. Multiple modalities are frequently used to enhance the quality and safety of procedures. The cardiac catheterization laboratory includes many opportunities for medical physicists to contribute substantially toward advancing patient care

Comparison of multislice computed tomography with intravascular ultrasound for detection and characterization of coronary artery plaques: A systematic review

Energy Technology Data Exchange (ETDEWEB)

Springer, Ivonne [Department of Radiology, Charite, Medical School, Humboldt-Universitaet zu Berlin (Germany); Dewey, Marc [Department of Radiology, Charite, Medical School, Humboldt-Universitaet zu Berlin (Germany)], E-mail: marc.dewey@charite.de

2009-08-15

Purpose: Multislice computed tomography (MSCT) is a novel non-invasive test for detection and analysis of coronary artery plaques. A systematic review was conducted of the literature to compare MSCT with IVUS as the reference standard for assessing coronary artery plaques. Materials and methods: We performed a literature search in the online database MEDLINE, which was accessed at (http://www.pubmed.gov) on 9th April 2008. Results: The search identified 14 studies with 340 patients (mean age 59 {+-} 5 years). The systematic review revealed a sensitivity of MSCT on the lesion level (n = 1779 coronary plaques) on the order of 90% (range from 87 to 92%) in comparison to IVUS. Per-segment analysis (n = 356) yielded a lower sensitivity of 81-86%. In the per-vessel analysis (n = 90), MSCT had a better sensitivity and specificity for the RCA (83-89% and 92-100%) and the LAD (83-87% and 93%) than for the LCX (71-85% and 77-89%), and on the vessel level and the cross-section analysis MSCT was more sensitive for calcified plaques than for non-calcified plaque. It is noteworthy that most studies provide only incomplete data on technical and methodological parameters such as radiation exposure and patient characteristics. Conclusion: MSCT is an accurate and reliable test for detection of coronary artery plaques in comparison to IVUS with limitations in regards to the LCX and non-calcified plaques. Studies published thus far are limited by the sample sizes and methodological quality issues.

A CT-ultrasound-coregistered augmented reality enhanced image-guided surgery system and its preliminary study on brain-shift estimation

International Nuclear Information System (INIS)

Huang, C H; Hsieh, C H; Lee, J D; Huang, W C; Lee, S T; Wu, C T; Sun, Y N; Wu, Y T

2012-01-01

With the combined view on the physical space and the medical imaging data, augmented reality (AR) visualization can provide perceptive advantages during image-guided surgery (IGS). However, the imaging data are usually captured before surgery and might be different from the up-to-date one due to natural shift of soft tissues. This study presents an AR-enhanced IGS system which is capable to correct the movement of soft tissues from the pre-operative CT images by using intra-operative ultrasound images. First, with reconstructing 2-D free-hand ultrasound images to 3-D volume data, the system applies a Mutual-Information based registration algorithm to estimate the deformation between pre-operative and intra-operative ultrasound images. The estimated deformation transform describes the movement of soft tissues and is then applied to the pre-operative CT images which provide high-resolution anatomical information. As a result, the system thus displays the fusion of the corrected CT images or the real-time 2-D ultrasound images with the patient in the physical space through a head mounted display device, providing an immersive augmented-reality environment. For the performance validation of the proposed system, a brain phantom was utilized to simulate brain-shift scenario. Experimental results reveal that when the shift of an artificial tumor is from 5mm ∼ 12mm, the correction rates can be improved from 32% ∼ 45% to 87% ∼ 95% by using the proposed system.

Outcome in hyperglycemic stroke with ultrasound-augmented thrombolytic therapy.

Science.gov (United States)

Martini, S R; Hill, M D; Alexandrov, A V; Molina, C A; Kent, T A

2006-08-22

Hyperglycemia independently predicts poor outcome after acute ischemic stroke. CLOTBUST (Combined Lysis Of Thrombus in Brain ischemia using transcranial Ultrasound and Systemic tPA) demonstrated that ultrasound-augmented thrombolysis improves recanalization and 24-hour outcome in patients with acute ischemic stroke. We hypothesized that ultrasound would preferentially benefit hyperglycemic patients, and reviewed CLOTBUST with respect to admission glucose and good outcome. We found that ultrasound's benefit on 90-day outcome was primarily apparent at higher glucose levels, suggesting that ultrasound therapy may improve outcome following hyperglycemic stroke.

Factors influencing the examinations by means of ultrasounds

International Nuclear Information System (INIS)

Brocco, M.

1988-01-01

The reliability of ultrasound examination can be influenced by many variables: the pulse generator and receiver, the material under examination, size, type, position and orientation of a defect inside the material. The results of a study aiming at evaluating the amplitude of the response signals as a means to size defects are exposed. The conclusions have been drawn considering the influence that a defect and an ultrasound system have on the power absorbed. The results show that the orientation, the geometry and the band width of the ultrasound system

Time reversal and phase coherent music techniques for super-resolution ultrasound imaging

Science.gov (United States)

Huang, Lianjie; Labyed, Yassin

2018-05-01

Systems and methods for super-resolution ultrasound imaging using a windowed and generalized TR-MUSIC algorithm that divides the imaging region into overlapping sub-regions and applies the TR-MUSIC algorithm to the windowed backscattered ultrasound signals corresponding to each sub-region. The algorithm is also structured to account for the ultrasound attenuation in the medium and the finite-size effects of ultrasound transducer elements. A modified TR-MUSIC imaging algorithm is used to account for ultrasound scattering from both density and compressibility contrasts. The phase response of ultrasound transducer elements is accounted for in a PC-MUSIC system.

The OMERACT ultrasound task force--status and perspectives.

LENUS (Irish Health Repository)

Naredo, Esperanza

2011-09-01

This article reports the most recent work of the Outcome Measures in Rheumatology (OMERACT) Ultrasound Task Force, and highlights the future research priorities discussed at the OMERACT 10 meeting. Results of the following studies were presented: (1) intra- and interobserver reliability of ultrasound detecting and scoring synovitis in different joints of patients with rheumatoid arthritis (RA); (2) systematic review of previous ultrasound scoring systems of synovitis in RA; (3) enthesitis systematic review and Delphi definition exercise in spondyloarthritis enthesitis; (4) enthesitis intra- and interobserver reliability exercise; and (5) Delphi definition exercise in hand osteoarthritis, and reliability exercises. Study conclusions were discussed, and a future research agenda was approved, notably further validation of an OMERACT ultrasound global synovitis score (GLOSS) in RA, emphasizing the importance of testing feasibility, predictive value, and added value over standard clinical variables. Future research areas will include validating scoring systems for enthesitis and osteoarthritis, and testing the metric qualities of ultrasound for evaluating tenosynovitis and structural damage in RA.

The feasibility of an infrared system for real-time visualization and mapping of ultrasound fields

Energy Technology Data Exchange (ETDEWEB)

Shaw, Adam; Nunn, John, E-mail: adam.shaw@npl.co.u [National Physical Laboratory, Teddington, Middlesex, TW11 0LW (United Kingdom)

2010-06-07

In treatment planning for ultrasound therapy, it is desirable to know the 3D structure of the ultrasound field. However, mapping an ultrasound field in 3D is very slow, with even a single planar raster scan taking typically several hours. Additionally, hydrophones that are used for field mapping are expensive and can be damaged in some therapy fields. So there is value in rapid methods which enable visualization and mapping of the ultrasound field in about 1 min. In this note we explore the feasibility of mapping the intensity distribution by measuring the temperature distribution produced in a thin sheet of absorbing material. A 0.2 mm thick acetate sheet forms a window in the wall of a water tank containing the transducer. The window is oriented at 45{sup 0} to the beam axis, and the distance from the transducer to the window can be varied. The temperature distribution is measured with an infrared camera; thermal images of the inclined plane could be viewed in real time or images could be captured for later analysis and 3D field reconstruction. We conclude that infrared thermography can be used to gain qualitative information about ultrasound fields. Thermal images are easily visualized with good spatial and thermal resolutions (0.044 mm and 0.05 {sup 0}C in our system). The focus and field structure such as side lobes can be identified in real time from the direct video output. 3D maps and image planes at arbitrary orientations to the beam axis can be obtained and reconstructed within a few minutes. In this note we are primarily interested in the technique for characterization of high intensity focused ultrasound (HIFU) fields, but other applications such as physiotherapy fields are also possible. (note)

The feasibility of an infrared system for real-time visualization and mapping of ultrasound fields

International Nuclear Information System (INIS)

Shaw, Adam; Nunn, John

2010-01-01

In treatment planning for ultrasound therapy, it is desirable to know the 3D structure of the ultrasound field. However, mapping an ultrasound field in 3D is very slow, with even a single planar raster scan taking typically several hours. Additionally, hydrophones that are used for field mapping are expensive and can be damaged in some therapy fields. So there is value in rapid methods which enable visualization and mapping of the ultrasound field in about 1 min. In this note we explore the feasibility of mapping the intensity distribution by measuring the temperature distribution produced in a thin sheet of absorbing material. A 0.2 mm thick acetate sheet forms a window in the wall of a water tank containing the transducer. The window is oriented at 45 0 to the beam axis, and the distance from the transducer to the window can be varied. The temperature distribution is measured with an infrared camera; thermal images of the inclined plane could be viewed in real time or images could be captured for later analysis and 3D field reconstruction. We conclude that infrared thermography can be used to gain qualitative information about ultrasound fields. Thermal images are easily visualized with good spatial and thermal resolutions (0.044 mm and 0.05 0 C in our system). The focus and field structure such as side lobes can be identified in real time from the direct video output. 3D maps and image planes at arbitrary orientations to the beam axis can be obtained and reconstructed within a few minutes. In this note we are primarily interested in the technique for characterization of high intensity focused ultrasound (HIFU) fields, but other applications such as physiotherapy fields are also possible. (note)

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... three types of pelvic ultrasound: abdominal, vaginal (for women), and rectal (for men). These exams are frequently ... pelvic ultrasound: abdominal ( transabdominal ) vaginal ( transvaginal / endovaginal ) for women rectal ( transrectal ) for men A Doppler ultrasound exam ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... a pelvic ultrasound examination. Doppler ultrasound , also called color Doppler ultrasonography, is a special ultrasound technique that ... and processes the sounds and creates graphs or color pictures that represent the flow of blood through ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. There are ... Ultrasound page for more information . Ultrasound examinations can help diagnose symptoms experienced by women such as: pelvic ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... ultrasound images are captured in real-time, they can show the structure and movement of the body's ... Obstetrical Ultrasound page for more information . Ultrasound examinations can help diagnose symptoms experienced by women such as: ...

Prostate ultrasound imaging: evaluation of a two-step scoring system in the diagnosis of prostate cancer.

Science.gov (United States)

Gao, Yong; Liao, Xin-Hong; Ma, Yan; Lu, Lu; Wei, Li-Yan; Yan, Xue

2017-12-01

This study aims to investigate the feasibility and performance of a two-step scoring system of ultrasound imaging in the diagnosis of prostate cancer. 75 patients with 888 consecutive histopathologically verified lesions were included in this study. Step 1, an initial 5-point scoring system was developed based on conventional transrectal ultrasound (TRUS). Step 2, a final scoring system was evaluated according to contrast-enhanced transrectal ultrasound (CE-TRUS). Each lesion was evaluated using the two-step scoring system (step 1 + step 2) and compared with only using conventional TRUS (step 1). 888 lesions were histologically verified: 315 of them were prostate cancer from 46 patients and 573 were benign prostatic hypertrophy (BPH) from 29 patients. According to the two-step scoring system, 284 lesions were upgraded and 130 lesions were downgraded from step 1 to step 2 (this means using step 2 to assess the results by step 1). However, 96 cases were improperly upgraded after step 2 and 48 malignant lesions were still missed after step 2 as score-1. For the two-step scoring system, the sensitivity, specificity, and accuracy were 84.7%, 83.2%, and 83.7%, respectively, versus 22.8%, 96.6%, and 70.4%, respectively, for conventional TRUS. The area under the ROC curve (AUC) for lesion diagnosis was 0.799-0.952 for the two-step scoring system, versus 0.479-0.712 for conventional TRUS. The difference in the diagnostic accuracy of the two-step scoring system and conventional TRUS was statistically significant (Pstep scoring system was straightforward to use and achieved a considerably accurate diagnostic performance for prostate cancer. The application of the two-step scoring system for prostate cancer is promising.

General Ultrasound Imaging

Medline Plus

Full Text Available ... What are the limitations of General Ultrasound Imaging? What is General Ultrasound Imaging? Ultrasound is safe and ... be heard with every heartbeat. top of page What are some common uses of the procedure? Ultrasound ...

General Ultrasound Imaging

Medline Plus

Full Text Available ... Index A-Z General Ultrasound Ultrasound imaging uses sound waves to produce pictures of the inside of ... pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or ...

General Ultrasound Imaging

Medline Plus

Full Text Available ... guide biopsy of breast cancer ( see the Ultrasound-Guided Breast Biopsy page . diagnose a variety of heart ... Articles and Media Angioplasty and Vascular Stenting Ultrasound-Guided Breast Biopsy Obstetric Ultrasound Ultrasound - Prostate Biopsies - Overview ...

General Ultrasound Imaging

Medline Plus

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

General Ultrasound Imaging

Medline Plus

Full Text Available ... those sound waves to create an image. Ultrasound examinations do not use ionizing radiation (as used in ... ultrasound study may be part of an ultrasound examination. Doppler ultrasound , also called color Doppler ultrasonography, is ...

Experimental ultrasound system for real-time synthetic imaging

DEFF Research Database (Denmark)

Jensen, Jørgen Arendt; Holm, Ole; Jensen, Lars Joost

1999-01-01

Digital signal processing is being employed more and more in modern ultrasound scanners. This has made it possible to do dynamic receive focusing for each sample and implement other advanced imaging methods. The processing, however, has to be very fast and cost-effective at the same time. Dedicated...... for synthetic aperture imaging, 2D and 3D B-mode and velocity imaging. The system can be used with 128 element transducers and can excite 128 channels and receive and sample data from 64 channels simultaneously at 40 MHz with 12 bits precision. Data can be processed in real time using the system's 80 signal...... chips are used in order to do real time processing. This often makes it difficult to implement radically different imaging strategies on one platform and makes the scanners less accessible for research purposes. Here flexibility is the prime concern, and the storage of data from all transducer elements...

Musculoskeletal ultrasound in rheumatology in Korea: targeted ultrasound initiative survey.

Science.gov (United States)

Kang, Taeyoung; Wakefield, Richard J; Emery, Paul

2016-04-01

In collaboration with the Targeted Ultrasound Initiative (TUI), to conduct the first study in Korea to investigate current practices in ultrasound use among Korean rheumatologists. We translated the TUI Global Survey into Korean and added questions to better understand the specific challenges facing rheumatologists in Korea. To target as many rheumatologists in Korea as possible, we created an on-line version of this survey, which was conducted from March to April 2013. Rheumatologists are in charge of ultrasound in many Korean hospitals. Rheumatologists in hospitals and private clinics use ultrasound to examine between one and five patients daily; they use ultrasound for diagnosis more than monitoring and receive compensation of about US$30-50 per patient. There are marked differences in the rates of ultrasound usage between rheumatologists who work in private practice compared with tertiary hospitals. Korean rheumatologists not currently using ultrasound in their practice appear eager to do so. This survey provides important insights into the current status of ultrasound in rheumatology in Korea and highlights several priorities; specifically, greater provision of formal training, standardization of reporting and accrual of greater experience among ultrasound users. If these needs are addressed, all rheumatology departments in Korea are likely to use ultrasound or have access to it in the future. © 2014 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

Development of Flexible Capacitive Ultrasound Transducers and the Use of Ultrasound for Bone Repair

Science.gov (United States)

Wentzell, Scott A.

devices have the potential to mediate both bone resorption and deposition, and also provide a new functional system for generating ultrasound on the irregular surfaces encountered in clinical settings.

WE-AB-206-02: ACR Ultrasound Accreditation: Requirements and Pitfalls

International Nuclear Information System (INIS)

Walter, J.

2016-01-01

The involvement of medical physicists in diagnostic ultrasound imaging service is increasing due to QC and accreditation requirements. The goal of this ultrasound hands-on workshop is to demonstrate quality control (QC) testing in diagnostic ultrasound and to provide updates in ACR ultrasound accreditation requirements. The first half of this workshop will include two presentations reviewing diagnostic ultrasound QA/QC and ACR ultrasound accreditation requirements. The second half of the workshop will include live demonstrations of basic QC tests. An array of ultrasound testing phantoms and ultrasound scanners will be available for attendees to learn diagnostic ultrasound QC in a hands-on environment with live demonstrations and on-site instructors. The targeted attendees are medical physicists in diagnostic imaging. Learning Objectives: Gain familiarity with common elements of a QA/QC program for diagnostic ultrasound imaging dentify QC tools available for testing diagnostic ultrasound systems and learn how to use these tools Learn ACR ultrasound accreditation requirements Jennifer Walter is an employee of American College of Radiology on Ultrasound Accreditation.

System-Level Design of an Integrated Receiver Front End for a Wireless Ultrasound Probe

DEFF Research Database (Denmark)

di Ianni, Tommaso; Hemmsen, Martin Christian; Llimos Muntal, Pere

2016-01-01

In this paper, a system-level design is presented for an integrated receive circuit for a wireless ultrasound probe, which includes analog front ends and beamformation modules. This paper focuses on the investigation of the effects of architectural design choices on the image quality. The point...

Ultrasound

Science.gov (United States)

Ultrasound is a useful procedure for monitoring the baby's development in the uterus. Ultrasound uses inaudible sound waves to produce a two-dimensional image of the baby while inside the mother's ...

The Diagnosis of Spontaneous Coronary Artery Dissection by Optical Coherence Tomography.

Science.gov (United States)

Kanda, Takahiro; Tawarahara, Kei; Matsukura, Gaku; Matsunari, Masayoshi; Takabayashi, Rumi; Tamura, Jun; Ozeki, Mariko; Ukigai, Hiroshi

2018-02-15

Spontaneous coronary artery dissection (SCAD) is rare, but it frequently presents as acute myocardial infarction. It is frequently fatal and most cases are diagnosed at autopsy. We herein present the case of a 65-year-old woman with ST-elevation and myocardial infarction due to SCAD. Optical coherence tomography (OCT) helped us to confirm the diagnosis. The information on the intravascular morphology provided by OCT imaging is much more detailed in comparison to that provided by coronary angiography (CAG) and intravascular ultrasound (IVUS).

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... transducer sends out high-frequency sound waves (that the human ear cannot hear) into the body and then ... ultrasound , there are no known harmful effects on humans. top of page What are the limitations of Pelvic Ultrasound Imaging? Ultrasound waves are ...

Windowed time-reversal music technique for super-resolution ultrasound imaging

Science.gov (United States)

Huang, Lianjie; Labyed, Yassin

2018-05-01

Systems and methods for super-resolution ultrasound imaging using a windowed and generalized TR-MUSIC algorithm that divides the imaging region into overlapping sub-regions and applies the TR-MUSIC algorithm to the windowed backscattered ultrasound signals corresponding to each sub-region. The algorithm is also structured to account for the ultrasound attenuation in the medium and the finite-size effects of ultrasound transducer elements.

Prediction of outcome after femoropopliteal balloon angioplasty by intravascular ultrasound

DEFF Research Database (Denmark)

Vogt, K C; Just, S; Rasmussen, John Bøje Grønvall

1997-01-01

limbs) undergoing PTA of the superficial femoral or popliteal artery. The degree of stenosis, the diameter and area of the lumen and the morphological changes in the plaque were related to the short-term patency of the intervention, as evaluated by duplex scan and ankle branchial index. RESULTS: Fifteen...... arteries remained patent. Two occlusions and two stenoses developed during the first 3 months after the intervention and one occlusion occurred after 1 year. The following IVUS parameters were related to a favourable patency: presence of calcification; dissection or plaque rupture and residual stenosis...

Motion Detection in Ultrasound Image-Sequences Using Tensor Voting

Science.gov (United States)

Inba, Masafumi; Yanagida, Hirotaka; Tamura, Yasutaka

2008-05-01

Motion detection in ultrasound image sequences using tensor voting is described. We have been developing an ultrasound imaging system adopting a combination of coded excitation and synthetic aperture focusing techniques. In our method, frame rate of the system at distance of 150 mm reaches 5000 frame/s. Sparse array and short duration coded ultrasound signals are used for high-speed data acquisition. However, many artifacts appear in the reconstructed image sequences because of the incompleteness of the transmitted code. To reduce the artifacts, we have examined the application of tensor voting to the imaging method which adopts both coded excitation and synthetic aperture techniques. In this study, the basis of applying tensor voting and the motion detection method to ultrasound images is derived. It was confirmed that velocity detection and feature enhancement are possible using tensor voting in the time and space of simulated ultrasound three-dimensional image sequences.

The OMERACT Ultrasound Group

DEFF Research Database (Denmark)

Terslev, Lene; Iagnocco, Annamaria; Bruyn, George A W

2017-01-01

OBJECTIVE: To provide an update from the Outcome Measures in Rheumatology (OMERACT) Ultrasound Working Group on the progress for defining ultrasound (US) minimal disease activity threshold at joint level in rheumatoid arthritis (RA) and for standardization of US application in juvenile idiopathic......) and power Doppler (PD). Synovial effusion (SE) was scored a binary variable. For JIA, a Delphi approach and subsequent validation in static images and patient-based exercises were used to developed preliminary definitions for synovitis and a scoring system. RESULTS: For minimal disease activity, 7% HC had...

The use of vertical constructed wetland and ultrasound in aquaponic systems.

Science.gov (United States)

Krivograd Klemenčič, A; Griessler Bulc, T

2015-01-01

Treatment performance, fish production, crop plant biomass production, water consumption, and water use efficiency of a pilot aquaponic system for small-scale land-based cyprinid fish farms were evaluated. The system consisted of a 36 m(3) Pond A with an initial carp load of 0.6 kg/m(3); of a treatment chain with a lamellar settler, a roughing filter, a vertical constructed wetland filled with expanded clay and planted with tomatoes; and of a low power ultrasound unit installed in the corner of the pond. The average circulation of the water in the system was 1.2 times per day. Pond A was compared with Pond B of the same dimensions and fish load but with no treatment chain or ultrasound. The treatment chain was efficient in mass removal of total suspended solids , biochemical oxygen demand, chemical oxygen demand, NH4-N, total nitrogen, and total phosphorous (57, 49, 35, 42, 31, and 25 %, respectively). Negative removal of NO3-N, NO2-N, and PO4-P indicated the need for the introduction of additional hydroponic beds in the system. Pond A had markedly lower nutrient concentrations compared with Pond B. Fish body weight increase and specific growth rate in Pond A were higher than in Pond B (102.6 %, 72.1 %; 0.19 %/day, 0.14 %/day, respectively) indicating better rearing conditions in Pond A. Tomato biomass production was high. Water use efficiency was higher in Pond A compared with Pond B (0.31 kg of produced fish/m(3) inflow water and 0.22 kg of produced fish/m(3) inflow water, respectively). The presented aquaponic system could be useful for semi-natural fish farming with fish loads up to 2 kg/m(3).

CISUS: an integrated 3D ultrasound system for IGT using a modular tracking API

Science.gov (United States)

Boctor, Emad M.; Viswanathan, Anand; Pieper, Steve; Choti, Michael A.; Taylor, Russell H.; Kikinis, Ron; Fichtinger, Gabor

2004-05-01

Ultrasound has become popular in clinical/surgical applications, both as the primary image guidance modality and also in conjunction with other modalities like CT or MRI. Three dimensional ultrasound (3DUS) systems have also demonstrated usefulness in image-guided therapy (IGT). At the same time, however, current lack of open-source and open-architecture multi-modal medical visualization systems prevents 3DUS from fulfilling its potential. Several stand-alone 3DUS systems, like Stradx or In-Vivo exist today. Although these systems have been found to be useful in real clinical setting, it is difficult to augment their functionality and integrate them in versatile IGT systems. To address these limitations, a robotic/freehand 3DUS open environment (CISUS) is being integrated into the 3D Slicer, an open-source research tool developed for medical image analysis and surgical planning. In addition, the system capitalizes on generic application programming interfaces (APIs) for tracking devices and robotic control. The resulting platform-independent open-source system may serve as a valuable tool to the image guided surgery community. Other researchers could straightforwardly integrate the generic CISUS system along with other functionalities (i.e. dual view visualization, registration, real-time tracking, segmentation, etc) to rapidly create their medical/surgical applications. Our current driving clinical application is robotically assisted and freehand 3DUS-guided liver ablation, which is fully being integrated under the CISUS-3D Slicer. Initial functionality and pre-clinical feasibility are demonstrated on phantom and ex-vivo animal models.

Dual-Modality Imaging of the Human Finger Joint Systems by Using Combined Multispectral Photoacoustic Computed Tomography and Ultrasound Computed Tomography

Directory of Open Access Journals (Sweden)

Yubin Liu

2016-01-01

Full Text Available We developed a homemade dual-modality imaging system that combines multispectral photoacoustic computed tomography and ultrasound computed tomography for reconstructing the structural and functional information of human finger joint systems. The fused multispectral photoacoustic-ultrasound computed tomography (MPAUCT system was examined by the phantom and in vivo experimental tests. The imaging results indicate that the hard tissues such as the bones and the soft tissues including the blood vessels, the tendon, the skins, and the subcutaneous tissues in the finger joints systems can be effectively recovered by using our multimodality MPAUCT system. The developed MPAUCT system is able to provide us with more comprehensive information of the human finger joints, which shows its potential for characterization and diagnosis of bone or joint diseases.

Applications of ultrasound in food and bioprocessing.

Science.gov (United States)

Ashokkumar, Muthupandian

2015-07-01

Improving the quality and nutritional aspects of food is one of the key issues for healthy life of human beings. The stability during storage is an important parameter in quality assurance of food products. Various processing techniques such as high pressure, thermal, pulsed electric field and microwave have been used to prolong the shelf-life of food products. In recent years, ultrasound technology has been found to be a potential food processing technique. The passage of ultrasound in a liquid matrix generates mechanical agitation and other physical effects due to acoustic cavitation. Owing to its importance, a number of review articles and book chapters on the applications of ultrasound in food processing have been published in recent years. This article provides an overview of recent developments in ultrasonic processing of food and dairy systems with a particular focus on functionality of food and dairy ingredients. More specifically, the use of high frequency ultrasound in fat separation from milk and viscosity modification in starch systems and the use of low frequency ultrasound in generating nutritional food emulsions, viscosity modification and encapsulation of nutrients have been highlighted. The issues associated with the development of large scale ultrasonic food processing equipment have also been briefly discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

An optimum method for pulsed high intensity focused ultrasound treatment of large volumes using the InSightec ExAblate (registered) 2000 system

Energy Technology Data Exchange (ETDEWEB)

O' Neill, B E; Karmonik, C; Li, K C P, E-mail: beoneill@tmhs.or [The Methodist Hospital Research Institute, 6565 Fannin, Houston TX 77030 (United States)

2010-11-07

Pulsed high intensity focused ultrasound (pHIFU) is a method for delivering ultrasound to tissue while avoiding high temperatures. The technique has been suggested for non-destructively enhancing local uptake of drugs. Side effects include thermal necrosis; therefore, real-time monitoring of tissue temperature is advantageous. This paper outlines a method for improving the treatment efficiency of pHIFU using the MR image-guided InSightec ExAblate (registered) 2000 system, an ultrasound system integrated into a whole body human MRI scanner with the ability to measure temperature at the treatment location in near real time. Thermal measurements obtained during treatment of a tissue phantom were used to determine appropriate heating parameters, and compared to in vivo treatment of rabbit muscle. Optimization of the treatment procedure and ultrasound transducer steering patterns was then conducted with the goal of minimizing treatment time while avoiding overheating. The optimization was performed on the basis of approximate solutions to the standard bioheat equation. The commercial system software of the Exablate (registered) system was modified to assist in this optimization. Depending on the size of the treatment volume, the presented results demonstrate that it is possible to use the technique described to cut treatment times significantly, up to one-third of that required by the current standard treatment cycle.

Application of Ultrasound in a Closed System: Optimum Condition for Antioxidants Extraction of Blackberry (Rubus fructicosus) Residues.

Science.gov (United States)

Zafra-Rojas, Quinatzin Y; Cruz-Cansino, Nelly S; Quintero-Lira, Aurora; Gómez-Aldapa, Carlos A; Alanís-García, Ernesto; Cervantes-Elizarrarás, Alicia; Güemes-Vera, Norma; Ramírez-Moreno, Esther

2016-07-21

Blackberry processing generates up to 20% of residues composed mainly of peel, seeds and pulp that are abundant in flavonoids. The objective of this study was to optimize the ultrasound conditions, in a closed system, for antioxidants extraction, using the response surface methodology. Blackberry (Rubus fructicosus) residues were analyzed for total phenolics, total anthocyanins, and antioxidant activity by ABTS and DPPH. The selected independent variables were ultrasound amplitude (X₁: 80%-90%) and extraction time (X₂: 10-15 min), and results were compared with conventional extraction methods. The optimal conditions for antioxidants extraction were 91% amplitude for 15 min. The results for total phenolic content and anthocyanins and antioxidant activity by ABTS and DPPH were of 1201.23 mg gallic acid equivalent (GAE)/100 g dry weight basis (dw); 379.12 mg/100 g·dw; 6318.98 µmol Trolox equivalent (TE)/100 g·dw and 9617.22 µmol TE/100 g·dw, respectively. Compared to solvent extraction methods (water and ethanol), ultrasound achieved higher extraction of all compounds except for anthocyanins. The results obtained demonstrated that ultrasound is an alternative to improve extraction yield of antioxidants from fruit residues such as blackberry.

Art care: A multi-modality coronary 3D reconstruction and hemodynamic status assessment software.

Science.gov (United States)

Siogkas, Panagiotis K; Stefanou, Kostas A; Athanasiou, Lambros S; Papafaklis, Michail I; Michalis, Lampros K; Fotiadis, Dimitrios I

2018-01-01

Due to the incremental increase of clinical interest in the development of software that allows the 3-dimensional (3D) reconstruction and the functional assessment of the coronary vasculature, several software packages have been developed and are available today. Taking this into consideration, we have developed an innovative suite of software modules that perform 3D reconstruction of coronary arterial segments using different coronary imaging modalities such as IntraVascular UltraSound (IVUS) and invasive coronary angiography images (ICA), Optical Coherence Tomography (OCT) and ICA images, or plain ICA images and can safely and accurately assess the hemodynamic status of the artery of interest. The user can perform automated or manual segmentation of the IVUS or OCT images, visualize in 3D the reconstructed vessel and export it to formats, which are compatible with other Computer Aided Design (CAD) software systems. We employ finite elements to provide the capability to assess the hemodynamic functionality of the reconstructed vessels by calculating the virtual functional assessment index (vFAI), an index that corresponds and has been shown to correlate well to the actual fractional flow reserve (FFR) value. All the modules of the proposed system have been thoroughly validated. In brief, the 3D-QCA module, compared to a successful commercial software of the same genre, presented very good correlation using several validation metrics, with a Pearson's correlation coefficient (R) for the calculated volumes, vFAI, length and minimum lumen diameter of 0.99, 0.99, 0.99 and 0.88, respectively. Moreover, the automatic lumen detection modules for IVUS and OCT presented very high accuracy compared to the annotations by medical experts with the Pearson's correlation coefficient reaching the values of 0.94 and 0.99, respectively. In this study, we have presented a user-friendly software for the 3D reconstruction of coronary arterial segments and the accurate hemodynamic

A real-time remote video streaming platform for ultrasound imaging.

Science.gov (United States)

Ahmadi, Mehdi; Gross, Warren J; Kadoury, Samuel

2016-08-01

Ultrasound is a viable imaging technology in remote and resources-limited areas. Ultrasonography is a user-dependent skill which depends on a high degree of training and hands-on experience. However, there is a limited number of skillful sonographers located in remote areas. In this work, we aim to develop a real-time video streaming platform which allows specialist physicians to remotely monitor ultrasound exams. To this end, an ultrasound stream is captured and transmitted through a wireless network into remote computers, smart-phones and tablets. In addition, the system is equipped with a camera to track the position of the ultrasound probe. The main advantage of our work is using an open source platform for video streaming which gives us more control over streaming parameters than the available commercial products. The transmission delays of the system are evaluated for several ultrasound video resolutions and the results show that ultrasound videos close to the high-definition (HD) resolution can be received and displayed on an Android tablet with the delay of 0.5 seconds which is acceptable for accurate real-time diagnosis.

Effect of modulated ultrasound parameters on ultrasound-induced thrombolysis

International Nuclear Information System (INIS)

Soltani, Azita; Volz, Kim R; Hansmann, Doulas R

2008-01-01

The potential of ultrasound to enhance enzyme-mediated thrombolysis by application of constant operating parameters (COP) has been widely demonstrated. In this study, the effect of ultrasound with modulated operating parameters (MOP) on enzyme-mediated thrombolysis was investigated. The MOP protocol was applied to an in vitro model of thrombolysis. The results were compared to a COP with the equivalent soft tissue thermal index (TIS) over the duration of ultrasound exposure of 30 min (p -2 ± 0.01 μm and 1.99 x 10 -2 ± 0.004 μm, respectively (p < 0.74). No signatures of inertial or stable cavitation were observed for either acoustic protocol. In conclusion, due to mechanisms other than cavitation, application of ultrasound with modulated operating parameters has the potential to significantly enhance the relative lysis enhancement compared to application of ultrasound with constant operating parameters.

P-shaped Coiled Stator Ultrasound Motor for Rotating Intravascular Surgery Device

Directory of Open Access Journals (Sweden)

Toshinobu ABE

2015-01-01

Full Text Available The primary focus of this paper is the development of an ultra-miniature ultrasound motor for use in the human blood vessel. Since the size of the drive source for rotating the atherectomy device and intravascular ultrasonography system are large currently in practical use, it is installed outside the body, and the rotational power for the atherectomy device and intravascular ultrasonography system are transmitted through the long tortuous blood vessel. Such systems suffer from the problem that the rotation becomes non-uniform, and the problem that the available time is limited. We have therefore developed a P-shaped coiled stator ultrasound motor as a miniature ultrasound motor for rotating the ultrasound sensor for use in blood vessels in order to solve these problems. In this paper, we describe measurement of the torque, revolution speed, output power, efficiency, and particle motion on acoustic waveguide of the P-shaped coiled stator ultrasound motor.

First steps towards ultrasound-based motion compensation for imaging and therapy: calibration with an optical system and 4D PET imaging

Directory of Open Access Journals (Sweden)

Julia eSchwaab

2015-11-01

Full Text Available Target motion, particularly in the abdomen, due to respiration or patient movement is still a challenge in many diagnostic and therapeutic processes. Hence, methods to detect and compensate this motion are required. Diagnostic ultrasound represents a non-invasive and dose-free alternative to fluoroscopy, providing more information about internal target motion than respiration belt or optical tracking.The goal of this project is to develop an ultrasound based motion tracking for real time motion correction in radiation therapy and diagnostic imaging, notably in 4D positron emission tomography (PET. In this work, a workflow is established to enable the transformation of ultrasound tracking data to the coordinates of the treatment delivery or imaging system – even if the ultrasound probe is moving due to respiration. It is shown that the ultrasound tracking signal is equally adequate for 4D PET image reconstruction as the clinically used respiration belt and provides additional opportunities in this concern. Furthermore, it is demonstrated that the ultrasound probe being within the PET field of view generally has no relevant influence on the image quality. The accuracy and precision of all the steps in the calibration workflow for ultrasound tracking based 4D PET imaging are found to be in an acceptable range for clinical implementation. Eventually, we show in vitro that an ultrasound based motion tracking in absolute room coordinates with a moving US-transducer is feasible.

Fast and Automatic Ultrasound Simulation from CT Images

Directory of Open Access Journals (Sweden)

Weijian Cong

2013-01-01

Full Text Available Ultrasound is currently widely used in clinical diagnosis because of its fast and safe imaging principles. As the anatomical structures present in an ultrasound image are not as clear as CT or MRI. Physicians usually need advance clinical knowledge and experience to distinguish diseased tissues. Fast simulation of ultrasound provides a cost-effective way for the training and correlation of ultrasound and the anatomic structures. In this paper, a novel method is proposed for fast simulation of ultrasound from a CT image. A multiscale method is developed to enhance tubular structures so as to simulate the blood flow. The acoustic response of common tissues is generated by weighted integration of adjacent regions on the ultrasound propagation path in the CT image, from which parameters, including attenuation, reflection, scattering, and noise, are estimated simultaneously. The thin-plate spline interpolation method is employed to transform the simulation image between polar and rectangular coordinate systems. The Kaiser window function is utilized to produce integration and radial blurring effects of multiple transducer elements. Experimental results show that the developed method is very fast and effective, allowing realistic ultrasound to be fast generated. Given that the developed method is fully automatic, it can be utilized for ultrasound guided navigation in clinical practice and for training purpose.

CO2 bubbling-based 'Nanobomb' System for Targetedly Suppressing Panc-1 Pancreatic Tumor via Low Intensity Ultrasound-activated Inertial Cavitation.

Science.gov (United States)

Zhang, Kun; Xu, Huixiong; Chen, Hangrong; Jia, Xiaoqing; Zheng, Shuguang; Cai, Xiaojun; Wang, Ronghui; Mou, Juan; Zheng, Yuanyi; Shi, Jianlin

2015-01-01

Noninvasive and targeted physical treatment is still desirable especially for those cancerous patients. Herein, we develop a new physical treatment protocol by employing CO2 bubbling-based 'nanobomb' system consisting of low-intensity ultrasound (1.0 W/cm(2)) and a well-constructed pH/temperature dual-responsive CO2 release system. Depending on the temperature elevation caused by exogenous low-intensity therapeutic ultrasound irradiation and the low pH caused by the endogenous acidic-environment around/within tumor, dual-responsive CO2 release system can quickly release CO2 bubbles, and afterwards, the generated CO2 bubbles waves will timely explode before dissolution due to triggering by therapeutic ultrasound waves. Related bio-effects (e.g., cavitation, mechanical, shock waves, etc) caused by CO2 bubbles' explosion effectively induce instant necrosis of panc-1 cells and blood vessel destruction within panc-1 tumor, and consequently inhibit the growth of panc-1 solid tumor, simultaneously minimizing the side effects to normal organs. This new physiotherapy employing CO2 bubbling-based 'nanobomb' system promises significant potentials in targetedly suppressing tumors, especially for those highly deadly cancers.

Intraoperative registered transrectal ultrasound guidance for robot-assisted laparoscopic radical prostatectomy.

Science.gov (United States)

Mohareri, Omid; Ischia, Joseph; Black, Peter C; Schneider, Caitlin; Lobo, Julio; Goldenberg, Larry; Salcudean, Septimiu E

2015-01-01

To provide unencumbered real-time ultrasound image guidance during robot-assisted laparoscopic radical prostatectomy, we developed a robotic transrectal ultrasound system that tracks the da Vinci® Surgical System instruments. We describe our initial clinical experience with this system. After an evaluation in a canine model, 20 patients were enrolled in the study. During each procedure the transrectal ultrasound transducer was manually positioned using a brachytherapy stabilizer to provide good imaging of the prostate. Then the transrectal ultrasound was registered to the da Vinci robot by a previously validated procedure. Finally, automatic rotation of the transrectal ultrasound was enabled such that the transrectal ultrasound imaging plane safely tracked the tip of the da Vinci instrument controlled by the surgeon, while real-time transrectal ultrasound images were relayed to the surgeon at the da Vinci console. Tracking was activated during all critical stages of the surgery. The transrectal ultrasound robot was easy to set up and use, adding 7 minutes (range 5 to 14) to the procedure. It did not require an assistant or additional control devices. Qualitative feedback was acquired from the surgeons, who found transrectal ultrasound useful in identifying the urethra while passing the dorsal venous complex suture, defining the prostate-bladder interface during bladder neck dissection, identifying the seminal vesicles and their location with respect to the rectal wall, and identifying the distal prostate boundary at the apex. Real-time, registered robotic transrectal ultrasound guidance with automatic instrument tracking during robot-assisted laparoscopic radical prostatectomy is feasible and potentially useful. The results justify further studies to establish whether the approach can improve procedure outcomes. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Intraluminal ultrasound guidance of transverse laser coronary atherectomy

Science.gov (United States)

Aretz, H. Thomas; Martinelli, Michael A.; LeDet, Earl G.; Sedlacek, Tomas; Hatch, G. F.; Gregg, Richard E.

1990-07-01

A coronary laser atherectomy system combining laser delivery and ultrasonic imaging capability is described. The system is being developed by Intra-Sonix, Inc. to treat severe stenoses. The imaging system provides the clinician with the guidance needed to remove substantial plaque without perforation. The ultrasound transducers and laser optics are mounted in a small (less than 4 F), flexible catheter, that is deliverable over a standard guidewire (0.016 inch). The laser and ultrasound beams are directed at the artery wall to permit debulking of lesions and ultrasonic depth profiling of the tissue structure throughout the thickness of the artery. This allows the physician to determine the level of therapy to be applied and to monitor the plaque removal as the therapy progresses. The precise location of the ultrasound and laser beams in the artery is determined by a navigation system. Navigation data are processed electronically in conjunction with ultrasound data to produce real-time cross-sectional and longitudinal images of the artery wall at selected locations, which are updated as the catheter progresses through the vessel lumen. Results of in vitro tests on human atherosclerotic arteries and early in vivo experiments in a canine-human xenograft model showing image construction and radial laser delivery are discussed.

Local inversions in ultrasound-modulated optical tomography

International Nuclear Information System (INIS)

Bal, Guillaume; Moskow, Shari

2014-01-01

Ultrasound-modulated optical tomography is a hybrid imaging modality that aims to combine the high contrast of optical waves with the high resolution of ultrasound. We follow the model of the influence of ultrasound modulation on the light intensity measurements developed in Bal and Schotland (2010 Phys. Rev. Lett. 104 043902). We present sufficient conditions ensuring that the absorption and diffusion coefficients modeling light propagation can locally be uniquely and stably reconstructed from the corresponding available information. We present an iterative procedure to solve such a problem based on the analysis of linear elliptic systems of redundant partial differential equations. (paper)

First-in-man study of simvastatin-eluting stent in de novo coronary lesions: the SIMVASTENT study.

Science.gov (United States)

Zago, Alexandre C; Matte, Bruno S; Reginato, Luciana; Iturry-Yamamoto, Germán; Krepsky, Ana; Bergoli, Luiz Carlos C; Balvedi, Julise; Raudales, José C; Saadi, Eduardo K; Zago, Alcides J

2012-01-01

Statins have anti-inflammatory and antiproliferative properties irrespective of their cholesterol-lowering effects. The aim of the present study was to evaluate a simvastatin-eluting stent (SimvES) in the treatment of de novo coronary lesions. Forty-two patients with de novo coronary artery lesions were assigned to SimvES, bare-metal stent (BMS) or everolimus-eluting stent (EES) implantation followed by intravascular ultrasound (IVUS) for neointimal quantitative analysis. Six months later, quantitative coronary angiography (QCA) and IVUS were repeated. QCA showed no binary restenosis, a mean in-stent late loss of 1.05 ± 0.25 mm (BMS, 1.12 ± 0.48 mm; EES, 0.20 ± 0.16 mm) and a diameter stenosis of 33.5 ± 7.1% (BMS, 35.5 ± 15.30%; EES, 7.2 ± 3.12%). Control IVUS showed a mean in-stent obstruction of 18.3 ± 9.4% (BMS, 32.8 ± 19.1%; EES, 9.8 ± 2.4%) and a neointimal volume index of 1.58 ± 0.75 mm(3)/mm (BMS, 2.93 ± 1.76 mm(3)/mm; EES, 0.80 ± 0.16 mm(3)/mm). Thrombus, late incomplete apposition and major adverse cardiac events were not observed. In this sample of patients with de novo coronary lesions, the use of a SimvES was not related to major adverse cardiac events, but it was associated with a higher level of neointimal proliferation than expected.

General Ultrasound Imaging

Medline Plus

Full Text Available ... ultrasound. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... modality for the diagnosis and monitoring of pregnant women and their unborn babies. Ultrasound provides real-time ...

General Ultrasound Imaging

Medline Plus

Full Text Available ... of page How is the procedure performed? For most ultrasound exams, you will be positioned lying face- ... Ultrasound examinations are painless and easily tolerated by most patients. Ultrasound exams in which the transducer is ...

General Ultrasound Imaging

Medline Plus

Full Text Available ... medical test that helps physicians diagnose and treat medical conditions. Conventional ultrasound displays the images in thin, flat sections of the body. Advancements in ultrasound technology include three-dimensional (3-D) ultrasound that formats ...

General Ultrasound Imaging

Medline Plus

Full Text Available ... D images. A Doppler ultrasound study may be part of an ultrasound examination. Doppler ultrasound , also called ... terms of the distance traveled per unit of time, rather than as a color picture. It can ...

Power MOSFET-diode-based limiter for high-frequency ultrasound systems.

Science.gov (United States)

Choi, Hojong; Kim, Min Gon; Cummins, Thomas M; Hwang, Jae Youn; Shung, K Kirk

2014-10-01

The purpose of the limiter circuits used in the ultrasound imaging systems is to pass low-voltage echo signals generated by ultrasonic transducers while preventing high-voltage short pulses transmitted by pulsers from damaging front-end circuits. Resistor-diode-based limiters (a 50 Ω resistor with a single cross-coupled diode pair) have been widely used in pulse-echo measurement and imaging system applications due to their low cost and simple architecture. However, resistor-diode-based limiters may not be suited for high-frequency ultrasound transducer applications since they produce large signal conduction losses at higher frequencies. Therefore, we propose a new limiter architecture utilizing power MOSFETs, which we call a power MOSFET-diode-based limiter. The performance of a power MOSFET-diode-based limiter was evaluated with respect to insertion loss (IL), total harmonic distortion (THD), and response time (RT). We compared these results with those of three other conventional limiter designs and showed that the power MOSFET-diode-based limiter offers the lowest IL (-1.33 dB) and fastest RT (0.10 µs) with the lowest suppressed output voltage (3.47 Vp-p) among all the limiters at 70 MHz. A pulse-echo test was performed to determine how the new limiter affected the sensitivity and bandwidth of the transducer. We found that the sensitivity and bandwidth of the transducer were 130% and 129% greater, respectively, when combined with the new power MOSFET-diode-based limiter versus the resistor-diode-based limiter. Therefore, these results demonstrate that the power MOSFET-diode-based limiter is capable of producing lower signal attenuation than the three conventional limiter designs at higher frequency operation. © The Author(s) 2014.

Ultrasound Picture Archiving And Communication Systems

Science.gov (United States)

Koestner, Ken; Hottinger, C. F.

1982-01-01

The ideal ultrasonic image communication and storage system must be flexible in order to optimize speed and minimize storage requirements. Various ultrasonic imaging modalities are quite different in data volume and speed requirements. Static imaging, for example B-Scanning, involves acquisition of a large amount of data that is averaged or accumulated in a desired manner. The image is then frozen in image memory before transfer and storage. Images are commonly a 512 x 512 point array, each point 6 bits deep. Transfer of such an image over a serial line at 9600 baud would require about three minutes. Faster transfer times are possible; for example, we have developed a parallel image transfer system using direct memory access (DMA) that reduces the time to 16 seconds. Data in this format requires 256K bytes for storage. Data compression can be utilized to reduce these requirements. Real-time imaging has much more stringent requirements for speed and storage. The amount of actual data per frame in real-time imaging is reduced due to physical limitations on ultrasound. For example, 100 scan lines (480 points long, 6 bits deep) can be acquired during a frame at a 30 per second rate. In order to transmit and save this data at a real-time rate requires a transfer rate of 8.6 Megabaud. A real-time archiving system would be complicated by the necessity of specialized hardware to interpolate between scan lines and perform desirable greyscale manipulation on recall. Image archiving for cardiology and radiology would require data transfer at this high rate to preserve temporal (cardiology) and spatial (radiology) information.

Ultrasound waiting lists: rational queue or extended capacity?

Science.gov (United States)

Brasted, Christopher

2008-06-01

The features and issues regarding clinical waiting lists in general and general ultrasound waiting lists in particular are reviewed, and operational aspects of providing a general ultrasound service are also discussed. A case study is presented describing a service improvement intervention in a UK NHS hospital's ultrasound department, from which arises requirements for a predictive planning model for an ultrasound waiting list. In the course of this, it becomes apparent that a booking system is a more appropriate way of describing the waiting list than a conventional queue. Distinctive features are identified from the literature and the case study as the basis for a predictive model, and a discrete event simulation model is presented which incorporates the distinctive features.

Co-registered photoacoustic, thermoacoustic, and ultrasound mouse imaging

Science.gov (United States)

Reinecke, Daniel R.; Kruger, Robert A.; Lam, Richard B.; DelRio, Stephen P.

2010-02-01

We have constructed and tested a prototype test bed that allows us to form 3D photoacoustic CT images using near-infrared (NIR) irradiation (700 - 900 nm), 3D thermoacoustic CT images using microwave irradiation (434 MHz), and 3D ultrasound images from a commercial ultrasound scanner. The device utilizes a vertically oriented, curved array to capture the photoacoustic and thermoacoustic data. In addition, an 8-MHz linear array fixed in a horizontal position provides the ultrasound data. The photoacoustic and thermoacoustic data sets are co-registered exactly because they use the same detector. The ultrasound data set requires only simple corrections to co-register its images. The photoacoustic, thermoacoustic, and ultrasound images of mouse anatomy reveal complementary anatomic information as they exploit different contrast mechanisms. The thermoacoustic images differentiate between muscle, fat and bone. The photoacoustic images reveal the hemoglobin distribution, which is localized predominantly in the vascular space. The ultrasound images provide detailed information about the bony structures. Superposition of all three images onto a co-registered hybrid image shows the potential of a trimodal photoacoustic-thermoacoustic-ultrasound small-animal imaging system.

Open-source, small-animal magnetic resonance-guided focused ultrasound system.

Science.gov (United States)

Poorman, Megan E; Chaplin, Vandiver L; Wilkens, Ken; Dockery, Mary D; Giorgio, Todd D; Grissom, William A; Caskey, Charles F

2016-01-01

MR-guided focused ultrasound or high-intensity focused ultrasound (MRgFUS/MRgHIFU) is a non-invasive therapeutic modality with many potential applications in areas such as cancer therapy, drug delivery, and blood-brain barrier opening. However, the large financial costs involved in developing preclinical MRgFUS systems represent a barrier to research groups interested in developing new techniques and applications. We aim to mitigate these challenges by detailing a validated, open-source preclinical MRgFUS system capable of delivering thermal and mechanical FUS in a quantifiable and repeatable manner under real-time MRI guidance. A hardware and software package was developed that includes closed-loop feedback controlled thermometry code and CAD drawings for a therapy table designed for a preclinical MRI scanner. For thermal treatments, the modular software uses a proportional integral derivative controller to maintain a precise focal temperature rise in the target given input from MR phase images obtained concurrently. The software computes the required voltage output and transmits it to a FUS transducer that is embedded in the delivery table within the magnet bore. The delivery table holds the FUS transducer, a small animal and its monitoring equipment, and a transmit/receive RF coil. The transducer is coupled to the animal via a water bath and is translatable in two dimensions from outside the magnet. The transducer is driven by a waveform generator and amplifier controlled by real-time software in Matlab. MR acoustic radiation force imaging is also implemented to confirm the position of the focus for mechanical and thermal treatments. The system was validated in tissue-mimicking phantoms and in vivo during murine tumor hyperthermia treatments. Sonications were successfully controlled over a range of temperatures and thermal doses for up to 20 min with minimal temperature overshoot. MR thermometry was validated with an optical temperature probe, and focus

Ultrasound in Space Medicine

Science.gov (United States)

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

2009-01-01

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

HIFU Ultrasound Power Measurements at INRiM

International Nuclear Information System (INIS)

Durando, G; Guglielmone, C; Musacchio, C

2011-01-01

In this work the new system for the ultrasound power measurement of High Intensity Focused Ultrasound transducers realized at INRIM ultrasounds laboratory is presented. The system is based on a submersible load cell that takes the place of the balance. This solution presents essentially two advantages. The first one, of mechanical nature, is relevant to the fact that the target is directly connected to the force transducer, eliminating unwanted target motion at high power. The second, of electric nature, concerns the possibility to reduce the insonation time (the ON period of the electric driving signal to the HIFU transducer) under of 2 s, and is allowed for by the faster response of the force transducer (700 Hz bandwidth). The main components of uncertainty and the overall budget of the measurement system are presented together with the results of measures of conductance, G, carried on a HIFU transducer, at the work frequencies 2.0 MHz and 6.38 MHz, for values of power ranging from 10 W to 100 W. The results of the ultrasonic conductance, G, obtained with the new system are compared with values obtained using the traditional measuring system for low powers (P ≤ 20W).

A novel ultrasound-guided shoulder arthroscopic surgery

Science.gov (United States)

Tyryshkin, K.; Mousavi, P.; Beek, M.; Chen, T.; Pichora, D.; Abolmaesumi, P.

2006-03-01

This paper presents a novel ultrasound-guided computer system for arthroscopic surgery of the shoulder joint. Intraoperatively, the system tracks and displays the surgical instruments, such as arthroscope and arthroscopic burrs, relative to the anatomy of the patient. The purpose of this system is to improve the surgeon's perception of the three-dimensional space within the anatomy of the patient in which the instruments are manipulated and to provide guidance towards the targeted anatomy. Pre-operatively, computed tomography images of the patient are acquired to construct virtual threedimensional surface models of the shoulder bone structure. Intra-operatively, live ultrasound images of pre-selected regions of the shoulder are captured using an ultrasound probe whose three-dimensional position is tracked by an optical camera. These images are used to register the surface model to the anatomy of the patient in the operating room. An initial alignment is obtained by matching at least three points manually selected on the model to their corresponding points identified on the ultrasound images. The registration is then improved with an iterative closest point or a sequential least squares estimation technique. In the present study the registration results of these techniques are compared. After the registration, surgical instruments are displayed relative to the surface model of the patient on a graphical screen visible to the surgeon. Results of laboratory experiments on a shoulder phantom indicate acceptable registration results and sufficiently fast overall system performance to be applicable in the operating room.

A high pulse repetition frequency ultrasound system for the ex vivo measurement of mechanical properties of crystalline lenses with laser-induced microbubbles interrogated by acoustic radiation force

International Nuclear Information System (INIS)

Yoon, Sangpil; Emelianov, Stanislav; Aglyamov, Salavat; Karpiouk, Andrei

2012-01-01

A high pulse repetition frequency ultrasound system for an ex vivo measurement of mechanical properties of an animal crystalline lens was developed and validated. We measured the bulk displacement of laser-induced microbubbles created at different positions within the lens using nanosecond laser pulses. An impulsive acoustic radiation force was applied to the microbubble, and spatio-temporal measurements of the microbubble displacement were assessed using a custom-made high pulse repetition frequency ultrasound system consisting of two 25 MHz focused ultrasound transducers. One of these transducers was used to emit a train of ultrasound pulses and another transducer was used to receive the ultrasound echoes reflected from the microbubble. The developed system was operating at 1 MHz pulse repetition frequency. Based on the measured motion of the microbubble, Young’s moduli of surrounding tissue were reconstructed and the values were compared with those measured using the indentation test. Measured values of Young’s moduli of four bovine lenses ranged from 2.6 ± 0.1 to 26 ± 1.4 kPa, and there was good agreement between the two methods. Therefore, our studies, utilizing the high pulse repetition frequency ultrasound system, suggest that the developed approach can be used to assess the mechanical properties of ex vivo crystalline lenses. Furthermore, the potential of the presented approach for in vivo measurements is discussed. (paper)

Image processing in medical ultrasound

DEFF Research Database (Denmark)

Hemmsen, Martin Christian

This Ph.D project addresses image processing in medical ultrasound and seeks to achieve two major scientific goals: First to develop an understanding of the most significant factors influencing image quality in medical ultrasound, and secondly to use this knowledge to develop image processing...... multiple imaging setups. This makes the system well suited for development of new processing methods and for clinical evaluations, where acquisition of the exact same scan location for multiple methods is important. The second project addressed implementation, development and evaluation of SASB using...... methods for enhancing the diagnostic value of medical ultrasound. The project is an industrial Ph.D project co-sponsored by BK Medical ApS., with the commercial goal to improve the image quality of BK Medicals scanners. Currently BK Medical employ a simple conventional delay-and-sum beamformer to generate...

Improving ultrasound gene transfection efficiency by controlling ultrasound excitation of microbubbles

Science.gov (United States)

Fan, Z.; Chen, D.; Deng, C.X.

2013-01-01

Ultrasound application in the presence of microbubbles has shown great potential for non-viral gene transfection via transient disruption of cell membrane (sonoporation). However, improvement of its efficiency has largely relied on empirical approaches without consistent and translatable results. The goal of this study is to develop a rational strategy based on new results obtained using novel experimental techniques and analysis to improve sonoporation gene transfection. We conducted experiments using targeted microbubbles that were attached to cell membrane to facilitate sonoporation. We quantified the dynamic activities of microbubbles exposed to pulsed ultrasound and the resulting sonoporation outcome and identified distinct regimes of characteristic microbubble behaviors: stable cavitation, coalescence and translation, and inertial cavitation. We found that inertial cavitation generated the highest rate of membrane poration. By establishing direct correlation of ultrasound-induced bubble activities with intracellular uptake and pore size, we designed a ramped pulse exposure scheme for optimizing microbubble excitation to improve sonoporation gene transfection. We implemented a novel sonoporation gene transfection system using an aqueous two phase system (ATPS) for efficient use of reagents and high throughput operation. Using plasmid coding for the green fluorescence protein (GFP), we achieved a sonoporation transfection efficiency in rate aortic smooth muscle cells (RASMCs) of 6.9% ± 2.2% (n = 9), comparable with lipofection (7.5% ± 0.8%, n = 9). Our results reveal characteristic microbubble behaviors responsible for sonoporation and demonstrated a rational strategy to improve sonoporation gene transfection. PMID:23770009

Ultrasound-triggered local release of lipophilic drugs from a novel polymeric ultrasound contrast agent

NARCIS (Netherlands)

Kooiman, K.; Böhmer, M.R.; Emmer, M.; Vos, Hendrik J.; Chlon, C.; Foppen-Harteveld, M.; Versluis, Michel; de Jong, N.; van Wamel, A.; Hennink, W.E.; Feijen, J.; Sam, A.P.

2008-01-01

The advantage of ultrasound contrast agents (UCAs) as drug delivery systems is the ability to non-invasively control the local and triggered release of a drug or gene. In this study we designed and characterized a novel UCA-based drug delivery system, based on polymer-shelled microcapsules filled

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... through blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. There are three types of pelvic ultrasound: ...

Stone fragmentation by ultrasound

Indian Academy of Sciences (India)

Unknown

In the present work, enhancement of the kidney stone fragmentation by using ultrasound is studied. The cavi- ... ment system like radiation pressure balance, the power is given by ... Thus the bubble size has direct relationship with its life and.

Comparison of a GPS needle-tracking system, multiplanar imaging and 2D imaging for real-time ultrasound-guided epidural anaesthesia: A randomized, comparative, observer-blinded study on phantoms.

Science.gov (United States)

Menacé, Cécilia; Choquet, Olivier; Abbal, Bertrand; Bringuier, Sophie; Capdevila, Xavier

2017-04-01

The real-time ultrasound-guided paramedian sagittal oblique approach for neuraxial blockade is technically demanding. Innovative technologies have been developed to improve nerve identification and the accuracy of needle placement. The aim of this study was to evaluate three types of ultrasound scans during ultrasound-guided epidural lumbar punctures in a spine phantom. Eleven sets of 20 ultrasound-guided epidural punctures were performed with 2D, GPS, and multiplanar ultrasound machines (660 punctures) on a spine phantom using an in-plane approach. For all punctures, execution time, number of attempts, bone contacts, and needle redirections were noted by an independent physician. Operator comfort and visibility of the needle (tip and shaft) were measured using a numerical scale. The use of GPS significantly decreased the number of punctures, needle repositionings, and bone contacts. Comfort of the physician was also significantly improved with the GPS system compared with the 2D and multiplanar systems. With the multiplanar system, the procedure was not facilitated and execution time was longer compared with 2D imaging after Bonferroni correction but interaction between the type of ultrasound system and mean execution time was not significant in a linear mixed model. There were no significant differences regarding needle tip and shaft visibility between the systems. Multiplanar and GPS needle-tracking systems do not reduce execution time compared with 2D imaging using a real-time ultrasound-guided paramedian sagittal oblique approach in spine phantoms. The GPS needle-tracking system can improve performance in terms of operator comfort, the number of attempts, needle redirections and bone contacts. Copyright © 2016 Société française d'anesthésie et de réanimation (Sfar). Published by Elsevier Masson SAS. All rights reserved.

Simulation Study of Effects of the Blind Deconvolution on Ultrasound Image

Science.gov (United States)

He, Xingwu; You, Junchen

2018-03-01

Ultrasonic image restoration is an essential subject in Medical Ultrasound Imaging. However, without enough and precise system knowledge, some traditional image restoration methods based on the system prior knowledge often fail to improve the image quality. In this paper, we use the simulated ultrasound image to find the effectiveness of the blind deconvolution method for ultrasound image restoration. Experimental results demonstrate that the blind deconvolution method can be applied to the ultrasound image restoration and achieve the satisfactory restoration results without the precise prior knowledge, compared with the traditional image restoration method. And with the inaccurate small initial PSF, the results shows blind deconvolution could improve the overall image quality of ultrasound images, like much better SNR and image resolution, and also show the time consumption of these methods. it has no significant increasing on GPU platform.

Localizing and Assessing Amputee Pain with Intense Focused Ultrasound

Science.gov (United States)

2016-10-01

active ultrasound images the target of iFU stimulation. Ultrasound device – integrated ig-iFU system. The imaging transducer was mounted within a...meditation, spinal cord stimulation, psychotherapy , continued watchful waiting, among other choices (28). Future research Future studies might consider

General Ultrasound Imaging

Medline Plus

Full Text Available ... transducer sends out high-frequency sound waves (that the human ear cannot hear) into the body and then ... ultrasound , there are no known harmful effects on humans. top of page What are the limitations of General Ultrasound Imaging? Ultrasound waves are ...

Gene delivery systems by the combination of lipid bubbles and ultrasound.

Science.gov (United States)

Negishi, Yoichi; Endo-Takahashi, Yoko; Maruyama, Kazuo

2016-11-28

Gene therapy is promising for the treatment of many diseases including cancers and genetic diseases. From the viewpoint of safety, ultrasound (US)-mediated gene delivery with nano/ microbubbles was recently developed as a novel non-viral vector system. US-mediated gene delivery using nano/microbubbles are able to produce transient changes in the permeability of the cell membrane after US-induced cavitation while reducing cellular damage and enables the tissue-specific or the site-specific intracellular delivery of gene both in vitro and in vivo. We have recently developed novel lipid nanobubbles (Lipid Bubbles). These nanobubbles can also be used to enhance the efficacy of the US-mediated genes (plasmid DNA, siRNA, and miRNA etc.) delivery. In this review, we describe US-mediated delivery systems combined with nano/microbubbles and discuss their feasibility as non-viral vector systems.

Ultrasound-guided drug delivery in cancer

Energy Technology Data Exchange (ETDEWEB)

Chowdhury, Sayan Mullick; Lee, Tae Hwa; Willmann, Jugen K. [Dept. of Radiology, Stanford University School of Medicine, Stanford (United States)

2017-07-15

Recent advancements in ultrasound and microbubble (USMB) mediated drug delivery technology has shown that this approach can improve spatially confined delivery of drugs and genes to target tissues while reducing systemic dose and toxicity. The mechanism behind enhanced delivery of therapeutics is sonoporation, the formation of openings in the vasculature, induced by ultrasound-triggered oscillations and destruction of microbubbles. In this review, progress and challenges of USMB mediated drug delivery are summarized, with special focus on cancer therapy.

Line fiducial material and thickness considerations for ultrasound calibration

Science.gov (United States)

Ameri, Golafsoun; McLeod, A. J.; Baxter, John S. H.; Chen, Elvis C. S.; Peters, Terry M.

2015-03-01

Ultrasound calibration is a necessary procedure in many image-guided interventions, relating the position of tools and anatomical structures in the ultrasound image to a common coordinate system. This is a necessary component of augmented reality environments in image-guided interventions as it allows for a 3D visualization where other surgical tools outside the imaging plane can be found. Accuracy of ultrasound calibration fundamentally affects the total accuracy of this interventional guidance system. Many ultrasound calibration procedures have been proposed based on a variety of phantom materials and geometries. These differences lead to differences in representation of the phantom on the ultrasound image which subsequently affect the ability to accurately and automatically segment the phantom. For example, taut wires are commonly used as line fiducials in ultrasound calibration. However, at large depths or oblique angles, the fiducials appear blurred and smeared in ultrasound images making it hard to localize their cross-section with the ultrasound image plane. Intuitively, larger diameter phantoms with lower echogenicity are more accurately segmented in ultrasound images in comparison to highly reflective thin phantoms. In this work, an evaluation of a variety of calibration phantoms with different geometrical and material properties for the phantomless calibration procedure was performed. The phantoms used in this study include braided wire, plastic straws, and polyvinyl alcohol cryogel tubes with different diameters. Conventional B-mode and synthetic aperture images of the phantoms at different positions were obtained. The phantoms were automatically segmented from the ultrasound images using an ellipse fitting algorithm, the centroid of which is subsequently used as a fiducial for calibration. Calibration accuracy was evaluated for these procedures based on the leave-one-out target registration error. It was shown that larger diameter phantoms with lower

Smart Ultrasound Remote Guidance Experiment (SURGE) Preliminary Findings

Science.gov (United States)

Hurst, Victor; Dulchavsky, Scott; Garcia, Kathleen; Sargsyan, Ashot; Ebert, Doug

2009-01-01

To date, diagnostic quality ultrasound images were obtained aboard the International Space Station (ISS) using the ultrasound of the Human Research Facility (HRF) rack in the Laboratory module. Through the Advanced Diagnostic Ultrasound in Microgravity (ADUM) and the Braslet-M Occlusion Cuffs (BRASLET SDTO) studies, non-expert ultrasound operators aboard the ISS have performed cardiac, thoracic, abdominal, vascular, ocular, and musculoskeletal ultrasound assessments using remote guidance from ground-based ultrasound experts. With exploration class missions to the lunar and Martian surfaces on the horizon, crew medical officers will necessarily need to operate with greater autonomy given communication delays (round trip times of up to 5 seconds for the Moon and 90 minutes for Mars) and longer periods of communication blackouts (due to orbital constraints of communication assets). The SURGE project explored the feasibility and training requirements of having non-expert ultrasound operators perform autonomous ultrasound assessments in a simulated exploration mission outpost. The project aimed to identify experience, training, and human factors requirements for crew medical officers to perform autonomous ultrasonography. All of these aims pertained to the following risks from the NASA Bioastronautics Road Map: 1) Risk 18: Major Illness and Trauna; 2) Risk 20) Ambulatory Care; 3) Risk 22: Medical Informatics, Technologies, and Support Systems; and 4) Risk 23: Medical Skill Training and Maintenance.

A Computer-Aided Diagnosis System Using Artificial Intelligence for the Diagnosis and Characterization of Thyroid Nodules on Ultrasound: Initial Clinical Assessment.

Science.gov (United States)

Choi, Young Jun; Baek, Jung Hwan; Park, Hye Sun; Shim, Woo Hyun; Kim, Tae Yong; Shong, Young Kee; Lee, Jeong Hyun

2017-04-01

An initial clinical assessment is described of a new, commercially available, computer-aided diagnosis (CAD) system using artificial intelligence (AI) for thyroid ultrasound, and its performance is evaluated in the diagnosis of malignant thyroid nodules and categorization of nodule characteristics. Patients with thyroid nodules with decisive diagnosis, whether benign or malignant, were consecutively enrolled from November 2015 to February 2016. An experienced radiologist reviewed the ultrasound image characteristics of the thyroid nodules, while another radiologist assessed the same thyroid nodules using the CAD system, providing ultrasound characteristics and a diagnosis of whether nodules were benign or malignant. The diagnostic performance and agreement of US characteristics between the experienced radiologist and the CAD system were compared. In total, 102 thyroid nodules from 89 patients were included; 59 (57.8%) were benign and 43 (42.2%) were malignant. The CAD system showed a similar sensitivity as the experienced radiologist (90.7% vs. 88.4%, p > 0.99), but a lower specificity and a lower area under the receiver operating characteristic (AUROC) curve (specificity: 74.6% vs. 94.9%, p = 0.002; AUROC: 0.83 vs. 0.92, p = 0.021). Classifications of the ultrasound characteristics (composition, orientation, echogenicity, and spongiform) between radiologist and CAD system were in substantial agreement (κ = 0.659, 0.740, 0.733, and 0.658, respectively), while the margin showed a fair agreement (κ = 0.239). The sensitivity of the CAD system using AI for malignant thyroid nodules was as good as that of the experienced radiologist, while specificity and accuracy were lower than those of the experienced radiologist. The CAD system showed an acceptable agreement with the experienced radiologist for characterization of thyroid nodules.

Comparison of longitudinal excursion of a nerve-phantom model using quantitative ultrasound imaging and motion analysis system methods: A convergent validity study.

Science.gov (United States)

Paquette, Philippe; El Khamlichi, Youssef; Lamontagne, Martin; Higgins, Johanne; Gagnon, Dany H

2017-08-01

Quantitative ultrasound imaging is gaining popularity in research and clinical settings to measure the neuromechanical properties of the peripheral nerves such as their capability to glide in response to body segment movement. Increasing evidence suggests that impaired median nerve longitudinal excursion is associated with carpal tunnel syndrome. To date, psychometric properties of longitudinal nerve excursion measurements using quantitative ultrasound imaging have not been extensively investigated. This study investigates the convergent validity of the longitudinal nerve excursion by comparing measures obtained using quantitative ultrasound imaging with those determined with a motion analysis system. A 38-cm long rigid nerve-phantom model was used to assess the longitudinal excursion in a laboratory environment. The nerve-phantom model, immersed in a 20-cm deep container filled with a gelatin-based solution, was moved 20 times using a linear forward and backward motion. Three light-emitting diodes were used to record nerve-phantom excursion with a motion analysis system, while a 5-cm linear transducer allowed simultaneous recording via ultrasound imaging. Both measurement techniques yielded excellent association ( r  = 0.99) and agreement (mean absolute difference between methods = 0.85 mm; mean relative difference between methods = 7.48 %). Small discrepancies were largely found when larger excursions (i.e. > 10 mm) were performed, revealing slight underestimation of the excursion by the ultrasound imaging analysis software. Quantitative ultrasound imaging is an accurate method to assess the longitudinal excursion of an in vitro nerve-phantom model and appears relevant for future research protocols investigating the neuromechanical properties of the peripheral nerves.

The OMERACT ultrasound task force--status and perspectives

DEFF Research Database (Denmark)

Naredo, Esperanza; Wakefield, Richard J; Iagnocco, Annamaria

2011-01-01

- and interobserver reliability exercise; and (5) Delphi definition exercise in hand osteoarthritis, and reliability exercises. Study conclusions were discussed, and a future research agenda was approved, notably further validation of an OMERACT ultrasound global synovitis score (GLOSS) in RA, emphasizing......This article reports the most recent work of the Outcome Measures in Rheumatology (OMERACT) Ultrasound Task Force, and highlights the future research priorities discussed at the OMERACT 10 meeting. Results of the following studies were presented: (1) intra- and interobserver reliability...... of ultrasound detecting and scoring synovitis in different joints of patients with rheumatoid arthritis (RA); (2) systematic review of previous ultrasound scoring systems of synovitis in RA; (3) enthesitis systematic review and Delphi definition exercise in spondyloarthritis enthesitis; (4) enthesitis intra...

Standards of the Polish Ultrasound Society – update. Ultrasound examination of thyroid gland and ultrasound-guided thyroid biopsy

Directory of Open Access Journals (Sweden)

Anna Trzebińska

2014-03-01

Full Text Available Ultrasonography is a primary imaging technique in patients with suspected thyroid disease. It allows to assess the location, size and echostructures of the thyroid gland as well as detect focal lesions, along with indication of their size, echogenicity, echostructure and vascularity. Based on these features, ultrasound examination allows to predict abnormal focal lesions for biopsy and monitor the biopsy needle track. This paper presents the standards of thyroid ultrasound examination regarding ultrasound apparatus technical requirements, scanning techniques, readings, measurements, and the description of the examination. It discusses the ultrasound features of increased malignancy risk in focal lesions (nodules found in the thyroid gland. It presents indications for fine needle aspiration biopsy of the thyroid gland for the visibility of single nodules (focal lesions and numerous lesions as well as discusses contraindications for thyroid biopsy. It describes the biopsy technique, possible complications and rules for post-biopsy monitoring of benign lesions. The paper is an update of the Standards of the Polish Ultrasound Society issued in 2011. It has been prepared on the basis of current literature, taking into account the information contained in the following publications: Thyroid ultrasound examination and Recommendations of the Polish Ultrasound Society for the performance of the FNAB of the thyroid.

PMO Delivery System Using Bubble Liposomes and Ultrasound Exposure for Duchenne Muscular Dystrophy Treatment.

Science.gov (United States)

Negishi, Yoichi; Ishii, Yuko; Nirasawa, Kei; Sasaki, Eri; Endo-Takahashi, Yoko; Suzuki, Ryo; Maruyama, Kazuo

2018-01-01

Duchenne muscular dystrophy (DMD) is a genetic disorder characterized by progressive muscle degeneration, caused by nonsense or frameshift mutations in the dystrophin (DMD) gene. Antisense oligonucleotides can be used to induce specific exon skipping; recently, a phosphorodiamidate morpholino oligomer (PMO) has been approved for clinical use in DMD. However, an efficient PMO delivery strategy is required to improve the therapeutic efficacy in DMD patients. We previously developed polyethylene glycol (PEG)-modified liposomes containing ultrasound contrast gas, "Bubble liposomes" (BLs), and found that the combination of BLs with ultrasound exposure is a useful gene delivery tool. Here, we describe an efficient PMO delivery strategy using the combination of BLs and ultrasound exposure to treat muscles in a DMD mouse model (mdx). This ultrasound-mediated BL technique can increase the PMO-mediated exon-skipping efficiency, leading to significantly increased dystrophin expression. Thus, the combination of BLs and ultrasound exposure may be a feasible PMO delivery method to improve therapeutic efficacy and reduce the PMO dosage for DMD treatment.

Active point out-of-plane ultrasound calibration

Science.gov (United States)

Cheng, Alexis; Guo, Xiaoyu; Zhang, Haichong K.; Kang, Hyunjae; Etienne-Cummings, Ralph; Boctor, Emad M.

2015-03-01

Image-guided surgery systems are often used to provide surgeons with informational support. Due to several unique advantages such as ease of use, real-time image acquisition, and no ionizing radiation, ultrasound is a common intraoperative medical imaging modality used in image-guided surgery systems. To perform advanced forms of guidance with ultrasound, such as virtual image overlays or automated robotic actuation, an ultrasound calibration process must be performed. This process recovers the rigid body transformation between a tracked marker attached to the transducer and the ultrasound image. Point-based phantoms are considered to be accurate, but their calibration framework assumes that the point is in the image plane. In this work, we present the use of an active point phantom and a calibration framework that accounts for the elevational uncertainty of the point. Given the lateral and axial position of the point in the ultrasound image, we approximate a circle in the axial-elevational plane with a radius equal to the axial position. The standard approach transforms all of the imaged points to be a single physical point. In our approach, we minimize the distances between the circular subsets of each image, with them ideally intersecting at a single point. We simulated in noiseless and noisy cases, presenting results on out-of-plane estimation errors, calibration estimation errors, and point reconstruction precision. We also performed an experiment using a robot arm as the tracker, resulting in a point reconstruction precision of 0.64mm.

Quality Assurance of Ultrasound Imaging Systems for Target Localization and Online Setup Corrections

International Nuclear Information System (INIS)

Tome, Wolfgang A.; Orton, Nigel P.

2008-01-01

We describe quality assurance paradigms for ultrasound imaging systems for target localization (UISTL). To determine the absolute localization accuracy of a UISTL, an absolute coordinate system can be established in the treatment room and spherical targets at various depths can be localized. To test the ability of such a system to determine the magnitude of internal organ motion, a phantom that mimics the human male pelvic anatomy can be used to simulate different organ motion ranges. To assess the interuser variability of ultrasound (US) guidance, different experienced users can independently determine the daily organ shifts for the same patients for a number of consecutive fractions. The average accuracy for a UISTL for the localization of spherical targets at various depths has been found to be 0.57 ± 0.47 mm in each spatial dimension for various focal depths. For the phantom organ motion test it was found that the true organ motion could be determined to within 1.0 mm along each axis. The variability between different experienced users who localized the same 5 patients for five consecutive fractions was small in comparison to the indicated shifts. In addition to the quality assurance tests that address the ability of a UISTL to accurately localize a target, a thorough quality assurance program should also incorporate the following two aspects to ensure consistent and accurate localization in daily clinical use: (1) adequate training and performance monitoring of users of the US target localization system, and (2) prescreening of patients who may not be good candidates for US localization

The Safety of Using High Frequency, Low Intensity Ultrasound to Enhance Thrombolysis

International Nuclear Information System (INIS)

Soltani, Azita

2006-01-01

The EKOS Ultrasound Infusion Systems (EKOS Corporation, Bothell, WA) use high frequency, low intensity ultrasound to accelerate thrombolysis by enhancing clot permeability and lytic drug penetration into thrombus. These systems are designed to provide efficacious catheter-directed treatment for the management of stroke, peripheral arterial occlusion and deep vein thrombosis. The in vitro and in vivo results of investigating the stability of therapeutic and diagnostic compounds used in combination with EKOS devices, the potential for adverse biological effects and the clot fragmentation confirmed the safety of EKOS ultrasound infusion systems in thrombolysis treatment

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... is used to evaluate the: bladder seminal vesicles prostate Transrectal ultrasound, a special study usually done to provide detailed evaluation of the prostate gland, involves inserting a specialized ultrasound transducer into ...

Obstetrical Ultrasound

Science.gov (United States)

... heartbeat can be seen as an ongoing ultrasound movie. Ultrasound devices also use Doppler, a special application ... the possible charges you will incur. Web page review process: This Web page is reviewed regularly by ...

Fetal stimulation by pulsed diagnostic ultrasound.

Science.gov (United States)

Fatemi, M; Ogburn, P L; Greenleaf, J F

2001-08-01

To show that pulsed ultrasound from a clinical ultrasonic imaging system can stimulate the fetus. Stimulation is defined mainly as increased fetal gross body movements in response to excitation. Fetuses of a group of 9 volunteer women (mean gestational age, 33.37 weeks; range, 25-40 weeks) were evaluated for body movement under 3 different conditions: (1) control, with no ultrasound exposure; (2) ultrasound in continuous wave Doppler mode; and (3) pulsed ultrasound in pulsed Doppler and B modes. A conventional external fetal monitor, with negligible ultrasonic output, was used to monitor fetal gross body motions. After an initial rest period of 3 minutes with 1 or no fetal motion, fetuses were monitored for an additional 3 minutes under the exposure criterion defined for each condition. Resulting fetal motions under the 3 conditions were compared using the Wilcoxon signed rank test. The test showed that fetuses moved significantly more frequently under condition 3 (mean +/- SD, 3.43 +/- 1.93 movements per minute) than under condition 1 (0.40 +/- 7.33 movements per minute) or condition 2 (0.63 +/- 7.67 movements per minute); P = .004 and .016, respectively. Fetal movements under conditions 1 and 2 did not differ significantly. Diagnostic ultrasound may stimulate fetal body motion.

Experience with a small animal hyperthermia ultrasound system (SAHUS): report on 83 tumours

International Nuclear Information System (INIS)

Novak, P; Moros, E G; Parry, J J; Rogers, B E; Myerson, R J; Zeug, A; Locke, J E; Rossin, R; Straube, W L; Singh, A K

2005-01-01

An external local ultrasound (US) system was developed to induce controlled hyperthermia of subcutaneously implanted tumours in small animals (e.g., mice and rats). It was designed to be compatible with a small animal positron emission tomography scanner (microPET) to facilitate studies of hyperthermia-induced tumour re-oxygenation using a PET radiopharmaceutical, but it is applicable for any small animal study requiring controlled heating. The system consists of an acrylic applicator bed with up to four independent 5 MHz planar disc US transducers of 1 cm in diameter, a four-channel radiofrequency (RF) generator, a multiple thermocouple thermometry unit, and a personal computer with custom monitoring and controlling software. Although the system presented here was developed to target tumours of up to 1 cm in diameter, the applicator design allows for different piezoelectric transducers to be exchanged and operated within the 3.5-6.5 MHz band to target different tumour sizes. Temperature feedback control software was developed on the basis of a proportional-integral-derivative (PID) approach when the measured temperatures were within a selectable temperature band about the target temperature. Outside this band, an on/off control action was applied. Perfused tissue-mimicking phantom experiments were performed to determine optimum controller gain constants, which were later employed successfully in animal experiments. The performance of the SAHUS (small animal hyperthermia ultrasound system) was tested using several tumour types grown in thighs of female nude (nu/nu) mice. To date, the system has successfully treated 83 tumours to target temperatures in the range of 41-43 deg. C for periods of 65 min on average

Ultrasound imaging

International Nuclear Information System (INIS)

Wells, P.N.T.

1983-01-01

Ultrasound is a form of energy which consists of mechanical vibrations the frequencies of which are so high that they are above the range of human hearing. The lower frequency limit of the ultrasonic spectrum may generally be taken to be about 20 kHz. Most biomedical applications of ultrasound employ frequencies in the range 1-15 MHz. At these frequencies, the wavelength is in the range 1.5 - 0.1 mm in soft tissues, and narrow beams of ultrasound can be generated which propagate through such tissues without excessive attenuation. This chapter begins with brief reviews of the physics of diagnostic ultrasound pulse-echo imaging methods and Doppler imaging methods. The remainder of the chapter is a resume of the applications of ultrasonic imaging to physiological measurement

Automatic Ultrasound Scanning

DEFF Research Database (Denmark)

Moshavegh, Ramin

on the user adjustments on the scanner interface to optimize the scan settings. This explains the huge interest in the subject of this PhD project entitled “AUTOMATIC ULTRASOUND SCANNING”. The key goals of the project have been to develop automated techniques to minimize the unnecessary settings...... on the scanners, and to improve the computer-aided diagnosis (CAD) in ultrasound by introducing new quantitative measures. Thus, four major issues concerning automation of the medical ultrasound are addressed in this PhD project. They touch upon gain adjustments in ultrasound, automatic synthetic aperture image...

Ultrasound guided electrochemotherapy for the treatment of a clear ...

African Journals Online (AJOL)

Ultrasound guided biopsy yielded a diagnosis of clear cell thymoma upon histopathology. After complete staging procedures, the owner elected to treat the cat with electrochemotherapy (ECT) using systemic bleomycin. Two sessions of ultrasound guided ECT were performed at two week intervals with trains of biphasic ...

Ultrasound-guided drug delivery in cancer

Directory of Open Access Journals (Sweden)

Sayan Mullick Chowdhury

2017-07-01

Full Text Available Recent advancements in ultrasound and microbubble (USMB mediated drug delivery technology has shown that this approach can improve spatially confined delivery of drugs and genes to target tissues while reducing systemic dose and toxicity. The mechanism behind enhanced delivery of therapeutics is sonoporation, the formation of openings in the vasculature, induced by ultrasound-triggered oscillations and destruction of microbubbles. In this review, progress and challenges of USMB mediated drug delivery are summarized, with special focus on cancer therapy.

Effect of ultrasound on flotation kinetics in the reactor-separator

International Nuclear Information System (INIS)

Filippov, L O; Matinin, A S; Samiguin, V D; Filippova, I V

2013-01-01

Effect of the ultrasound on flotation kinetics in reactor-separator has been studied for chalcopyrite/quartz mix mineral system. Under ultrasound treatment, recovery of chalcopyrite into bulk concentrate is higher than that at reagent-only treatment. It can be explained by increased of flotation rate for slow fraction as defined by Kelsall model. The slow fraction flotation rate increase multiplied by 6 vs. ultrasound treatment. Additional effect of the ultrasound treatment has been noticed under conditions when gangue minerals detachment from bubbles can be controlled. Reactor-separator has advantages over other types of flotation cells for this purpose providing a special zone for the ultrasound treatment that can be easily designed in this impeller less machine. The ultrasound influence on particles collision probability is able to explain of chalcopyrite recovery increase in the concentrate and activation chalcopyrite particles flotation.

Effect of ultrasound on flotation kinetics in the reactor-separator

Science.gov (United States)

Filippov, L. O.; Matinin, A. S.; Samiguin, V. D.; Filippova, I. V.

2013-03-01

Effect of the ultrasound on flotation kinetics in reactor-separator has been studied for chalcopyrite/quartz mix mineral system. Under ultrasound treatment, recovery of chalcopyrite into bulk concentrate is higher than that at reagent-only treatment. It can be explained by increased of flotation rate for slow fraction as defined by Kelsall model. The slow fraction flotation rate increase multiplied by 6 vs. ultrasound treatment. Additional effect of the ultrasound treatment has been noticed under conditions when gangue minerals detachment from bubbles can be controlled. Reactor-separator has advantages over other types of flotation cells for this purpose providing a special zone for the ultrasound treatment that can be easily designed in this impeller less machine. The ultrasound influence on particles collision probability is able to explain of chalcopyrite recovery increase in the concentrate and activation chalcopyrite particles flotation.

Diuretic Agent and Normal Saline Infusion Technique for Ultrasound-Guided Percutaneous Nephrostomies in Nondilated Pelvicaliceal Systems

International Nuclear Information System (INIS)

Yagci, Cemil; Ustuner, Evren; Atman, Ebru Dusunceli; Baltaci, Sumer; Uzun, Caglar; Akyar, Serdar

2013-01-01

Percutaneous nephrostomy (PCN) in a nondilated pelvicaliceal system is technically challenging. We describe an effective method to achieve transient dilatation of the pelvicaliceal system via induction of diuresis using infusion of a diuretic agent in normal saline, therefore allowing easier access to the pelvicaliceal system. Under real-time ultrasound guidance, the technique had been tested in 22 nephrostomies with nondilated system (a total of 20 patients with 2 patients having bilateral nephrostomies) during a 5-year period. Patients were given 40 mg of furosemide in 250 ml of normal saline solution intravenously by rapid infusion. As soon as maximum calyceal dilatation of more than 5 mm was observed, which is usually 15 min later after the end of rapid infusion, patients were positioned obliquely, and PCN procedure under ultrasound guidance was performed. The procedure was successful in 19 of the nephrostomies in 17 patients with a success rate of 86.36 % per procedure and 85 % per patient in nondilated pelvicaliceal systems. No major nephrostomy-, drug-, or technique-related complications were encountered. The technique failed to work in three patients due to the presence of double J catheters and preexisting calyceal perforation which avoided transient dilation of the pelvicaliceal system with diuresis. Diuretic infusion in saline is a feasible and effective method for PCN in nondilated pelvicaliceal systems.

Diuretic Agent and Normal Saline Infusion Technique for Ultrasound-Guided Percutaneous Nephrostomies in Nondilated Pelvicaliceal Systems

Energy Technology Data Exchange (ETDEWEB)

Yagci, Cemil, E-mail: cemil.yagci@medicine.ankara.edu.tr; Ustuner, Evren, E-mail: evrenustuner@hotmail.com; Atman, Ebru Dusunceli, E-mail: ebrumd2001@yahoo.com [Ankara University, Department of Radiology, School of Medicine (Turkey); Baltaci, Sumer, E-mail: sbaltaci@hotmail.com [Ankara University, Department of Urology, School of Medicine (Turkey); Uzun, Caglar, E-mail: cuzun77@yahoo.com; Akyar, Serdar, E-mail: yusuf.s.akyar@medicine.ankara.edu.tr [Ankara University, Department of Radiology, School of Medicine (Turkey)

2013-04-15

Percutaneous nephrostomy (PCN) in a nondilated pelvicaliceal system is technically challenging. We describe an effective method to achieve transient dilatation of the pelvicaliceal system via induction of diuresis using infusion of a diuretic agent in normal saline, therefore allowing easier access to the pelvicaliceal system. Under real-time ultrasound guidance, the technique had been tested in 22 nephrostomies with nondilated system (a total of 20 patients with 2 patients having bilateral nephrostomies) during a 5-year period. Patients were given 40 mg of furosemide in 250 ml of normal saline solution intravenously by rapid infusion. As soon as maximum calyceal dilatation of more than 5 mm was observed, which is usually 15 min later after the end of rapid infusion, patients were positioned obliquely, and PCN procedure under ultrasound guidance was performed. The procedure was successful in 19 of the nephrostomies in 17 patients with a success rate of 86.36 % per procedure and 85 % per patient in nondilated pelvicaliceal systems. No major nephrostomy-, drug-, or technique-related complications were encountered. The technique failed to work in three patients due to the presence of double J catheters and preexisting calyceal perforation which avoided transient dilation of the pelvicaliceal system with diuresis. Diuretic infusion in saline is a feasible and effective method for PCN in nondilated pelvicaliceal systems.

Ultrasound -- Pelvis

Medline Plus

Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Ultrasound - Pelvis Ultrasound imaging ...

Prostate Ultrasound

Medline Plus

Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Ultrasound - Prostate Ultrasound of ...

Design Issues for Therapeutic Ultrasound Angioplasty Waveguides

OpenAIRE

Noone, Declan; Gavin, Graham; McGuinness, Garrett

2008-01-01

Therapeutic ultrasound angioplasty is a new minimally invasive cardiovascular procedure for disrupting atherosclerotic lesions. Mechanical energy is transmitted in the form of ultrasound waves via long, flexible wire waveguides navigated to the lesion site through the vascular system. The underpinning principle of this technology is that plaque may be disrupted through a combination of direct contact ablation, pressure waves, cavitation and acoustic streaming, which all depend on the amplitud...

Ultrasound guided implantation of chest port systems via the lateral subclavian vein

International Nuclear Information System (INIS)

Zaehringer, M.; Hilgers, J.; Krueger, K.; Strohe, D.; Bangard, C.; Neumann, L.; Lackner, K.; Warm, M.; Reiser, M.; Toex, U.

2006-01-01

Purpose: Retrospective analysis of the success and complication rates of chest port implantation via the lateral subclavian vein. Materials and methods: Between January 2003 and June 2004, the lateral subclavian vein in 271 patients (186 women, 85 men, mean age 53.2 years) was punctured guided by ultrasound. This access was used to insert a port system, and the catheter tip was placed at the cavoatrial junction. The port reservoir was implanted in a subcutaneous infraclavicular pocket and fixed to the fascia of the pectoralis muscle. Indications for port implantation were chemotherapy (n=239), total parenteral nutrition (n=2) and intravenous medication (n=30). The patient follow-up was mainly performed either by the oncology division of the department of gynecology or by the department of internal medicine. Results: A chest port catheter system was successfully implanted in all patients. The catheter remained in place for a mean duration of 269.4 days (SD 192.3 days). No complications occurred during implantation. In the post-interventional period, 6 catheter dysfunctions were found (thrombotic 0.09 per 1000 catheter days; mechanic 0.05 per 1000 catheter days). While one local infection occurred in the early post-interventional period, 3 local and 15 systemic infections were independent of the port catheter placement (0.39 per 1000 catheter days). The rate of port catheter explantations due to dysfunction or infection was 0.07 per 1000 catheter days. Conclusion: Ultrasound-guided puncture of the lateral subclavian vein is a safe procedure for the insertion of central venous port catheter systems and had a very low complication rate in our study. For further evaluation of our port placement technique, prospective studies compared to placement through the internal jugular vein are necessary. (orig.)

Adaptive lesion formation using dual mode ultrasound array system

Science.gov (United States)

Liu, Dalong; Casper, Andrew; Haritonova, Alyona; Ebbini, Emad S.

2017-03-01

We present the results from an ultrasound-guided focused ultrasound platform designed to perform real-time monitoring and control of lesion formation. Real-time signal processing of echogenicity changes during lesion formation allows for identification of signature events indicative of tissue damage. The detection of these events triggers the cessation or the reduction of the exposure (intensity and/or time) to prevent overexposure. A dual mode ultrasound array (DMUA) is used for forming single- and multiple-focus patterns in a variety of tissues. The DMUA approach allows for inherent registration between the therapeutic and imaging coordinate systems providing instantaneous, spatially-accurate feedback on lesion formation dynamics. The beamformed RF data has been shown to have high sensitivity and specificity to tissue changes during lesion formation, including in vivo. In particular, the beamformed echo data from the DMUA is very sensitive to cavitation activity in response to HIFU in a variety of modes, e.g. boiling cavitation. This form of feedback is characterized by sudden increase in echogenicity that could occur within milliseconds of the application of HIFU (see http://youtu.be/No2wh-ceTLs for an example). The real-time beamforming and signal processing allowing the adaptive control of lesion formation is enabled by a high performance GPU platform (response time within 10 msec). We present results from a series of experiments in bovine cardiac tissue demonstrating the robustness and increased speed of volumetric lesion formation for a range of clinically-relevant exposures. Gross histology demonstrate clearly that adaptive lesion formation results in tissue damage consistent with the size of the focal spot and the raster scan in 3 dimensions. In contrast, uncontrolled volumetric lesions exhibit significant pre-focal buildup due to excessive exposure from multiple full-exposure HIFU shots. Stopping or reducing the HIFU exposure upon the detection of such an

Ultrasound -- Pelvis

Medline Plus

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

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... insertion. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... modality for the diagnosis and monitoring of pregnant women and their unborn babies. Ultrasound provides real-time ...

Prostate Ultrasound

Medline Plus

Full Text Available ... top of page What are the benefits vs. risks? Benefits Ultrasound is widely available, easy-to-use ... procedures such as needle biopsies and fluid aspiration. Risks For standard diagnostic ultrasound , there are no known ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... the procedure? In women, a pelvic ultrasound is most often performed to evaluate the: uterus cervix ovaries ... page How is the procedure performed? Transabdominal: For most ultrasound exams, you will be positioned lying face- ...

Prostate Ultrasound

Medline Plus

Full Text Available ... to-use and less expensive than other imaging methods. Ultrasound imaging uses no ionizing radiation. Ultrasound scanning ... radiation oncology provider in your community, you can search the ACR-accredited facilities database . This website does ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... diagnose symptoms experienced by women such as: pelvic pain abnormal vaginal bleeding other menstrual problems Ultrasound exams ... pelvic ultrasound can help evaluate: pelvic masses pelvic pain ambiguous genitalia and anomalies of pelvic organs early ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... size, shape and consistency (whether the object is solid or filled with fluid). In medicine, ultrasound is ... ultrasound, measures the direction and speed of blood cells as they move through vessels. The movement of ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... by women such as: pelvic pain abnormal vaginal bleeding other menstrual problems Ultrasound exams also help identify: ... fibroids cancer, especially in patients with abnormal uterine bleeding Some physicians also use 3-D ultrasound or ...

Prostate Ultrasound

Medline Plus

Full Text Available ... those sound waves to create an image. Ultrasound examinations do not use ionizing radiation (as used in ... abnormal masses, such as tumors. In an ultrasound examination, a transducer both sends the sound waves into ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... There are three types of pelvic ultrasound: abdominal, vaginal (for women), and rectal (for men). These exams ... are three types of pelvic ultrasound: abdominal ( transabdominal ) vaginal ( transvaginal / endovaginal ) for women rectal ( transrectal ) for men ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... object is solid or filled with fluid). In medicine, ultrasound is used to detect changes in appearance, ... have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Sonohysterography Ultrasound - ...

Prostate Ultrasound

Medline Plus

Full Text Available ... and produces pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound ... from the probe through the gel into the body. The transducer collects the sounds that bounce back ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... and produces pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound ... from the probe through the gel into the body. The transducer collects the sounds that bounce back ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... investigation of the uterine cavity . Three-dimensional (3-D) ultrasound permits evaluation of the uterus and ovaries ... abnormal uterine bleeding Some physicians also use 3-D ultrasound or sonohysterography for patients with infertility. In ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... insertion. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Sonohysterography Ultrasound - ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... Imaging? Ultrasound waves are disrupted by air or gas; therefore ultrasound is not an ideal imaging technique ... page Additional Information and Resources RTAnswers.org Radiation Therapy for Gynecologic Cancers Radiation Therapy for Prostate Cancer ...

Prostate Ultrasound

Medline Plus

Full Text Available ... of page What will I experience during and after the procedure? Ultrasound exams in which the transducer ... in the sperm or urine following the procedure. After an ultrasound examination, you should be able to ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... Ultrasound is the preferred imaging modality for the diagnosis and monitoring of pregnant women and their unborn ... sexes without x-ray exposure. Risks For standard diagnostic ultrasound , there are no known harmful effects on ...

Prostate Ultrasound

Medline Plus

Full Text Available ... ultrasound images are captured in real-time, they can show the structure and movement of the body's ... Because ultrasound provides real-time images, it also can be used to guide procedures such as needle ...

Prostate Ultrasound

Medline Plus

Full Text Available ... patient. Because ultrasound images are captured in real-time, they can show the structure and movement of ... test result. difficulty urinating. Because ultrasound provides real-time images, it also can be used to guide ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... patient. Because ultrasound images are captured in real-time, they can show the structure and movement of ... help to distract the child and make the time pass quickly. The ultrasound exam room may have ...

Prostate Ultrasound

Medline Plus

Full Text Available ... Ultrasound provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as ... bowel (rectum) removed during prior surgery are not good candidates for ultrasound of the prostate gland because ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... image. Ultrasound examinations do not use ionizing radiation (as used in x-rays ), thus there is no ... structure and movement of the body's internal organs, as well as blood flowing through blood vessels. Ultrasound ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... and development of an embryo or fetus during pregnancy. See the Obstetrical Ultrasound page for more information . ... object is solid or filled with fluid). In medicine, ultrasound is used to detect changes in appearance, ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... menstrual problems Ultrasound exams also help identify: palpable masses such as ovarian cysts and uterine fibroids ovarian ... In children, pelvic ultrasound can help evaluate: pelvic masses pelvic pain ambiguous genitalia and anomalies of pelvic ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... most ultrasound exams, you will be positioned lying face-up on an examination table that can be ... region of the prostate. A biopsy will add time to the procedure. If a Doppler ultrasound study ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... ultrasound: abdominal, vaginal (for women), and rectal (for men). These exams are frequently used to evaluate the ... vaginal ( transvaginal / endovaginal ) for women rectal ( transrectal ) for men A Doppler ultrasound exam may be part of ...

Ceramic membrane ultrafiltration of natural surface water with ultrasound enhanced backwashing.

Science.gov (United States)

Boley, A; Narasimhan, K; Kieninger, M; Müller, W-R

2010-01-01

Ultrafiltration membrane cleaning with ultrasound enhanced backwashing was investigated with two ceramic membrane systems in parallel. One of them was subjected to ultrasound during backwashing, the other acted as a reference system. The feed water was directly taken from a creek with a sedimentation process as only pre-treatment. The cleaning performance was improved with ultrasound but after 3 weeks of operation damages occurred on the membranes. These effects were studied with online measurements of flux, trans-membrane-pressure and temperature, but also with integrity tests, turbidity measurements and visual examination.

Tele-ultrasound using ATM over a T-1 satellite connection

Science.gov (United States)

Williamson, Morgan P.; Suitor, Charles T.; de Treville, Robert E.; Freckleton, Michael W.; Kinsey, Van; Goeringer, Fred; Lyche, David K.; Hunter, Bruce; Jennings, Neal E.; Shelton, Philip D.; Marcy, Jon; Poore, Tom; North, Jack

1996-04-01

In September 1995 the United States military conducted a demonstration project to provide live ultrasound video and diagnostic DICOM still images using GTE's asynchronous transfer mode (ATM) technologies over an Orion T-1 satellite link. Still images were frame-grabbed from a Diasonics ultrasound and sent to the ALI Wide Area Network system. A group of diagnostic images was then sent in DICOM 3.0 format over a virtual ethernet satellite link from Chantilly, Virginia to Dayton, Ohio. These images came across a DICOM gateway into the Medical Diagnostic Imaging Support (MDIS) System. Live video from the ultrasound was also routed through a CLI Radiance VTC over the satellite to a VTC in Ohio. The video bandwidth was progressively narrowed with two radiologists determining the minimal acceptable bandwidth for detecting test objects in a phantom. The radiologists accepted live video ultrasound at bandwidths as low as 384 kbps from the hands of an experienced ultrasonographer located hundreds of miles away. DICOM still images were sent uncompressed and were of acceptable image quality when viewed on the MDIS system. The technology demonstrated holds great promise for both deployed U.S. Military Forces and civil uses of remote radiology. Detailed network drawings and videotapes of the ultrasound examinations at the remote site are provided.

Can airborne ultrasound monitor bubble size in chocolate?

International Nuclear Information System (INIS)

Watson, N; Hazlehurst, T; Povey, M; Vieira, J; Sundara, R; Sandoz, J-P

2014-01-01

Aerated chocolate products consist of solid chocolate with the inclusion of bubbles and are a popular consumer product in many countries. The volume fraction and size distribution of the bubbles has an effect on their sensory properties and manufacturing cost. For these reasons it is important to have an online real time process monitoring system capable of measuring their bubble size distribution. As these products are eaten by consumers it is desirable that the monitoring system is non contact to avoid food contaminations. In this work we assess the feasibility of using an airborne ultrasound system to monitor the bubble size distribution in aerated chocolate bars. The experimental results from the airborne acoustic experiments were compared with theoretical results for known bubble size distributions using COMSOL Multiphysics. This combined experimental and theoretical approach is used to develop a greater understanding of how ultrasound propagates through aerated chocolate and to assess the feasibility of using airborne ultrasound to monitor bubble size distribution in these systems. The results indicated that a smaller bubble size distribution would result in an increase in attenuation through the product

Can airborne ultrasound monitor bubble size in chocolate?

Science.gov (United States)

Watson, N.; Hazlehurst, T.; Povey, M.; Vieira, J.; Sundara, R.; Sandoz, J.-P.

2014-04-01

Aerated chocolate products consist of solid chocolate with the inclusion of bubbles and are a popular consumer product in many countries. The volume fraction and size distribution of the bubbles has an effect on their sensory properties and manufacturing cost. For these reasons it is important to have an online real time process monitoring system capable of measuring their bubble size distribution. As these products are eaten by consumers it is desirable that the monitoring system is non contact to avoid food contaminations. In this work we assess the feasibility of using an airborne ultrasound system to monitor the bubble size distribution in aerated chocolate bars. The experimental results from the airborne acoustic experiments were compared with theoretical results for known bubble size distributions using COMSOL Multiphysics. This combined experimental and theoretical approach is used to develop a greater understanding of how ultrasound propagates through aerated chocolate and to assess the feasibility of using airborne ultrasound to monitor bubble size distribution in these systems. The results indicated that a smaller bubble size distribution would result in an increase in attenuation through the product.

Improving ultrasound gene transfection efficiency by controlling ultrasound excitation of microbubbles.

Science.gov (United States)

Fan, Z; Chen, D; Deng, C X

2013-09-28

Ultrasound application in the presence of microbubbles has shown great potential for non-viral gene transfection via transient disruption of cell membrane (sonoporation). However, improvement of its efficiency has largely relied on empirical approaches without consistent and translatable results. The goal of this study is to develop a rational strategy based on new results obtained using novel experimental techniques and analysis to improve sonoporation gene transfection. In this study, we conducted experiments using targeted microbubbles that were attached to cell membrane to facilitate sonoporation. We quantified the dynamic activities of microbubbles exposed to pulsed ultrasound and the resulting sonoporation outcome, and identified distinct regimes of characteristic microbubble behaviors: stable cavitation, coalescence and translation, and inertial cavitation. We found that inertial cavitation generated the highest rate of membrane poration. By establishing direct correlation of ultrasound-induced bubble activities with intracellular uptake and pore size, we designed a ramped pulse exposure scheme for optimizing microbubble excitation to improve sonoporation gene transfection. We implemented a novel sonoporation gene transfection system using an aqueous two phase system (ATPS) for efficient use of reagents and high throughput operation. Using plasmids coding for the green fluorescence protein (GFP), we achieved a sonoporation transfection efficiency in rate aortic smooth muscle cells (RASMCs) of 6.9%±2.2% (n=9), comparable with lipofection (7.5%±0.8%, n=9). Our results reveal characteristic microbubble behaviors responsible for sonoporation and demonstrated a rational strategy to improve sonoporation gene transfection. Copyright © 2013 Elsevier B.V. All rights reserved.

Prostate Ultrasound

Medline Plus

Full Text Available ... pictures of a man’s prostate gland and to help diagnose symptoms such as difficulty urinating or an ... Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. Prostate ultrasound, ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... ovarian cysts and uterine fibroids ovarian or uterine cancers A transvaginal ultrasound is usually performed to view the endometrium (the lining of the uterus) and the ovaries. Transvaginal ultrasound also evaluates the myometrium (muscular walls ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... Obstetric Ultrasound Ultrasound - Prostate Kidney and Bladder Stones Abnormal Vaginal Bleeding ... questions or for a referral to a radiologist or other physician. To locate a medical imaging or radiation oncology provider in your community, you ...

The Use of the OMERACT Ultrasound Tenosynovitis Scoring System in Multicenter Clinical Trials.

Science.gov (United States)

Ammitzbøll-Danielsen, Mads; Østergaard, Mikkel; Naredo, Esperanza; Iagnocco, Annamaria; Möller, Ingrid; D'Agostino, Maria-Antonietta; Gandjbakhch, Frédérique; Terslev, Lene

2018-02-01

To test the sensitivity to change of the Outcome Measures in Rheumatology Clinical Trials (OMERACT) ultrasound (US) scoring system for tenosynovitis when applied in a multicenter design. RA patients with US-verified tenosynovitis were recruited when scheduled for treatment intensification. Tenosynovitis was assessed at baseline, and 3 and 6 months followup, using the semiquantitative OMERACT scoring system. Expressed in median (25th; 75th percentiles), the overall greyscale and Doppler score decreased significantly from baseline at 4 (2; 7) and 3 (2; 6), to 6 months at 2 (0; 3) and 0 (0; 1, p The OMERACT US scoring system for tenosynovitis showed high responsiveness, supporting its use for diagnosing and monitoring tenosynovitis in multicenter trials.

Prostate Ultrasound

Medline Plus

Full Text Available ... Ultrasound is safe, noninvasive, and does not use ionizing radiation. This procedure requires little to no special preparation. ... create an image. Ultrasound examinations do not use ionizing radiation (as used in x-rays ), thus there is ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... Ultrasound is safe, noninvasive and does not use ionizing radiation. This procedure requires little to no special preparation. ... create an image. Ultrasound examinations do not use ionizing radiation (as used in x-rays ), thus there is ...

Prostate Ultrasound

Medline Plus

Full Text Available ... the patient. Because ultrasound images are captured in real-time, they can show the structure and movement of ... blood test result. difficulty urinating. Because ultrasound provides real-time images, it also can be used to guide ...

Novel Use of Ultrasound to Teach Reproductive System Physical Examination Skills and Pelvic Anatomy.

Science.gov (United States)

Parikh, Tejal; Czuzak, Maria; Bui, Naomi; Wildner, Corinna; Koch, Bryna; Leko, Elizabeth; Rappaport, William; Adhikari, Srikar; Gordon, Paul; Gura, Mike; Ellis, Susan

2018-03-01

To determine whether integration of ultrasound (US) into a reproductive system examination clinical skills lab can increase confidence in palpating key reproductive structures during testicular and bimanual pelvic examinations, reduce anxiety about conducting testicular and bimanual pelvic examinations, and improve performance on multiple-choice questions based on structure identification using US images. Second-year medical students enrolled in the Life Cycle preclinical course participated in this cross-sectional study. A single learning activity was developed to pair the teaching of the reproductive system physical examination with the use of US in the clinical skills lab. The evaluation of the teaching session consisted of a pre-post analysis of student self-reported knowledge, confidence, and anxiety. The response rate for the pre survey was 82% (n = 96), and the rate for the post survey was 79% (n = 93). Students' confidence in their ability to identify reproductive system structures on US images increased from pre to post survey. Their confidence in their ability to palpate the epididymis, uterus, and ovary during a physical examination improved, and their anxiety about conducting testicular and bimanual pelvic examinations decreased. Student satisfaction with the session was high. Students' performance on multiple-choice questions based on structure identification using US images was at 96% or higher. Our study findings support the integration of US into a reproductive system examination clinical skills lab. Medical students acquire competency and confidence in reproductive system physical examination skills with US integration. © 2017 by the American Institute of Ultrasound in Medicine.

Solubilization of bovine gelatin using power ultrasound: gelation without heating.

Science.gov (United States)

Farahnaky, Asgar; Zendeboodi, Fatemeh; Azizi, Rezvan; Mesbahi, Gholamreza; Majzoobi, Mahsa

2017-04-01

The aim of this study was to investigate the efficacy of power ultrasound without using any heating stage in solubilizeing gelatin dispersions, and to characterize the mechanical and microstructural properties of the resulting gels using texture analysis and scanning electron microscopy, respectively. Usually to prepare a gel from gelatin, a primary heating stage of at about 40C or above is required to solubilize gelatin macromolecules. In this study solubilizing gelatin dispersions using power ultrasound without any heating was successfully performed. For solubilising gelatin, an ultrasound equipment with a frequency of 20 kHz, amplitude of 100% and power range of 50-150 W was used. Aqueous gelatin dispersions (4% w/v) were subjected to ultrasound for different times (40-240 s) at a constant temperature of 13C. Applying ultrasound to gelatin dispersions caused increases in water absorption and water solubility of the hydrocolloid. The textural parameters of the resulting gelatin gels, increased with increasing time and power of ultrasound. Moreover, a generalized Maxwell model with three elements was used for calculating relaxation times of the gels. The microstructural observations by SEM showed that the structural cohesiveness of the gels increased by increasing ultrasonication time. Ultrasound-assisted solubilization of gelatin can have emerging implications for industrial uses in pharmaceuticals, food and non-food systems. Usually to prepare a gel from gelatin, a primary heating stage of at about 40C or above is required to solubilize gelatin macromolecules. Therefore, the use of gelatin as a hydrocolloid in food processings or pharmaceutical formulations which lack a heating step has been a technological and practical challenge. In this study solubilizing gelatin dispersions using power ultrasound without any heating was successfully performed. Ultrasound-assisted solubilisation of gelatin can have emerging implications for industrial uses in pharmaceuticals

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... internal organs, as well as blood flowing through blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. There are three types of pelvic ultrasound: abdominal ( transabdominal ) vaginal ( transvaginal / endovaginal ) ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... to-use and less expensive than other imaging methods. Ultrasound imaging is extremely safe and does not use any ionizing radiation. Ultrasound scanning gives a clear picture of soft tissues that do not show up well on ...

Varying ultrasound power level to distinguish surgical instruments and tissue.

Science.gov (United States)

Ren, Hongliang; Anuraj, Banani; Dupont, Pierre E

2018-03-01

We investigate a new framework of surgical instrument detection based on power-varying ultrasound images with simple and efficient pixel-wise intensity processing. Without using complicated feature extraction methods, we identified the instrument with an estimated optimal power level and by comparing pixel values of varying transducer power level images. The proposed framework exploits the physics of ultrasound imaging system by varying the transducer power level to effectively distinguish metallic surgical instruments from tissue. This power-varying image-guidance is motivated from our observations that ultrasound imaging at different power levels exhibit different contrast enhancement capabilities between tissue and instruments in ultrasound-guided robotic beating-heart surgery. Using lower transducer power levels (ranging from 40 to 75% of the rated lowest ultrasound power levels of the two tested ultrasound scanners) can effectively suppress the strong imaging artifacts from metallic instruments and thus, can be utilized together with the images from normal transducer power levels to enhance the separability between instrument and tissue, improving intraoperative instrument tracking accuracy from the acquired noisy ultrasound volumetric images. We performed experiments in phantoms and ex vivo hearts in water tank environments. The proposed multi-level power-varying ultrasound imaging approach can identify robotic instruments of high acoustic impedance from low-signal-to-noise-ratio ultrasound images by power adjustments.

Ultrasound - Aided ejection in micro injection molding

Science.gov (United States)

Masato, D.; Sorgato, M.; Lucchetta, G.

2018-05-01

In this work, an ultrasound-aided ejection system was designed and tested for different polymers (PS, COC and POM) and mold topographies. The proposed solution aims at reducing the ejection friction by decreasing the adhesion component of the frictional force, which is controlled by the contact area developed during the filling stage of the injection molding process. The experimental results indicate a positive effect of ultrasound vibration on the friction force values, with a maximum reduction of 16. Moreover, it is demonstrated that the ultrasound effect is strictly related to both polymer selection and mold roughness. The combined effect on the ejection force of mold surface roughness, melt viscosity during filling and polymer elastic modulus at ejection was modeled to the experimental data, in order to demonstrate that the effect of ultrasound vibration on the ejection friction reduction is due to the heating of the contact interface and the consequent reduction of the polymer elastic modulus.

Ultrasound arthroscopy of human knee cartilage and subchondral bone in vivo.

Science.gov (United States)

Liukkonen, Jukka; Lehenkari, Petri; Hirvasniemi, Jukka; Joukainen, Antti; Virén, Tuomas; Saarakkala, Simo; Nieminen, Miika T; Jurvelin, Jukka S; Töyräs, Juha

2014-09-01

Arthroscopic ultrasound imaging enables quantitative evaluation of articular cartilage. However, the potential of this technique for evaluation of subchondral bone has not been investigated in vivo. In this study, we address this issue in clinical arthroscopy of the human knee (n = 11) by determining quantitative ultrasound (9 MHz) reflection and backscattering parameters for cartilage and subchondral bone. Furthermore, in each knee, seven anatomical sites were graded using the International Cartilage Repair Society (ICRS) system based on (i) conventional arthroscopy and (ii) ultrasound images acquired in arthroscopy with a miniature transducer. Ultrasound enabled visualization of articular cartilage and subchondral bone. ICRS grades based on ultrasound images were higher (p ultrasound-based ICRS grades were expected as ultrasound reveals additional information on, for example, the relative depth of the lesion. In line with previous literature, ultrasound reflection and scattering in cartilage varied significantly (p ultrasound parameters and structure or density of subchondral bone could be demonstrated. To conclude, arthroscopic ultrasound imaging had a significant effect on clinical grading of cartilage, and it was found to provide quantitative information on cartilage. The lack of correlation between the ultrasound parameters and bone properties may be related to lesser bone change or excessive attenuation in overlying cartilage and insufficient power of the applied miniature transducer. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Ultrasound stethoscopy

NARCIS (Netherlands)

E.C. Vourvouri (Eleni)

2002-01-01

textabstractIn this thesis we repmi the many evaluation studies with the hand-held ultrasound device in the assessment of different cardiac pathologies and in different clinical settings. The reason for using the tetm "ultrasound stethoscopy" is that these devices are augmenting our

Ultrasound -- Pelvis

Medline Plus

Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Ultrasound - Pelvis Ultrasound imaging of the pelvis uses sound waves to ...

Application of power ultrasound in radiochemistry

International Nuclear Information System (INIS)

Moisy, Ph.; Venault, L.; Blanc, P.; Madic, C.; Nikitenko, S.

1998-01-01

The chemical effects of ultrasound are related to cavitation process: nucleation, bubble growth and cavitation collapse. Sono-chemical reactions occur due to the rapid heating of the contents of cavitation bubbles. The shock-waves generated by cavitation collapse cause intense emulsification of the immiscible liquids. The CEA/Marcoule research group investigated the effect of power ultrasound on the homogeneous and heterogeneous (liquid-liquid) actinide reactions, in aqueous nitric acid media. It was found that U(IV), Np(V) and Pu(III) can be rapidly oxidized in HNO 3 solutions by HNO 2 , generated by the effect of power ultrasound on HNO 3 solutions. HNO 2 , formed during HNO 3 sono-lysis, decomposes hydrazinium nitrate within the cavitation bubbles. This makes it possible to the control actinide oxidation states without adding any side chemical reagents (NaNO 2 , for example). The quantitative data on the effect in the ultrasonic field in nitric acid medium are discussed, and sono-chemical mechanisms are proposed for nitrous acid formation and hydrazinium nitrate decomposition. In the presence of anti-nitrous reagents, such as hydrazinium nitrate and sulfamic acid, U(IV) was found to be oxidized and Pu(IV) reduced by H 2 O 2 formed as the result of aqueous nitric acid sono-lysis. The kinetics of H 2 O 2 formation is faster than in water, for the same sono-chemical conditions. Np(V) is rapidly oxidized, by aqueous phase HNO 2 , under the effect of ultrasound on the two-phase system TBP-dodecane/HNO 3 . Intense emulsification of the liquid/liquid system accelerates the mass transfer, of Np(VI) formed, into the organic phase. The quantitative effect of power ultrasound in aqueous nitric acid, with or without anti-nitrous reagents, can be used to predict the behavior of actinides in the ultrasonic field in nitric acid medium. (author)

Differential diagnosis between benign and malignant soft tissue tumors utilizing ultrasound parameters.

Science.gov (United States)

Morii, Takeshi; Kishino, Tomonori; Shimamori, Naoko; Motohashi, Mitsue; Ohnishi, Hiroaki; Honya, Keita; Aoyagi, Takayuki; Tajima, Takashi; Ichimura, Shoichi

2018-01-01

Preoperative discrimination between benign and malignant soft tissue tumors is critical for the prevention of excess application of magnetic resonance imaging and biopsy as well as unplanned resection. Although ultrasound, including power Doppler imaging, is an easy, noninvasive, and cost-effective modality for screening soft tissue tumors, few studies have investigated reliable discrimination between benign and malignant soft tissue tumors. To establish a modality for discrimination between benign and malignant soft tissue tumors using ultrasound, we extracted the significant risk factors for malignancy based on ultrasound information from 40 malignant and 56 benign pathologically diagnosed soft tissue tumors and established a scoring system based on these risk factors. The maximum size, tumor margin, and vascularity evaluated using ultrasound were extracted as significant risk factors. Using the odds ratio from a multivariate regression model, a scoring system was established. Receiver operating characteristic analyses revealed a high area under the curve value (0.85), confirming the accuracy of the scoring system. Ultrasound is a useful modality for establishing the differential diagnosis between benign and malignant soft tissue tumors.

Chest-wall thickness and percent thoracic fat estimation by B-mode ultrasound: system and procedure review

International Nuclear Information System (INIS)

Berger, C.D.; Lane, B.H.; Dunsmore, M.R.

1983-02-01

Accurate measurement of chest wall thickness is necessary for estimation of lung burden of transuranic elements in humans. To achieve tis capability, the ORNL Whole Body Counter has acquired a B-mode ultrasonic imaging system for defining the structure within the thorax of the body. This report contains a review of the ultrasound system in use at the ORNL Whole Body Counter, including its theory of operation, and te procedure for use of the system. Future developmental plans are also presented

Hybrid Photoacoustic/Ultrasound Tomograph for Real-Time Finger Imaging.

Science.gov (United States)

Oeri, Milan; Bost, Wolfgang; Sénégond, Nicolas; Tretbar, Steffen; Fournelle, Marc

2017-10-01

We report a target-enclosing, hybrid tomograph with a total of 768 elements based on capacitive micromachined ultrasound transducer technology and providing fast, high-resolution 2-D/3-D photoacoustic and ultrasound tomography tailored to finger imaging. A freely programmable ultrasound beamforming platform sampling data at 80 MHz was developed to realize plane wave transmission under multiple angles. A multiplexing unit enables the connection and control of a large number of elements. Fast image reconstruction is provided by GPU processing. The tomograph is composed of four independent and fully automated movable arc-shaped transducers, allowing imaging of all three finger joints. The system benefits from photoacoustics, yielding high optical contrast and enabling visualization of finger vascularization, and ultrasound provides morphologic information on joints and surrounding tissue. A diode-pumped, Q-switched Nd:YAG laser and an optical parametric oscillator are used to broaden the spectrum of emitted wavelengths to provide multispectral imaging. Custom-made optical fiber bundles enable illumination of the region of interest in the plane of acoustic detection. Precision in positioning of the probe in motion is ensured by use of a motor-driven guide slide. The current position of the probe is encoded by the stage and used to relate ultrasound and photoacoustic signals to the corresponding region of interest of the suspicious finger joint. The system is characterized in phantoms and a healthy human finger in vivo. The results obtained promise to provide new opportunities in finger diagnostics and establish photoacoustic/ultrasound-tomography in medical routine. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Real-time ultrasound elastography: an assessment of enlarged cervical lymph nodes.

Science.gov (United States)

Lo, Wu-Chia; Cheng, Po-Wen; Wang, Chi-Te; Liao, Li-Jen

2013-09-01

To determine the efficacy of real-time elastography (RTE), compared with our previously proposed prediction model, in the detection of malignancy in cervical lymph nodes (LNs). One hundred and thirty-one patients underwent ultrasound-guided fine needle aspiration biopsy (ultrasound FNAB) after ultrasound and RTE evaluation. The formula of the RTE scoring system was a four-point visual scale, based on a previously determined model. The formula of the prediction model was: [Formula: see text]. An extended model was constructed with four previous predictors and elasticity scores, using a logistic regression model. Final histology revealed 77 benign and 54 malignant LNs. In the elasticity score system, sensitivity was 66.7 %, specificity was 57.1 %, the positive predictive value (PPV) was 52.2 % and the negative predictive value (NPV) was 71.0 %. In the prediction model system, sensitivity was 79.6 %, specificity was 92.2 %, the PPV was 87.8 % and the NPV was 86.6 %. When the extended and the original model were compared, the areas under the receiver operating characteristic curve (c-statistic) was 0.94 and 0.95, respectively (P > 0.05). Qualitative RTE offers no additional value over conventional ultrasound in predicting malignancy in cervical LNs. • An ultrasound system can help in the assessment of cervical lymph nodes. • Grey-scale and power Doppler ultrasound remain fundamental for neck nodal evaluation. • Qualitative real-time elastography provided no additional value compared with current prediction models.

Application of High Power Ultrasound in Drying of Fruits and Vegetables

Directory of Open Access Journals (Sweden)

Werner, Z.

2010-04-01

deteriorating alterations and nutritive loss of compounds in fruits and vegetables.In this paper, the basic theory of ultrasound has been described. In the figures, the range of sound by frequency is described, as is the amplitude of ultrasound and its effect on the material also l, the wavelength and attenuation coefficient have been explained. The most common usage of power ultrasound as probe type of high intensity ultrasound set system with piezoelectric transducer have been introduced as a system for ultrasound drying. When the ultrasound wave passes through material the basic effect occurs. It is called cavitation and is divided generally in two types: stable and transient cavitation. Also, when imploding cavitation bubble causes elevated temperatures and pressures several chemical reactions can happen. In the figure one can see the visualisation of sonochemical reactions that occur around the decomposed bubble. Several reactions of decomposition, polymerisations, formation of aggregates, breaking of aggregates, bonding,breaking of bonds, formation of radicals, hydroxyl radicals etc. The main aim of this paper was to introduce the new non-thermal pre-treatment or direct treatment of ultrasound probe, or set of probes in the drying of vegetables and fruits. The basic target of the paper was to improve the knowledge of experts in the food industry and technologists in the chemical and other industries to learn of the possibility of implementing new techniques in their facilities. One can observe the modern scheme of the system for drying of materials with direct contact and also the example of the ultrasound treatment of fruits, water diffusivity in fruit and total processing time of applying ultrasound. The most important thing is to conduct the drying process in the best way to reduce treatment time, and to optimize the system. The most commonly used mathematical models for determination of drying kinetics have been pointed out. The lack of information is about energy

Ultrasound guided supraclavicular block.

LENUS (Irish Health Repository)

Hanumanthaiah, Deepak

2013-09-01

Ultrasound guided regional anaesthesia is becoming increasingly popular. The supraclavicular block has been transformed by ultrasound guidance into a potentially safe superficial block. We reviewed the techniques of performing supraclavicular block with special focus on ultrasound guidance.

Focused ultrasound in ophthalmology

Directory of Open Access Journals (Sweden)

Silverman RH

2016-09-01

Full Text Available Ronald H Silverman1,2 1Department of Ophthalmology, Columbia University Medical Center, 2F.L. Lizzi Center for Biomedical Engineering, Riverside Research, New York, NY, USA Abstract: The use of focused ultrasound to obtain diagnostically significant information about the eye goes back to the 1950s. This review describes the historical and technological development of ophthalmic ultrasound and its clinical application and impact. Ultrasound, like light, can be focused, which is crucial for formation of high-resolution, diagnostically useful images. Focused, single-element, mechanically scanned transducers are most common in ophthalmology. Specially designed transducers have been used to generate focused, high-intensity ultrasound that through thermal effects has been used to treat glaucoma (via cilio-destruction, tumors, and other pathologies. Linear and annular transducer arrays offer synthetic focusing in which precise timing of the excitation of independently addressable array elements allows formation of a converging wavefront to create a focus at one or more programmable depths. Most recently, linear array-based plane-wave ultrasound, in which the array emits an unfocused wavefront and focusing is performed solely on received data, has been demonstrated for imaging ocular anatomy and blood flow. While the history of ophthalmic ultrasound extends back over half-a-century, new and powerful technologic advances continue to be made, offering the prospect of novel diagnostic capabilities. Keywords: ophthalmic ultrasound, ultrasound biomicroscopy (UBM, high-intensity focused ultrasound (HIFU, ultrafast imaging, Doppler imaging 

Molecular imaging with targeted contrast ultrasound.

Science.gov (United States)

Piedra, Mark; Allroggen, Achim; Lindner, Jonathan R

2009-01-01

Molecular imaging with contrast-enhanced ultrasound uses targeted microbubbles that are retained in diseased tissue. The resonant properties of these microbubbles produce acoustic signals in an ultrasound field. The microbubbles are targeted to diseased tissue by using certain chemical constituents in the microbubble shell or by attaching disease-specific ligands such as antibodies to the microbubble. In this review, we discuss the applications of this technique to pathological states in the cerebrovascular system including atherosclerosis, tumor angiogenesis, ischemia, intravascular thrombus, and inflammation. Copyright 2009 S. Karger AG, Basel.

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

Science.gov (United States)

Bui, Nhat Quang; Hlaing, Kyu Kyu; Nguyen, Van Phuc; Nguyen, Trung Hau; Oh, Yun-Ok; Fan, Xiao Feng; Lee, Yong Wook; Nam, Seung Yun; Kang, Hyun Wook; Oh, Junghwan

2015-10-01

Intravascular ultrasound (IVUS) imaging is extremely important for detection and characterization of high-risk atherosclerotic plaques as well as gastrointestinal diseases. Recently, intravascular photoacoustic (IVPA) imaging has been used to differentiate the composition of biological tissues with high optical contrast and ultrasonic resolution. The combination of these imaging techniques could provide morphological information and molecular screening to characterize abnormal tissues, which would help physicians to ensure vital therapeutic value and prognostic significance for patients before commencing therapy. In this study, integration of a high-frequency IVUS imaging catheter (45MHz, single-element, unfocused, 0.7mm in diameter) with a multi-mode optical fiber (0.6mm in core diameter, 0.22 NA), an integrated intravascular ultrasonic-photoacoustic (IVUP) imaging catheter, was developed to provide spatial and functional information on light distribution in a turbid sample. Simultaneously, IVUS imaging was co-registered to IVPA imaging to construct 3D volumetric sample images. In a phantom study, a polyvinyl alcohol (PVA) tissue-mimicking arterial vessel phantom with indocyanine green (ICG) and methylene blue (MB) inclusion was used to demonstrate the feasibility of mapping the biological dyes, which are used in cardiovascular and cancer diagnostics. For the ex vivo study, an excised sample of pig intestine with ICG was utilized to target the biomarkers present in the gastrointestinal tumors or the atherosclerotic plaques with the proposed hybrid technique. The results indicated that IVUP endoscope with the 2.2-mm diameter catheter could be a useful tool for medical imaging. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ultrasound diagnostics of thyroid diseases

International Nuclear Information System (INIS)

Kharchenko, Vladimir P.; Kotlyarov, Peter M.; Mogutov, Mikhail S.; Sencha, Alexander N.; Patrunov, Yury N.; Belyaev, Denis V.; Alexandrov, Yury K.

2010-01-01

This book is based on the authors' extensive practical experience in the use of modern ultrasound, and other radiological methods, in the diagnosis of thyroid diseases. The authors have analyzed more than 100,000 ultrasound examinations performed between 1995 and 2008 in patients with thyroid and parathyroid disease, as well as many thousands of diagnostic and therapeutic ultrasound-guided minimally invasive procedures. The opening chapters include discussion of current ultrasound techniques, pitfalls, and the specifics of ultrasound examination of the thyroid in children. Detailed attention is then devoted to findings in the normal thyroid and in the presence of diffuse and focal changes. Further chapters focus on such topics as ultrasound examination after thyroid surgery and ultrasound diagnosis of parathyroid disease, recurrent goiter, and neck masses. Ultrasound-guided minimally invasive techniques, such as fine-needle aspiration biopsy, percutaneous laser ablation, and ethanol and glucocorticoid injections, are considered in depth. This up-to-date and richly illustrated book will interest and assist specialists in ultrasound diagnostics, radiologists, endocrinologists, and neck surgeons. (orig.)

Validation of an ultrasound dilution technology for cardiac output measurement and shunt detection in infants and children.

Science.gov (United States)

Lindberg, Lars; Johansson, Sune; Perez-de-Sa, Valeria

2014-02-01

To validate cardiac output measurements by ultrasound dilution technology (COstatus monitor) against those obtained by a transit-time ultrasound technology with a perivascular flow probe and to investigate ultrasound dilution ability to estimate pulmonary to systemic blood flow ratio in children. Prospective observational clinical trial. Pediatric cardiac operating theater in a university hospital. In 21 children (6.1 ± 2.6 kg, mean ± SD) undergoing heart surgery, cardiac output was simultaneously recorded by ultrasound dilution (extracorporeal arteriovenous loop connected to existing arterial and central venous catheters) and a transit-time ultrasound probe applied to the ascending aorta, and when possible, the main pulmonary artery. The pulmonary to systemic blood flow ratio estimated from ultrasound dilution curve analysis was compared with that estimated from transit-time ultrasound technology. Bland-Altman analysis of the whole cohort (90 pairs, before and after surgery) showed a bias between transit-time ultrasound (1.01 ± 0.47 L/min) and ultrasound dilution technology (1.03 ± 0.51 L/min) of -0.02 L/min, limits of agreement -0.3 to 0.3 L/min, and percentage error of 31%. In children with no residual shunts, the bias was -0.04 L/min, limits of agreement -0.28 to 0.2 L/min, and percentage error 19%. The pooled co efficient of variation was for the whole cohort 3.5% (transit-time ultrasound) and 6.3% (ultrasound dilution), and in children without shunt, it was 2.9% (transit-time ultrasound) and 4% (ultrasound dilution), respectively. Ultrasound dilution identified the presence of shunts (pulmonary to systemic blood flow ≠ 1) with a sensitivity of 100% and a specificity of 92%. Mean pulmonary to systemic blood flow ratio by transit-time ultrasound was 2.6 ± 1.0 and by ultrasound dilution 2.2 ± 0.7 (not significant). The COstatus monitor is a reliable technique to measure cardiac output in children with high sensitivity and specificity for detecting the

Impact of positive and negative lesion site remodeling on clinical outcomes: insights from PROSPECT.

Science.gov (United States)

Inaba, Shinji; Mintz, Gary S; Farhat, Naim Z; Fajadet, Jean; Dudek, Dariusz; Marzocchi, Antonio; Templin, Barry; Weisz, Giora; Xu, Ke; de Bruyne, Bernard; Serruys, Patrick W; Stone, Gregg W; Maehara, Akiko

2014-01-01

This study investigated coronary artery remodeling patterns associated with clinical outcomes. In the prospective, multicenter PROSPECT (Providing Regional Observations to Study Predictors of Events in the Coronary Tree: An Imaging Study in Patients With Unstable Atherosclerotic Lesions) study, reported predictors of nonculprit lesion (NCL) major adverse cardiac events (MACE) were an intravascular ultrasound (IVUS) minimal lumen area (MLA) ≤4 mm(2), a plaque burden ≥70%, and a IVUS-virtual histology (VH) thin-cap fibroatheroma (TCFA), but not lesion site remodeling. Overall, 697 consecutive patients with an acute coronary syndrome were enrolled and underwent 3-vessel gray-scale and IVUS-VH; 3,223 NCLs were identified by IVUS. The remodeling index (RI) was calculated as the external elastic membrane area at the MLA site divided by the average of the proximal and distal reference external elastic membrane areas. First, one third of the patients were randomly selected to determine RI cutoffs related to NCL MACE (development cohort). Receiver-operating characteristic analysis showed that there were 2 separate cut points that predicted NCL MACE: RI = 0.8789 and RI = 1.0046 (area under the curve = 0.663). These cut points were used to define negative remodeling as an RI 1.00. Second, we used the remaining two-thirds of patients to validate these cut points with respect to lesion morphology and clinical outcomes (validation cohort). Kaplan-Meier curve analysis in the validation cohort showed that NCL MACE occurred more frequent (and equally) in negative and positive remodeling lesions compared with intermediate remodeling lesions. In this cohort, negative remodeling lesions had the smallest MLA, positive remodeling lesions had the largest plaque burden, and VH TCFA, especially VH TCFA with multiple necrotic cores, was most common in negatively remodeling lesions. The present study showed the novel concept that positive and negative lesion site remodeling was

Prostate Ultrasound

Science.gov (United States)

... be able to give a clearer picture of soft tissues that do not show up well on x-ray images. Ultrasound causes no health problems and may be repeated as often as is necessary if medically indicated. Ultrasound provides real-time imaging, making it a good tool for guiding ...

Prostate Ultrasound

Medline Plus

Full Text Available ... the best way to see if treatment is working or if a finding is stable or changed over time. top of page What are the benefits vs. risks? Benefits Ultrasound is widely available, easy-to-use and less expensive than other imaging methods. Ultrasound imaging uses ...

Trans-abdominal ultrasound evaluation of high-intensity focused ultrasound treatment of uterine leiomyoma

International Nuclear Information System (INIS)

Miao Wei; Huang Jin; Wang Junhua; Wang Yuling

2010-01-01

Objective: To determine the value of dynamic trans-abdominal ultrasound after high-intensity focused ultrasound (HIFU) treatment of uterine leiomyomas. Methods: The trans-abdominal ultrasound images of 63 patients before and after HIFU treatment of uterine leiomyomas were compared. Results: The volume and blood flow of leiomyomas were reduced after the HIFU treatment. Conclusion: Trans-abdominal ultrasound is a valuable method for evaluating the results of HIFU treatment of uterine leiomyomas. (authors)

On the reproducibility of expert-operated and robotic ultrasound acquisitions.

Science.gov (United States)

Kojcev, Risto; Khakzar, Ashkan; Fuerst, Bernhard; Zettinig, Oliver; Fahkry, Carole; DeJong, Robert; Richmon, Jeremy; Taylor, Russell; Sinibaldi, Edoardo; Navab, Nassir

2017-06-01

We present the evaluation of the reproducibility of measurements performed using robotic ultrasound imaging in comparison with expert-operated sonography. Robotic imaging for interventional procedures may be a valuable contribution, but requires reproducibility for its acceptance in clinical routine. We study this by comparing repeated measurements based on robotic and expert-operated ultrasound imaging. Robotic ultrasound acquisition is performed in three steps under user guidance: First, the patient is observed using a 3D camera on the robot end effector, and the user selects the region of interest. This allows for automatic planning of the robot trajectory. Next, the robot executes a sweeping motion following the planned trajectory, during which the ultrasound images and tracking data are recorded. As the robot is compliant, deviations from the path are possible, for instance due to patient motion. Finally, the ultrasound slices are compounded to create a volume. Repeated acquisitions can be performed automatically by comparing the previous and current patient surface. After repeated image acquisitions, the measurements based on acquisitions performed by the robotic system and expert are compared. Within our case series, the expert measured the anterior-posterior, longitudinal, transversal lengths of both of the left and right thyroid lobes on each of the 4 healthy volunteers 3 times, providing 72 measurements. Subsequently, the same procedure was performed using the robotic system resulting in a cumulative total of 144 clinically relevant measurements. Our results clearly indicated that robotic ultrasound enables more repeatable measurements. A robotic ultrasound platform leads to more reproducible data, which is of crucial importance for planning and executing interventions.

General Ultrasound Imaging

Medline Plus

Full Text Available ... and treat medical conditions. Conventional ultrasound displays the images in thin, flat sections of the body. Advancements in ultrasound technology include three-dimensional (3- ...

Mammography and ultrasound in the evaluation of male breast disease

Energy Technology Data Exchange (ETDEWEB)

Munoz Carrasco, Rafaela; Alvarez Benito, Marina; Raya Povedano, Jose Luis [Hospital Universitario ' Reina Sofia' , Radiology Department, Cordoba (Spain); Munoz Gomariz, Elisa [Hospital Universitario ' Reina Sofia' , Support Unit for Research, Cordoba (Spain); Martinez Paredes, Maria [University of Cordoba, Radiology and Physical Medicine Area, Cordoba (Spain)

2010-12-15

To assess clinical variables that may be useful in differentiating gynaecomastia from carcinoma and to analyse the contribution of mammography and ultrasound to the evaluation of male breast disease. All men who underwent mammography and/or ultrasound between 1993 and 2006 in our hospital were retrospectively evaluated. Clinical characteristics in patients with gynaecomastia and those with carcinoma were compared. Radiological findings were classified according to the BI-RADS (Breast Imaging Reporting and Data System) criteria. The diagnostic performance of physical examination, mammography and ultrasound was determined and compared. A total of 628 patients with 518 mammograms and 423 ultrasounds were reviewed. The final diagnoses were: 19 carcinomas, 526 gynaecomastias, 84 other benign conditions and 25 normal. There were statistically significant differences in age, bilateral involvement, clinical presentation and physical examination between patients with carcinoma and those with gynaecomastia. The diagnostic performance of physical examination was lower than that of mammography and ultrasound (p < 0.05 for specificity). Mammography was the most sensitive (94.7%) and ultrasound the most specific (95.3%) for detection of malignancy (p > 0.05). We propose an algorithm for the use of mammography and ultrasound in men. Mammography and ultrasound, with a negative predictive value close to 100%, make it possible to avoid very many unnecessary surgical procedures in men. (orig.)

General Ultrasound Imaging

Medline Plus

Full Text Available ... through blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. Conventional ultrasound displays the images in thin, ...

Manipulation of Microbubble Clusters Using Focused Ultrasound

Science.gov (United States)

Matsuzaki, Hironobu; Osaki, Taichi; Kawaguchi, Kei; Unga, Johan; Ichiyanagi, Mitsuhisa; Azuma, Takashi; Suzuki, Ryo; Maruyama, Kazuo; Takagi, Shu

2017-11-01

In recent years, microbubbles (MBs) are expected to be utilized for the ultrasound drug delivery system (DDS). For the MB-DDS, it is important to establish a method of controlling bubbles and bubble clusters using ultrasound field. The objective of this study is to clarify behaviors of bubble clusters with various physical conditions. MBs in the ultrasound field are subjected to the primary Bjerknes force. The force traps MBs at the focal region of the focused ultrasound field. The trapped MBs form a bubble cluster at the region. A bubble cluster continues growing with absorbing surrounding bubbles until it reaches a maximum size beyond which it disappears from the focal region. In the present study, two kinds of MBs are used for the experiment. One is Sonazoid with average diameter of 2.6 um and resonant frequency of 5 MHz. The other is developed by Teikyo Univ., with average diameter of 1.5 um and presumed resonant frequency of 4 MHz. The bubble cluster's behaviors are analyzed using the high-speed camera. Sonazoid clusters have larger critical size than the other in every frequency, and its cluster size is inversely proportional to the ultrasound frequency, while Teikyo-bubble clusters have different tendency. These results are discussed in the presentation.

Quality control culture of diagnostic ultrasound parameters

International Nuclear Information System (INIS)

Andam, A.A.B; Addison, E.C.K.; Aggry-Smith, S.; Nani, E.K.

2003-01-01

A phantom, consisting of two phases, has been designed and constructed to mimic the human body. The phase one phantom was designed to mimic a a surface lesion in the human body and the phase two phantom designed to mimic a section of the whole body. Ultrasound scans of the phantom were acquired for various material in the phantom at six hospitals in Kumasi, Ghana. A linear array transducer with parallel beams having a convex probe and a 3.5 MHz ultrasound frequency were used to carry out the experiment. It was observed that the depth of penetration of ultrasound, which constitutes the maximum depth of visualization or sensitivity, is determined by the frequency of the transducer, the attenuation of the medium being imaged and the system settings. Uniformity and linearity of the machines investigated were found to be within clinically acceptable standards. Spatial resolution, comprising axial and lateral resolutions, was observed to be satisfactory for the machines tested. It was observed that lateral resolution improved with the narrowing of the beam width. The ultrasound scanners at the selected hospitals were found to be operating at the expected level of performance. This work highlights the importance of putting in place a locally based mechanism for quality control of diagnostic ultrasound machines (author)

The Indian ultrasound paradox

OpenAIRE

Akbulut-Yuksel, Mevlude; Rosenblum, Daniel

2012-01-01

The liberalization of the Indian economy in the 1990s made prenatal ultrasound technology affordable and available to a large fraction of the population. As a result, ultrasound use amongst pregnant women rose dramatically in many parts of India. This paper provides evidence on the consequences of the expansion of prenatal ultrasound use on sex-selection. We exploit state-by-cohort variation in ultrasound use in India as a unique quasi-experiment. We find that sex-selective abortion of female...

Point of Care Ultrasound

DEFF Research Database (Denmark)

Dietrich, Christoph F; Goudie, Adrian; Chiorean, Liliana

2017-01-01

Over the last decade, the use of portable ultrasound scanners has enhanced the concept of point of care ultrasound (PoC-US), namely, "ultrasound performed at the bedside and interpreted directly by the treating clinician." PoC-US is not a replacement for comprehensive ultrasound, but rather allows...... and critical care medicine, cardiology, anesthesiology, rheumatology, obstetrics, neonatology, gynecology, gastroenterology and many other applications. In the future, PoC-US will be more diverse than ever and be included in medical student training....

A 3D freehand ultrasound system for multi-view reconstructions from sparse 2D scanning planes.

Science.gov (United States)

Yu, Honggang; Pattichis, Marios S; Agurto, Carla; Beth Goens, M

2011-01-20

A significant limitation of existing 3D ultrasound systems comes from the fact that the majority of them work with fixed acquisition geometries. As a result, the users have very limited control over the geometry of the 2D scanning planes. We present a low-cost and flexible ultrasound imaging system that integrates several image processing components to allow for 3D reconstructions from limited numbers of 2D image planes and multiple acoustic views. Our approach is based on a 3D freehand ultrasound system that allows users to control the 2D acquisition imaging using conventional 2D probes.For reliable performance, we develop new methods for image segmentation and robust multi-view registration. We first present a new hybrid geometric level-set approach that provides reliable segmentation performance with relatively simple initializations and minimum edge leakage. Optimization of the segmentation model parameters and its effect on performance is carefully discussed. Second, using the segmented images, a new coarse to fine automatic multi-view registration method is introduced. The approach uses a 3D Hotelling transform to initialize an optimization search. Then, the fine scale feature-based registration is performed using a robust, non-linear least squares algorithm. The robustness of the multi-view registration system allows for accurate 3D reconstructions from sparse 2D image planes. Volume measurements from multi-view 3D reconstructions are found to be consistently and significantly more accurate than measurements from single view reconstructions. The volume error of multi-view reconstruction is measured to be less than 5% of the true volume. We show that volume reconstruction accuracy is a function of the total number of 2D image planes and the number of views for calibrated phantom. In clinical in-vivo cardiac experiments, we show that volume estimates of the left ventricle from multi-view reconstructions are found to be in better agreement with clinical

3D ultrasound imaging for prosthesis fabrication and diagnostic imaging

Energy Technology Data Exchange (ETDEWEB)

Morimoto, A.K.; Bow, W.J.; Strong, D.S. [and others

1995-06-01

The fabrication of a prosthetic socket for a below-the-knee amputee requires knowledge of the underlying bone structure in order to provide pressure relief for sensitive areas and support for load bearing areas. The goal is to enable the residual limb to bear pressure with greater ease and utility. Conventional methods of prosthesis fabrication are based on limited knowledge about the patient`s underlying bone structure. A 3D ultrasound imaging system was developed at Sandia National Laboratories. The imaging system provides information about the location of the bones in the residual limb along with the shape of the skin surface. Computer assisted design (CAD) software can use this data to design prosthetic sockets for amputees. Ultrasound was selected as the imaging modality. A computer model was developed to analyze the effect of the various scanning parameters and to assist in the design of the overall system. The 3D ultrasound imaging system combines off-the-shelf technology for image capturing, custom hardware, and control and image processing software to generate two types of image data -- volumetric and planar. Both volumetric and planar images reveal definition of skin and bone geometry with planar images providing details on muscle fascial planes, muscle/fat interfaces, and blood vessel definition. The 3D ultrasound imaging system was tested on 9 unilateral below-the- knee amputees. Image data was acquired from both the sound limb and the residual limb. The imaging system was operated in both volumetric and planar formats. An x-ray CT (Computed Tomography) scan was performed on each amputee for comparison. Results of the test indicate beneficial use of ultrasound to generate databases for fabrication of prostheses at a lower cost and with better initial fit as compared to manually fabricated prostheses.

Algorithms for estimating blood velocities using ultrasound

DEFF Research Database (Denmark)

Jensen, Jørgen Arendt

2000-01-01

Ultrasound has been used intensively for the last 15 years for studying the hemodynamics of the human body. Systems for determining both the velocity distribution at one point of interest (spectral systems) and for displaying a map of velocity in real time have been constructed. A number of schemes...... have been developed for performing the estimation, and the various approaches are described. The current systems only display the velocity along the ultrasound beam direction and a velocity transverse to the beam is not detected. This is a major problem in these systems, since most blood vessels...... are parallel to the skin surface. Angling the transducer will often disturb the flow, and new techniques for finding transverse velocities are needed. The various approaches for determining transverse velocities will be explained. This includes techniques using two-dimensional correlation (speckle tracking...

[Ultrasound findings in rhabdomyolysis].

Science.gov (United States)

Carrillo-Esper, Raúl; Galván-Talamantes, Yazmin; Meza-Ayala, Cynthia Margarita; Cruz-Santana, Julio Alberto; Bonilla-Reséndiz, Luis Ignacio

Rhabdomyolysis is defined as skeletal muscle necrosis. Ultrasound assessment has recently become a useful tool for the diagnosis and monitoring of muscle diseases, including rhabdomyolysis. A case is presented on the ultrasound findings in a patient with rhabdomyolysis. To highlight the importance of ultrasound as an essential part in the diagnosis in rhabdomyolysis, to describe the ultrasound findings, and review the literature. A 30 year-old with post-traumatic rhabdomyolysis of both thighs. Ultrasound was performed using a Philips Sparq model with a high-frequency linear transducer (5-10MHz), in low-dimensional scanning mode (2D), in longitudinal and transverse sections at the level of both thighs. The images obtained showed disorganisation of the orientation of the muscle fibres, ground glass image, thickening of the muscular fascia, and the presence of anechoic areas. Ultrasound is a useful tool in the evaluation of rhabdomyolysis. Copyright © 2015 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

Practical sonochemistry power ultrasound uses and applications

CERN Document Server

Mason, T J

2002-01-01

This updated version of Practical Sonochemistry for advanced students and teachers in chemistry and chemical engineering conveys the increasing growth in applications and equipment to power ultrasound. Equipment now on the market offers a wider range of frequencies with more reproducible experimentation and a variety of scale-up systems. The book provides detailed descriptions of newer ultrasonic equipment and its applications, and practical laboratory uses of ultrasound technology for industrial scale performance.Modern exercises familiarise readers with recent sonochemical operations

Inter-rater reliability of postnatal ultrasound interpretation in infants with congenital hydronephrosis.

Science.gov (United States)

Vemulakonda, V M; Wilcox, D T; Torok, M R; Hou, A; Campbell, J B; Kempe, A

2015-09-01

The most common measurements of hydronephrosis are the anterior-posterior (AP) diameter and the Society for Fetal Urology (SFU) grading systems. To date, the inter-rater reliability (IRR) of these measures has not been compared in the postnatal period. The objectives of this study were to compare the IRR of the AP diameter and the SFU grading system in infants and to determine whether ultrasound findings other than pelvicalyceal dilation are associated with higher SFU grades. Initial postnatal ultrasounds of infants seen from February 1, 2011, to January 31, 2012, with a primary diagnosis of congenital hydronephrosis were included for review. Ultrasound images were de-identified and reviewed by four pediatric urologists. IRR was calculated using the intraclass correlation (ICC) measure. A paired t test was used to compare ICCs. Associations between SFU grade and other ultrasound findings were tested using Chi-square or Fisher's exact tests. A total of 112 kidneys in 56 patients were reviewed. IRR of the SFU grading system was high (right kidney ICC = 0.83, left kidney ICC = 0.85); however, IRR of AP diameter measurement was higher (right kidney ICC = 00.97, left kidney ICC = 0.98; p hydronephrosis on bivariable and multivariable analysis. The SFU grading system is associated with excellent IRR, although the AP diameter appears to have higher IRR. Physicians may consider ultrasound findings that are not explicitly included in the SFU system when assigning hydronephrosis grade, which may lead to variability in use of this classification system.

IVUS Findings in Late and Very Late Stent Thrombosis. A Comparison Between Bare-metal and Drug-eluting Stents.

Science.gov (United States)

Fuentes, Lara; Gómez-Lara, Josep; Salvatella, Neus; Gonzalo, Nieves; Hernández-Hernández, Felipe; Fernández-Nofrerias, Eduard; Sánchez-Recalde, Ángel; Alfonso, Fernando; Romaguera, Rafael; Ferreiro, José Luis; Roura, Gerard; Teruel, Luis; Gracida, Montserrat; Marcano, Ana Lucrecia; Gómez-Hospital, Joan-Antoni; Cequier, Ángel

2018-05-01

Stent thrombosis (ST) is a life-threatening complication after stent implantation. Intravascular ultrasound is able to discern most causes of ST. The aim of this study was to compare intravascular ultrasound findings between bare-metal stents (BMS) and drug-eluting stents (DES) in patients with late (31 days to 1 year) or very late ST (> 1 year). Of 250 consecutive patients with late or very late ST in 7 Spanish institutions, 114 patients (45.5% BMS and 54.5% DES) were imaged with intravascular ultrasound. Off-line intravascular ultrasound analysis was performed to assess malapposition, underexpansion, and neoatherosclerosis. The median time from stent implantation to ST was 4.0 years with BMS and 3.4 years with DES (P = .04). Isolated malapposition was similarly observed in both groups (36.5% vs 46.8%; P = .18) but was numerically lower with BMS (26.6% vs 48.0%; P = .07) in patients with very late ST. Isolated underexpansion was similarly observed in both groups (13.5% vs 11.3%; P = .47). Isolated neoatherosclerosis occurred only in patients with very late ST and was more prevalent with BMS (22.9%) than with DES (6.0%); P = .02. At 2.9 years' follow-up, there were 0% and 6.9% cardiac deaths, respectively (P = .06) and recurrent ST occurred in 4.0% and 5.2% of patients, respectively (P = .60). Malapposition was the most common finding in patients with late and very late ST and is more prevalent with DES in very late ST. In contrast, neoatherosclerosis was exclusively observed in patients with very late ST and mainly with BMS. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Prostate Ultrasound

Medline Plus

Full Text Available ... be able to give a clearer picture of soft tissues that do not show up well on x-ray images. Ultrasound causes no health problems and may be repeated as often as is necessary if medically indicated. Ultrasound provides real-time imaging, making it a good tool for guiding ...

Counterbalancing the use of ultrasound contrast agents by a cavitation-regulated system.

Science.gov (United States)

Desjouy, C; Fouqueray, M; Lo, C W; Muleki Seya, P; Lee, J L; Bera, J C; Chen, W S; Inserra, C

2015-09-01

The stochastic behavior of cavitation can lead to major problems of initiation and maintenance of cavitation during sonication, responsible of poor reproducibility of US-induced bioeffects in the context of sonoporation for instance. To overcome these disadvantages, the injection of ultrasound contrast agents as cavitation nuclei ensures fast initiation and lower acoustic intensities required for cavitation activity. More recently, regulated-cavitation devices based on the real-time modulation of the applied acoustic intensity have shown their potential to maintain a stable cavitation state during an ultrasonic shot, in continuous or pulsed wave conditions. In this paper is investigated the interest, in terms of cavitation activity, of using such regulated-cavitation device or injecting ultrasound contrast agents in the sonicated medium. When using fixed applied acoustic intensity, results showed that introducing ultrasound contrast agents increases reproducibility of cavitation activity (coefficient of variation 62% and 22% without and with UCA, respectively). Moreover, the use of the regulated-cavitation device ensures a given cavitation activity (coefficient of variation less 0.4% in presence of UCAs or not). This highlights the interest of controlling cavitation over time to free cavitation-based application from the use of UCAs. Interestingly, during a one minute sonication, while ultrasound contrast agents progressively disappear, the regulated-cavitation device counterbalance their destruction to sustain a stable inertial cavitation activity. Copyright © 2015 Elsevier B.V. All rights reserved.

Adaptive ultrasound temperature imaging for monitoring radiofrequency ablation.

Directory of Open Access Journals (Sweden)

Yi-Da Liu

Full Text Available Radiofrequency ablation (RFA has been widely used as an alternative treatment modality for liver tumors. Monitoring the temperature distribution in the tissue during RFA is required to assess the thermal dosage. Ultrasound temperature imaging based on the detection of echo time shifts has received the most attention in the past decade. The coefficient k, connecting the temperature change and the echo time shift, is a medium-dependent parameter used to describe the confounding effects of changes in the speed of sound and thermal expansion as temperature increases. The current algorithm of temperature estimate based on echo time shift detection typically uses a constant k, resulting in estimation errors when ablation temperatures are higher than 50°C. This study proposes an adaptive-k algorithm that enables the automatic adjustment of the coefficient k during ultrasound temperature monitoring of RFA. To verify the proposed algorithm, RFA experiments on in vitro porcine liver samples (total n = 15 were performed using ablation powers of 10, 15, and 20 W. During RFA, a clinical ultrasound system equipped with a 7.5-MHz linear transducer was used to collect backscattered signals for ultrasound temperature imaging using the constant- and adaptive-k algorithms. Concurrently, an infrared imaging system and thermocouples were used to measure surface temperature distribution of the sample and internal ablation temperatures for comparisons with ultrasound estimates. Experimental results demonstrated that the proposed adaptive-k method improved the performance in visualizing the temperature distribution. In particular, the estimation errors were also reduced even when the temperature of the tissue is higher than 50°C. The proposed adaptive-k ultrasound temperature imaging strategy has potential to serve as a thermal dosage evaluation tool for monitoring high-temperature RFA.

Quantitative shear wave ultrasound elastography: initial experience in solid breast masses

OpenAIRE

Evans, Andrew; Whelehan, Patsy; Thomson, Kim; McLean, Denis; Brauer, Katrin; Purdie, Colin; Jordan, Lee; Baker, Lee; Thompson, Alastair

2010-01-01

Introduction Shear wave elastography is a new method of obtaining quantitative tissue elasticity data during breast ultrasound examinations. The aims of this study were (1) to determine the reproducibility of shear wave elastography (2) to correlate the elasticity values of a series of solid breast masses with histological findings and (3) to compare shear wave elastography with greyscale ultrasound for benign/malignant classification. Methods Using the Aixplorer® ultrasound system (SuperSoni...