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Sample records for endoscopic ultrasound elastography

  1. Endoscopic Ultrasound Elastography: Current Clinical Use in Pancreas.

    PubMed

    Mondal, Utpal; Henkes, Nichole; Patel, Sandeep; Rosenkranz, Laura

    2016-08-01

    Elastography is a newer technique for the assessment of tissue elasticity using ultrasound. Cancerous tissue is known to be stiffer (hence, less elastic) than corresponding healthy tissue, and as a result, could be identified in an elasticity-based imaging. Ultrasound elastography has been used in the breast, thyroid, and cervix to differentiate malignant from benign neoplasms and to guide or avoid unnecessary biopsies. In the liver, elastography has enabled a noninvasive and reliable estimate of fibrosis. Endoscopic ultrasound has become a robust diagnostic and therapeutic tool for the management of pancreatic diseases. The addition of elastography to endoscopic ultrasound enabled further characterization of pancreas lesions, and several European and Asian studies have reported encouraging results. The current clinical role of endoscopic ultrasound elastography in the management of pancreas disorders and related literature are reviewed. PMID:26825864

  2. Endoscopic ultrasound elastography: Current status and future perspectives

    PubMed Central

    Cui, Xin-Wu; Chang, Jian-Min; Kan, Quan-Cheng; Chiorean, Liliana; Ignee, Andre; Dietrich, Christoph F

    2015-01-01

    Elastography is a new ultrasound modality that provides images and measurements related to tissue stiffness. Endoscopic ultrasound (EUS) has played an important role in the diagnosis and management of numerous abdominal and mediastinal diseases. Elastography by means of EUS examination can assess the elasticity of tumors in the proximity of the digestive tract that are hard to reach with conventional transcutaneous ultrasound probes, such as pancreatic masses and mediastinal or abdominal lymph nodes, thus improving the diagnostic yield of the procedure. Results from previous studies have promised benefits for EUS elastography in the differential diagnosis of lymph nodes, as well as for assessing masses with pancreatic or gastrointestinal (GI) tract locations. It is important to mention that EUS elastography is not considered a modality that can replace biopsy. However, it may be a useful adjunct, improving the accuracy of EUS-fine needle aspiration biopsy (EUS-FNAB) by selecting the most suspicious area to be targeted. Even more, it may be useful for guiding further clinical management when EUS-FNAB is negative or inconclusive. In the present paper we will discuss the current knowledge of EUS elastography, including the technical aspects, along with its applications in the differential diagnosis between benign and malignant solid pancreatic masses and lymph nodes, as well as its aid in the differentiation between normal pancreatic tissues and chronic pancreatitis. Moreover, the emergent indication and future perspectives are summarized, such as the benefit of EUS elastography in EUS-guided fine needle aspiration biopsy, and its uses for characterization of lesions in liver, biliary tract, adrenal glands and GI tract. PMID:26715804

  3. Endoscopic ultrasound elastography: Current status and future perspectives.

    PubMed

    Cui, Xin-Wu; Chang, Jian-Min; Kan, Quan-Cheng; Chiorean, Liliana; Ignee, Andre; Dietrich, Christoph F

    2015-12-21

    Elastography is a new ultrasound modality that provides images and measurements related to tissue stiffness. Endoscopic ultrasound (EUS) has played an important role in the diagnosis and management of numerous abdominal and mediastinal diseases. Elastography by means of EUS examination can assess the elasticity of tumors in the proximity of the digestive tract that are hard to reach with conventional transcutaneous ultrasound probes, such as pancreatic masses and mediastinal or abdominal lymph nodes, thus improving the diagnostic yield of the procedure. Results from previous studies have promised benefits for EUS elastography in the differential diagnosis of lymph nodes, as well as for assessing masses with pancreatic or gastrointestinal (GI) tract locations. It is important to mention that EUS elastography is not considered a modality that can replace biopsy. However, it may be a useful adjunct, improving the accuracy of EUS-fine needle aspiration biopsy (EUS-FNAB) by selecting the most suspicious area to be targeted. Even more, it may be useful for guiding further clinical management when EUS-FNAB is negative or inconclusive. In the present paper we will discuss the current knowledge of EUS elastography, including the technical aspects, along with its applications in the differential diagnosis between benign and malignant solid pancreatic masses and lymph nodes, as well as its aid in the differentiation between normal pancreatic tissues and chronic pancreatitis. Moreover, the emergent indication and future perspectives are summarized, such as the benefit of EUS elastography in EUS-guided fine needle aspiration biopsy, and its uses for characterization of lesions in liver, biliary tract, adrenal glands and GI tract. PMID:26715804

  4. Endobronchial ultrasound elastography

    PubMed Central

    Dietrich, Christoph F.; Jenssen, Christian; Herth, Felix J. F.

    2016-01-01

    Elastographic techniques have recently become available as advanced diagnostic tools for tissue characterization. Strain elastography is a real-time technique used with transcutaneous ultrasound (US) and endoscopic US. Convincing evidence is available demonstrating a significant value of strain elastography for the discrimination of benign and malignant lymph nodes (LNs). This paper reviews preliminary data demonstrating the feasibility of performing real-time elastography during endobronchial US (EBUS) and a potential application of this technique for selection of LNs for EBUS-guided transbronchial needle aspiration in patients with lung cancer and extrathoracic malignancies. PMID:27503154

  5. Contrast enhancement and elastography in endoscopic ultrasound: an update of clinical applications in pancreatic diseases.

    PubMed

    Serrani, Marta; Lisotti, Andrea; Caletti, Giancarlo; Fusaroli, Pietro

    2016-08-01

    It is well established that endoscopic ultrasound (EUS) is fundamental in the characterization of many diseases concerning different organs, i.e. pancreaticobiliary diseases, gastrointestinal pathologic conditions, and lymph nodes of unknown origin. It is also well known that many factors can hamper the accuracy of EUS, i.e. biliary stents, chronic pancreatitis, poor operator's expertise. These factors can also lead to suboptimal accuracy when cytological confirmation through EUS-fine needle aspiration (EUS-FNA) is indicated. In recent years, new technological tools have rapidly increased their clinical impact improving the diagnostic power of EUS and EUS-FNA. Among these new tools, the most investigated and useful ones are represented by contrast harmonic-EUS (CH-EUS) and EUS-elastography (EUS-E). The purpose of this paper is to provide, through a review of the literature, an update of the applications of CH-EUS and EUS-E in the routine clinical practice in pancreatic diseases. We discussed the first reports and applications of these techniques in our previous review published in Minerva Medica. The applications of CH-EUS and EUS-E to the study of pancreatic diseases appear feasible and safe. The use of both techniques is very simple and does not require any relevant additional workload for the endoscopic personnel. CH-EUS is now considered an important and accurate tool in the diagnosis of solid pancreatic masses and in the differential diagnosis of pancreatic cystic lesions. CH-EUS targeted FNA is an active field of research. However the available studies show that CH-EUS increases FNA accuracy by a little extent, without statistical significance; moreover, CH-EUS FNA showed a trend toward being more efficient vs. simple EUS FNA (less needle passes and more abundance in cytological material) but this trend did not reach statistical significance. On the other hand, the clinical impact of EUS-E in terms of differential diagnosis of pancreatic masses is still under

  6. Endoscopic ultrasound

    MedlinePlus

    Endoscopic ultrasound is a type of imaging test. It is used to see organs in and near the digestive ... Ultrasound is a way to see the inside of the body using high-frequency sound waves. Endoscopic ...

  7. Tracked ultrasound elastography (TRUE)

    NASA Astrophysics Data System (ADS)

    Foroughi, Pezhman

    Medical ultrasound research has experienced a renaissance in the past decade leading to innovations in flow mapping, elasticity and thermal imaging, measurement of optical properties, beamforming, and image enhancement. In this thesis, we focus on ultrasound elastography, an emerging imaging modality with great potential to become a part of several ultrasound diagnostic applications. Elastography images the stiffness of soft tissue by applying a mechanical stimulus and estimating the disturbance created by this stimulus. In freehand elastography, soft tissue is palpated by hand using the ultrasound transducer. The elastography image is generated by comparing the pre- and post-compression images to form a displacement map which is then differentiated to produce the final strain map. To achieve the best result in freehand elastography, the sonographer must compress and decompress the tissue uniformly in a specific direction with adequate compression. This can be a difficult task even for trained users. A small rotational or out-of-plane motion in the collected ultrasound frames can render them unusable for elastography. This has made freehand elastography highly qualitative and user-dependent. We tackle this issue by incorporating the extra information from a position sensor attached to the ultrasound transducer. Our aim is to show that the localization information of ultrasound images may be utilized to improve the quality and reliability of freehand elastography. For this purpose, we have developed a frame selection scheme that finds pairs of images with optimal compression and minimal lateral and out-of-plane displacement. Relying on the localization information, our algorithm merges multiple strain images computed from the selected frame pairs. This method is applicable to both 2D and 3D elastography. Our 3D elastography does not require for the transducer to be held still during the acquisition of each volume. Instead, the sonographer freely palpates the tissue

  8. Introduction to ultrasound elastography.

    PubMed

    Nowicki, Andrzej; Dobruch-Sobczak, Katarzyna

    2016-06-01

    For centuries tissue palpation has been an important diagnostic tool. During palpation, tumors are felt as tissues harder than the surrounding tissues. The significance of palpation is related to the relationship between mechanical properties of different tissue lesions. The assessment of tissue stiffness through palpation is based on the fact that mechanical properties of tissues are changing as a result of various diseases. A higher tissue stiffness translates into a higher elasticity modulus. In the 90's, ultrasonography was extended by the option of examining the stiffness of tissue by estimating the difference in backscattering of ultrasound in compressed and non-compressed tissue. This modality is referred to as the static, compression elastography and is based on tracking the deformation of tissue subjected to the slowly varying compression through the recording of the backscattered echoes. The displacement is estimated using the methods of cross-correlation between consecutive ultrasonic lines of examined tissue, so calculating the degree of similarity of ultrasonic echoes acquired from tissue before and after the compression was applied. The next step in the development of ultrasound palpation was to apply the local remote tissue compression by using the acoustic radiation force generated through the special beam forming of the ultrasonic beam probing the tissue. The acoustic radiation force causes a slight deformation the tissue thereby forming a shear wave propagating in the tissue at different speeds dependent on the stiffness of the tissue. Shear wave elastography, carries great hopes in the field of quantitative imaging of tissue lesions. This article describes the physical basis of both elastographic methods: compression elastography and shear wave elastography. PMID:27446596

  9. Introduction to ultrasound elastography

    PubMed Central

    Dobruch-Sobczak, Katarzyna

    2016-01-01

    For centuries tissue palpation has been an important diagnostic tool. During palpation, tumors are felt as tissues harder than the surrounding tissues. The significance of palpation is related to the relationship between mechanical properties of different tissue lesions. The assessment of tissue stiffness through palpation is based on the fact that mechanical properties of tissues are changing as a result of various diseases. A higher tissue stiffness translates into a higher elasticity modulus. In the 90's, ultrasonography was extended by the option of examining the stiffness of tissue by estimating the difference in backscattering of ultrasound in compressed and non-compressed tissue. This modality is referred to as the static, compression elastography and is based on tracking the deformation of tissue subjected to the slowly varying compression through the recording of the backscattered echoes. The displacement is estimated using the methods of cross-correlation between consecutive ultrasonic lines of examined tissue, so calculating the degree of similarity of ultrasonic echoes acquired from tissue before and after the compression was applied. The next step in the development of ultrasound palpation was to apply the local remote tissue compression by using the acoustic radiation force generated through the special beam forming of the ultrasonic beam probing the tissue. The acoustic radiation force causes a slight deformation the tissue thereby forming a shear wave propagating in the tissue at different speeds dependent on the stiffness of the tissue. Shear wave elastography, carries great hopes in the field of quantitative imaging of tissue lesions. This article describes the physical basis of both elastographic methods: compression elastography and shear wave elastography. PMID:27446596

  10. Real-time ultrasound elastography

    NASA Astrophysics Data System (ADS)

    Bae, Unmin; Kim, Yongmin

    2007-03-01

    Ultrasound elastography can provide tissue stiffness information that is complementary to the anatomy and blood flow information offered by conventional ultrasound machines, but it is computationally challenging due to many time-consuming modules and a large amount of data. To facilitate real-time implementations of ultrasound elastography, we have developed new methods that can significantly reduce the computational burden of common processing components in ultrasound elastography, such as the crosscorrelation analysis and spatial filtering applied to displacement and strain estimates. Using the new correlation-based search algorithm, the computational requirement of correlation-based search does not increase with the correlation window size. For typical parameters used in ultrasound elastography, the computation in correlation-based search can be reduced by a factor of more than 30. Median filtering is often performed to suppress the spike-like noise that results from correlation-based search. For fast median filtering, we have developed a method that efficiently finds a new median value utilizing the sort result of the previous pixel. With careful mapping of the new algorithms on digital signal processors, our work has led to development of a clinical ultrasound machine supporting real-time elastography. Our methods can help real-time implementations of various applications including ultrasound elastography, which could lead to increased use of ultrasound elastography in the clinic.

  11. Ultrasound Elastography in Breast Cancer Diagnosis.

    PubMed

    Carlsen, J; Ewertsen, C; Sletting, S; Vejborg, I; Schäfer, F K W; Cosgrove, D; Bachmann Nielsen, M

    2015-12-01

    Ultrasound elastography is an established method for characterization of focal lesions in the breast. Different techniques and analyses of the images may be used for the characterization. This article addresses the use of ultrasound elastography in breast cancer diagnosis. In the first part of the article the techniques behind both strain- and shear-wave-elastography are explained and followed by a section on how to obtain adequate elastography images and measurements. In the second part of the article the application of elastography as an adjunct to B-mode ultrasound in clinical practice is described, and the potential diagnostic gains and limitations of elastography are discussed. PMID:26274379

  12. Ultrasound elastography for musculoskeletal applications

    PubMed Central

    Drakonaki, E E; Allen, G M; Wilson, D J

    2012-01-01

    Ultrasound elastography (EUS) is a method to assess the mechanical properties of tissue, by applying stress and detecting tissue displacement using ultrasound. There are several EUS techniques used in clinical practice; strain (compression) EUS is the most common technique that allows real-time visualisation of the elastographic map on the screen. There is increasing evidence that EUS can be used to measure the mechanical properties of musculoskeletal tissue in clinical practice, with the future potential for early diagnosis to both guide and monitor therapy. This review describes the various EUS techniques available for clinical use, presents the published evidence on musculoskeletal applications of EUS and discusses the technical issues, limitations and future perspectives of this method in the assessment of the musculoskeletal system. PMID:23091287

  13. Ultrasound elastography: principles, techniques, and clinical applications.

    PubMed

    Dewall, Ryan J

    2013-01-01

    Ultrasound elastography is an emerging set of imaging modalities used to image tissue elasticity and are often referred to as virtual palpation. These techniques have proven effective in detecting and assessing many different pathologies, because tissue mechanical changes often correlate with tissue pathological changes. This article reviews the principles of ultrasound elastography, many of the ultrasound-based techniques, and popular clinical applications. Originally, elastography was a technique that imaged tissue strain by comparing pre- and postcompression ultrasound images. However, new techniques have been developed that use different excitation methods such as external vibration or acoustic radiation force. Some techniques track transient phenomena such as shear waves to quantitatively measure tissue elasticity. Clinical use of elastography is increasing, with applications including lesion detection and classification, fibrosis staging, treatment monitoring, vascular imaging, and musculoskeletal applications. PMID:23510006

  14. Ultrasound elastography for imaging tendons and muscles

    PubMed Central

    2012-01-01

    Ultrasound elastography is a recently developed ultrasound-based method which allows the qualitative or quantitative evaluation of the mechanical properties of tissue. Strain (compression) ultrasound elastography is the commonest technique performed by applying mild compression with the hand-held transducer to create real-time strain distribution maps, which are color-coded and superimposed on the B-mode images. There is increasing evidence that ultrasound elastography can be used in the investigation of muscle, tendon and soft tissue disease in the clinical practice, as a supplementary tool to conventional ultrasound examination. Based on preliminary data, potential clinical applications include early diagnosis, staging, and guiding interventions musculotendinous and neuromuscular disease as well as monitoring disease during rehabilitation. Ultrasound elastography could also be used for research into the biomechanics and pathophysiology of musculotendinous disease. Despite the great interest in the technique, there is still limited evidence in the literature and there are several technical issues which limit the reproducibility of the method, including differences in quantification methods, artefacts, limitations and variation in the application of the technique by different users. This review presents the published evidence on musculoskeletal applications of strain elastography, discusses the technical issues and future perspectives of this method and emphasizes the need for standardization and further research. PMID:26673318

  15. Ultrasound Elastography and MR Elastography for Assessing Liver Fibrosis: Part 1, Principles and Techniques

    PubMed Central

    Tang, An; Cloutier, Guy; Szeverenyi, Nikolaus M.; Sirlin, Claude B.

    2016-01-01

    Objective The purpose of this article is to provide an overview of ultrasound and magnetic resonance elastography, including a glossary of relevant terminology, a classification of elastography techniques, and a discussion of their respective strengths and limitations. Conclusion Elastography is an emerging technique for the non-invasive assessment of mechanical tissue properties. These techniques report metrics related to tissue stiffness such as shear wave speed, magnitude of the complex shear modulus, and Young’s modulus. PMID:25905647

  16. Endoscopic ultrasound in mediastinal tuberculosis

    PubMed Central

    Sharma, Malay; Ecka, Ruth Shifa; Somasundaram, Aravindh; Shoukat, Abid; Kirnake, Vijendra

    2016-01-01

    Background: Tubercular lymphadenitis is the commonest extra pulmonary manifestation in cervical and mediastinal locations. Normal characteristics of lymph nodes (LN) have been described on ultrasonography as well as by Endoscopic Ultrasound. Many ultrasonic features have been described for evaluation of mediastinal lymph nodes. The inter and intraobserver agreement of the endosonographic features have not been uniformly established. Methods and Results: A total of 266 patients underwent endoscopic ultrasound guided fine needle aspiration and 134 cases were diagnosed as mediastinal tuberculosis. The endoscopic ultrasound location and features of these lymph nodes are described. Conclusion: Our series demonstrates the utility of endoscopic ultrasound guided fine needle aspiration as the investigation of choice for diagnosis of mediastinal tuberculosis and also describes various endoscopic ultrasound features of such nodes. PMID:27051097

  17. Therapeutic Endoscopic Ultrasound

    PubMed Central

    Cheriyan, Danny

    2015-01-01

    Endoscopic ultrasound (EUS) technology has evolved dramatically over the past 20 years, from being a supplementary diagnostic aid available only in large medical centers to being a core diagnostic and therapeutic tool that is widely available. Although formal recommendations and practice guidelines have not been developed, there are considerable data supporting the use of EUS for its technical accuracy in diagnosing pancreaticobiliary and gastrointestinal pathology. Endosonography is now routine practice not only for pathologic diagnosis and tumor staging but also for drainage of cystic lesions and celiac plexus neurolysis. In this article, we cover the use of EUS in biliary and pancreatic intervention, ablative therapy, enterostomy, and vascular intervention. PMID:27118942

  18. Elastography: A New Ultrasound and MRI Procedure

    SciTech Connect

    Pavan, Theo Z.; Vieira, Silvio L.; Carneiro, Antonio A. O.

    2008-08-11

    Elastography is an imaging technique whereby local tissue strains are estimated from small displacements of internal tissue structure. These displacements are generated from a weak, quasi-static or dynamic stress field. Displacement evaluation through ultrasound is based on time delay estimation between speckle patterns of echo maps acquired for different levels of tissue deformation. A classical model of deformation is applying a quasi-static compression on a sample during echoes acquisition. The elastogram map corresponds to the spatial derivation of the displacement map. By magnetic resonance, the displacement is evaluated from a map of phase acquired using a sequence gradient echo synchronized with a mechanical end sinusoidal excitation. The map of shear elastic modulus is obtained from the phase map.

  19. [Radiology Update Ultrasound Elastography – Quintessence for the Primary Care Physician].

    PubMed

    Franckenberg, Sabine; Gubler, Christoph; Frauenfelder, Thomas; Rominger, Marga

    2016-02-01

    Ultrasound elastography visualizes and measures elasticity of tissue. Depending on the methods there are four types of elastography: strain elastography (SE), transient elastography (TE), acoustic radiation force impulse imaging (ARFI) and shear wave elastography (SWE). Due to the fact that pathological changes in the tissue in most of the cases mean a lower elasticity, ultrasound elastography is able to diagnose diseases such as liver fibrosis, liver cirrhosis, to help in the diagnosis of suspicious lesions in mamma, prostate and thyroid gland. So far, ultrasound elastography is not yet able to replace other standardized diagnostic tools but can add valuable diagnostic information. PMID:26837322

  20. Ultrasound-based transient elastography compared to magnetic resonance elastography in soft tissue-mimicking gels.

    PubMed

    Oudry, Jennifer; Vappou, Jonathan; Choquet, Philippe; Willinger, Rémy; Sandrin, Laurent; Constantinesco, André

    2009-11-21

    Ultrasound-based transient elastography (TE) and magnetic resonance elastography (MRE) are increasingly used methods for the clinical evaluation of soft tissue mechanical properties and their alteration under diseased conditions. This study proposes a comparison between magnetic resonance elastography (MRE) and ultrasound-based transient elastography (TE). Both methods were tested on the same soft tissue-mimicking gels in a common frequency range in order to allow for direct quantitative comparison. For the four gels tested, relatively good agreement was found between the shear moduli measured by both methods, with an averaged relative difference of 23%. This study demonstrates that under the assumption of homogeneous media that are significantly more elastic than viscous, quantitative results obtained by both methods are comparable. PMID:19887718

  1. Liver ultrasound elastography: More than staging the disease

    PubMed Central

    Gherlan, George S

    2015-01-01

    Ultrasound elastography is perhaps the most important breakthrough in the evolution of ultrasonography in the last 15 years. Since transient elastography was introduced, many other methods have been developed and became more and more widely available. The value of ultrasound elastography in staging a chronic liver disease has been established by numerous studies. There have been many studies that have shown that using liver elastography it is possible to predict the presence of the complications of cirrhosis: portal hypertension, presence of esophageal varices (and even their risk of bleeding) and hepatocellular carcinoma. It has been shown that liver elastography can predict the progression of liver fibrosis and also the survival (hepatic events - free) of the patients with chronic liver diseases. These are the real quests of the clinicians, this is the ultimate scope of any medical investigation - to predict the outcome of a patient and to help making therapeutic decisions. I brought together only a small amount of the data that has already been written on this subject to support my affirmation that liver ultrasound elastography is more than a tool for staging the liver disease, but it is also comparable to a crystal ball which in the hands of a skilled clinician can reveal the future of the patient and can help to improve this future. PMID:26140079

  2. Liver ultrasound elastography: More than staging the disease.

    PubMed

    Gherlan, George S

    2015-06-28

    Ultrasound elastography is perhaps the most important breakthrough in the evolution of ultrasonography in the last 15 years. Since transient elastography was introduced, many other methods have been developed and became more and more widely available. The value of ultrasound elastography in staging a chronic liver disease has been established by numerous studies. There have been many studies that have shown that using liver elastography it is possible to predict the presence of the complications of cirrhosis: portal hypertension, presence of esophageal varices (and even their risk of bleeding) and hepatocellular carcinoma. It has been shown that liver elastography can predict the progression of liver fibrosis and also the survival (hepatic events - free) of the patients with chronic liver diseases. These are the real quests of the clinicians, this is the ultimate scope of any medical investigation - to predict the outcome of a patient and to help making therapeutic decisions. I brought together only a small amount of the data that has already been written on this subject to support my affirmation that liver ultrasound elastography is more than a tool for staging the liver disease, but it is also comparable to a crystal ball which in the hands of a skilled clinician can reveal the future of the patient and can help to improve this future. PMID:26140079

  3. Ultrasound elastography using empirical mode decomposition analysis.

    PubMed

    Sadeghi, Sajjad; Behnam, Hamid; Tavakkoli, Jahan

    2014-01-01

    Ultrasound elastography is a non-invasive method which images the elasticity of soft-tissues. To make an image, pre and after a small compression, ultrasound radio frequency (RF) signals are acquired and the time delays between them are estimated. The first differentiation of displacement estimations is called elastogram. In this study, we are going to make an elastogram using the processing method named empirical mode decomposition (EMD). EMD is an analytic technique which decomposes a complicated signal to a collection of simple signals called intrinsic mode functions (IMFs). The idea of paper is using these IMFs instead of primary RF signals. To implement the algorithms two different datasets selected. The first one was data from a sandwich structure of normal and cooked tissue. The second dataset consisted of around 180 frames acquired from a malignant breast tumor. For displacement estimating, two different methods, cross-correlation and wavelet transform, were used too and for evaluating the quality, two conventional parameters, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) calculated for each image. Results show that in both methods after using EMD the quality improves. In first dataset and cross correlation technique CNR and SNR improve about 16 dB and 9 dB respectively. In same dataset by using wavelet technique, the parameters show 14 dB and 10 dB improvement respectively. In second dataset (breast tumor data) CNR and SNR in cross correlation method improve 18 dB and 7 dB and in wavelet technique improve 17 dB and 6 dB respectively. PMID:24696805

  4. Dynamic programming on a tree for ultrasound elastography

    NASA Astrophysics Data System (ADS)

    Shams, Roozbeh; Boily, Mathieu; Martineau, Paul A.; Rivaz, Hassan

    2016-04-01

    Ultrasound Elastography is an emerging imaging technique that allows estimation of the mechanical characteristics of tissue. Two issues that need to be addressed before widespread use of elastography in clinical environments are real time constraints and deteriorating effects of signal decorrelation between pre- and post-compression images. Previous work has used Dynamic Programming (DP) to estimate tissue deformation. However, in case of large signal decorrelation, DP can fail. In this paper we, have proposed a novel solution to this problem by solving DP on a tree instead of a single Radio-Frequency line. Formulation of DP on a tree allows exploiting significantly more information, and as such, is more robust and accurate. Our results on phantom and in-vivo human data show that DP on tree significantly outperforms traditional DP in ultrasound elastography.

  5. Ultrasound Elastography and MR Elastography for Assessing Liver Fibrosis: Part 2, Diagnostic Performance, Confounders, and Future Directions

    PubMed Central

    Tang, An; Cloutier, Guy; Szeverenyi, Nikolaus M.; Sirlin, Claude B.

    2016-01-01

    OBJECTIVE The purpose of the article is to review the diagnostic performance of ultrasound and MR elastography techniques for detection and staging of liver fibrosis, the main current clinical applications of elastography in the abdomen. CONCLUSION Technical and instrument-related factors and biologic and patient-related factors may constitute potential confounders of stiffness measurements for assessment of liver fibrosis. Future developments may expand the scope of elastography for monitoring liver fibrosis and predict complications of chronic liver disease. PMID:25905762

  6. JSUM ultrasound elastography practice guidelines: breast.

    PubMed

    Nakashima, Kazutaka; Shiina, Tsuyoshi; Sakurai, Masaru; Enokido, Katsutoshi; Endo, Tokiko; Tsunoda, Hiroko; Takada, Etsuo; Umemoto, Takeshi; Ueno, Ei

    2013-10-01

    Ten years have passed since the first elastography application: Real-time Tissue Elastography™. Now there are several elastography applications in existence. The Quality Control Research Team of The Japan Association of Breast and Thyroid Sonology (JABTS) and the Breast Elasticity Imaging Terminology and Diagnostic Criteria Subcommittee, Terminology and Diagnostic Criteria Committee of the Japan Society of Ultrasonics in Medicine (JSUM) have advocated breast elastography classifications for exact knowledge and good clinical use. We suggest two types of classifications: the technical classification and the classification for interpretation. The technical classification has been created to use vibration energy and to make images, and also shows how to obtain a good elastic image. The classification for interpretation has been prepared on the basis of interpretation of evidence in this decade. Finally, we describe the character and specificity of each vender equipment. We expect the present guidelines to be useful for many physicians and examiners throughout the world. PMID:27277451

  7. Endoscopic Ultrasound: Indian Perspective.

    PubMed

    Vora, Agam

    2015-09-01

    Mediastinoscopy is a minimally invasive surgical procedure that allows visualization and tissue sampling of mediastinal nodes. Mediastinoscopy has been extremely valuable in the evaluation and staging of lung cancer and therefore has been considered the gold standard for this purpose for over 30 years. Historically, this procedure has been associated with a low morbidity and mortality and a high sensitivity for diagnosing lung cancer with certain procedural limitations. Recently, it has been reported that not only is mediastinoscopy use limited in community practice, concomitant biopsy rates are limited as well.1 While mediastinoscopy does provide a tissue diagnosis, the procedure has its limitations. Cervical mediastinoscopy allows access to nodal stations 2, 3, 4 and 7, leaving out commonly involved pulmonary ligament and aortopulmonary window nodes.1 It requires general anesthesia and has a morbidity of 1% and a mortality of 0.2%. The procedure adds considerable expense to the staging workup. The estimated current cost is $1,700 for the procedure alone and $7,500 for a mediastinoscopy with a 2-day hospital stay. This prompted the development of endobronchial ultrasound(EBUS) in the 1990s.2. PMID:27608860

  8. Real-time quasi-static ultrasound elastography

    PubMed Central

    Treece, Graham; Lindop, Joel; Chen, Lujie; Housden, James; Prager, Richard; Gee, Andrew

    2011-01-01

    Ultrasound elastography is a technique used for clinical imaging of tissue stiffness with a conventional ultrasound machine. It was first proposed two decades ago, but active research continues in this area to the present day. Numerous clinical applications have been investigated, mostly related to cancer imaging, and though these have yet to prove conclusive, the technique has seen increasing commercial and clinical interest. This paper presents a review of the most widely adopted, non-quantitative, techniques focusing on technical innovations rather than clinical applications. The review is not intended to be exhaustive, concentrating instead on placing the various techniques in context according to the authors' perspective of the field. PMID:22866230

  9. Possibilities of interventional endoscopic ultrasound

    PubMed Central

    Nishimura, Makoto; Togawa, Osamu; Matsukawa, Miho; Shono, Takashi; Ochiai, Yasutoshi; Nakao, Masamitsu; Ishikawa, Keiko; Arai, Shin; Kita, Hiroto

    2012-01-01

    Since endoscopic ultrasound (EUS) was developed in the 1990s, EUS has become widely accepted as an imaging tool. EUS is categorized into radial and linear in design. Radial endoscopes provide cross-sectional imaging of the mediastinum, gastrointestinal tract, liver, spleen, kidney, adrenal gland, and pancreas, which has highly accuracy in the T and N staging of esophageal, lung, gastric, rectal, and pancreatic cancer. Tumor staging is common indication of radial-EUS, and EUS-staging is predictive of surgical resectability. In contrast, linear array endoscope uses a side-viewing probe and has advantages in the ability to perform EUS-guides fine needle aspiration (EUS-FNA), which has been established for cytologic diagnosis. For example, EUS-FNA arrows accurate nodal staging of esophageal cancer before surgery, which provides more accurate assessment of nodes than radial-EUS imaging alone. EUS-FNA has been also commonly used for diagnose of pancreatic diseases because of the highly accuracy than US or computed tomography. EUS and EUS-FNA has been used not only for TNM staging and cytologic diagnosis of pancreatic cancer, but also for evaluation of chronic pancreatitis, pancreatic cystic lesions, and other pancreatic masses. More recently, EUS-FNA has developed into EUS-guided fine needle injection including EUS-guided celiac plexus neurolysis, celiac plexus block, and other “interventional EUS” procedures. In this review, we have summarized the new possibilities offered by “interventional EUS”. PMID:22816010

  10. Possibilities of interventional endoscopic ultrasound.

    PubMed

    Nishimura, Makoto; Togawa, Osamu; Matsukawa, Miho; Shono, Takashi; Ochiai, Yasutoshi; Nakao, Masamitsu; Ishikawa, Keiko; Arai, Shin; Kita, Hiroto

    2012-07-16

    Since endoscopic ultrasound (EUS) was developed in the 1990s, EUS has become widely accepted as an imaging tool. EUS is categorized into radial and linear in design. Radial endoscopes provide cross-sectional imaging of the mediastinum, gastrointestinal tract, liver, spleen, kidney, adrenal gland, and pancreas, which has highly accuracy in the T and N staging of esophageal, lung, gastric, rectal, and pancreatic cancer. Tumor staging is common indication of radial-EUS, and EUS-staging is predictive of surgical resectability. In contrast, linear array endoscope uses a side-viewing probe and has advantages in the ability to perform EUS-guides fine needle aspiration (EUS-FNA), which has been established for cytologic diagnosis. For example, EUS-FNA arrows accurate nodal staging of esophageal cancer before surgery, which provides more accurate assessment of nodes than radial-EUS imaging alone. EUS-FNA has been also commonly used for diagnose of pancreatic diseases because of the highly accuracy than US or computed tomography. EUS and EUS-FNA has been used not only for TNM staging and cytologic diagnosis of pancreatic cancer, but also for evaluation of chronic pancreatitis, pancreatic cystic lesions, and other pancreatic masses. More recently, EUS-FNA has developed into EUS-guided fine needle injection including EUS-guided celiac plexus neurolysis, celiac plexus block, and other "interventional EUS" procedures. In this review, we have summarized the new possibilities offered by "interventional EUS". PMID:22816010

  11. Therapeutic aspects of endoscopic ultrasound

    NASA Astrophysics Data System (ADS)

    Woodward, Timothy A.

    1999-06-01

    Endoscopic ultrasound (EUS) is a technology that had been used primarily as a passive imaging modality. Recent advances have enabled us to move beyond the use of EUS solely as a staging tool to an interventional device. Current studies suggest that interventional applications of EUS will allow for minimally invasive assessment and therapies in a cost-effective manner. Endoscopic ultrasound with fine needle aspiration (EUS-FNA) has been demonstrated to be a technically feasible, relatively safe method of obtaining cytologic specimens. The clinical utility of EUS- FNA appears to be greatest in the diagnosis and staging of pancreatic cancer and in the nodal staging of gastrointestinal and pulmonary malignancies. In addition, EUS-FNA has demonstrated utility in the sampling pleural and ascitic fluid not generally appreciated or assessable to standard interventions. Interventional applications of EUS include EUS-guided pseudocyst drainage, EUS-guided injection of botulinum toxin in the treatment of achalasia, and EUS- guided celiac plexus neurolysis in the treatment of pancreatic cancer pain. Finally, EUS-guided fine-needle installation is being evaluated, in conjunction with recent bimolecular treatment modalities, as a delivery system in the treatment of certain gastrointestinal tumors.

  12. Contrast-Enhanced Endoscopic Ultrasound

    PubMed Central

    Dietrich, Christoph F.; Sharma, M.; Hocke, M.

    2012-01-01

    The European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) introduced guidelines on the use of contrast-enhanced ultrasound (CEUS) in 2004. This EFSUMB-document focused mainly on liver applications. However, new applications extending beyond the liver were developed thereafter. Increased interest in recent years in CEUS technique and in the application of CEUS in novel fields like endoscopic ultrasound (EUS) has revolutionized indications and applications. As a result, the EFSUMB initiated a new update of the guidelines in 2011 to include this additional knowledge. Some of the contrast-enhanced EUS (CE-EUS) indications are established, whereas others are preliminary; these latter indications are categorized as emergent CEUS applications since the available evidence is insufficient for general recommendation. This article focuses on the use of CE-EUS in various clinical settings. The reader will get an overview of current indications and possible applications of CE-EUS. This involves the introduction of different contrast studies including color Doppler techniques (known as contrast-enhanced high mechanical index endosonography or CEHMI-EUS) as well as more modern high-resolution contrast-enhanced techniques (known as contrast-enhanced low mechanical index endosonography or CELMI EUS). PMID:24949350

  13. Ultrasound elastography: enabling technology for image guided laparoscopic prostatectomy

    NASA Astrophysics Data System (ADS)

    Fleming, Ioana N.; Rivaz, Hassan; Macura, Katarzyna; Su, Li-Ming; Hamper, Ulrike; Lagoda, Gwen A.; Burnett, Arthur L., II; Lotan, Tamara; Taylor, Russell H.; Hager, Gregory D.; Boctor, Emad M.

    2009-02-01

    Radical prostatectomy using the laparoscopic and robot-assisted approach lacks tactile feedback. Without palpation, the surgeon needs an affordable imaging technology which can be easily incorporated into the laparoscopic surgical procedure, allowing for precise real time intraoperative tumor localization that will guide the extent of surgical resection. Ultrasound elastography (USE) is a novel ultrasound imaging technology that can detect differences in tissue density or stiffness based on tissue deformation. USE was evaluated here as an enabling technology for image guided laparoscopic prostatectomy. USE using a 2D Dynamic Programming (DP) algorithm was applied on data from ex vivo human prostate specimens. It proved consistent in identification of lesions; hard and soft, malignant and benign, located in the prostate's central gland or in the peripheral zone. We noticed the 2D DP method was able to generate low-noise elastograms using two frames belonging to the same compression or relaxation part of the palpation excitation, even at compression rates up to 10%. Good preliminary results were validated by pathology findings, and also by in vivo and ex vivo MR imaging. We also evaluated the use of ultrasound elastography for imaging cavernous nerves; here we present data from animal model experiments.

  14. Endoscopic ultrasound guided antitumor therapy.

    PubMed

    Bhutani, M S

    2003-08-01

    This paper will review the possibilities of EUS guided anti-tumor therapy. Ablative energy may be delivered to a tumor under EUS guidance to destruct tumor cells by ultrasound itself, radiofrequency or radiation. Pilot results of endoscopic high intensity focused ultrasound in a human trial have been reported. The feasibility of performing EUS guided radiofrequency ablation has been reported in a swine model. An EUS bases radiation target simulation method has been developed for anal cancer therapy. Targeted delivery of an anti-cancer agent into a tumor under EUS guidance is possible as reported in an early clinical trial of local immunotherapy (Cytoimplant) or modified viruses delivered by EUS guided fine needle injection in patients with advanced pancreatic carcinoma. Image guided injection of alcohol is another approach used for local tumor ablation. Application of other ablation therapies such as laser, microwave and cryo is also conceptually feasible. We will have to wait and see where these initial and ongoing attempts for applying EUS against cancer take us. PMID:12929056

  15. Endoscopic ultrasound guided interventional procedures

    PubMed Central

    Sharma, Vishal; Rana, Surinder S; Bhasin, Deepak K

    2015-01-01

    Endoscopic ultrasound (EUS) has emerged as an important diagnostic and therapeutic modality in the field of gastrointestinal endoscopy. EUS provides access to many organs and lesions which are in proximity to the gastrointestinal tract and thus giving an opportunity to target them for therapeutic and diagnostic purposes. This modality also provides a real time opportunity to target the required area while avoiding adjacent vascular and other structures. Therapeutic EUS has found role in management of pancreatic fluid collections, biliary and pancreatic duct drainage in cases of failed endoscopic retrograde cholangiopancreatography, drainage of gallbladder, celiac plexus neurolysis/blockage, drainage of mediastinal and intra-abdominal abscesses and collections and in targeted cancer chemotherapy and radiotherapy. Infact, therapeutic EUS has emerged as the therapy of choice for management of pancreatic pseudocysts and recent innovations like fully covered removable metallic stents have improved results in patients with organised necrosis. Similarly, EUS guided drainage of biliary tract and pancreatic duct helps drainage of these systems in patients with failed cannulation, inaccessible papilla as with duodenal/gastric obstruction or surgically altered anatomy. EUS guided gall bladder drainage is a useful emergent procedure in patients with acute cholecystitis who are not fit for surgery. EUS guided celiac plexus neurolysis and blockage is more effective and less morbid vis-à-vis the percutaneous technique. The field of interventional EUS is rapidly advancing and many more interventions are being continuously added. This review focuses on the current status of evidence vis-à-vis the established indications of therapeutic EUS. PMID:26078831

  16. A new shear wave imaging system for ultrasound elastography.

    PubMed

    Qiu, Weibao; Wang, Congzhi; Xiao, Yang; Qian, Ming; Zheng, Hairong

    2015-08-01

    Ultrasound elastography is able to provide a non-invasive measurement of tissue elasticity properties. Shear wave imaging (SWI) technique is a quantitative method for tissue stiffness assessment. However, traditional SWI implementations cannot acquire 2D quantitative images of tissue elasticity distribution. In this study, a new shear wave imaging system is proposed and evaluated. Detailed delineation of hardware and image processing algorithms are presented. Programmable devices are selected to support flexible control of the system and the image processing algorithms. Analytic signal based cross-correlation method and a Radon transform based shear wave speed determination method are proposed with parallel computation ability. Tissue mimicking phantom imaging, and in vitro imaging measurements are conducted to demonstrate the performance of the proposed system. The system has the ability to provide a new choice for quantitative mapping of the tissue elasticity, and has good potential to be implemented into commercial ultrasound scanner. PMID:26737133

  17. Use of Ultrasound Elastography in the Assessment of the Musculoskeletal System.

    PubMed

    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

  18. Use of Ultrasound Elastography in the Assessment of the Musculoskeletal System

    PubMed Central

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

    2016-01-01

    Summary 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

  19. Pulmonary ultrasound elastography: a feasibility study with phantoms and ex-vivo tissue

    NASA Astrophysics Data System (ADS)

    Nguyen, Man Minh; Xie, Hua; Paluch, Kamila; Stanton, Douglas; Ramachandran, Bharat

    2013-03-01

    Elastography has become widely used for minimally invasive diagnosis in many tumors as seen with breast, liver and prostate. Among different modalities, ultrasound-based elastography stands out due to its advantages including being safe, real-time, and relatively low-cost. While lung cancer is the leading cause of cancer mortality among both men and women, the use of ultrasound elastography for lung cancer diagnosis has hardly been investigated due to the limitations of ultrasound in air. In this work, we investigate the use of static-compression based endobronchial ultrasound elastography by a 3D trans-oesophageal echocardiography (TEE) transducer for lung cancer diagnosis. A water-filled balloon was designed to 1) improve the visualization of endobronchial ultrasound and 2) to induce compression via pumping motion inside the trachea and bronchiole. In a phantom study, we have successfully generated strain images indicating the stiffness difference between the gelatin background and agar inclusion. A similar strain ratio was confirmed with Philips ultrasound strain-based elastography product. For ex-vivo porcine lung study, different tissue ablation methods including chemical injection, Radio Frequency (RF) ablation, and direct heating were implemented to achieve tumor-mimicking tissue. Stiff ablated lung tissues were obtained and detected with our proposed method. These results suggest the feasibility of pulmonary elastography to differentiate stiff tumor tissue from normal tissue.

  20. Endoscopic ultrasound for the characterization and staging of rectal cancer. Current state of the method. Technological advances and perspectives.

    PubMed

    Gersak, Mariana M; Badea, Radu; Graur, Florin; Hajja, Nadim Al; Furcea, Luminita; Dudea, Sorin M

    2015-06-01

    Endoscopic ultrasound is the most accurate type of examination for the assessment of rectal tumors. Over the years, the method has advanced from gray-scale examination to intravenous contrast media administration and to different types of elastography. The multimodal approach of tumors (transrectal, transvaginal) is adapted to each case. 3D ultrasound is useful for spatial representation and precise measurement of tumor formations, using CT/MR image reconstruction; color elastography is useful for tumor characterization and staging; endoscopic ultrasound using intravenous contrast agents can help study the amount of contrast agent targeted at the level of the tumor formations and contrast wash-in/wash-out time, based on the curves displayed on the device. The transvaginal approach often allows better visualization of the tumor than the transrectal approach. Performing the procedure with the rectal ampulla distended with contrast agent may be seen as an optimization of the examination methodology. All these aspects are additional methods for gray-scale endoscopic ultrasound, capable of increasing diagnostic accuracy. This paper aims at reviewing the progress of transrectal and transvaginal ultrasound, generically called endoscopic ultrasound, for rectal tumor diagnosis and staging, with emphasis on the current state of the method and its development trends. PMID:26052575

  1. Hepatic applications of endoscopic ultrasound: Current status and future directions

    PubMed Central

    Srinivasan, Indu; Tang, Shou-Jiang; Vilmann, Andreas S; Menachery, John; Vilmann, Peter

    2015-01-01

    The diagnosis and staging of various gastrointestinal malignancies have been made possible with the use of endoscopic ultrasound, which is a relatively safe procedure. The field of endoscopic ultrasound is fast expanding due to advancements in therapeutic endoscopic ultrasound. Though various studies have established its role in gastrointestinal malignancies and pancreatic conditions, its potential in the field of hepatic lesions still remains vastly untapped. In this paper the authors attempt to review important and landmark trials, case series and case studies involving hepatic applications of endoscopic ultrasound, thus not only providing an overview of utilization of endoscopic ultrasound in various liver conditions but also speculating its future role. PMID:26640331

  2. Prostate clinical study of a full inversion unconstrained ultrasound elastography technique

    NASA Astrophysics Data System (ADS)

    Mousavi, S. Reza; Sadeghi-Naini, Ali; Czarnota, Gregory J.; Samani, Abbas

    2014-03-01

    Prostate cancer detection at early stages is crucial for desirable treatment outcome. Among available imaging modalities, ultrasound (US) elastography is being developed as an effective clinical tool for prostate cancer diagnosis. Current clinical US elastography systems utilise strain imaging where tissue strain images are generated to approximate the tissue elastic modulus distribution. While strain images can be generated in real-time fashion, they lack the accuracy necessary for having desirable sensitivity and specificity. To improve strain imaging, full inversion based elastography techniques were proposed. Among these techniques, a constrained elastography technique was developed which showed promising results as long as the tumor and prostate geometry can be obtained accurately from the imaging modality used in conjunction with the elastography system. This requirement is not easy to fulfill, especially with US imaging. To address this issue, we present an unconstrained full inversion prostate elastography method in conjunction with US imaging where knowledge of tissue geometry is not necessary. One of the reasons that full inversion elastography techniques have not been routinely used in the clinic is lack of clinical validation studies. To our knowledge, no quasistatic full inversion based prostate US elastography technique has been applied in vivo before. In this work, the proposed method was applied to clinical prostate data and reconstructed elasticity images were compared to corresponding annotated histopathology images which is the first quasi-static full inversion based prostate US elastography technique applied successfully in vivo. Results demonstrated a good potential for clinical utility of the proposed method.

  3. Two-dimensional shear-wave elastography on conventional ultrasound scanners with time-aligned sequential tracking (TAST) and comb-push ultrasound shear elastography (CUSE).

    PubMed

    Song, Pengfei; Macdonald, Michael; Behler, Russell; Lanning, Justin; Wang, Michael; Urban, Matthew; Manduca, Armando; Zhao, Heng; Callstrom, Matthew; Alizad, Azra; Greenleaf, James; Chen, Shigao

    2015-02-01

    Two-dimensional shear-wave elastography presents 2-D quantitative shear elasticity maps of tissue, which are clinically useful for both focal lesion detection and diffuse disease diagnosis. Realization of 2-D shear-wave elastography on conventional ultrasound scanners, however, is challenging because of the low tracking pulse-repetition-frequency (PRF) of these systems. Although some clinical and research platforms support software beamforming and plane-wave imaging with high PRF, the majority of current clinical ultrasound systems do not have the software beamforming capability, which presents a critical challenge for translating the 2-D shear-wave elastography technique from laboratory to clinical scanners. To address this challenge, this paper presents a time-aligned sequential tracking (TAST) method for shear-wave tracking on conventional ultrasound scanners. TAST takes advantage of the parallel beamforming capability of conventional systems and realizes high-PRF shear-wave tracking by sequentially firing tracking vectors and aligning shear wave data in the temporal direction. The comb-push ultrasound shear elastography (CUSE) technique was used to simultaneously produce multiple shear wave sources within the field-of-view (FOV) to enhance shear wave SNR and facilitate robust reconstructions of 2-D elasticity maps. TAST and CUSE were realized on a conventional ultrasound scanner. A phantom study showed that the shear-wave speed measurements from the conventional ultrasound scanner were in good agreement with the values measured from other 2-D shear wave imaging technologies. An inclusion phantom study showed that the conventional ultrasound scanner had comparable performance to a state-of-the-art shear-wave imaging system in terms of bias and precision in measuring different sized inclusions. Finally, in vivo case analysis of a breast with a malignant mass, and a liver from a healthy subject demonstrated the feasibility of using the conventional ultrasound

  4. An overview of endoscopic ultrasound equipment.

    PubMed

    LeBlanc, J K

    2008-06-01

    Endoscopic ultrasound imaging technology has significantly improved over the last decade. Innovative design of equipment and devices has broadened the utility of EUS as diagnostic and therapeutic tools. Lesions as small as 3 mm can be imaged and targeted for endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). EUS imaging with the latest generation electronic radial and linear scopes is excellent and does not vary significantly between models. Miniprobes should not be used in place of routine EUS echoendoscopes when available and technically feasible. The drawbacks of ultrasound miniprobes are the inability to perform fine needle aspiration and the limited depth of imaging. Transpapillary intraductal ultrasound (IDUS) improves staging of biliary tumors and improves imaging of biliary and pancreatic duct strictures. Endoscopic ultrasound-guided celiac plexus neurolysis or block (EUS-CPN/CPB) can be performed with the EUS-FNA needle or a specially designed celiac plexus block needle which distributes the neurolytic agent into the celiac plexus in a radial fashion. Use of the core biopsy needle is safe and should be used with a therapeutic linear scope through the gastric wall. PMID:18319690

  5. Evaluation of cervical stiffness during pregnancy using semiquantitative ultrasound elastography

    PubMed Central

    Hernandez-Andrade, Edgar; Hassan, Sonia S; Ahn, Hyunyoung; Korzeniewski, Steven J.; Yeo, Lami; Chaiworapongsa, Tinnakorn; Romero, Roberto

    2014-01-01

    Objective To evaluate cervical stiffness during pregnancy using ultrasound-derived elastography, a method used to estimate the average tissue displacement (strain) on a defined region of interest when oscillatory compression is applied. Methods Strain was calculated in two regions of interest, the endocervical canal and the entire cervix, from three anatomical planes of the cervix: mid-sagittal in the plane used for cervical length measurement, and in cross-sectional planes located at the internal and external cervical os. Associations between strain values, method of ascertainment and patient characteristics were assessed using linear mixed models to account for within-subject correlation. Inter-rater agreement in defining the degree of cervical stiffness was evaluated in 120 regions of interest acquired by two operators in 20 patients. Results A total of 1557 strain estimations were performed in 262 patients at 8-40 weeks of gestation. Adjusting for other sources of variation, 1) cervical tissue strain estimates obtained in the endocervical canal were on average 33% greater than those obtained in the entire cervix; 2) measures obtained in the cross-sectional plane of the external cervical os and sagittal plane were 45% and 13% greater compared to those measured in the cross-sectional plane of the internal cervical os, respectively; 3) mean strain rate was 14% and 5% greater among multiparous women with and without a history of preterm delivery compared to nulliparous women, respectively, and was on average 13% greater among women with a cervical length between 25-30mm compared to those with a cervical length >30mm; and 4) cervical tissue strain was more strongly associated with cervical length than with gestational age. Conclusion Semiquantitative elastography can be employed to evaluate changes in cervical stiffness during pregnancy. PMID:23151941

  6. WFUMB guidelines and recommendations for clinical use of ultrasound elastography: Part 3: liver.

    PubMed

    Ferraioli, Giovanna; Filice, Carlo; Castera, Laurent; Choi, Byung Ihn; Sporea, Ioan; Wilson, Stephanie R; Cosgrove, David; Dietrich, Christoph F; Amy, Dominique; Bamber, Jeffrey C; Barr, Richard; Chou, Yi-Hong; Ding, Hong; Farrokh, Andre; Friedrich-Rust, Mireen; Hall, Timothy J; Nakashima, Kazutaka; Nightingale, Kathryn R; Palmeri, Mark L; Schafer, Fritz; Shiina, Tsuyoshi; Suzuki, Shinichi; Kudo, Masatoshi

    2015-05-01

    The World Federation for Ultrasound in Medicine and Biology (WFUMB) has produced these guidelines for the use of elastography techniques in liver disease. For each available technique, the reproducibility, results, and limitations are analyzed, and recommendations are given. Finally, recommendations based on the international literature and the findings of the WFUMB expert group are established as answers to common questions. The document has a clinical perspective and is aimed at assessing the usefulness of elastography in the management of liver diseases. PMID:25800942

  7. Endoscopic Ultrasound-Assisted Pancreaticobiliary Access.

    PubMed

    Weilert, Frank; Binmoeller, Kenneth F

    2015-10-01

    Endoscopic retrograde cholangiopancreatography (ERCP) is the primary approach to drain an obstructed pancreatic or biliary duct. Failed biliary drainage is traditionally referred for percutaneous transhepatic biliary drainage or surgical bypass, which carry significantly higher morbidity and mortality rates compared with ERCP and transpapillary drainage. Endoscopic ultrasound provides a real-time imaging platform to access and deliver therapy to organs and tissues outside of the bowel lumen. The bile and pancreatic ducts can be directly accessed from the stomach and duodenum, offering an alternative to ERCP when this fails or is not feasible. PMID:26431606

  8. Thymic carcinoma diagnosed by using endoscopic ultrasound with fine-needle aspiration.

    PubMed

    Patel, Pragnesh; Guider, Julie; Rahimi, Erik; Guha, Sushovan; Zhang, Songlin; Thosani, Nirav

    2016-01-01

    There is a paucity of literature on the use of endoscopic ultrasound (EUS) for evaluating superior mediastinal structures, especially the thymus gland. We report a case of thymic carcinoma diagnosed by using EUS elastography with strain ratio and fine-needle aspiration (FNA). A 64-year-old woman presented with altered mental status and was diagnosed with autoimmune encephalitis. Further work-up suggested a superior mediastinal mass, for which she underwent EUS. A hypoechoic mass was found in the superior mediastinum at the level of the aortic arch. Real-time EUS elastography showed a predominantly blue hue to the mass concerning for malignancy. FNA of the mass was performed, which revealed numerous large neoplastic cells under a background of a small lymphoid infiltrate. Immunohistochemistry was strongly positive for PAX8, pancytokeratin, and CAM5.2. The pathologic and immunohistochemical stains were consistent with thymic carcinoma. PMID:27386480

  9. Thymic carcinoma diagnosed by using endoscopic ultrasound with fine-needle aspiration

    PubMed Central

    Patel, Pragnesh; Guider, Julie; Rahimi, Erik; Guha, Sushovan; Zhang, Songlin; Thosani, Nirav

    2016-01-01

    There is a paucity of literature on the use of endoscopic ultrasound (EUS) for evaluating superior mediastinal structures, especially the thymus gland. We report a case of thymic carcinoma diagnosed by using EUS elastography with strain ratio and fine-needle aspiration (FNA). A 64-year-old woman presented with altered mental status and was diagnosed with autoimmune encephalitis. Further work-up suggested a superior mediastinal mass, for which she underwent EUS. A hypoechoic mass was found in the superior mediastinum at the level of the aortic arch. Real-time EUS elastography showed a predominantly blue hue to the mass concerning for malignancy. FNA of the mass was performed, which revealed numerous large neoplastic cells under a background of a small lymphoid infiltrate. Immunohistochemistry was strongly positive for PAX8, pancytokeratin, and CAM5.2. The pathologic and immunohistochemical stains were consistent with thymic carcinoma. PMID:27386480

  10. System for robot-assisted real-time laparoscopic ultrasound elastography

    NASA Astrophysics Data System (ADS)

    Billings, Seth; Deshmukh, Nishikant; Kang, Hyun Jae; Taylor, Russell; Boctor, Emad M.

    2012-02-01

    Surgical robots provide many advantages for surgery, including minimal invasiveness, precise motion, high dexterity, and crisp stereovision. One limitation of current robotic procedures, compared to open surgery, is the loss of haptic information for such purposes as palpation, which can be very important in minimally invasive tumor resection. Numerous studies have reported the use of real-time ultrasound elastography, in conjunction with conventional B-mode ultrasound, to differentiate malignant from benign lesions. Several groups (including our own) have reported integration of ultrasound with the da Vinci robot, and ultrasound elastography is a very promising image guidance method for robotassisted procedures that will further enable the role of robots in interventions where precise knowledge of sub-surface anatomical features is crucial. We present a novel robot-assisted real-time ultrasound elastography system for minimally invasive robot-assisted interventions. Our system combines a da Vinci surgical robot with a non-clinical experimental software interface, a robotically articulated laparoscopic ultrasound probe, and our GPU-based elastography system. Elasticity and B-mode ultrasound images are displayed as picture-in-picture overlays in the da Vinci console. Our system minimizes dependence on human performance factors by incorporating computer-assisted motion control that automatically generates the tissue palpation required for elastography imaging, while leaving high-level control in the hands of the user. In addition to ensuring consistent strain imaging, the elastography assistance mode avoids the cognitive burden of tedious manual palpation. Preliminary tests of the system with an elasticity phantom demonstrate the ability to differentiate simulated lesions of varied stiffness and to clearly delineate lesion boundaries.

  11. Endoscopic Ultrasound in Gastroenteropancreatic Neuroendocrine Tumors

    PubMed Central

    2012-01-01

    Endoscopic ultrasound (EUS) is an advanced endoscopic technique currently used in the staging and diagnosis of many gastrointestinal neoplasms. The proximity of the echoendoscope to the gastrointestinal tract lends itself to a detailed view of the luminal pathology and the pancreas. This unique ability enables endoscopists to use EUS in patients with gastroenteropancreatic neuroendocrine tumors (GEP-NETs). Diagnostic EUS allows previously unidentified NETs to be localized. EUS also determines tumor management by staging the GEP-NETS, enabling the clinicians to choose the appropriate endoscopic or surgical management. The ability to obtain a tissue diagnosis with EUS guidance enables disease confirmation. Finally, recent developments suggest that EUS may be used to deliver therapeutic agents for the treatment of NETs. This review will highlight the advances in our knowledge of EUS in the clinical management of these tumors. PMID:23170141

  12. Ultrasound Elastography: The New Frontier in Direct Measurement of Muscle Stiffness

    PubMed Central

    Brandenburg, Joline E.; Eby, Sarah F.; Song, Pengfei; Zhao, Heng; Brault, Jeffrey S.; Chen, Shigao; An, Kai-Nan

    2014-01-01

    The use of brightness-mode ultrasound and Doppler ultrasound in physical medicine and rehabilitation has increased dramatically. The continuing evolution of ultrasound technology has also produced ultrasound elastography, a cutting-edge technology that can directly measure the mechanical properties of tissue, including muscle stiffness. Its real-time and direct measurements of muscle stiffness can aid the diagnosis and rehabilitation of acute musculoskeletal injuries and chronic myofascial pain. It can also help monitor outcomes of interventions affecting muscle in neuromuscular and musculoskeletal diseases, and it can better inform the functional prognosis. This technology has implications for even broader use of ultrasound in physical medicine and rehabilitation practice, but more knowledge about its uses and limitations is essential to its appropriate clinical implementation. In this review, we describe different ultrasound elastography techniques for studying muscle stiffness, including strain elastography, acoustic radiation force impulse imaging, and shear-wave elastography. We discuss the basic principles of these techniques, including the strengths and limitations of their measurement capabilities. We review the current muscle research, discuss physiatric clinical applications of these techniques, and note directions for future research. PMID:25064780

  13. WFUMB guidelines and recommendations for clinical use of ultrasound elastography: Part 2: breast.

    PubMed

    Barr, Richard G; Nakashima, Kazutaka; Amy, Dominique; Cosgrove, David; Farrokh, Andre; Schafer, Fritz; Bamber, Jeffrey C; Castera, Laurent; Choi, Byung Ihn; Chou, Yi-Hong; Dietrich, Christoph F; Ding, Hong; Ferraioli, Giovanna; Filice, Carlo; Friedrich-Rust, Mireen; Hall, Timothy J; Nightingale, Kathryn R; Palmeri, Mark L; Shiina, Tsuyoshi; Suzuki, Shinichi; Sporea, Ioan; Wilson, Stephanie; Kudo, Masatoshi

    2015-05-01

    The breast section of these Guidelines and Recommendations for Elastography produced under the auspices of the World Federation of Ultrasound in Medicine and Biology (WFUMB) assesses the clinically used applications of all forms of elastography used in breast imaging. The literature on various breast elastography techniques is reviewed, and recommendations are made on evidence-based results. Practical advice is given on how to perform and interpret breast elastography for optimal results, with emphasis placed on avoiding pitfalls. Artifacts are reviewed, and the clinical utility of some artifacts is discussed. Both strain and shear wave techniques have been shown to be highly accurate in characterizing breast lesions as benign or malignant. The relationship between the various techniques is discussed, and recommended interpretation based on a BI-RADS-like malignancy probability scale is provided. This document is intended to be used as a reference and to guide clinical users in a practical way. PMID:25795620

  14. Ultrasound elastography using carotid artery pulsation in the differential diagnosis of sonographically indeterminate thyroid nodules.

    PubMed

    Choi, Woo Jung; Park, Jeong Seon; Koo, Hye Ryoung; Kim, Soo-Yeon; Chung, Min Sung; Tae, Kyung

    2015-02-01

    OBJECTIVE. The purpose of this study was to evaluate the diagnostic performance of gray-scale ultrasound and a new method of thyroid ultrasound elastography using carotid artery pulsation in the differential diagnosis of sonographically indeterminate thyroid nodules. MATERIALS AND METHODS. A total of 102 thyroid nodules with indeterminate gray-scale ultrasound features from 102 patients (20 males and 82 females; age range, 16-74 years; mean age, 51 years) were included. The gray-scale ultrasound images of each nodule were reviewed and assigned a score from 1 (low) to 5 (high) according to the possibility of malignancy. Ultrasound elastography was performed using carotid pulsation as the compression source. The elasticity contrast index (ECI), which quantifies local strain contrast within a nodule, was automatically calculated. The radiologist reassessed the scores after concurrently reviewing gray-scale ultrasound and elastography. ROC curve analysis was used to evaluate the diagnostic performances of each dataset and to compare the AUC (Az) values of gray-scale ultrasound score alone, ECI alone, and a combined assessment. RESULTS. Significantly more malignant thyroid nodules were hypoechoic than benign nodules (p = 0.014). The ECI was significantly higher in malignant nodules than in benign thyroid nodules. The Az values of each dataset were 0.755 (95% CI, 0.660-0.835) for gray-scale ultrasound score, 0.835 (0.748-0.901) for ECI, and 0.853 (0.769-0.915) for a combined assessment. The Az value for a combined assessment of the gray-scale ultrasound score and the ECI was significantly higher than that for the gray-scale ultrasound score alone (p = 0.022). CONCLUSION. Combined assessment with gray-scale ultrasound and elastography using carotid artery pulsation is helpful for characterizing sonographically indeterminate thyroid nodules as benign or malignant. PMID:25615763

  15. Accuracy of localization of prostate lesions using manual palpation and ultrasound elastography

    NASA Astrophysics Data System (ADS)

    Kut, Carmen; Schneider, Caitlin; Carter-Monroe, Naima; Su, Li-Ming; Boctor, Emad; Taylor, Russell

    2009-02-01

    Purpose: To compare the accuracy of detecting tumor location and size in the prostate using both manual palpation and ultrasound elastography (UE). Methods: Tumors in the prostate were simulated using both synthetic and ex vivo tissue phantoms. 25 participants were asked to provide the presence, size and depth of these simulated lesions using manual palpation and UE. Ultrasound images were captured using a laparoscopic ultrasound probe, fitted with a Gore-Tetrad transducer with frequency of 7.5 MHz and a RF capture depth of 4-5 cm. A MATLAB GUI application was employed to process the RF data for ex vivo phantoms, and to generate UE images using a cross-correlation algorithm. Ultrasonix software was used to provide real time elastography during laparoscopic palpation of the synthetic phantoms. Statistical analyses were performed based on a two-tailed, student t-test with α = 0.05. Results: UE displays both a higher accuracy and specificity in tumor detection (sensitivity = 84%, specificity = 74%). Tumor diameters and depths are better estimated using ultrasound elastography when compared with manual palpation. Conclusions: Our results indicate that UE has strong potential in assisting surgeons to intra-operatively evaluate the tumor depth and size. We have also demonstrated that ultrasound elastography can be implemented in a laparoscopic environment, in which manual palpation would not be feasible. With further work, this application can provide accurate and clinically relevant information for surgeons during prostate resection.

  16. Value of ultrasound elastography in the diagnosis of native kidney fibrosis.

    PubMed

    Peride, Ileana; Rădulescu, Daniela; Niculae, Andrei; Ene, Vladimir; Bratu, Ovidiu Gabriel; Checheriță, Ionel Alexandru

    2016-09-01

    In the last decade, ultrasound elastography, an already widely used technique in the diagnosis of hepatic fibrosis, has raised the attention of nephrologists as a potential valuable noninvasive tool for the diagnosis of renal fibrosis. Due to renal deep location and anatomic complexity, the shear wave techniques are the most appropriate elastography methods for exploring native kidneys. Recent research offers promising results, but further larger studies are required for a better standardization of this method and also for establishing reference values of normal kidney elasticity. This article reviews the studies conducted for exploring the native kidney, highlighting the advantages and limitations of ultrasound elastography for assessing fibrosis development in chronic kidney diseases. PMID:27622414

  17. Reality named endoscopic ultrasound biliary drainage.

    PubMed

    Guedes, Hugo Gonçalo; Lopes, Roberto Iglesias; de Oliveira, Joel Fernandez; Artifon, Everson Luiz de Almeida

    2015-10-25

    Endoscopic ultrasound (EUS) is used for diagnosis and evaluation of many diseases of the gastrointestinal (GI) tract. In the past, it was used to guide a cholangiography, but nowadays it emerges as a powerful therapeutic tool in biliary drainage. The aims of this review are: outline the rationale for endoscopic ultrasound-guided biliary drainage (EGBD); detail the procedural technique; evaluate the clinical outcomes and limitations of the method; and provide recommendations for the practicing clinician. In cases of failed endoscopic retrograde cholangiopancreatography (ERCP), patients are usually referred for either percutaneous transhepatic biliary drainage (PTBD) or surgical bypass. Both these procedures have high rates of undesirable complications. EGBD is an attractive alternative to PTBD or surgery when ERCP fails. EGBD can be performed at two locations: transhepatic or extrahepatic, and the stent can be inserted in an antegrade or retrograde fashion. The drainage route can be transluminal, duodenal or transpapillary, which, again, can be antegrade or retrograde [rendezvous (EUS-RV)]. Complications of all techniques combined include pneumoperitoneum, bleeding, bile leak/peritonitis and cholangitis. We recommend EGBD when bile duct access is not possible because of failed cannulation, altered upper GI tract anatomy, gastric outlet obstruction, a distorted ampulla or a periampullary diverticulum, as a minimally invasive alternative to surgery or radiology. PMID:26504507

  18. Reality named endoscopic ultrasound biliary drainage

    PubMed Central

    Guedes, Hugo Gonçalo; Lopes, Roberto Iglesias; de Oliveira, Joel Fernandez; Artifon, Everson Luiz de Almeida

    2015-01-01

    Endoscopic ultrasound (EUS) is used for diagnosis and evaluation of many diseases of the gastrointestinal (GI) tract. In the past, it was used to guide a cholangiography, but nowadays it emerges as a powerful therapeutic tool in biliary drainage. The aims of this review are: outline the rationale for endoscopic ultrasound-guided biliary drainage (EGBD); detail the procedural technique; evaluate the clinical outcomes and limitations of the method; and provide recommendations for the practicing clinician. In cases of failed endoscopic retrograde cholangiopancreatography (ERCP), patients are usually referred for either percutaneous transhepatic biliary drainage (PTBD) or surgical bypass. Both these procedures have high rates of undesirable complications. EGBD is an attractive alternative to PTBD or surgery when ERCP fails. EGBD can be performed at two locations: transhepatic or extrahepatic, and the stent can be inserted in an antegrade or retrograde fashion. The drainage route can be transluminal, duodenal or transpapillary, which, again, can be antegrade or retrograde [rendezvous (EUS-RV)]. Complications of all techniques combined include pneumoperitoneum, bleeding, bile leak/peritonitis and cholangitis. We recommend EGBD when bile duct access is not possible because of failed cannulation, altered upper GI tract anatomy, gastric outlet obstruction, a distorted ampulla or a periampullary diverticulum, as a minimally invasive alternative to surgery or radiology. PMID:26504507

  19. Hydatid Cyst Diagnosed by Endoscopic Ultrasound.

    PubMed

    Castro-Poças, F; Araújo, Tarcísio; Coelho, André; Silva, Donzilia; Pedroto, Isabel

    2016-01-01

    A 69-year-old female with unremarkable past history underwent endoscopy for dyspepsia. She denied weight loss or anorexia. Upper endoscopy revealed a bulge in the lesser curvature and posterior wall of the stomach with 4-5 cm. Endoscopic ultrasound was performed which showed a heterogeneous lesion, anechogenic in the major part, with a floating membrane inside, the greatest diameter of 90.8 × 17.2 mm, originated in the left liver lobe. Surgical resection was performed. Pathologic examination revealed a cystic lesion with an acellular thick fibrous wall, surrounded by a conspicuous inflammatory reaction. The cyst wall revealed a characteristic lamellar pattern of the fibers. In the internal surface of the lesion, there were remains of membranous structures, amidst which a vestigial Protoscolex was noted. In the presented case, a floating membrane was observed, which is a pathognomonic feature, establishing the diagnosis of hydatid cyst type 3. Fine needle aspiration guided by ultrasound was not performed due to the certainty in the diagnosis. To the authors' knowledge, these are the first images by endoscopic ultrasound of hydatid cyst of liver presented as a bulge in the stomach with pathognomonic features, which allowed the definitive diagnosis with no need for further diagnostic tests. PMID:27446863

  20. Hydatid Cyst Diagnosed by Endoscopic Ultrasound

    PubMed Central

    Castro-Poças, F.; Araújo, Tarcísio; Coelho, André; Silva, Donzilia; Pedroto, Isabel

    2016-01-01

    A 69-year-old female with unremarkable past history underwent endoscopy for dyspepsia. She denied weight loss or anorexia. Upper endoscopy revealed a bulge in the lesser curvature and posterior wall of the stomach with 4-5 cm. Endoscopic ultrasound was performed which showed a heterogeneous lesion, anechogenic in the major part, with a floating membrane inside, the greatest diameter of 90.8 × 17.2 mm, originated in the left liver lobe. Surgical resection was performed. Pathologic examination revealed a cystic lesion with an acellular thick fibrous wall, surrounded by a conspicuous inflammatory reaction. The cyst wall revealed a characteristic lamellar pattern of the fibers. In the internal surface of the lesion, there were remains of membranous structures, amidst which a vestigial Protoscolex was noted. In the presented case, a floating membrane was observed, which is a pathognomonic feature, establishing the diagnosis of hydatid cyst type 3. Fine needle aspiration guided by ultrasound was not performed due to the certainty in the diagnosis. To the authors' knowledge, these are the first images by endoscopic ultrasound of hydatid cyst of liver presented as a bulge in the stomach with pathognomonic features, which allowed the definitive diagnosis with no need for further diagnostic tests. PMID:27446863

  1. Mirizzi Syndrome with Endoscopic Ultrasound Image

    PubMed Central

    Rayapudi, K.; Gholami, P.; Olyaee, M.

    2013-01-01

    We describe a 66-year-old Caucasian man with type 1 Mirizzi syndrome diagnosed on endoscopic ultrasound. He presented with acute onset of jaundice, malaise, dark urine over 3–4 days, and was found to have obstructive jaundice on lab testing. CT scan of the abdomen showed intrahepatic biliary ductal dilation, a 1.5 cm common bile duct (CBD) above the pancreas, and possible stones in the CBD, but no masses. Endoscopic retrograde cholangiopancreatography (ERCP) by a community gastroenterologist failed to cannulate the CBD. At the University Center, type 1 Mirizzi syndrome was noted on endoscopic ultrasound with narrowing of the CBD with extrinsic compression from cystic duct stone. During repeat ERCP, the CBD could be cannulated over the pancreatic duct wire. A mid CBD narrowing, distal CBD stones, proximal CBD and extrahepatic duct dilation were noted, and biliary sphincterotomy was performed. A small stone in the distal CBD was removed with an extraction balloon. The cystic duct stone was moved with the biliary balloon into the CBD, mechanical basket lithotripsy was performed and stone fragments were delivered out with an extraction balloon. The patient was seen 7 weeks later in the clinic. Skin and scleral icterus had cleared up and he is scheduled for an elective cholecystectomy. Mirizzi syndrome refers to biliary obstruction resulting from impacted stone in the cystic duct or neck of the gallbladder and commonly presents with obstructive jaundice. Type 1 does not have cholecystocholedochal fistulas, but they present in types 2, 3 and 4. Surgery is the mainstay of therapy. Endoscopic treatment is effective and can also be used as a temporizing measure or definitive treatment in poor surgical risk candidates. PMID:23741207

  2. Ultrasound-based elastography for the diagnosis of portal hypertension in cirrhotics

    PubMed Central

    Şirli, Roxana; Sporea, Ioan; Popescu, Alina; Dănilă, Mirela

    2015-01-01

    Progressive fibrosis is encountered in almost all chronic liver diseases. Its clinical signs are diagnostic in advanced cirrhosis, but compensated liver cirrhosis is harder to diagnose. Liver biopsy is still considered the reference method for staging the severity of fibrosis, but due to its drawbacks (inter and intra-observer variability, sampling errors, unequal distribution of fibrosis in the liver, and risk of complications and even death), non-invasive methods were developed to assess fibrosis (serologic and elastographic). Elastographic methods can be ultrasound-based or magnetic resonance imaging-based. All ultrasound-based elastographic methods are valuable for the early diagnosis of cirrhosis, especially transient elastography (TE) and acoustic radiation force impulse (ARFI) elastography, which have similar sensitivities and specificities, although ARFI has better feasibility. TE is a promising method for predicting portal hypertension in cirrhotic patients, but it cannot replace upper digestive endoscopy. The diagnostic accuracy of using ARFI in the liver to predict portal hypertension in cirrhotic patients is debatable, with controversial results in published studies. The accuracy of ARFI elastography may be significantly increased if spleen stiffness is assessed, either alone or in combination with liver stiffness and other parameters. Two-dimensional shear-wave elastography, the ElastPQ technique and strain elastography all need to be evaluated as predictors of portal hypertension. PMID:26556985

  3. Towards intraoperative monitoring of ablation using tracked 3D ultrasound elastography and internal palpation

    NASA Astrophysics Data System (ADS)

    Foroughi, Pezhman; Burgner, Jessica; Choti, Michael A.; Webster, Robert J., III; Hager, Gregory D.; Boctor, Emad M.

    2012-03-01

    B-mode ultrasound is widely used in liver ablation. However, the necrosis zone is typically not visible under b-mode ultrasound, since ablation does not necessarily change the acoustic properties of the tissue. In contrast, the change in tissue stiffness makes elastography ideal for monitoring ablation. Tissue palpation for elastography is typically applied at the imaging probe, by indenting it slightly into the tissue surface. However, in this paper we propose an alternate approach, where palpation is applied by a surgical instrument located inside the tissue. In our approach, the ablation needle is placed inside a steerable device called an active cannula and inserted into the tissue. A controlled motion is applied to the center of the ablation zone via the active cannula. Since the type and direction of motion is known, displacement can then be computed from two frames with the desired motion. The elastography results show the ablated region around the needle. While internal palpation provides excellent local contrast, freehand palpation from outside of the tissue via the transducer can provide a more global view of the region of the interest. For this purpose, we used a tracked 3D transducer to generate volumetric elastography images covering the ablated region. The tracking information is employed to improve the elastography results by selecting volume pairs suitable for elastography. This is an extension of our 2D frame selection technique which can cope with uncertainties associated with intra-operative elastography. In our experiments with phantom and ex-vivo tissue, we were able to generate high-quality images depicting the boundaries of the hard lesions.

  4. Generating Shear Waves in the Human Brain for Ultrasound Elastography: A new Approach

    NASA Astrophysics Data System (ADS)

    Nicolas, Emmanuel; Callé, Samuel; Remenieras, Jean-Pierre

    One of the challenges of brain elastography is the generation of the shear waves inside the brain. The generation system has to bypass the body's natural protection while keeping a good level of comfort for the patient. We propose a shear wave inducing system for brain ultrasound elastography. In this paper we will validate this system in vitro on a tissue mimicking phantom by doing shear wave velocity measurements. The system proves to work well on phantoms and to be comfortable for the patient. Further work will include measurements in vivo.

  5. Elastography Using Multi-Stream GPU: An Application to Online Tracked Ultrasound Elastography, In-Vivo and the da Vinci Surgical System

    PubMed Central

    Deshmukh, Nishikant P.; Kang, Hyun Jae; Billings, Seth D.; Taylor, Russell H.; Hager, Gregory D.; Boctor, Emad M.

    2014-01-01

    A system for real-time ultrasound (US) elastography will advance interventions for the diagnosis and treatment of cancer by advancing methods such as thermal monitoring of tissue ablation. A multi-stream graphics processing unit (GPU) based accelerated normalized cross-correlation (NCC) elastography, with a maximum frame rate of 78 frames per second, is presented in this paper. A study of NCC window size is undertaken to determine the effect on frame rate and the quality of output elastography images. This paper also presents a novel system for Online Tracked Ultrasound Elastography (O-TRuE), which extends prior work on an offline method. By tracking the US probe with an electromagnetic (EM) tracker, the system selects in-plane radio frequency (RF) data frames for generating high quality elastograms. A novel method for evaluating the quality of an elastography output stream is presented, suggesting that O-TRuE generates more stable elastograms than generated by untracked, free-hand palpation. Since EM tracking cannot be used in all systems, an integration of real-time elastography and the da Vinci Surgical System is presented and evaluated for elastography stream quality based on our metric. The da Vinci surgical robot is outfitted with a laparoscopic US probe, and palpation motions are autonomously generated by customized software. It is found that a stable output stream can be achieved, which is affected by both the frequency and amplitude of palpation. The GPU framework is validated using data from in-vivo pig liver ablation; the generated elastography images identify the ablated region, outlined more clearly than in the corresponding B-mode US images. PMID:25541954

  6. Elastography using multi-stream GPU: an application to online tracked ultrasound elastography, in-vivo and the da Vinci Surgical System.

    PubMed

    Deshmukh, Nishikant P; Kang, Hyun Jae; Billings, Seth D; Taylor, Russell H; Hager, Gregory D; Boctor, Emad M

    2014-01-01

    A system for real-time ultrasound (US) elastography will advance interventions for the diagnosis and treatment of cancer by advancing methods such as thermal monitoring of tissue ablation. A multi-stream graphics processing unit (GPU) based accelerated normalized cross-correlation (NCC) elastography, with a maximum frame rate of 78 frames per second, is presented in this paper. A study of NCC window size is undertaken to determine the effect on frame rate and the quality of output elastography images. This paper also presents a novel system for Online Tracked Ultrasound Elastography (O-TRuE), which extends prior work on an offline method. By tracking the US probe with an electromagnetic (EM) tracker, the system selects in-plane radio frequency (RF) data frames for generating high quality elastograms. A novel method for evaluating the quality of an elastography output stream is presented, suggesting that O-TRuE generates more stable elastograms than generated by untracked, free-hand palpation. Since EM tracking cannot be used in all systems, an integration of real-time elastography and the da Vinci Surgical System is presented and evaluated for elastography stream quality based on our metric. The da Vinci surgical robot is outfitted with a laparoscopic US probe, and palpation motions are autonomously generated by customized software. It is found that a stable output stream can be achieved, which is affected by both the frequency and amplitude of palpation. The GPU framework is validated using data from in-vivo pig liver ablation; the generated elastography images identify the ablated region, outlined more clearly than in the corresponding B-mode US images. PMID:25541954

  7. Advances in endoscopic ultrasound imaging of colorectal diseases

    PubMed Central

    Cârțână, Elena Tatiana; Gheonea, Dan Ionuț; Săftoiu, Adrian

    2016-01-01

    The development of endoscopic ultrasound (EUS) has had a significant impact for patients with digestive diseases, enabling enhanced diagnostic and therapeutic procedures, with most of the available evidence focusing on upper gastrointestinal (GI) and pancreatico-biliary diseases. For the lower GI tract the main application of EUS has been in staging rectal cancer, as a complementary technique to other cross-sectional imaging methods. EUS can provide highly accurate in-depth assessments of tumour infiltration, performing best in the diagnosis of early rectal tumours. In the light of recent developments other EUS applications for colorectal diseases have been also envisaged and are currently under investigation, including beyond-rectum tumour staging by means of the newly developed forward-viewing radial array echoendoscope. Due to its high resolution, EUS might be also regarded as an ideal method for the evaluation of subepithelial lesions. Their differential diagnosis is possible by imaging the originating wall layer and the associated echostructure, and cytological and histological confirmation can be obtained through EUS-guided fine needle aspiration or trucut biopsy. However, reports on the use of EUS in colorectal subepithelial lesions are currently limited. EUS allows detailed examination of perirectal and perianal complications in Crohn’s disease and, as a safe and less expensive investigation, can be used to monitor therapeutic response of fistulae, which seems to improve outcomes and reduce the need for additional surgery. Furthermore, EUS image enhancement techniques, such as the use of contrast agents or elastography, have recently been evaluated for colorectal indications as well. Possible applications of contrast enhancement include the assessment of tumour angiogenesis in colorectal cancer, the monitoring of disease activity in inflammatory bowel disease based on quantification of bowel wall vascularization, and differentiating between benign and

  8. Advances in endoscopic ultrasound imaging of colorectal diseases.

    PubMed

    Cârțână, Elena Tatiana; Gheonea, Dan Ionuț; Săftoiu, Adrian

    2016-02-01

    The development of endoscopic ultrasound (EUS) has had a significant impact for patients with digestive diseases, enabling enhanced diagnostic and therapeutic procedures, with most of the available evidence focusing on upper gastrointestinal (GI) and pancreatico-biliary diseases. For the lower GI tract the main application of EUS has been in staging rectal cancer, as a complementary technique to other cross-sectional imaging methods. EUS can provide highly accurate in-depth assessments of tumour infiltration, performing best in the diagnosis of early rectal tumours. In the light of recent developments other EUS applications for colorectal diseases have been also envisaged and are currently under investigation, including beyond-rectum tumour staging by means of the newly developed forward-viewing radial array echoendoscope. Due to its high resolution, EUS might be also regarded as an ideal method for the evaluation of subepithelial lesions. Their differential diagnosis is possible by imaging the originating wall layer and the associated echostructure, and cytological and histological confirmation can be obtained through EUS-guided fine needle aspiration or trucut biopsy. However, reports on the use of EUS in colorectal subepithelial lesions are currently limited. EUS allows detailed examination of perirectal and perianal complications in Crohn's disease and, as a safe and less expensive investigation, can be used to monitor therapeutic response of fistulae, which seems to improve outcomes and reduce the need for additional surgery. Furthermore, EUS image enhancement techniques, such as the use of contrast agents or elastography, have recently been evaluated for colorectal indications as well. Possible applications of contrast enhancement include the assessment of tumour angiogenesis in colorectal cancer, the monitoring of disease activity in inflammatory bowel disease based on quantification of bowel wall vascularization, and differentiating between benign and

  9. Ultrasound elastography in the head and neck. Part I. Basic principles and practical aspects

    PubMed Central

    Bhatia, Kunwar S.S.; Lee, Yolanda Y.P.; Yuen, Edmund H.Y.

    2013-01-01

    Abstract Ultrasound elastography (USE) is a rapidly developing field of imaging that measures and displays tissue elasticity or stiffness properties using ultrasound. In recent years, real-time USE modes have appeared on commercially available clinical ultrasound machines, stimulating an explosion of research into potential oncologic and non-oncologic clinical applications of USE. Preliminary evidence suggests that USE can differentiate benign and malignant conditions accurately in several different tissues. This article presents an overview of the basic principles of different USE technologies that are currently under investigation in the head and neck region. In addition, more practical aspects pertaining to the optimal performance of USE at this site are discussed. PMID:23876352

  10. Cross-Validation of Magnetic Resonance Elastography and Ultrasound-Based Transient Elastography: A Preliminary Phantom Study

    PubMed Central

    Chen, Jun; Glaser, Kevin J; Miette, Véronique; Sandrin, Laurent; Ehman, Richard L

    2010-01-01

    Purpose To cross-validate two recent noninvasive elastographic techniques, Ultrasound-based Transient Elastography (UTE) and Magnetic Resonance Elastography (MRE). As potential alternatives to liver biopsy, UTE and MRE are undergoing clinical investigations for liver fibrosis diagnosis and liver disease management around the world. These two techniques use tissue stiffness as a marker for disease state and it is important to do a cross-validation study of both elastographic techniques to determine the consistency with which the two techniques can measure the mechanical properties of materials. Materials and Methods In this paper, 19 well-characterized phantoms with a range of stiffness values were measured by two clinical devices (a Fibroscan and a MRE system based respectively on the UTE and MRE techniques) successively with the operators double-blinded. Results Statistical analysis showed that the correlation coefficient was r2=0.93 between MRE and UTE, and there was no evidence of a systematic difference between them within the range of stiffnesses examined. Conclusion These two noninvasive methods, MRE and UTE, provide clinicians with important new options for improving patient care regarding liver diseases in terms of the diagnosis, prognosis, and monitoring of fibrosis progression, as well for evaluating the efficacy of treatment. PMID:19856447

  11. Role of endoscopic ultrasound in pancreatic cancer.

    PubMed

    Chang, David K; Nguyen, Nam Q; Merrett, Neil D; Dixson, Hugh; Leong, Rupert W L; Biankin, Andrew V

    2009-06-01

    Pancreatic cancer (PC) is the fourth most common cause of cancer deaths in Western societies. It is an aggressive tumor with an overall 5-year survival rate of less than 5%. Surgical resection offers the only possibility of cure and long-term survival for patients suffering from PC; however, unfortunately, fewer than 20% of patients suffering from PC have disease that is amendable to surgical resection. Therefore, it is important to accurately diagnose and stage these patients to enable optimal treatment of their disease. The imaging modalities involved in the diagnosis and staging of PC include multidetector CT scanning, endoscopic ultrasound (EUS), endoscopic retrograde cholangiopancreaticography and MRI. The roles and relative importance of these imaging modalities have changed over the last few decades and continue to change owing to the rapid technological advances in medical imaging, but these investigations continue to be complementary. EUS was first introduced in the mid-1980s in Japan and Germany and has quickly gained acceptance. Its widespread use in the last decade has revolutionized the management of pancreatic disease as it simultaneously provides primary diagnostic and staging information, as well as enabling tissue biopsy. This article discusses the potential benefits and drawbacks of EUS in the primary diagnosis, staging and assessment of resectability, and EUS-guided fine-needle aspiration in PC. Difficult diagnostic scenarios and pitfalls are also discussed. A suggested management algorithm for patients with suspected PC is also presented. PMID:19485810

  12. Imaging of the pancreatic duct by linear endoscopic ultrasound

    PubMed Central

    Sharma, Malay; Rai, Praveer; Rameshbabu, Chittapuram Srinivasan; Arya, Shalini

    2015-01-01

    The current gold standard investigation for anatomic exploration of the pancreatic duct (PD) is endoscopic retrograde cholangiopancreatography. Magnetic resonance cholangiopancreatography is a noninvasive method for exploration of the PD. A comprehensive evaluation of the course of PD and its branches has not been described by endoscopic ultrasound (EUS). In this article, we describe the techniques of imaging of PD using linear EUS. PMID:26374577

  13. Object detection in ultrasound elastography for use in HIFU treatment of cancer

    NASA Astrophysics Data System (ADS)

    Huang, Alex; Mankani, Soumya; Choo, Chang

    2014-03-01

    High intensity focused ultrasound (HIFU), has applications in treating various cancers, such as prostate, liver and breast cancer. In order for HIFU to be effective and efficient it needs to be guided by an imaging modality. While there are several options for guiding HIFU treatment, one of the most promising is ultrasound elastography. Current commercial devices use Brightness-Mode (B-mode) imaging or MRI, and are manual processes. Ultrasound elastography, allows complete automation of HIFU treatment due to the enhanced image, that elastography provides. The elastic image provides more information and less noise. To show that segmentation was possible on elastic images, nine algorithms were implemented in matlab and used on three distinct images for object detection. The three images used, have varying properties regarding object intensity and placement, as well as different noise patterns. Using PSNR, to gauge the effectiveness of each algorithm, it was shown that segmentation was possible on all images using different algorithms. The bilateral-shock-bilateral algorithm proved to be an overall effective algorithm in every situation with a PSNR of 83.87db on the phantom image. The segmentation results clearly highlight any object in the images. Future work includes fine tuning the algorithm with different phantom images and in-vivo images to distinguish between noise and desired object.

  14. An H∞ Strategy for Strain Estimation in Ultrasound Elastography Using Biomechanical Modeling Constraint

    PubMed Central

    Yuan, Jinwei; Lu, Minhua; Chen, Siping; Liu, Huafeng

    2013-01-01

    The purpose of ultrasound elastography is to identify lesions by reconstructing the hardness characteristics of tissue reconstructed from ultrasound data. Conventional quasi-static ultrasound elastography is easily applied to obtain axial strain components along the compression direction, with the results inverted to represent the distribution of tissue hardness under the assumption of constant internal stresses. However, previous works of quasi-static ultrasound elastography have found it difficult to obtain the lateral and shear strain components, due to the poor lateral resolution of conventional ultrasound probes. The physical nature of the strain field is a continuous vector field, which should be fully described by the axial, lateral, and shear strain components, and the clinical value of lateral and shear strain components of deformed tissue is gradually being recognized by both engineers and clinicians. Therefore, a biomechanical-model-constrained filtering framework is proposed here for recovering a full displacement field at a high spatial resolution from the noisy ultrasound data. In our implementation, after the biomechanical model constraint is integrated into the state-space equation, both the axial and lateral displacement components can be recovered at a high spatial resolution from the noisy displacement measurements using a robust filter, which only requires knowledge of the worst-case noise levels in the measurements. All of the strain components can then be calculated by applying a gradient operator to the recovered displacement field. Numerical experiments on synthetic data demonstrated the robustness and effectiveness of our approach, and experiments on phantom data and in-vivo clinical data also produced satisfying results. PMID:24058460

  15. The use of 2D ultrasound elastography for measuring tendon motion and strain.

    PubMed

    Chernak Slane, Laura; Thelen, Darryl G

    2014-02-01

    The goal of the current study was to investigate the fidelity of a 2D ultrasound elastography method for the measurement of tendon motion and strain. Ultrasound phantoms and ex vivo porcine flexor tendons were cyclically stretched to 4% strain while cine ultrasound radiofrequency (RF) data and video data were simultaneously collected. 2D ultrasound elastography was used to estimate tissue motion and strain from RF data, and surface tissue motion and strain were separately estimated using digital image correlation (DIC). There were strong correlations (R(2)>0.97) between DIC and RF measurements of phantom displacement and strain, and good agreement in estimates of peak phantom strain (DIC: 3.5±0.2%; RF: 3.7±0.1%). For tendon, elastographic estimates of displacement profiles also correlated well with DIC measurements (R(2)>0.92), and exhibited similar estimated peak tendon strain (DIC: 2.6±1.4%; RF: 2.2±1.3%). Elastographic tracking with B-Mode images tended to under-predict peak strain for both the phantom and tendon. This study demonstrates the capacity to use quantitative elastographic techniques to measure tendon displacement and strain within an ultrasound image window. The approach may be extendible to in vivo use on humans, which would allow for the non-invasive analysis of tendon deformation in both normal and pathological states. PMID:24388164

  16. The Use of 2D Ultrasound Elastography for Measuring Tendon Motion and Strain

    PubMed Central

    Slane, Laura Chernak; Thelen, Darryl G.

    2014-01-01

    The goal of the current study was to investigate the fidelity of a 2D ultrasound elastography method for the measurement of tendon motion and strain. Ultrasound phantoms and ex vivo porcine flexor tendons were cyclically stretched to 4% strain while cine ultrasound radiofrequency (RF) data and video data were simultaneously collected. 2D ultrasound elastography was used to estimate tissue motion and strain from RF data, and surface tissue motion and strain were separately estimated using digital image correlation (DIC). There were strong correlations (R2 > 0.97) between DIC and RF measurements of phantom displacement and strain, and good agreement in estimates of peak phantom strain (DIC: 3.5 ± 0.2%; RF: 3.7 ± 0.1%). For tendon, elastographic estimates of displacement profiles also correlated well with DIC measurements (R2 > 0.92), and exhibited similar estimated peak tendon strain (DIC: 2.6 ± 1.4%; RF: 2.2 ± 1.3%). Elastographic tracking with B-Mode images tended to under-predict peak strain for both the phantom and tendon. This study demonstrates the capacity to use quantitative elastographic techniques to measure tendon displacement and strain within an ultrasound image window. The approach may be extendible to in vivo use on humans, which would allow for the non-invasive analysis of tendon deformation in both normal and pathological states. PMID:24388164

  17. Endoscopic Ultrasound Practice Survey in Latin America

    PubMed Central

    Drigo, Juliana Marques; Castillo, Cecilia; Wever, Wallia; Obaldía, José Ricardo Ruíz; Fillipi, Sheila; Ribeiro, Manoel C. S. A.; Rossini, Lucio G. B.

    2013-01-01

    Objective: Endoscopic ultrasound (EUS) has become an important imaging modality for the diagnosis, staging and treatment of gastrointestinal disorders. However, no official data exists regarding clinical EUS practice in Latin America (LA). This study assessed current EUS practice and training. Patients and Methods: A direct mail survey questionnaire was sent to 268 Capítulo Latino Americano de Ultrasonido Endoscópico members between August 2012 and January 2013. The questionnaire was sent out in English, Spanish and Portuguese languages and was available through the following site: http://www.cleus-encuesta.com. Responses were requested only from physicians who perform EUS. Results: A total of 70 LA physicians answered the questionnaire until January 2013. Most of the participants were under 42 years of age (53%) and 80% were men. Most participants (45.7%) perform EUS in Brazil, 53% work in a private hospital. The majority (70%) also perform endoscopic retrograde cholangiopancreatography. A total 42% had performed EUS for 2 years or less and 22.7% for 11 years or more. Only 10% performed more than 5000 EUS. The most common indication was an evaluation of pancreatic-biliary-ampullary lesions. Regarding training, 48.6% had more than 6 months of dedicated hands-on EUS and 37% think that at least 6 months of formal training is necessary to acquire competence. Furthermore, 64% think that more than 50 procedures for pancreatic-biliary lesions are necessary. Conclusion: This survey provides insight into the status of EUS in LA. EUS is performed mostly by young endoscopists in LA. Diagnostic upper EUS is the most common EUS procedure. Most endosonographers believe that formal training is necessary to acquire competence. PMID:24949398

  18. Ultrasound-assisted endoscopic partial plantar fascia release.

    PubMed

    Ohuchi, Hiroshi; Ichikawa, Ken; Shinga, Kotaro; Hattori, Soichi; Yamada, Shin; Takahashi, Kazuhisa

    2013-01-01

    Various surgical treatment procedures for plantar fasciitis, such as open surgery, percutaneous release, and endoscopic surgery, exist. Skin trouble, nerve disturbance, infection, and persistent pain associated with prolonged recovery time are complications of open surgery. Endoscopic partial plantar fascia release offers the surgeon clear visualization of the anatomy at the surgical site. However, the primary medial portal and portal tract used for this technique have been shown to be in close proximity to the posterior tibial nerves and their branches, and there is always the risk of nerve damage by introducing the endoscope deep to the plantar fascia. By performing endoscopic partial plantar fascia release under ultrasound assistance, we could dynamically visualize the direction of the endoscope and instrument introduction, thus preventing nerve damage from inadvertent insertion deep to the fascia. Full-thickness release of the plantar fascia at the ideal position could also be confirmed under ultrasound imaging. We discuss the technique for this new procedure. PMID:24265989

  19. Comb-push ultrasound shear elastography (CUSE) with various ultrasound push beams.

    PubMed

    Song, Pengfei; Urban, Matthew W; Manduca, Armando; Zhao, Heng; Greenleaf, James F; Chen, Shigao

    2013-08-01

    Comb-push ultrasound shear elastography (CUSE) has recently been shown to be a fast and accurate 2-D elasticity imaging technique that can provide a full field-of-view (FOV) shear wave speed map with only one rapid data acquisition. The initial version of CUSE was termed U-CUSE because unfocused ultrasound push beams were used. In this paper, we present two new versions of CUSE-focused CUSE (F-CUSE) and marching CUSE (M-CUSE), which use focused ultrasound push beams to improve acoustic radiation force penetration and produce stronger shear waves in deep tissues (e.g., kidney and liver). F-CUSE divides transducer elements into several subgroups which transmit multiple focused ultrasound beams simultaneously. M-CUSE uses more elements for each focused push beam and laterally marches the push beams. Both F-CUSE and M-CUSE can generate comb-shaped shear wave fields that have shear wave motion at each imaging pixel location so that a full FOV 2-D shear wave speed map can be reconstructed with only one data acquisition. Homogeneous phantom experiments showed that U-CUSE, F-CUSE, and M-CUSE can all produce smooth shear wave speed maps with accurate shear wave speed estimates. An inclusion phantom experiment showed that all CUSE methods could provide good contrast between the inclusion and background with sharp boundaries while F-CUSE and M-CUSE require shorter push durations to achieve shear wave speed maps with comparable SNR to U-CUSE. A more challenging inclusion phantom experiment with a very stiff and deep inclusion shows that better shear wave penetration could be gained by using F-CUSE and M-CUSE. Finally, a shallow inclusion experiment showed that good preservations of inclusion shapes could be achieved by both U-CUSE and F-CUSE in the near field. Safety measurements showed that all safety parameters are below FDA regulatory limits for all CUSE methods. These promising results suggest that, using various push beams, CUSE is capable of reconstructing a 2-D full FOV

  20. Tendon motion and strain patterns evaluated with two-dimensional ultrasound elastography.

    PubMed

    Chernak, Laura A; Thelen, Darryl G

    2012-10-11

    The purpose of this study was to evaluate the use of 2D ultrasound elastography to assess tendon tissue motion and strain under axial loading conditions. Four porcine flexor tendons were cyclically loaded to 4% peak strain using a servo hydraulic test system. An ultrasound transducer was positioned to image a longitudinal cross-section of the tendon during loading. Ultrasound radiofrequency (RF) data were collected at 63 frames per second simultaneously with applied force and crosshead displacement. A grid of nodes was manually positioned on an ultrasound image of the unloaded tendon. Small kernels (2×1 mm) centered at each node were then cross-correlated with search regions centered at corresponding nodal locations in the subsequent frame. Frame-to-frame nodal displacements were defined as the values that maximized the normalized cross-correlations. This process was repeated across all frames in the loading cycle, providing a measurement of the 2D trajectories of tissue motion throughout the loading cycle. The high resolution displacement measures along the RF beam direction were spatially differentiated to estimate the transverse (relative to tendon fibers) tissue strains. The nodal displacements obtained using this method were very repeatable, with average along-fiber trajectories that were highly correlated (average r=0.99) with the prescribed crosshead displacements. The elastography transverse strains were also repeatable and were consistent with average transverse strains estimated via changes in tendon width. The apparent Poisson's ratios (0.82-1.64) exceeded the incompressibility limit, but are comparable to values found for tendon in prior experimental and computational studies. The results demonstrate that 2D ultrasound elastography is a promising approach for noninvasively assessing localized tissue motion and strain patterns. PMID:22939179

  1. Tendon motion and strain patterns evaluated with two-dimensional ultrasound elastography

    PubMed Central

    Chernak, Laura A.; Thelen, Darryl G.

    2012-01-01

    The purpose of this study was to evaluate the use of 2D ultrasound elastography to assess tendon tissue motion and strains under axial loading conditions. Four porcine flexor tendons were cyclically loaded to 4% peak strain using a servo hydraulic test system. An ultrasound transducer was positioned to image a longitudinal cross-section of the tendon during loading. Ultrasound radiofrequency (RF) data were collected at 63 frames per second simultaneously with applied force and crosshead displacement. A grid of nodes was manually positioned on an ultrasound image of the unloaded tendon. Small kernels (2 × 1 mm) centered at each node were then cross-correlated with search regions centered at corresponding nodal locations in the subsequent frame. Frame-to-frame nodal displacements were defined as the values that maximized the normalized cross-correlations. This process was repeated across all frames in the loading cycle, providing a measurement of the 2D trajectories of tissue motion through out the loading cycle. The high resolution displacement measures along the RF beam direction were spatially differentiated to estimate the transverse (relative to tend on fibers) tissue strains. The nodal displacements obtained using this method were very repeatable, with average along-fiber trajectories that were highly correlated (r2>0.98) with the prescribed crosshead displacements. The elastography transverse strains were also repeatable and were consistent with average transverse strains estimated via changes in tendon width. The apparent Poisson’s ratios (0.82-1.64) exceeded the incompressibility limit, but are comparable to values found for tendon in prior experimental and computational studies. The results demonstrate that 2D ultrasound elastography is a promising approach for noninvasively assessing localized tissue motion and strain patterns. PMID:22939179

  2. Ultrasound Elastography for Estimation of Regional Strain of Multilayered Hydrogels and Tissue-Engineered Cartilage.

    PubMed

    Chung, Chen-Yuan; Heebner, Joseph; Baskaran, Harihara; Welter, Jean F; Mansour, Joseph M

    2015-12-01

    Tissue-engineered (TE) cartilage constructs tend to develop inhomogeneously, thus, to predict the mechanical performance of the tissue, conventional biomechanical testing, which yields average material properties, is of limited value. Rather, techniques for evaluating regional and depth-dependent properties of TE cartilage, preferably non-destructively, are required. The purpose of this study was to build upon our previous results and to investigate the feasibility of using ultrasound elastography to non-destructively assess the depth-dependent biomechanical characteristics of TE cartilage while in a sterile bioreactor. As a proof-of-concept, and to standardize an assessment protocol, a well-characterized three-layered hydrogel construct was used as a surrogate for TE cartilage, and was studied under controlled incremental compressions. The strain field of the construct predicted by elastography was then validated by comparison with a poroelastic finite-element analysis (FEA). On average, the differences between the strains predicted by elastography and the FEA were within 10%. Subsequently engineered cartilage tissue was evaluated in the same test fixture. Results from these examinations showed internal regions where the local strain was 1-2 orders of magnitude greater than that near the surface. These studies document the feasibility of using ultrasound to evaluate the mechanical behaviors of maturing TE constructs in a sterile environment. PMID:26077987

  3. External Vibration Multi-directional Ultrasound Shearwave Elastography (EVMUSE): Application in Liver Fibrosis Staging

    PubMed Central

    Zhao, Heng; Song, Pengfei; Meixner, Duane D.; Kinnick, Randall R.; Callstrom, Matthew R.; Sanchez, William; Urban, Matthew W.; Manduca, Armando; Greenleaf, James F.

    2014-01-01

    Shear wave speed can be used to assess tissue elasticity, which is associated with tissue health. Ultrasound shear wave elastography techniques based on measuring the propagation speed of the shear waves induced by acoustic radiation force are becoming promising alternatives to biopsy in liver fibrosis staging. However, shear waves generated by such methods are typically very weak. Therefore, the penetration may become problematic, especially for overweight or obese patients. In this study, we developed a new method called External Vibration Multi-directional Ultrasound Shearwave Elastography (EVMUSE), in which external vibration from a loudspeaker was used to generate a multi-directional shear wave field. A directional filter was then applied to separate the complex shear wave field into several shear wave fields propagating in different directions. A two-dimensional (2D) shear wave speed map was reconstructed from each individual shear wave field, and a final 2D shear wave speed map was constructed by compounding these individual wave speed maps. The method was validated using two homogeneous phantoms and one multi-purpose tissue-mimicking phantom. Ten patients undergoing liver Magnetic Resonance Elastography (MRE) were also studied with EVMUSE to compare results between the two methods. Phantom results showed EVMUSE was able to quantify tissue elasticity accurately with good penetration. In vivo EVMUSE results were well correlated with MRE results, indicating the promise of using EVMUSE for liver fibrosis staging. PMID:25020066

  4. External vibration multi-directional ultrasound shearwave elastography (EVMUSE): application in liver fibrosis staging.

    PubMed

    Zhao, Heng; Song, Pengfei; Meixner, Duane D; Kinnick, Randall R; Callstrom, Matthew R; Sanchez, William; Urban, Matthew W; Manduca, Armando; Greenleaf, James F; Chen, Shigao

    2014-11-01

    Shear wave speed can be used to assess tissue elasticity, which is associated with tissue health. Ultrasound shear wave elastography techniques based on measuring the propagation speed of the shear waves induced by acoustic radiation force are becoming promising alternatives to biopsy in liver fibrosis staging. However, shear waves generated by such methods are typically very weak. Therefore, the penetration may become problematic, especially for overweight or obese patients. In this study, we developed a new method called external vibration multi-directional ultrasound shearwave elastography (EVMUSE), in which external vibration from a loudspeaker was used to generate a multi-directional shear wave field. A directional filter was then applied to separate the complex shear wave field into several shear wave fields propagating in different directions. A 2-D shear wave speed map was reconstructed from each individual shear wave field, and a final 2-D shear wave speed map was constructed by compounding these individual wave speed maps. The method was validated using two homogeneous phantoms and one multi-purpose tissue-mimicking phantom. Ten patients undergoing liver magnetic resonance elastography (MRE) were also studied with EVMUSE to compare results between the two methods. Phantom results showed EVMUSE was able to quantify tissue elasticity accurately with good penetration. In vivo EVMUSE results were well correlated with MRE results, indicating the promise of using EVMUSE for liver fibrosis staging. PMID:25020066

  5. Elastography for the pancreas: Current status and future perspective

    PubMed Central

    Kawada, Natsuko; Tanaka, Sachiko

    2016-01-01

    Elastography for the pancreas can be performed by either ultrasound or endoscopic ultrasound (EUS). There are two types of pancreatic elastographies based on different principles, which are strain elastography and shear wave elastography. The stiffness of tissue is estimated by measuring the grade of strain generated by external pressure in the former, whereas it is estimated by measuring propagation speed of shear wave, the transverse wave, generated by acoustic radiation impulse (ARFI) in the latter. Strain elastography is difficult to perform when the probe, the pancreas and the aorta are not located in line. Accordingly, a fine elastogram can be easily obtained in the pancreatic body but not in the pancreatic head and tail. In contrast, shear wave elastography can be easily performed in the entire pancreas because ARFI can be emitted to wherever desired. However, shear wave elastography cannot be performed by EUS to date. Recently, clinical guidelines for elastography specialized in the pancreas were published from Japanese Society of Medical Ultrasonics. The guidelines show us technical knacks of performing elastography for the pancreas. PMID:27076756

  6. Interventional endoscopic ultrasound in pancreatic diseases.

    PubMed

    Buscail, Louis; Faure, Patrick; Bournet, Barbara; Selves, Janick; Escourrou, Jean

    2006-01-01

    During the last 15 years, endoscopic ultrasound (EUS) has become an important imaging procedure for diagnosis and management of pancreatic diseases. The clinical interest of EUS is now enhanced by interventional procedures. Noteworthy, fine-needle aspiration biopsy is one of the most important contributions of EUS, in particular for the investigation of patients with pancreatic cancer and cystic tumors. EUS-guided fine-needle aspiration appears to be a safe and reliable technique to obtain tissue from pancreatic masses with a low risk of complications. EUS became also a therapeutic procedure, especially applied for celiac plexus neurolysis, pseudocyst drainage, and pancreaticogastrostomy. Further developments are expected by improvement of needle devices such as pancreatic pseudocyst drainage kits. In the future, EUS might be also a support for local application of new treatments of pancreatic tumors, such as gene or cellular therapy products. In this review, we discuss the current clinical applications of interventional EUS and the future development for diagnosis and management of pancreatic diseases. PMID:16327280

  7. Detection and Measurement of Stones With Ultrasound Strain Elastography: A Phantom Study.

    PubMed

    Li, Qian; Chen, Lei; Halpern, Elkan F; Samir, Anthony E

    2015-12-01

    The sonoelastographic appearances of stones in a phantom were evaluated in this study. Ten stones were embedded into a tissue-mimicking meat phantom. The stone axial (vertical) and transverse (horizontal) dimensions measured by an electronic digital caliper, gray-scale ultrasound, and strain elastography (SE) were compared in 5 groups with stones embedded at different depths. In this study, physically measured axial and transverse stone dimensions were 1.17 to 6.86 and 1.30 to 11.15 mm, respectively. Strain elastography showed a characteristic 3-layer pattern associated with stones, comprising a superficial transition region, a hard region, and a deep transition region. As SE data were available in group 5, only data of groups 1 to 4 were analyzed. Compared with physical measurements, measurement mean errors of SE horizontal and SE vertical dimensions ranged from -0.20 to 0.42 mm and from -1.28 to -0.05 mm, respectively, in the 4 groups. Paired t testing demonstrated a significant horizontal dimension measurement error difference between B mode and SE method in group 4 (0.44 vs -0.20 mm, P < 0.05; F = 1.18, P > 0.05), but not in the other groups. Strain elastography horizontal dimension measurement error was not statistically correlated with stone size in the 4 groups. Strain elastography vertical dimension measurement error significantly correlated with stone size only in group 4 (P < 0.05). Preliminary results indicate that stone horizontal and vertical dimensions can be measured using SE in a soft tissue phantom, including when shadowing precludes measurement of vertical dimension on conventional 2-dimensional ultrasound. These results provide substantial motivation to further investigate SE as a modality to image stones in clinical practice. PMID:26656990

  8. Endoscopic ultrasound-guided drainage of pancreatic pseudocysts

    PubMed Central

    Săftoiu, Adrian; Vilmann, Andreas; Vilmann, Peter

    2015-01-01

    Pancreatic pseudocysts are fluid collections in the peripancreatic tissues associated with acute or chronic pancreatitis. Endoscopic ultrasound (EUS)-guided drainage has become an established indication, having better results as compared to percutaneous drainage, nonguided endoscopic drainage, or surgical drainage. The aim of this review is to assess critically the current literature concerning EUS-guided pseudocyst drainage and to review the place of the procedure in the clinical decision management algorithms of these patients. PMID:26643700

  9. Endoscopic ultrasound-guided drainage of pancreatic pseudocysts.

    PubMed

    Saftoiu, Adrian; Vilmann, Andreas; Vilmann, Peter

    2015-01-01

    Pancreatic pseudocysts are fluid collections in the peripancreatic tissues associated with acute or chronic pancreatitis. Endoscopic ultrasound (EUS)-guided drainage has become an established indication, having better results as compared to percutaneous drainage, nonguided endoscopic drainage, or surgical drainage. The aim of this review is to assess critically the current literature concerning EUS-guided pseudocyst drainage and to review the place of the procedure in the clinical decision management algorithms of these patients. PMID:26643700

  10. Ultrasound elastography assessment of bone/soft tissue interface

    NASA Astrophysics Data System (ADS)

    Parmar, Biren J.; Yang, Xu; Chaudhry, Anuj; Shafeeq Shajudeen, Peer; Nair, Sanjay P.; Weiner, Bradley K.; Tasciotti, Ennio; Krouskop, Thomas A.; Righetti, Raffaella

    2016-01-01

    We report on the use of elastographic imaging techniques to assess the bone/soft tissue interface, a region that has not been previously investigated but may provide important information about fracture and bone healing. The performance of axial strain elastograms and axial shear strain elastograms at the bone/soft tissue interface was studied ex vivo on intact and fractured canine and ovine tibias. Selected ex vivo results were corroborated on intact sheep tibias in vivo. The elastography results were statistically analyzed using elastographic image quality tools. The results of this study demonstrate distinct patterns in the distribution of the normalized local axial strains and axial shear strains at the bone/soft tissue interface with respect to the background soft tissue. They also show that the relative strength and distribution of the elastographic parameters change in the presence of a fracture and depend on the degree of misalignment between the fracture fragments. Thus, elastographic imaging modalities might be used in the future to obtain information regarding the integrity of bones and to assess the severity of fractures, alignment of bone fragments as well as to follow bone healing.

  11. Elastography Assessment of Liver Fibrosis: Society of Radiologists in Ultrasound Consensus Conference Statement.

    PubMed

    Barr, Richard G; Ferraioli, Giovanna; Palmeri, Mark L; Goodman, Zachary D; Garcia-Tsao, Guadalupe; Rubin, Jonathan; Garra, Brian; Myers, Robert P; Wilson, Stephanie R; Rubens, Deborah; Levine, Deborah

    2015-09-01

    The Society of Radiologists in Ultrasound convened a panel of specialists from radiology, hepatology, pathology, and basic science and physics to arrive at a consensus regarding the use of elastography in the assessment of liver fibrosis in chronic liver disease. The panel met in Denver, Colo, on October 21-22, 2014, and drafted this consensus statement. The recommendations in this statement are based on analysis of current literature and common practice strategies and are thought to represent a reasonable approach to the noninvasive assessment of diffuse liver fibrosis. PMID:26079489

  12. Endoscopic ultrasound: state-of-the-art GI tumor staging

    NASA Astrophysics Data System (ADS)

    Trowers, Eugene A.

    1999-06-01

    Videoendoscopy has truly enlarged the scope of diagnostic and therapeutic gastroenterology. However, videoendoscopic examinations are limited to the mucosal surface. Endoscopic ultrasound allows the endoscopist a view beyond the intestinal wall which opens the door to a variety of new gastroenterologic techniques. The evaluation of plain images in combination with contrast-enhanced imags has been found to be helpful when applied to CT and MRI. A similar advantage may be found for endoscopic ultrasound (EUS) studies. The efficacy of EUS with and without contrast enhancement is critically reviewed.

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

    PubMed Central

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

    2015-01-01

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

  14. Modeling transversely isotropic, viscoelastic, incompressible tissue-like materials with application in ultrasound shear wave elastography

    NASA Astrophysics Data System (ADS)

    Qiang, Bo; Brigham, John C.; Aristizabal, Sara; Greenleaf, James F.; Zhang, Xiaoming; Urban, Matthew W.

    2015-02-01

    In this paper, we propose a method to model the shear wave propagation in transversely isotropic, viscoelastic and incompressible media. The targeted application is ultrasound-based shear wave elastography for viscoelasticity measurements in anisotropic tissues such as the kidney and skeletal muscles. The proposed model predicts that if the viscoelastic parameters both across and along fiber directions can be characterized as a Voigt material, then the spatial phase velocity at any angle is also governed by a Voigt material model. Further, with the aid of Taylor expansions, it is shown that the spatial group velocity at any angle is close to a Voigt type for weakly attenuative materials within a certain bandwidth. The model is implemented in a finite element code by a time domain explicit integration scheme and shear wave simulations are conducted. The results of the simulations are analyzed to extract the shear wave elasticity and viscosity for both the spatial phase and group velocities. The estimated values match well with theoretical predictions. The proposed theory is further verified by an ex vivo tissue experiment measured in a porcine skeletal muscle by an ultrasound shear wave elastography method. The applicability of the Taylor expansion to analyze the spatial velocities is also discussed. We demonstrate that the approximations from the Taylor expansions are subject to errors when the viscosities across or along the fiber directions are large or the maximum frequency considered is beyond the bandwidth defined by radii of convergence of the Taylor expansions.

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

    PubMed

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

    2015-06-01

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

  16. Modeling Transversely Isotropic, Viscoelastic, Incompressible Tissue-like Materials with Application in Ultrasound Shear Wave Elastography

    PubMed Central

    Qiang, Bo; Brigham, John C.; Aristizabal, Sara; Greenleaf, James F.; Zhang, Xiaoming; Urban, Matthew W.

    2015-01-01

    In this paper, we propose a method to model the shear wave propagation in transversely isotropic, viscoelastic and incompressible media. The targeted application is ultrasound-based shear wave elastography for viscoelasticity measurements in anisotropic tissues such as the kidney and skeletal muscles. The proposed model predicts that if the viscoelastic parameters both across and along fiber directions can be characterized as a Voigt material, then the spatial phase velocity at any angle is also governed by a Voigt material model. Further, with the aid of Taylor expansions, it is shown that the spatial group velocity at any angle is close to a Voigt type for weakly attenuative materials within a certain bandwidth. The model is implemented in a finite element code by a time domain explicit integration scheme and shear wave simulations are conducted. The results of the simulations are analyzed to extract the shear wave elasticity and viscosity for both the spatial phase and group velocities. The estimated values match well with theoretical predictions. The proposed theory is further verified by an ex vivo tissue experiment measured in a porcine skeletal muscle by an ultrasound shear wave elastography method. The applicability of the Taylor expansion to analyze the spatial velocities is also discussed. We demonstrate that the approximations from the Taylor expansions are subject to errors when the viscosities across or along the fiber directions are large or the maximum frequency considered is beyond the bandwidth defined by radii of convergence of the Taylor expansions. PMID:25591921

  17. Endoscopic Ultrasound-Guided Therapies in Pancreatic Neoplasms

    PubMed Central

    Yang, Dennis; DiMaio, Christopher J.

    2015-01-01

    Endoscopic ultrasound (EUS) has evolved from being primarily a diagnostic modality into an interventional endoscopic tool for the management of both benign and malignant gastrointestinal illnesses. EUS-guided therapy has garnered particular interest as a minimally invasive approach for the treatment of pancreatic cancer, a disease often complicated by its aggressive course and poor survival. The potential advantage of an EUS-guided approach revolves around real-time imaging for targeted therapy of a difficult to reach organ. In this review, we focus on EUS-guided therapies for pancreatic neoplasms. PMID:25802863

  18. Effect of Calcifications on Breast Ultrasound Shear Wave Elastography: An Investigational Study

    PubMed Central

    Gregory, Adriana; Mehrmohammadi, Mohammad; Denis, Max; Bayat, Mahdi; Stan, Daniela L.; Fatemi, Mostafa; Alizad, Azra

    2015-01-01

    Purpose To investigate the effects of macrocalcifications and clustered microcalcifications associated with benign breast masses on shear wave elastography (SWE). Methods SuperSonic Imagine (SSI) and comb-push ultrasound shear elastography (CUSE) were performed on three sets of phantoms to investigate how calcifications of different sizes and distributions influence measured elasticity. To demonstrate the effect in vivo, three female patients with benign breast masses associated with mammographically-identified calcifications were evaluated by CUSE. Results Apparent maximum elasticity (Emax) estimates resulting from individual macrocalcifications (with diameters of 2mm, 3mm, 5mm, 6mm, 9mm, 11mm, and 15mm) showed values over 50 kPa for all cases, which represents more than 100% increase over background (~21kPa). We considered a 2cm-diameter circular region of interest for all phantom experiments. Mean elasticity (Emean) values varied from 26 kPa to 73 kPa, depending on the macrocalcification size. Highly dense clusters of microcalcifications showed higher Emax values than clusters of microcalcification with low concentrations, but the difference in Emean values was not significant. Conclusions Our results demonstrate that the presence of large isolated macrocalcifications and highly concentrated clusters of microcalcifications can introduce areas with apparent high elasticity in SWE. Considering that benign breast masses normally have significantly lower elasticity values than malignant tumors, such areas with high elasticity appearing due to presence of calcification in benign breast masses may lead to misdiagnosis. PMID:26368939

  19. Assessment of Diffuse Thyroid Disease by Strain Ratio in Ultrasound Elastography.

    PubMed

    Yang, Zhi; Zhang, Haixian; Wang, Kun; Cui, Guanghe; Fu, Fengkui

    2015-11-01

    The goal of this study was to explore the value of strain ratio from real-time elastography in the semi-quantitative assessment of diffuse thyroid disease. Fifty-one patients with primary hyperthyroidism, 70 with Hashimoto's thyroiditis, 8 with subacute thyroiditis and 43 with normal healthy thyroids were recruited to measure the strain ratio (SR) of thyroid tissue and sternocleidomastoid muscle (on the same side of the thyroid). SR values of all groups were subjected to statistical analysis. The SRs (mean ± standard deviation) of patients with hyperthyroidism, Hashimoto's thyroiditis and subacute thyroiditis were 2.30 ± 1.08, 7.04 ± 7.74 and 24.09 ± 13.56, respectively. The SR of the control group was 1.76 ± 0.54. SR values ranked in ascending order were control group < hyperthyroidism group < Hashimoto's thyroiditis group < subacute thyroiditis group. There were statistically significant (p < 0.05) differences in thyroid hardness between groups with different diffuse thyroid diseases. SR values of the hyperthyroidism and control groups did not statistically differ (p > 0.05). It is feasible to assess diffuse thyroid disease with strain ratios obtained with ultrasound elastography. PMID:26306430

  20. Comb-push Ultrasound Shear Elastography (CUSE) for Evaluation of Thyroid Nodules: Preliminary In vivo Results

    PubMed Central

    Mehrmohammadi, Mohammad; Song, Pengfei; Meixner, Duane D.; Fazzio, Robert T.; Chen, Shigao; Greenleaf, James F.; Fatemi, Mostafa; Alizad, Azra

    2014-01-01

    In clinical practice, an overwhelming majority of biopsied thyroid nodules are benign. Therefore, there is a need for a complementary and noninvasive imaging tool to provide clinically relevant diagnostic information about thyroid nodules to reduce the rate of unnecessary biopsies. The goal of this study was to evaluate the feasibility of utilizing Comb-push Ultrasound Shear Elastography (CUSE) to measure the mechanical properties (i.e., stiffness) of thyroid nodules and use this information to help classify nodules as benign or malignant. CUSE is a fast and robust 2D shear elastography technique in which multiple laterally distributed acoustic radiation force beams are utilized simultaneously to produce shear waves. Unlike other shear elasticity imaging modalities, CUSE does not suffer from limited field of view (FOV) due to shear wave attenuation and can provide a large FOV at high frame rates. To evaluate the utility of CUSE in thyroid imaging, a preliminary study was performed on a group of 5 healthy volunteers and 10 patients with ultrasound (US)-detected thyroid nodules prior to fine needle aspiration biopsy (FNAB). The measured shear wave speeds in normal thyroid tissue and thyroid nodules were converted to Young's modulus (E), indicating a measure of tissue stiffness. Our results indicate an increase in E for thyroid nodules compared to normal thyroid tissue. This increase was significantly higher in malignant nodules compared to benign. The Young's modulus in normal thyroid tissue, benign and malignant nodules were found to be 23.2±8.29 kPa, 91.2±34.8 kPa, and 173.0±17.1 kPa, respectively. Results of this study suggest the utility of CUSE in differentiating between benign and malignant thyroid nodules. PMID:25122532

  1. Cervical strain determined by ultrasound elastography and its association with spontaneous preterm delivery

    PubMed Central

    Hernandez-Andrade, Edgar; Romero, Roberto; Korzeniewski, Steven J.; Ahn, Hyunyoung; Aurioles-Garibay, Alma; Garcia, Maynor; Schwartz, Alyse G.; Yeo, Lami; Chaiworapongsa, Tinnakorn; Hassan, Sonia S.

    2014-01-01

    Objective To determine if there is an association between cervical strain, evaluated using ultrasound elastography, and spontaneous preterm delivery (sPTD) <37 weeks of gestation. Methods One hundred and eighty nine (189) women at 16–24 weeks of gestation were evaluated. Ultrasound elastography was used to estimate cervical strain in three anatomical planes: one mid-sagittal in the same plane used for cervical length measurement, and two cross sectional images: one at the level of the internal cervical os, and the other at the level of the external cervical os. In each plane, two regions of interest (endocervix and entire cervix) were examined; a total of six regions of interest were evaluated. Results The prevalence of sPTD was 11% (21/189). Strain values from each of the six cervical regions correlated weakly with cervical length (r= −0.24, p<0.001 to r= −0.03, p=0.69). Strain measurements obtained in a cross sectional view of the internal cervical os were significantly associated with sPTD. Women with strain values ≤25th centile in the endocervical canal (0.19) and in the entire cervix (0.14) were 80% less likely to have a sPTD than women with strain values >25th centile (endocervical: odds ratio [OR] 0.2; 95% confidence interval [CI], 0.03–0.96; entire cervix: OR 0.17; 95% CI, 0.03–0.9). Additional adjustment for gestational age, race, smoking status, parity, maternal age, pre-pregnancy body mass index and previous preterm delivery did not appreciably alter the magnitude or statistical significance of these associations. Strain values obtained from the external cervical os and from the sagittal view were not associated with sPTD. Conclusion Low strain values in the internal cervical os were associated with a significantly lower risk of spontaneous preterm delivery <37 weeks of gestation. PMID:24356388

  2. Review of current and evolving clinical indications for endoscopic ultrasound

    PubMed Central

    Luthra, Anjuli K; Evans, John A

    2016-01-01

    For the first several years after its development, endoscopic ultrasound (EUS) was primarily limited to identification of pancreatic malignancies. Since this time, the field of EUS has advanced at a tremendous speed in terms of additional clinical diagnostic and therapeutic uses. The combination of ultrasound with endoscopy provides a unique interventional modality that is a minimally invasive alternative to various surgical interventions. Given the expanding recommended indications for EUS, this article will serve to review the most common uses with supporting evidence, while also exploring innovative endeavors that may soon become common clinical practice. PMID:26862365

  3. Microscale characterization of the viscoelastic properties of hydrogel biomaterials using dual-mode ultrasound elastography.

    PubMed

    Hong, Xiaowei; Stegemann, Jan P; Deng, Cheri X

    2016-05-01

    Characterization of the microscale mechanical properties of biomaterials is a key challenge in the field of mechanobiology. Dual-mode ultrasound elastography (DUE) uses high frequency focused ultrasound to induce compression in a sample, combined with interleaved ultrasound imaging to measure the resulting deformation. This technique can be used to non-invasively perform creep testing on hydrogel biomaterials to characterize their viscoelastic properties. DUE was applied to a range of hydrogel constructs consisting of either hydroxyapatite (HA)-doped agarose, HA-collagen, HA-fibrin, or preosteoblast-seeded collagen constructs. DUE provided spatial and temporal mapping of local and bulk displacements and strains at high resolution. Hydrogel materials exhibited characteristic creep behavior, and the maximum strain and residual strain were both material- and concentration-dependent. Burger's viscoelastic model was used to extract characteristic parameters describing material behavior. Increased protein concentration resulted in greater stiffness and viscosity, but did not affect the viscoelastic time constant of acellular constructs. Collagen constructs exhibited significantly higher modulus and viscosity than fibrin constructs. Cell-seeded collagen constructs became stiffer with altered mechanical behavior as they developed over time. Importantly, DUE also provides insight into the spatial variation of viscoelastic properties at sub-millimeter resolution, allowing interrogation of the interior of constructs. DUE presents a novel technique for non-invasively characterizing hydrogel materials at the microscale, and therefore may have unique utility in the study of mechanobiology and the characterization of hydrogel biomaterials. PMID:26928595

  4. Breast-lesion Segmentation Combining B-Mode and Elastography Ultrasound.

    PubMed

    Pons, Gerard; Martí, Joan; Martí, Robert; Ganau, Sergi; Noble, J Alison

    2016-05-01

    Breast ultrasound (BUS) imaging has become a crucial modality, especially for providing a complementary view when other modalities (i.e., mammography) are not conclusive in the task of assessing lesions. The specificity in cancer detection using BUS imaging is low. These false-positive findings often lead to an increase of unnecessary biopsies. In addition, increasing sensitivity is also challenging given that the presence of artifacts in the B-mode ultrasound (US) images can interfere with lesion detection. To deal with these problems and improve diagnosis accuracy, ultrasound elastography was introduced. This paper validates a novel lesion segmentation framework that takes intensity (B-mode) and strain information into account using a Markov Random Field (MRF) and a Maximum a Posteriori (MAP) approach, by applying it to clinical data. A total of 33 images from two different hospitals are used, composed of 14 cancerous and 19 benign lesions. Results show that combining both the B-mode and strain data in a unique framework improves segmentation results for cancerous lesions (Dice Similarity Coefficient of 0.49 using B-mode, while including strain data reaches 0.70), which are difficult images where the lesions appear with blurred and not well-defined boundaries. PMID:26062760

  5. Automated 3D ultrasound elastography of the breast: a phantom validation study

    NASA Astrophysics Data System (ADS)

    Hendriks, Gijs A. G. M.; Holländer, Branislav; Menssen, Jan; Milkowski, Andy; Hansen, Hendrik H. G.; de Korte, Chris L.

    2016-04-01

    In breast cancer screening, the automated breast volume scanner (ABVS) was introduced as an alternative for mammography since the latter technique is less suitable for women with dense breasts. Although clinical studies show promising results, clinicians report two disadvantages: long acquisition times (>90 s) introducing breathing artefacts, and high recall rates due to detection of many small lesions of uncertain malignant potential. Technical improvements for faster image acquisition and better discrimination between benign and malignant lesions are thus required. Therefore, the aim of this study was to investigate if 3D ultrasound elastography using plane-wave imaging is feasible. Strain images of a breast elastography phantom were acquired by an ABVS-mimicking device that allowed axial and elevational movement of the attached transducer. Pre- and post-deformation volumes were acquired with different constant speeds (between 1.25 and 40.0 mm s-1) and by three protocols: Go-Go (pre- and post-volumes with identical start and end positions), Go-Return (similar to Go-Go with opposite scanning directions) and Control (pre- and post-volumes acquired per position, this protocol can be seen as reference). Afterwards, 2D and 3D cross-correlation and strain algorithms were applied to the acquired volumes and the results were compared. The Go-Go protocol was shown to be superior with better strain image quality (CNRe and SNRe) than Go-Return and to be similar as Control. This can be attributed to applying opposite mechanical forces to the phantom during the Go-Return protocol, leading to out-of-plane motion. This motion was partly compensated by using 3D cross-correlation. However, the quality was still inferior to Go-Go. Since these results were obtained in a phantom study with controlled deformations, the effect of possible uncontrolled in vivo tissue motion artefacts has to be addressed in future studies. In conclusion, it seems feasible to implement 3D ultrasound

  6. Automated 3D ultrasound elastography of the breast: a phantom validation study.

    PubMed

    Hendriks, Gijs A G M; Holländer, Branislav; Menssen, Jan; Milkowski, Andy; Hansen, Hendrik H G; de Korte, Chris L

    2016-04-01

    In breast cancer screening, the automated breast volume scanner (ABVS) was introduced as an alternative for mammography since the latter technique is less suitable for women with dense breasts. Although clinical studies show promising results, clinicians report two disadvantages: long acquisition times (>90 s) introducing breathing artefacts, and high recall rates due to detection of many small lesions of uncertain malignant potential. Technical improvements for faster image acquisition and better discrimination between benign and malignant lesions are thus required. Therefore, the aim of this study was to investigate if 3D ultrasound elastography using plane-wave imaging is feasible. Strain images of a breast elastography phantom were acquired by an ABVS-mimicking device that allowed axial and elevational movement of the attached transducer. Pre- and post-deformation volumes were acquired with different constant speeds (between 1.25 and 40.0 mm s(-1)) and by three protocols: Go-Go (pre- and post-volumes with identical start and end positions), Go-Return (similar to Go-Go with opposite scanning directions) and Control (pre- and post-volumes acquired per position, this protocol can be seen as reference). Afterwards, 2D and 3D cross-correlation and strain algorithms were applied to the acquired volumes and the results were compared. The Go-Go protocol was shown to be superior with better strain image quality (CNRe and SNRe) than Go-Return and to be similar as Control. This can be attributed to applying opposite mechanical forces to the phantom during the Go-Return protocol, leading to out-of-plane motion. This motion was partly compensated by using 3D cross-correlation. However, the quality was still inferior to Go-Go. Since these results were obtained in a phantom study with controlled deformations, the effect of possible uncontrolled in vivo tissue motion artefacts has to be addressed in future studies. In conclusion, it seems feasible to implement 3D

  7. Endoscopic ultrasound-guided drainage of pancreatic fluid collections

    PubMed Central

    Fabbri, Carlo; Luigiano, Carmelo; Maimone, Antonella; Polifemo, Anna Maria; Tarantino, Ilaria; Cennamo, Vincenzo

    2012-01-01

    Pancreatic fluid collections (PFCs) develop secondary to either fluid leakage or liquefaction of pancreatic necrosis following acute pancreatitis, chronic pancreatitis, surgery or abdominal trauma. Pancreatic fluid collections include acute fluid collections, acute and chronic pancreatic pseudocysts, pancreatic abscesses and pancreatic necrosis. Before the introduction of linear endoscopic ultrasound (EUS) in the 1990s and the subsequent development of endoscopic ultrasound-guided drainage (EUS-GD) procedures, the available options for drainage in symptomatic PFCs included surgical drainage, percutaneous drainage using radiological guidance and conventional endoscopic transmural drainage. In recent years, it has gradually been recognized that, due to its lower morbidity rate compared to the surgical and percutaneous approaches, endoscopic treatment may be the preferred first-line approach for managing symptomatic PFCs. Endoscopic ultrasound-guided drainage has the following advantages, when compared to other alternatives such as surgical, percutaneous and non-EUS-guided endoscopic drainage. EUS-GD is less invasive than surgery and therefore does not require general anesthesia. The morbidity rate is lower, recovery is faster and the costs are lower. EUS-GD can avoid local complications related to percutaneous drainage. Because the endoscope is placed adjacent to the fluid collection, it can have direct access to the fluid cavity, unlike percutaneous drainage which traverses the abdominal wall. Complications such as bleeding, inadvertent puncture of adjacent viscera, secondary infection and prolonged periods of drainage with resultant pancreatico-cutaneous fistulae may be avoided. The only difference between EUS and non-EUS drainage is the initial step, namely, gaining access to the pancreatic fluid collection. All the subsequent steps are similar, i.e., insertion of guide-wires with fluoroscopic guidance, balloon dilatation of the cystogastrostomy and insertion of

  8. Pancreatic cystic lesions: How endoscopic ultrasound morphology and endoscopic ultrasound fine needle aspiration help unlock the diagnostic puzzle

    PubMed Central

    Barresi, Luca; Tarantino, Ilaria; Granata, Antonino; Curcio, Gabriele; Traina, Mario

    2012-01-01

    Cystic lesions of the pancreas are being diagnosed with increasing frequency, covering a vast spectrum from benign to malignant and invasive lesions. Numerous investigations can be done to discriminate between benign and non-evolutive lesions from those that require surgery. At the moment, there is no single test that will allow a correct diagnosis in all cases. Endoscopic ultrasound (EUS) morphology, cyst fluid analysis and cytohistology with EUS-guided fine needle aspiration can aid in this difficult diagnosis. PMID:22720127

  9. [The role of endoscopic ultrasound in the diagnosis and therapy of gastrointestinal disorders].

    PubMed

    Czakó, László; Dubravcsik, Zsolt; Gasztonyi, Beáta; Hamvas, József; Pakodi, Ferenc; Szepes, Attila; Szepes, Zoltán

    2014-04-01

    Endoscopic ultrasound is one of those diagnostic methods in gastrointestinal endoscopy which has developed rapidly in the last decade and has became exceedingly available to visualize the walls of the internal organs in details corresponding to histological layers, or analyze the adjacent structures. Fine needles and other endoscopic accessories can be introduced into the neighbouring tissues under the guidance of endoscopic ultrasound, and diagnostic and minimally invasive therapeutic interventions can be performed. The endoscopic ultrasound became more widely available in Hungary in recent years. This review focuses on the indications, benefits and complications of diagnostic and therapeutic endoscopic ultrasound. We recommend this article to gastroenterologists, surgeons, internists, pulmonologists, and to specialists in oncology and radiology. This recommendation was based on the consensus of the Board members of the Endoscopic Ultrasound Section of the Hungarian Gastroenterological Society. PMID:24681675

  10. Ultrasound Elastography Used for Preventive Non-Invasive Screening in Early Detection of Liver Fibrosis

    PubMed Central

    Bert, Florian; Stahmeyer, Jona T.; Rossol, Siegbert

    2016-01-01

    Background Early discovery of liver fibrosis is becoming more popular because of enhanced incidence of hepatocellular carcinoma. Ultrasound-based liver elastography is a method used to approve suspected liver fibrosis or cirrhosis. We assessed the clinical usefulness of acoustic radiation force impulse shear wave elasticity imaging (ARFI-SWEI) as a preventive screening method to uncover fibrosis. Methods We screened 382 patients by native routine sonography for abnormal liver results and divided them into six groups: group 1: normal liver, groups 2-4: fatty liver grade I-III, group 5: liver cirrhosis, and group 6: inhomogenic liver tissue. Then ARFI-SWEI was performed and the results were compared with published shear wave velocity cut-off values that were predictive of each fibrosis stage (F0-4). A control group consisted of 20 healthy volunteers. Results The part of liver fibrosis ≥ F2 was in groups 1-4: 20-32%, group 5: 100%, and group 6: 91%. Main causes for fibrosis stage ≥ F2 were (non)-alcoholic steatohepatitis, chronic viral or autoimmune hepatitis and chronic heart failure. Conclusions Screening of the liver tissue in b-mode ultrasound can underestimate possible liver fibrosis; by using ARFI-SWEI, liver fibrosis can be uncovered early. It is a suitable preventive method comparable to colonoscopy for colon cancer. PMID:27540438

  11. C-plane Reconstructions from Sheaf Acquisition for Ultrasound Electrode Vibration Elastography

    PubMed Central

    Ingle, Atul; Varghese, Tomy

    2014-01-01

    This paper presents a novel algorithm for reconstructing and visualizing ablated volumes using radiofrequency ultrasound echo data acquired with the electrode vibration elastography approach. The ablation needle is vibrated using an actuator to generate shear wave pulses that are tracked in the ultrasound image plane at different locations away from the needle. This data is used for reconstructing shear wave velocity maps for each imaging plane. A C-plane reconstruction algorithm is proposed which estimates shear wave velocity values on a collection of transverse planes that are perpendicular to the imaging planes. The algorithm utilizes shear wave velocity maps from different imaging planes that share a common axis of intersection. These C-planes can be used to generate a 3D visualization of the ablated region. Experimental validation of this approach was carried out using data from a tissue mimicking phantom. The shear wave velocity estimates were within 20% of those obtained from a clinical scanner, and a contrast of over 4 dB was obtained between the stiff and soft regions of the phantom. PMID:25530690

  12. Multi-frame elastography using a handheld force-controlled ultrasound probe.

    PubMed

    Kuzmin, Andrey; Zakrzewski, Aaron M; Anthony, Brian W; Lempitsky, Victor

    2015-08-01

    We propose a new method for strain field estimation in quasi-static ultrasound elastography based on matching RF data frames of compressed tissues. The method benefits from using a handheld force-controlled ultrasound probe, which provides the contact force magnitude and therefore improves repeatability of displacement field estimation. The displacement field is estimated in a two-phase manner using triplets of RF data frames consisting of a pre-compression image and two post-compression images obtained with lower and higher compression ratios. First, a reliable displacement field estimate is calculated for the first post-compression frame. Second, we use this displacement estimate to warp the second post-compression frame while using linear elasticity to obtain an initial approximation. Final displacement estimation is refined using the warped image. The two-phase displacement estimation allows for higher compression ratios, thus increasing the practical resolution of the strain estimates. The strain field is computed from a displacement field using a smoothness- regularized energy functional, which takes into consideration local displacement estimation quality. The minimization is performed using an efficient primal-dual hybrid gradient algorithm, which can leverage the architecture of a graphical processing unit. The method is quantitatively evaluated using finite element simulations. We compute strain estimates for tissue-mimicking phantoms with known elastic properties and finally perform a qualitative validation using in vivo patient data. PMID:26276958

  13. WFUMB guidelines and recommendations for clinical use of ultrasound elastography: Part 1: basic principles and terminology.

    PubMed

    Shiina, Tsuyoshi; Nightingale, Kathryn R; Palmeri, Mark L; Hall, Timothy J; Bamber, Jeffrey C; Barr, Richard G; Castera, Laurent; Choi, Byung Ihn; Chou, Yi-Hong; Cosgrove, David; Dietrich, Christoph F; Ding, Hong; Amy, Dominique; Farrokh, Andre; Ferraioli, Giovanna; Filice, Carlo; Friedrich-Rust, Mireen; Nakashima, Kazutaka; Schafer, Fritz; Sporea, Ioan; Suzuki, Shinichi; Wilson, Stephanie; Kudo, Masatoshi

    2015-05-01

    Conventional diagnostic ultrasound images of the anatomy (as opposed to blood flow) reveal differences in the acoustic properties of soft tissues (mainly echogenicity but also, to some extent, attenuation), whereas ultrasound-based elasticity images are able to reveal the differences in the elastic properties of soft tissues (e.g., elasticity and viscosity). The benefit of elasticity imaging lies in the fact that many soft tissues can share similar ultrasonic echogenicities but may have different mechanical properties that can be used to clearly visualize normal anatomy and delineate pathologic lesions. Typically, all elasticity measurement and imaging methods introduce a mechanical excitation and monitor the resulting tissue response. Some of the most widely available commercial elasticity imaging methods are 'quasi-static' and use external tissue compression to generate images of the resulting tissue strain (or deformation). In addition, many manufacturers now provide shear wave imaging and measurement methods, which deliver stiffness images based upon the shear wave propagation speed. The goal of this review is to describe the fundamental physics and the associated terminology underlying these technologies. We have included a questions and answers section, an extensive appendix, and a glossary of terms in this manuscript. We have also endeavored to ensure that the terminology and descriptions, although not identical, are broadly compatible across the WFUMB and EFSUMB sets of guidelines on elastography (Bamber et al. 2013; Cosgrove et al. 2013). PMID:25805059

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

    PubMed Central

    Richards, Michael S.; Doyley, Marvin M.

    2013-01-01

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

  15. Endoscopic ultrasound using ultrasound probes for the diagnosis of early esophageal and gastric cancers.

    PubMed

    Yoshinaga, Shigetaka; Oda, Ichiro; Nonaka, Satoru; Kushima, Ryoji; Saito, Yutaka

    2012-06-16

    Endoscopic ultrasound (EUS) devices were first designed and manufactured more than 30 years ago, and since then investigators have reported EUS is effective for determining both the staging and the depth of invasion of esophageal and gastric cancers. We review the present status, the methods, and the findings of EUS when used to diagnose and stage early esophageal and gastric cancer. EUS using high-frequency ultrasound probes is more accurate than conventional EUS for the evaluation of the depth of invasion of superficial esophageal carcinoma. The rates of accurate evaluation of the depth of invasion by EUS using high-frequency ultrasound probes were 70%-88% for intramucosal cancer, and 83%-94% for submucosal invasive cancer. But the sensitivity of EUS using high-frequency ultrasound probes for the diagnosis of submucosal invasive cancer was relatively low, making it difficult to confirm minute submucosal invasion. The accuracy of EUS using high-frequency ultrasound probes for early gastric tumor classification can be up to 80% compared with 63% for conventional EUS, although the accuracy of EUS using high-frequency ultrasound probes relatively decreases for those patients with depressed-type lesions, undifferentiated cancer, concomitant ulceration, expanded indications, type 0-I lesions, and lesions located in the upper-third of the stomach. A 92% overall accuracy rate was achieved when both the endoscopic appearance and the findings from EUS using high-frequency ultrasound probes were considered together for tumor classification. Although EUS using high-frequency ultrasound probes has limitations, it has a high depth of invasion accuracy and is a useful procedure to distinguish lesions in the esophagus and stomach that are indicated for endoscopic resection. PMID:22720122

  16. Ultrasound Shear Wave Elastography for Liver Disease. A Critical Appraisal of the Many Actors on the Stage.

    PubMed

    Piscaglia, F; Salvatore, V; Mulazzani, L; Cantisani, V; Schiavone, C

    2016-02-01

    In the last 12 - 18 months nearly all ultrasound manufacturers have arrived to implement ultrasound shear wave elastography modality in their equipment for the assessment of chronic liver disease; the few remaining players are expected to follow in 2016.When all manufacturers rush to a new technology at the same time, it is evident that the clinical demand for this information is of utmost value. Around 1990, there was similar demand for color Doppler ultrasound; high demand for contrast-enhanced ultrasonography was evident at the beginning of this century, and around 2010 demand increased for strain elastography. However, some issues regarding the new shear wave ultrasound technologies must be noted to avoid misuse of the resulting information for clinical decisions. As new articles are expected to appear in 2016 reporting the findings of the new technologies from various companies, we felt that the beginning of this year was the right time to present an appraisal of these issues. We likewise expect that in the meantime EFSUMB will release a new update of the existing guidelines 1 2.The first ultrasound elastography method became available 13 years ago in the form of transient elastography with Fibroscan(®) 3. It was the first technique providing non-invasive quantitive information about the stiffness of the liver and hence regarding the amount of fibrosis in chronic liver disease 3. The innovation was enormous, since a non-invasive modality was finally available to provide findings otherwise achievable only by liver biopsy. In fact, prior to ultrasound elastography, a combination of conventional and Doppler ultrasound parameters were utilized to inform the physician about the presence of cirrhosis and portal hypertension 4. However, skilled operators were required, reproducibility and diagnostic accuracy were suboptimal, and it was not possible to differentiate the pre-cirrhotic stages of fibrosis. All these limitations were substantially improved by

  17. Endoscopic ultrasound-assisted gastrointestinal hemostasis: an evolving technique

    PubMed Central

    Jain, Deepanshu; Thosani, Nirav; Singhal, Shashideep

    2016-01-01

    Gastrointestinal bleeding can range from grossly visible blood in stool or vomitus to microscopic bleed. However, any kind of bleeding can lead to potential life-threatening consequences. A small proportion of patients with gastrointestinal bleeding remain refractory to initial endoscopic hemostasis. While some are successfully managed by repeat endoscopic intervention, a few fail to respond or are not amenable to endoscopic hemostasis. As of now, the next level of intervention is passed on to either surgeons or interventional radiologists. There is new evidence suggesting the increased utility of endoscopic ultrasound (EUS) in diagnosis and treatment of culprit vascular lesions across the gut. In addition, EUS-assisted technique has also been used in the primary prevention of bleeding from gastroesophageal varices. In this review article, we have summarized case series and reports describing the use of EUS-assisted hemostasis. Indications, techniques, complications and success rates reported are discussed. While most of the authors describe their experience with primary and secondary treatment of gastric varices, treatment of other gastrointestinal lesions with EUS assisted hemostatic techniques is also discussed. PMID:27366229

  18. Performance study of a new time-delay estimation algorithm in ultrasonic echo signals and ultrasound elastography.

    PubMed

    Shaswary, Elyas; Xu, Yuan; Tavakkoli, Jahan

    2016-07-01

    Time-delay estimation has countless applications in ultrasound medical imaging. Previously, we proposed a new time-delay estimation algorithm, which was based on the summation of the sign function to compute the time-delay estimate (Shaswary et al., 2015). We reported that the proposed algorithm performs similar to normalized cross-correlation (NCC) and sum squared differences (SSD) algorithms, even though it was significantly more computationally efficient. In this paper, we study the performance of the proposed algorithm using statistical analysis and image quality analysis in ultrasound elastography imaging. Field II simulation software was used for generation of ultrasound radio frequency (RF) echo signals for statistical analysis, and a clinical ultrasound scanner (Sonix® RP scanner, Ultrasonix Medical Corp., Richmond, BC, Canada) was used to scan a commercial ultrasound elastography tissue-mimicking phantom for image quality analysis. The statistical analysis results confirmed that, in overall, the proposed algorithm has similar performance compared to NCC and SSD algorithms. The image quality analysis results indicated that the proposed algorithm produces strain images with marginally higher signal-to-noise and contrast-to-noise ratios compared to NCC and SSD algorithms. PMID:27010697

  19. A coupled subsample displacement estimation method for ultrasound-based strain elastography

    NASA Astrophysics Data System (ADS)

    Jiang, Jingfeng; Hall, Timothy J.

    2015-11-01

    Obtaining accurate displacement estimates along both axial (parallel to the acoustic beam) and lateral (perpendicular to the beam) directions is an important task for several clinical applications such as shear strain imaging, modulus reconstruction and temperature imaging, where a full description of the two or three-dimensional (2D/3D) deformation field is required. In this study we propose an improved speckle tracking algorithm where axial and lateral motion estimations are simultaneously performed to enhance motion tracking accuracy. More specifically, using conventional ultrasound echo data, this algorithm first finds an iso-contour in the vicinity of the peak correlation between two segments of the pre- and post-deformation ultrasound radiofrequency echo data. The algorithm then attempts to find the center of the iso-contour of the correlation function that corresponds to the unknown (sub-sample) motion vector between these two segments of echo data. This algorithm has been tested using computer-simulated data, studies with a tissue-mimicking phantom, and in vivo breast lesion data. Computer simulation results show that the method improves the accuracy of both lateral and axial tracking. Such improvements are more significant when the deformation is small or along the lateral direction. Results from the tissue-mimicking phantom study are consistent with findings observed in computer simulations. Using in vivo breast lesion data we found that, compared to the 2D quadratic subsample displacement estimation methods, higher quality axial strain and shear strain images (e.g. 18.6% improvement in contrast-to-noise ratio for shear strain images) can be obtained for large deformations (up to 5% frame-to-frame and 15% local strains) in a multi-compression technique. Our initial results demonstrated that this conceptually and computationally simple method could improve the image quality of ultrasound-based strain elastography with current clinical equipment.

  20. A noninvasive ultrasound elastography technique for measuring surface waves on the lung.

    PubMed

    Zhang, Xiaoming; Osborn, Thomas; Kalra, Sanjay

    2016-09-01

    The purpose of this work was to demonstrate an ultrasound based surface wave elastography (SWE) technique for generating and detecting surface waves on the lung. The motivation was to develop a noninvasive technique for assessing superficial lung tissue disease including interstitial lung disease (ILD). ILD comprises a number of lung disorders in which the lung tissue is stiffened and damaged due to fibrosis of the lung tissue. Currently, chest radiographs and computed tomography (CT) are the most common clinical methods for evaluating lung disease, but they are associated with radiation and cannot measure lung mechanical properties. The novelty of SWE is to develop a noninvasive and nonionizing technique to measure the elastic properties of superficial lung tissue. We propose to generate waves on the lung surface through wave propagation from a local harmonic vibration excitation on the chest through an intercostal space. The resulting surface wave propagation on the lung is detected using an ultrasound probe through the intercostal space. To demonstrate that surface waves can be generated on the lung, an ex vivo muscle-lung model was developed to evaluate lung surface wave generation and detection. In this model, swine muscle was laid atop a swine lung. A vibration excitation of 0.1s 100Hz wave was generated on the muscle surface and the surface waves on the lung were detected using a linear array ultrasound probe at 5MHz. To test its feasibility for patient use, SWE was used to measure both lungs of an ILD patient through eight intercostal spaces. The mean wave speed was 1.71±0.20m/s (±SD) at the functional residual capacity, while the mean wave speed was 2.36±0.33m/s at the total lung capacity. These studies support the feasibility of SWE for noninvasive measurement of elastic properties of lung and demonstrate potential for assessment of ILD. PMID:27392204

  1. Endoscopic ultrasound-guided hepaticogastrostomy using a 6-F cystotome and 12-cm covered metal stent

    PubMed Central

    Mandai, Koichiro; Uno, Koji; Okada, Yusuke; Suzuki, Azumi; Yasuda, Kenjiro

    2016-01-01

    Background and study aims: An iincreasing number of reports describe endoscopic ultrasound-guided hepaticogastrostomy for malignant biliary obstruction in patients with endoscopic retrograde cholangiopancreatography failure. However, this procedure has not yet been standardized; as a result, the rate of adverse events, including bile leakage and stent migration, is relatively high. Here, we report our experience with four cases of endoscopic ultrasound-guided hepaticogastrostomy performed according to our institutional procedure. PMID:27004245

  2. Endoscopic ultrasound in the diagnosis and management of carcinoma pancreas

    PubMed Central

    Puri, Rajesh; Manrai, Manish; Thandassery, Ragesh Babu; Alfadda, Abdulrahman A

    2016-01-01

    Endoscopic ultrasound (EUS) has become an important component in the diagnosis and treatment of carcinoma pancreas. With the advent of advanced imaging techniques and tissue acquisition methods the role of EUS is becoming increasingly important. Small pancreatic tumors can be reliably diagnosed with EUS. EUS guided fine needle aspiration establishes diagnosis in some cases. EUS plays an important role in staging of carcinoma pancreas and in some important therapeutic methods that include celiac plexus neurolysis, EUS guided biliary drainage and drug delivery. In this review we attempt to review the role of EUS in diagnosis and management of carcinoma pancreas. PMID:26839647

  3. [Digital scanning converter for medical endoscopic ultrasound imaging].

    PubMed

    Chen, Xiaodong; Zhang, Hongxu; Zhou, Peifan; Wen, Shijie; Yu, Daoyin

    2009-02-01

    This paper mainly introduces the design of digital scanning converter (DSC) for medical endoscopic ultrasound imaging. Fast modified vector totational CORDIC (FMVR-CORDIC) arithmetic complete coordinate conversion is used to increase the speed of ultrasonic scanning imaging. FPGA is used as the kernel module to control data transferring, related circuits and relevant chips' working, and to accomplish data preprocessing. With the advantages of simple structure, nice flexibility and convenience, it satisfies the demand for real-time displaying in this system. Finally, the original polar coordinate image is transformed to rectangular coordinate grey image through coordinate transformation. The system performances have been validated by the experimental result. PMID:19334546

  4. Monitoring of high-intensity focused ultrasound treatment by shear wave elastography induced by two-dimensional-array therapeutic transducer

    NASA Astrophysics Data System (ADS)

    Iwasaki, Ryosuke; Takagi, Ryo; Nagaoka, Ryo; Jimbo, Hayato; Yoshizawa, Shin; Saijo, Yoshifumi; Umemura, Shin-ichiro

    2016-07-01

    Shear wave elastography (SWE) is expected to be a noninvasive monitoring method of high-intensity focused ultrasound (HIFU) treatment. However, conventional SWE techniques encounter difficulty in inducing shear waves with adequate displacements in deep tissue. To observe tissue coagulation at the HIFU focal depth via SWE, in this study, we propose using a two-dimensional-array therapeutic transducer for not only HIFU exposure but also creating shear sources. The results show that the reconstructed shear wave velocity maps detected the coagulated regions as the area of increased propagation velocity even in deep tissue. This suggests that “HIFU-push” shear elastography is a promising solution for the purpose of coagulation monitoring in deep tissue, because push beams irradiated by the HIFU transducer can naturally reach as deep as the tissue to be coagulated by the same transducer.

  5. Comparison between shear wave dispersion magneto motive ultrasound and transient elastography for measuring tissue-mimicking phantom viscoelasticity.

    PubMed

    Almeida, Thiago W J; Sampaio, Diego R Thomaz; Bruno, Alexandre Colello; Pavan, Theo Z; Carneiro, Antonio A O

    2015-12-01

    Several methods have been developed over the last several years to analyze the mechanical properties of soft tissue. Elastography, for example, was proposed to evaluate soft tissue stiffness in an attempt to reduce the need for invasive procedures, such as breast biopsies; however, its qualitative nature and the fact that it is operator-dependent have proven to be limitations of the technique. Quantitative shearwave- based techniques have been proposed to obtain information about tissue stiffness independent of the operator. This paper describes shear wave dispersion magnetomotive ultrasound (SDMMUS), a new shear-wave-based method in which a viscoelastic medium labeled with iron oxide nanoparticles is displaced by an external tone burst magnetic field. As in magnetomotive ultrasound (MMUS), SDMMUS uses ultrasound to detect internal mechanical vibrations induced by the interaction between a magnetic field and magnetic nanoparticles. These vibrations generated shear waves that were evaluated to estimate the viscoelastic properties of tissue-mimicking phantoms. These phantoms were manufactured with different concentrations of gelatin and labeled with iron oxide nanoparticles. The elasticity and viscosity obtained with SDMMUS agreed well with the results obtained by traditional ultrasound-based transient elastography. PMID:26670853

  6. Fusion of ultrasound B-mode and vibro-elastography images for automatic 3D segmentation of the prostate.

    PubMed

    Mahdavi, S Sara; Moradi, Mehdi; Morris, William J; Goldenberg, S Larry; Salcudean, Septimiu E

    2012-11-01

    Prostate segmentation in B-mode images is a challenging task even when done manually by experts. In this paper we propose a 3D automatic prostate segmentation algorithm which makes use of information from both ultrasound B-mode and vibro-elastography data.We exploit the high contrast to noise ratio of vibro-elastography images of the prostate, in addition to the commonly used B-mode images, to implement a 2D Active Shape Model (ASM)-based segmentation algorithm on the midgland image. The prostate model is deformed by a combination of two measures: the gray level similarity and the continuity of the prostate edge in both image types. The automatically obtained mid-gland contour is then used to initialize a 3D segmentation algorithm which models the prostate as a tapered and warped ellipsoid. Vibro-elastography images are used in addition to ultrasound images to improve boundary detection.We report a Dice similarity coefficient of 0.87±0.07 and 0.87±0.08 comparing the 2D automatic contours with manual contours of two observers on 61 images. For 11 cases, a whole gland volume error of 10.2±2.2% and 13.5±4.1% and whole gland volume difference of -7.2±9.1% and -13.3±12.6% between 3D automatic and manual surfaces of two observers is obtained. This is the first validated work showing the fusion of B-mode and vibro-elastography data for automatic 3D segmentation of the prostate. PMID:22829391

  7. Vascular plaque characterization using intravascular ultrasound elastography and NIR Raman spectroscopy in vitro

    NASA Astrophysics Data System (ADS)

    de Korte, Chris L.; Buschman, Hendrik P. J.; van de Poll, Sweder W. E.; van der Steen, Anton F. W.; Puppels, Gerwin J.; van der Laarse, Arnoud

    2000-04-01

    The composition and morphology of the atherosclerotic lesion are considered to be important determinants of acute coronary ischemic syndromes. We investigated the potentials of a combination of intravascular ultrasound (IVUS) elastography and intravascular Near Infrared Raman (NIR) spectroscopy, to assess the physical and chemical composition of the vessel wall and plaque. Intact human coronary arteries were mounted in an in vitro pressurized perfusion setup and investigated with a 20 MHz VisionsR IVUS catheter. At selected cross- sections, two echo-frames were acquired at intraluminal pressures of 80 and 100 mmHg to strain the tissue in order to obtain elastograms. Next, Raman spectra were obtained during 30 seconds at 4 angles (0, 90, 180 and 270 degrees) using a sideways viewing probe. Spectra were modeled to obtain quantitative chemical information, while leaving the specimens intact. Calcified areas were identifiable on the echograms, elastograms and Raman spectra. A combination of geometric information provided by the echogram, chemical information as obtained with Raman spectroscopy, and high stress regions determined by the elastogram, may prove to be a valuable tool to identify plaque vulnerability.

  8. Relationship between ultrasound elastography and myofibroblast distribution in breast cancer and its clinical significance.

    PubMed

    Hao, Yi; Guo, Xia; Ma, Binlin; Zhu, Lin; Liu, Lisha

    2016-01-01

    The study investigated the relationship between ultrasound elastography (USE) scoring and myofibroblast distribution with expression features of α-SMA +/CD34- in patients of Uyghur and Han ethnicities with breast masses in Xinjiang, China. The data was used to evaluate its clinical significance in the early diagnosis of breast cancer. A total of 300 patients with breast masses were included in the study, which involved conventional sonography and USE, with histopathologic diagnosis as the reference standard. Myofibroblast distribution was investigated by detecting the expression levels of α-SMA and CD34 in lesions using immunohistochemistry and real-time PCR. Out of 300 lesions, 185 were histologically malignant and 115 benign. The mean elasticity score for malignant lesions was significantly higher than for benign lesions. The expression level of α-SMA was elevated while the expression level of CD34 was lower in malignancies, compared with benign lesions. The expression of α-SMA was positively associated with the USE scores, while a negative relationship was observed between CD34 expression and USE scoring. The combination of USE and molecular diagnosis provides a promising modality for the early diagnosis and evaluation of the risks in particular types of breast cancer. PMID:26846996

  9. Feasibility Study of Texture Analysis Using Ultrasound Shear Wave Elastography to Predict Malignancy in Thyroid Nodules.

    PubMed

    Bhatia, Kunwar Suryaveer Singh; Lam, Absalom Chung Lung; Pang, Sze Wing Angel; Wang, Defeng; Ahuja, Anil Tejbhan

    2016-07-01

    Textural analysis of ultrasound shear wave elastography (SWE) was evaluated to discriminate benign and malignant thyroid nodules. Sixteen papillary thyroid cancers and 89 benign hyperplastic nodules in 105 patients underwent SWE using four static pre-compression levels. Fifteen gray level co-occurrence matrix textural features and six absolute SWE indices were computed from SWE images. Diagnostic performances of each SWE index for malignancy were calculated and compared using the area under the receiver operating characteristic curve (AUC), and optimal models were generated at each pre-compression level. The optimal model comprised two SWE textural features at the highest pre-compression level, which attained AUC, sensitivity and specificity of 0.973, 97.5% and 90.0%, respectively. By comparison, absolute SWE indices attained AUC of 0.709 as well as 18.8% sensitivity and 95.8% specificity. These preliminary results suggest SWE textural analysis can distinguish benign and malignant thyroid nodules and SWE spatial heterogeneity is greater in malignant nodules. PMID:27126245

  10. Relationship between ultrasound elastography and myofibroblast distribution in breast cancer and its clinical significance

    PubMed Central

    Hao, Yi; Guo, Xia; Ma, Binlin; Zhu, Lin; Liu, Lisha

    2016-01-01

    The study investigated the relationship between ultrasound elastography (USE) scoring and myofibroblast distribution with expression features of α-SMA + /CD34− in patients of Uyghur and Han ethnicities with breast masses in Xinjiang, China. The data was used to evaluate its clinical significance in the early diagnosis of breast cancer. A total of 300 patients with breast masses were included in the study, which involved conventional sonography and USE, with histopathologic diagnosis as the reference standard. Myofibroblast distribution was investigated by detecting the expression levels of α-SMA and CD34 in lesions using immunohistochemistry and real-time PCR. Out of 300 lesions, 185 were histologically malignant and 115 benign. The mean elasticity score for malignant lesions was significantly higher than for benign lesions. The expression level of α-SMA was elevated while the expression level of CD34 was lower in malignancies, compared with benign lesions. The expression of α-SMA was positively associated with the USE scores, while a negative relationship was observed between CD34 expression and USE scoring. The combination of USE and molecular diagnosis provides a promising modality for the early diagnosis and evaluation of the risks in particular types of breast cancer. PMID:26846996

  11. The Feasibility of Integrating Elastography Measurements into MRI-Guided Transurethral Ultrasound Therapy

    NASA Astrophysics Data System (ADS)

    Arani, Arvin; Huang, Yuexi; Bronskill, Michael; Chopra, Rajiv

    2009-04-01

    MRI-guided transurethral ultrasound therapy is being developed as a minimally invasive treatment for localized prostate cancer. The capability to identify target regions prior to therapy would provide an integrated diagnostic and therapeutic solution to the management of this disease. The objective of this project is to evaluate the feasibility of performing elastography using a transurethral actuator. Shear waves were generated in the prostate by vibrating the transurethral actuator longitudinally and resolving the tissue displacements with a 1.5 Tesla MRI. A piezoelectric actuator was used to vibrate the transurethral device with an amplitude of 32 um at frequencies of 100 and 250 Hz. GRE imaging sequences with displacement encoded along the direction of vibration were acquired transverse and parallel to the rod to visualize the dynamics of wave propagation. Experiments were performed in phantoms (8% gelatin) and in a canine model (n = 5). Vibration was achieved in the MRI without significant loss of SNR in the images. The shear waves produced in the gel were cylindrical in nature, and extended along the length of the rod. Shear wave propagation in the canine prostate gland was observed at 100 and 250 Hz, and shear modulus values agreed with previously published values.

  12. Validation of Ultrasound Elastography Imaging for Nondestructive Characterization of Stiffer Biomaterials.

    PubMed

    Zhou, Haoyan; Goss, Monika; Hernandez, Christopher; Mansour, Joseph M; Exner, Agata

    2016-05-01

    Ultrasound elastography (UE) has been widely used as a "digital palpation" tool to characterize tissue mechanical properties in the clinic. UE benefits from the capability of noninvasively generating 2-D elasticity encoded maps. This spatial distribution of elasticity can be especially useful in the in vivo assessment of tissue engineering scaffolds and implantable drug delivery platforms. However, the detection limitations have not been fully characterized and thus its true potential has not been completely discovered. Characterization studies have focused primarily on the range of moduli corresponding to soft tissues, 20-600 kPa. However, polymeric biomaterials used in biomedical applications such as tissue scaffolds, stents, and implantable drug delivery devices can be much stiffer. In order to explore UE's potential to assess mechanical properties of biomaterials in a broader range of applications, this work investigated the detection limit of UE strain imaging beyond soft tissue range. To determine the detection limit, measurements using standard mechanical testing and UE on the same polydimethylsiloxane samples were compared and statistically evaluated. The broadest detection range found based on the current optimized setup is between 47 kPa and 4 MPa which exceeds the modulus of normal soft tissue suggesting the possibility of using this technique for stiffer materials' mechanical characterization. The detectable difference was found to be as low as 157 kPa depending on sample stiffness and experimental setup. PMID:26369634

  13. Utility of endoscopic ultrasound in patients with portal hypertension.

    PubMed

    Hammoud, Ghassan M; Ibdah, Jamal A

    2014-10-21

    Endoscopic ultrasound (EUS) has revolutionized the diagnostic and therapeutic approach to patients with gastrointestinal disorders. Its application in patients with liver disease and portal hypertension is increasing. Patients with chronic liver disease are at risk for development of portal hypertension sequale such as ascites, spontaneous bacterial peritonitis and gastroesophageal varices. Bleeding esophageal and gastric varices are among the most common causes of mortality in patients with cirrhosis. Thus, early detection and treatment improve the outcome in this population. EUS can improve the detection and diagnosis of gastroesophageal varices and collateral veins and can provide endoscopic therapy of gastroesophageal varices such as EUS-guided sclerotherapy of esophageal collateral vessels and EUS-guided cynoacrylate (Glue) injection of gastric varices. EUS can also provide knowledge on the efficacy of pharmacotherapy of portal hypertension. Furthermore, EUS can provide assessment and prediction of variceal recurrence after endoscopic therapy and assessment of portal hemodynamics such as E-Flow and Doppler study of the azygous and portal veins. Moreover, EUS-guided fine needle aspiration may provide cytologic diagnosis of focal hepatic tumors and analysis of free abdominal fluid. Using specialized EUS-guided needle biopsy, a sample of liver tissue can be obtained to diagnose and evaluate for chronic liver disease. EUS-guided fine needle injection can be used to study portal vein pressure and hemodynamics, and potentially could be used to assist in exact measurement of portal vein pressure and placement of intrahepatic portosystemic shunt. PMID:25339809

  14. Endoscopic ultrasound-guided biliary drainage of hilar biliary obstruction.

    PubMed

    Park, Do Hyun

    2015-09-01

    Only 20-30% of patients with hilar cholangiocarcinoma (CC) are candidates for potentially curative resection. However, even after curative (R0) resection, these patients have a disease recurrence rate of up to 76%. The prognosis of hilar cholangiocarcinoma (CC) is limited by tumor spread along the biliary tree leading to obstructive jaundice, cholangitis, and liver failure. Therefore, palliative biliary drainage may be a major goal for patients with hilar CC. Endoscopic retrograde cholangiopancreatography (ERCP) with stent placement is an established method for palliation of patients with malignant biliary obstruction. However, there are patients for whom endoscopic stent placement is not possible because of failed biliary cannulation or tumor infiltration that limits transpapillary access. In this situation, percutaneous transhepatic biliary drainage (PTBD) is an alternative method. However, PTBD has a relatively high rate of complications and is frequently associated with patient discomfort related to external drainage. Endoscopic ultrasound-guided biliary drainage has therefore been introduced as an alternative to PTBD in cases of biliary obstruction when ERCP is unsuccessful. In this review, the indications, technical tips, outcomes, and the future role of EUS-guided intrahepatic biliary drainage, such as hepaticogastrostomy or hepaticoduodenostomy, for hilar biliary obstruction will be summarized. PMID:26178753

  15. Imaging of common bile duct by linear endoscopic ultrasound

    PubMed Central

    Sharma, Malay; Pathak, Amit; Shoukat, Abid; Rameshbabu, Chittapuram Srinivasan; Ajmera, Akash; Wani, Zeeshn Ahamad; Rai, Praveer

    2015-01-01

    Imaging of common bile duct (CBD) can be done by many techniques. Endoscopic retrograde cholangiopancreaticography is considered the gold standard for imaging of CBD. A standard technique of imaging of CBD by endoscopic ultrasound (EUS) has not been specifically described. The available descriptions mention different stations of imaging from the stomach and duodenum. The CBD lies closest to duodenum and choice of imaging may be restricted to duodenum for many operators. Generally most operators prefer multi station imaging during EUS and the choice of selecting the initial station varies from operator to operator. Detailed evaluation of CBD is frequently the main focus of imaging during EUS and in such situations multi station imaging with a high-resolution ultrasound scanner may provide useful information. Examination of the CBD is one of the primary indications for doing an EUS and it can be done from five stations: (1) the fundus of stomach; (2) body of stomach; (3) duodenal bulb; (4) descending duodenum; and (5) antrum. Following down the upper 1/3rd of CBD can do imaging of entire CBD from the liver window and following up the lower 1/3rd of CBD can do imaging of entire CBD from the pancreatic window. This article aims at simplifying the techniques of imaging of CBD by linear EUS. PMID:26504506

  16. A unified approach to combine temperature estimation and elastography for thermal lesion determination in focused ultrasound thermal therapy.

    PubMed

    Liu, Hao-Li; Li, Meng-Lin; Tsui, Po-Hsiang; Lin, Ming-Shi; Huang, Sheng-Min; Bai, Jing

    2011-01-01

    Sonogram-based temperature estimation and elastography have both shown promise as methods of monitoring focused ultrasound (FUS) treatments to induce thermal ablation in tissue. However, each method has important limitations. Temperature estimates based on echo delays become invalid when the relationship between sound speed and temperature is nonlinear, and are further complicated by thermal expansion and other changes in tissue. Elastography can track thermal lesion formation over a wider range of elasticity, but with low specificity and high noise. Furthermore, this method is poor at small lesion detection. This study proposes integrating the two estimates to improve the quality of monitoring FUS-induced thermal lesions. Our unified computational kernel is tested on three types of phantoms. Experiments with type I and type II phantoms were conducted to calibrate the thermal mapping and elastography methods, respectively. The optimal settings were then used in experiments with the type III phantom, which contains ex vivo swine liver tissue. Three different spatial-peak temporal-average intensities (I(spta); 35, 133 and 240 W cm(-2)) were delivered with a sonication time of 60 s. The new procedure can closely monitor heating while identifying the dimensions of the thermal lesion, and is significantly better at the latter task than either approach alone. This work may help improve the current clinical practice, which employs sonograms to guide the FUS-induced thermal ablation procedure. PMID:21149945

  17. A unified approach to combine temperature estimation and elastography for thermal lesion determination in focused ultrasound thermal therapy

    NASA Astrophysics Data System (ADS)

    Liu, Hao-Li; Li, Meng-Lin; Tsui, Po-Hsiang; Lin, Ming-Shi; Huang, Sheng-Min; Bai, Jing

    2011-01-01

    Sonogram-based temperature estimation and elastography have both shown promise as methods of monitoring focused ultrasound (FUS) treatments to induce thermal ablation in tissue. However, each method has important limitations. Temperature estimates based on echo delays become invalid when the relationship between sound speed and temperature is nonlinear, and are further complicated by thermal expansion and other changes in tissue. Elastography can track thermal lesion formation over a wider range of elasticity, but with low specificity and high noise. Furthermore, this method is poor at small lesion detection. This study proposes integrating the two estimates to improve the quality of monitoring FUS-induced thermal lesions. Our unified computational kernel is tested on three types of phantoms. Experiments with type I and type II phantoms were conducted to calibrate the thermal mapping and elastography methods, respectively. The optimal settings were then used in experiments with the type III phantom, which contains ex vivo swine liver tissue. Three different spatial-peak temporal-average intensities (Ispta; 35, 133 and 240 W cm-2) were delivered with a sonication time of 60 s. The new procedure can closely monitor heating while identifying the dimensions of the thermal lesion, and is significantly better at the latter task than either approach alone. This work may help improve the current clinical practice, which employs sonograms to guide the FUS-induced thermal ablation procedure.

  18. A PDE-Based Regularization Algorithm Toward Reducing Speckle Tracking Noise: A Feasibility Study for Ultrasound Breast Elastography.

    PubMed

    Guo, Li; Xu, Yan; Xu, Zhengfu; Jiang, Jingfeng

    2015-10-01

    Obtaining accurate ultrasonically estimated displacements along both axial (parallel to the acoustic beam) and lateral (perpendicular to the beam) directions is an important task for various clinical elastography applications (e.g., modulus reconstruction and temperature imaging). In this study, a partial differential equation (PDE)-based regularization algorithm was proposed to enhance motion tracking accuracy. More specifically, the proposed PDE-based algorithm, utilizing two-dimensional (2D) displacement estimates from a conventional elastography system, attempted to iteratively reduce noise contained in the original displacement estimates by mathematical regularization. In this study, tissue incompressibility was the physical constraint used by the above-mentioned mathematical regularization. This proposed algorithm was tested using computer-simulated data, a tissue-mimicking phantom, and in vivo breast lesion data. Computer simulation results demonstrated that the method significantly improved the accuracy of lateral tracking (e.g., a factor of 17 at 0.5% compression). From in vivo breast lesion data investigated, we have found that, as compared with the conventional method, higher quality axial and lateral strain images (e.g., at least 78% improvements among the estimated contrast-to-noise ratios of lateral strain images) were obtained. Our initial results demonstrated that this conceptually and computationally simple method could be useful for improving the image quality of ultrasound elastography with current clinical equipment as a post-processing tool. PMID:25452434

  19. The diagnosis value of acoustic radiation force impulse (ARFI) elastography for thyroid malignancy without highly suspicious features on conventional ultrasound

    PubMed Central

    Liu, Bo-Ji; Lu, Feng; Xu, Hui-Xiong; Guo, Le-Hang; Li, Dan-Dan; Bo, Xiao-Wan; Li, Xiao-Long; Zhang, Yi-Feng; Xu, Jun-Mei; Xu, Xiao-Hong; Qu, Shen

    2015-01-01

    Objective: The aim of this study was to evaluate the potential diagnostic performance of acoustic radiation force impulse (ARFI) elastography in identifying malignancy in nodules that do not appear highly suspicious on conventional ultrasound (US). Methods: 330 pathologically confirmed thyroid nodules (40 malignant and 290 benign; mean size, 22.0±11.6 mm) not suspicious of malignancy on conventional US in 330 patients (mean age 52.8±11.7 years) underwent ARFI elastography before surgery. ARFI elastography included qualitative ARFI-induced strain elastography (SE) and quantitative point shear wave elastography (p-SWE). ARFI-induced SE image was assessed by SE score, while p-SWE was denoted with shear wave velocity (SWV, m/s). The diagnostic performance of four criteria sets was evaluated: criteria set 1 (ARFI-induced SE), criteria set 2 (p-SWE), criteria set 3 (either set 1 or 2), criteria set 4 (both set 1 and 2). Receiver operating characteristic curve (ROC) analyses were performed to assess the diagnostic performance. Results: SE score ≥4 was more frequently found in malignant nodules (32/40) than in benign nodules (30/290, P<0.001). The mean SWV of malignant nodules (3.64±2.23 m/s) was significantly higher than that of benign nodules (2.02±0.69 m/s) (P<0.001). ARFI-induced SE (set 1) had a sensitivity of 80.0% (32/40) and a specificity of 89.7% (260/290) with a cut-off point of SE score ≥4; p-SWE (set 2) had a sensitivity of 80.0% (32/40) and a specificity of 57.9% (168/290) with a cut-off point of SWV ≥2.15 m/s. When ARFI-induced SE and p-SWE were combined, set 3 had the highest sensitivity (92.5%, 37/40) while set 4 had the highest specificity (95.2%, 276/290). Conclusion: ARFI elastography can be used for differential diagnosis of malignant thyroid nodules without highly suspicious features on US. The combination of ARFI-induced SE and p-SWE leads to improved sensitivity and specificity. PMID:26629025

  20. Ultrasound techniques in the evaluation of the mediastinum, part I: endoscopic ultrasound (EUS), endobronchial ultrasound (EBUS) and transcutaneous mediastinal ultrasound (TMUS), introduction into ultrasound techniques

    PubMed Central

    Annema, Jouke Tabe; Clementsen, Paul; Cui, Xin Wu; Borst, Mathias Maximilian; Jenssen, Christian

    2015-01-01

    Ultrasound imaging has gained importance in pulmonary medicine over the last decades including conventional transcutaneous ultrasound (TUS), endoscopic ultrasound (EUS), and endobronchial ultrasound (EBUS). Mediastinal lymph node staging affects the management of patients with both operable and inoperable lung cancer (e.g., surgery vs. combined chemoradiation therapy). Tissue sampling is often indicated for accurate nodal staging. Recent international lung cancer staging guidelines clearly state that endosonography (EUS and EBUS) should be the initial tissue sampling test over surgical staging. Mediastinal nodes can be sampled from the airways [EBUS combined with transbronchial needle aspiration (EBUS-TBNA)] or the esophagus [EUS fine needle aspiration (EUS-FNA)]. EBUS and EUS have a complementary diagnostic yield and in combination virtually all mediastinal lymph nodes can be biopsied. Additionally endosonography has an excellent yield in assessing granulomas in patients suspected of sarcoidosis. The aim of this review, in two integrative parts, is to discuss the current role and future perspectives of all ultrasound techniques available for the evaluation of mediastinal lymphadenopathy and mediastinal staging of lung cancer. A specific emphasis will be on learning mediastinal endosonography. Part I is dealing with an introduction into ultrasound techniques, mediastinal lymph node anatomy and diagnostic reach of ultrasound techniques and part II with the clinical work up of neoplastic and inflammatory mediastinal lymphadenopathy using ultrasound techniques and how to learn mediastinal endosonography. PMID:26543620

  1. Performance of 2-D ultrasound shear wave elastography in liver fibrosis detection using magnetic resonance elastography as the reference standard: A pilot study

    PubMed Central

    Song, Pengfei; Mellema, Daniel C.; Sheedy, Shannon P.; Meixner, Duane D.; Karshen, Ryan M.; Urban, Matthew W.; Manduca, Armando; Sanchez, William; Callstrom, Matthew R.; Greenleaf, James F.; Chen, Shigao

    2015-01-01

    Objective To investigate the correlation between 2-D ultrasound shear wave elastography (SWE) and magnetic resonance elastography (MRE) in liver stiffness measurement and the diagnostic performance of 2-D SWE for liver fibrosis when imaging from different intercostal spaces and using MRE as the reference standard. Methods 2-D SWE was performed on 47 patients (22 females and 25 males, age 19–77) using the GE LOGIQ E9 scanner. Each of the 47 patients had same day MRE obtained for clinical purposes. The study was HIPAA-compliant and approved by the institutional review board. Informed consent was obtained from each subject. 2-D SWE measurements were acquired from the 9th, 8th, and 7th intercostal spaces. Correlation with MRE was calculated at each intercostal space and multiple intercostal spaces combined. The performance of 2-D SWE in diagnosing liver fibrosis was evaluated with receiver operating characteristic (ROC) curve analysis using MRE as the standard. Results The highest correlation between 2-D SWE and MRE was from the 8th and 7th intercostal spaces (r = 0.68 – 0.76). The range of the areas under the ROC curve for separating normal or inflamed livers from fibrotic livers using MRE as the clinical reference were 0.84 – 0.92 when using 8th and 7th intercostal spaces individually, and 0.89 –0.9 when combined. Conclusion The results suggest that 2-D SWE and MRE are well correlated when SWE is performed at the 8th and 7th intercostal spaces. The 9th intercostal space is less reliable for diagnosing fibrosis using 2-D SWE. Combining measurements from multiple intercostal spaces does not significantly improve 2-D SWE performance for the detection of fibrosis. PMID:26782164

  2. Clinical, endoscopic and endoscopic ultrasound features of duodenal varices: A report of 10 cases

    PubMed Central

    Rana, Surinder Singh; Bhasin, Deepak Kumar; Sharma, Vishal; Chaudhary, Vinita; Sharma, Ravi; Singh, Kartar

    2014-01-01

    Background: Duodenal varices (DV) although an uncommon cause, are an important cause due to the severe nature of the bleed and associated adverse outcome. Materials and Methods: We retrospectively evaluated patients with DV seen at our institution over past 4 years. Results: A total of 10 patients (nine males; mean age was 35.8 ± 7.68 years) with DV were studied. Five patients had underlying cirrhosis and five had DV because of non-cirrhotic portal hypertension (four patients had extra-hepatic portal venous obstruction and one patient had non-cirrhotic portal fibrosis). Five patients presented with upper gastrointestinal (GI) bleed, whereas in the remaining five patients DV were detected on endoscopy performed for evaluation of portal hypertension. Endoscopy revealed submucosal lesion in nine patients, whereas in one patient an initial endoscopic diagnosis of Dieulafoy's lesion was made. However endoscopic ultrasound (EUS) could clearly identify DV in all patients. Of five patients presenting with upper GI bleed, three had the esophageal varices eradicated and two presented 1st time with bleed form DV and did not have esophagogastric varices. All patients with acute upper GI bleed were initially treated with intravenous terlipressin followed by glue (n-butyl cyanoacrylate) injection in 4/5 patients with one patient refusing further endoscopic therapy. The variceal obliteration was documented by EUS in all these four patients and there has been no recurrence of bleed in these four patients over a follow-up period of 4-46 months. The five non-bleeding DV were already on beta- blockers and the same were continued. Two of these five patients succumbed to progressive liver failure with none of these five patients having GI bleed on follow-up. Conclusion: EUS is a useful investigational modality for evaluating patients with DV and endoscopic injection of glue is an effective therapy for controlling and preventing recurrence of bleed from DV. PMID:24949411

  3. A Hertzian contact mechanics based formulation to improve ultrasound elastography assessment of uterine cervical tissue stiffness.

    PubMed

    Briggs, Brandi N; Stender, Michael E; Muljadi, Patrick M; Donnelly, Meghan A; Winn, Virginia D; Ferguson, Virginia L

    2015-06-25

    Clinical practice requires improved techniques to assess human cervical tissue properties, especially at the internal os, or orifice, of the uterine cervix. Ultrasound elastography (UE) holds promise for non-invasively monitoring cervical stiffness throughout pregnancy. However, this technique provides qualitative strain images that cannot be linked to a material property (e.g., Young's modulus) without knowledge of the contact pressure under a rounded transvaginal transducer probe and correction for the resulting non-uniform strain dissipation. One technique to standardize elastogram images incorporates a material of known properties and uses one-dimensional, uniaxial Hooke's law to calculate Young's modulus within the compressed material half-space. However, this method does not account for strain dissipation and the strains that evolve in three-dimensional space. We demonstrate that an analytical approach based on 3D Hertzian contact mechanics provides a reasonable first approximation to correct for UE strain dissipation underneath a round transvaginal transducer probe and thus improves UE-derived estimates of tissue modulus. We validate the proposed analytical solution and evaluate sources of error using a finite element model. As compared to 1D uniaxial Hooke's law, the Hertzian contact-based solution yields significantly improved Young's modulus predictions in three homogeneous gelatin tissue phantoms possessing different moduli. We also demonstrate the feasibility of using this technique to image human cervical tissue, where UE-derived moduli estimations for the uterine cervix anterior lip agreed well with published, experimentally obtained values. Overall, UE with an attached reference standard and a Hertzian contact-based correction holds promise for improving quantitative estimates of cervical tissue modulus. PMID:26003483

  4. Endoscopic ultrasound-fine needle injection for oncological therapy

    PubMed Central

    Kaplan, Jeremy; Khalid, Amaara; Cosgrove, Natalie; Soomro, Ayesha; Mazhar, Syed Mohsin; Siddiqui, Ali A

    2015-01-01

    The minimal invasiveness and precision of endoscopic ultrasound (EUS) has lead to both its widespread use as a diagnostic and staging modality for gastrointestinal and pancreaticobiliary malignancies, and to its expanding role as a therapeutic modality. EUS-guided celiac plexus neurolysis is now a well-accepted modality for palliation of pain in patients with pancreatic cancer. EUS-guided ablation, brachytherapy, fiducial marker placement, and antitumor agent injection have been described as methods of performing minimally invasive oncological therapy. EUS-fine needle injection may be performed as adjunctive, alternative, or palliative treatment. This review summarizes the studies to date that have described these methods. A literature search using the PubMed/MEDLINE databases was performed. While most published studies to date are limited with disappointing outcomes, the concept of a role of EUS in oncological therapy seems promising. PMID:26691224

  5. New Scopes, New Accessories, New Stents for Interventional Endoscopic Ultrasound

    PubMed Central

    Chapman, Christopher G.; Siddiqui, Uzma D.

    2016-01-01

    Technological advances have rapidly expanded the therapeutic potential of endoscopic ultrasound (EUS). Innovations in stent technology; directed adjunctive therapy for pancreatic tumors, including radiofrequency ablation and fiducial marker placement; advanced imaging modalities, including needle-based confocal laser endomicroscopy; and new echoendoscopes, such as the forward-viewing linear echoendoscope, are emerging as safe and effective tools and devices for providing a broad range of treatments and therapies previously not thought possible. In this review, we summarize and discuss the new echoendoscopes, accessories, and stents for interventional EUS and highlight the recent literature on technical and therapeutic efficacy. The therapeutic role and indications for EUS are rapidly evolving well beyond its current limits as new EUS-specific designed tools are designed, and ultimately, should help achieve the goal of improving patient outcomes. PMID:26855923

  6. New Scopes, New Accessories, New Stents for Interventional Endoscopic Ultrasound.

    PubMed

    Chapman, Christopher G; Siddiqui, Uzma D

    2016-01-01

    Technological advances have rapidly expanded the therapeutic potential of endoscopic ultrasound (EUS). Innovations in stent technology; directed adjunctive therapy for pancreatic tumors, including radiofrequency ablation and fiducial marker placement; advanced imaging modalities, including needle-based confocal laser endomicroscopy; and new echoendoscopes, such as the forward-viewing linear echoendoscope, are emerging as safe and effective tools and devices for providing a broad range of treatments and therapies previously not thought possible. In this review, we summarize and discuss the new echoendoscopes, accessories, and stents for interventional EUS and highlight the recent literature on technical and therapeutic efficacy. The therapeutic role and indications for EUS are rapidly evolving well beyond its current limits as new EUS-specific designed tools are designed, and ultimately, should help achieve the goal of improving patient outcomes. PMID:26855923

  7. Technical tips for endoscopic ultrasound-guided hepaticogastrostomy

    PubMed Central

    Ogura, Takeshi; Higuchi, Kazuhide

    2016-01-01

    Interventional procedures using endoscopic ultrasound (EUS) have recently been developed. For biliary drainage, EUS-guided trans-luminal drainage has been reported. In this procedure, the transduodenal approach for extrahepatic bile ducts is called EUS-guided choledochoduodenostomy, and the transgastric approach for intrahepatic bile ducts is called EUS-guided hepaticogastrostomy (EUS-HGS). These procedures have several effects, such as internal drainage and avoiding post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis, and they are indicated for an inaccessible ampulla of Vater due to duodenal obstruction or surgical anatomy. EUS-HGS has particularly wide indications and clinical impact as an alternative biliary drainage method. In this procedure, it is necessary to dilate the fistula, and several devices and approaches have been reported. Stent selection is also important. In previous reports, the overall technical success rate was 82% (221/270), the clinical success rate was 97% (218/225), and the overall adverse event rate for EUS-HGS was 23% (62/270). Adverse events of EUS-biliary drainage are still high compared with ERCP or PTCD. EUS-HGS should continue to be performed by experienced endoscopists who can use various strategies when adverse events occur. PMID:27099437

  8. Technical tips of endoscopic ultrasound-guided choledochoduodenostomy.

    PubMed

    Ogura, Takeshi; Higuchi, Kazuhide

    2015-01-21

    Endoscopic ultrasound (EUS) is clinically useful not only as a diagnostic tool during EUS-guided fine needle aspiration, but also during interventional EUS. EUS-guided biliary drainage has been developed and performed by experienced endoscopists. EUS-guided choledocoduodenostomy (EUS-CDS) is relatively well established as an alternative biliary drainage method for biliary decompression in patients with biliary obstruction. The reported technical success rate of EUS-CDS ranges from 50% to 100%, and the clinical success rate ranges from 92% to 100%. Further, the over-all technical success rate was 93%, and clinical success rate was 98%. Based on the currently available literature, the overall adverse event rate for EUS-CDS is 16%. The data on the cumulative technical and clinical success rate for EUS-CDS is promising. However, EUS-CDS can still lead to several problems, so techniques or devices that are more feasible and safe need to be established. EUS-CDS has the potential to become a first-line biliary drainage procedure, although standardizing the technique in multicenter clinical trials and comparisons with endoscopic biliary drainage by randomized clinical trials are still needed. PMID:25624715

  9. Emerging applications of endoscopic ultrasound in gastrointestinal cancers.

    PubMed

    Hernandez, Lyndon V; Bhutani, Manoop S

    2008-07-01

    Endoscopic ultrasound (EUS) has been adopted into numerous interventional techniques and strategies that promise to improve diagnosis and management of gastrointestinal (GI) cancers. EUS-guided fine-needle aspiration (EUS-FNA) is recommended as a procedure of choice for tissue diagnosis of pancreatic cancer. Potential benefits of EUS-FNA in diagnosis of pancreatic cancer include the ability to detect small, discrete lesions compared with conventional imaging and the ability to provide staging information by examination of blood vessels surrounding the pancreas. EUS-FNA currently is being evaluated in strategies for improving diagnosis in pancreatic cancer through analysis of molecular markers, including strategies for distinguishing malignant pancreatic cysts. EUS-guided fineneedle injection currently is being investigated in a broad range of settings in GI cancers, including use in intratumoral injection in pancreas and esophageal cancers, ethanol lavage for nonmalignant pancreatic cystic tumors, and brachytherapy in nonresectable pancreatic cancer. Other applications of EUS currently being evaluated include EUS-guided biliary access in patients with unsuccessful endoscopic retrograde cholangiopancreatography and EUS-guided anastamoses in the GI tract. EUS-guided interventions have enormous potential to advance diagnosis and treatment of GI cancers. PMID:19259286

  10. Endoscopic ultrasound-guided interventions in special situations

    PubMed Central

    Prachayakul, Varayu; Aswakul, Pitulak

    2016-01-01

    Endoscopic ultrasound (EUS) was introduced in 1982 and has since become a popular advanced procedure for diagnosis and therapeutic intervention. Initially, EUS was most commonly used for the diagnosis of pancreatobiliary diseases and tissue acquisition. EUS was first used for guided cholangiography in 1996, followed by EUS-guided biliary drainage in 2001. Advancements in equipment and endoscopic accessories have led to an expansion of EUS-guided procedures, which now include EUS-guided drainage of intra-abdominal abscesses or collections, intra-vascular treatment of refractory variceal and nonvariceal bleeding, transmural pancreatic drainage, common bile duct stone clearance, enteral feeding tube placement and entero-enteric anastomosis. Patients with surgically altered upper gastrointestinal anatomies have greatly benefited from EUS also. This systematic review describes and discusses EUS procedures performed in uncommon diseases and conditions, as well as applications on more vulnerable patients such as young children and pregnant women. In these cases, routine approaches do not always apply, and thus may require the use of innovative and unconventional techniques. Increased knowledge of such special applications will help increase the success rates of these procedures and provide a foundation for additional advances and utilizations of the technique. PMID:26839650

  11. Technical tips for endoscopic ultrasound-guided hepaticogastrostomy.

    PubMed

    Ogura, Takeshi; Higuchi, Kazuhide

    2016-04-21

    Interventional procedures using endoscopic ultrasound (EUS) have recently been developed. For biliary drainage, EUS-guided trans-luminal drainage has been reported. In this procedure, the transduodenal approach for extrahepatic bile ducts is called EUS-guided choledochoduodenostomy, and the transgastric approach for intrahepatic bile ducts is called EUS-guided hepaticogastrostomy (EUS-HGS). These procedures have several effects, such as internal drainage and avoiding post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis, and they are indicated for an inaccessible ampulla of Vater due to duodenal obstruction or surgical anatomy. EUS-HGS has particularly wide indications and clinical impact as an alternative biliary drainage method. In this procedure, it is necessary to dilate the fistula, and several devices and approaches have been reported. Stent selection is also important. In previous reports, the overall technical success rate was 82% (221/270), the clinical success rate was 97% (218/225), and the overall adverse event rate for EUS-HGS was 23% (62/270). Adverse events of EUS-biliary drainage are still high compared with ERCP or PTCD. EUS-HGS should continue to be performed by experienced endoscopists who can use various strategies when adverse events occur. PMID:27099437

  12. Ultrasound real-time elastography can predict malignancy in BI-RADS®-US 3 lesions

    PubMed Central

    2013-01-01

    Background Lesions of the breast that are classified BI-RADS®-US 3 by ultrasound are probably benign and observation is recommended, although malignancy may occasionally occur. In our study, we focus exclusively on BI-RADS®-US 3 lesions and hypothesize that sonoelastography as an adjunct to conventional ultrasound can identify a high-risk-group and a low-risk-group within these patients. Methods A group of 177 breast lesions that were classified BI-RADS®-US 3 were additionally examined with real-time sonoelastography. Elastograms were evaluated according to the Tsukuba Elasticity Score. Pretest and posttest probability of disease (POD), sensitivity (SE), specificity (SP), positive (PPV) and negative predictive values (NPV) and likelihood-ratios (LR) were calculated. Furthermore, we analyzed the false-negative and false-positive cases and performed a model calculation to determine how elastography could affect the proceedings in population screening. Results In our collection of BI-RADS®-US 3 cases there were 169 benign and eight malignant lesions. The pretest POD was 4.5% (95% confidence interval (CI): 2.1–9.0). In patients with a suspicious elastogram (high-risk group), the posttest POD was significantly higher (13.2%, p = 0.041) and the positive LR was 3.2 (95% CI: 1.7–5.9). With a benign elastogram (low-risk group), the posttest POD decreased to 2.2%. SE, SP, PPV and NPV for sonoelastography in BI-RADS®-US 3 lesions were 62.5% (95% CI: 25.9–89.8), 80.5% (95% CI: 73.5–86.0), 13.2% (95% CI: 5.0–28.9) and 97.8% (95% CI: 93.3–99.4), respectively. Conclusions Sonoelastography yields additional diagnostic information in the evaluation of BI-RADS®-US 3 lesions of the breast. The examiner can identify a low-risk group that can be vigilantly observed and a high-risk group that should receive immediate biopsy due to an elevated breast cancer risk. PMID:23530903

  13. Reconstruction of elasticity: a stochastic model-based approach in ultrasound elastography

    PubMed Central

    2013-01-01

    Background The convectional strain-based algorithm has been widely utilized in clinical practice. It can only provide the information of relative information of tissue stiffness. However, the exact information of tissue stiffness should be valuable for clinical diagnosis and treatment. Methods In this study we propose a reconstruction strategy to recover the mechanical properties of the tissue. After the discrepancies between the biomechanical model and data are modeled as the process noise, and the biomechanical model constraint is transformed into a state space representation the reconstruction of elasticity can be accomplished through one filtering identification process, which is to recursively estimate the material properties and kinematic functions from ultrasound data according to the minimum mean square error (MMSE) criteria. In the implementation of this model-based algorithm, the linear isotropic elasticity is adopted as the biomechanical constraint. The estimation of kinematic functions (i.e., the full displacement and velocity field), and the distribution of Young’s modulus are computed simultaneously through an extended Kalman filter (EKF). Results In the following experiments the accuracy and robustness of this filtering framework is first evaluated on synthetic data in controlled conditions, and the performance of this framework is then evaluated in the real data collected from elastography phantom and patients using the ultrasound system. Quantitative analysis verifies that strain fields estimated by our filtering strategy are more closer to the ground truth. The distribution of Young’s modulus is also well estimated. Further, the effects of measurement noise and process noise have been investigated as well. Conclusions The advantage of this model-based algorithm over the conventional strain-based algorithm is its potential of providing the distribution of elasticity under a proper biomechanical model constraint. We address the model

  14. A scanning-mode 2D shear wave imaging (s2D-SWI) system for ultrasound elastography.

    PubMed

    Qiu, Weibao; Wang, Congzhi; Li, Yongchuan; Zhou, Juan; Yang, Ge; Xiao, Yang; Feng, Ge; Jin, Qiaofeng; Mu, Peitian; Qian, Ming; Zheng, Hairong

    2015-09-01

    Ultrasound elastography is widely used for the non-invasive measurement of tissue elasticity properties. Shear wave imaging (SWI) is a quantitative method for assessing tissue stiffness. SWI has been demonstrated to be less operator dependent than quasi-static elastography, and has the ability to acquire quantitative elasticity information in contrast with acoustic radiation force impulse (ARFI) imaging. However, traditional SWI implementations cannot acquire two dimensional (2D) quantitative images of the tissue elasticity distribution. This study proposes and evaluates a scanning-mode 2D SWI (s2D-SWI) system. The hardware and image processing algorithms are presented in detail. Programmable devices are used to support flexible control of the system and the image processing algorithms. An analytic signal based cross-correlation method and a Radon transformation based shear wave speed determination method are proposed, which can be implemented using parallel computation. Imaging of tissue mimicking phantoms, and in vitro, and in vivo imaging test are conducted to demonstrate the performance of the proposed system. The s2D-SWI system represents a new choice for the quantitative mapping of tissue elasticity, and has great potential for implementation in commercial ultrasound scanners. PMID:26025508

  15. Management of gastric variceal bleeding: Role of endoscopy and endoscopic ultrasound

    PubMed Central

    Girotra, Mohit; Raghavapuram, Saikiran; Abraham, Rtika R; Pahwa, Mrinal; Pahwa, Archna R; Rego, Rayburn F

    2014-01-01

    Gastric varices (GVs) are notorious to bleed massively and often difficult to manage with conventional techniques. This mini-review addresses endoscopic management principles for gastric variceal bleeding, including limitations of ligation and sclerotherapy and merits of endoscopic variceal obliteration. The article also discusses how emerging use of endoscopic ultrasound provides optimism of better diagnosis, improved classification, innovative management strategies and confirmatory tool for eradication of GVs. PMID:24672642

  16. [Renal elastography].

    PubMed

    Correas, Jean-Michel; Anglicheau, Dany; Gennisson, Jean-Luc; Tanter, Mickael

    2016-04-01

    Renal elastography has become available with the development of noninvasive quantitative techniques (including shear-wave elastography), following the rapidly growing field of diagnosis and quantification of liver fibrosis, which has a demonstrated major clinical impact. Ultrasound or even magnetic resonance techniques are leaving the pure research area to reach the routine clinical use. With the increased incidence of chronic kidney disease and its specific morbidity and mortality, the noninvasive diagnosis of renal fibrosis can be of critical value. However, it is difficult to simply extend the application from one organ to the other due to a large number of anatomical and technical issues. Indeed, the kidney exhibits various features that make stiffness assessment more complex, such as the presence of various tissue types (cortex, medulla), high spatial orientation (anisotropy), local blood flow, fatty sinus with variable volume and echotexture, perirenal space with variable fatty content, and the variable depth of the organ. Furthermore, the stiffness changes of the renal parenchyma are not exclusively related to fibrosis, as renal perfusion or hydronephrosis will impact the local elasticity. Renal elastography might be able to diagnose acute or chronic obstruction, or to renal tumor or pseudotumor characterization. Today, renal elastography appears as a promising application that still requires optimization and validation, which is the contrary for liver stiffness assessment. PMID:26976058

  17. Imaging of spaces of neck and mediastinum by endoscopic ultrasound

    PubMed Central

    Sharma, Malay; Pathak, Amit; Shoukat, Abid; Somani, Piyush

    2016-01-01

    Endoscopic ultrasound (EUS) of the mediastinum was pioneered by gastroenterologists, and it was taken up by pulmonologists when the smaller-diameter endobronchial ultrasound (EBUS) scope was designed after a few years. The pulmonologists’ approach remained largely confined to entry from the trachea, but they soon realized that the esophagus was an alternative route of entry by the EBUS scope. The new generations of interventionists are facing the challenge of learning two techniques (EUS and EBUS) from two routes (esophagus and trachea). The International Association for the Study of Lung Cancer (IASLC) proposed a classification of mediastinal lymph nodes at different stations that lie within the boundaries of specific spaces. These interventionists need clear definitions of landmarks and clear techniques to identify the spaces. There are enough descriptions of spaces of the neck and the mediastinum in the literature, yet the topic mentioned above has never been discussed separately. The anatomical structures, landmarks, and boundaries of spaces will be important to interventionists in the near future during performances of endosonography. This article combines the baseline anatomy of the spaces with the actual imaging during EUS. PMID:27185994

  18. Impact of endoscopic ultrasound quality assessment on improving endoscopic ultrasound reports and procedures

    PubMed Central

    Schwab, Ryan; Pahk, Eugene; Lachter, Jesse

    2016-01-01

    AIM: To evaluate the impact of endoscopic ultrasonography (EUS) quality assessment on EUS procedures by comparing the most recent 2013-2014 local EUS procedural reports against relevant corresponding data from a 2009 survey of EUS using standardized quality indicators (QIs). METHODS: Per EUS exam, 27 QIs were assessed individually and by grouping pre-, intra-, and post-procedural parameters. The recorded QI frequencies from 200 reports (2013-2014) were compared to corresponding data of 100 reports from the quality control study of EUS in 2009. Data for QIs added after 2009 to professional guidelines (added after 2010) were also tabulated. RESULTS: Significant differences (P-value < 0.05) were found for 13 of 20 of the relevant QIs examined. 4 of 5 pre-procedural QIs, 6 of 10 intra-procedural QIs, and 3 of 5 post-procedural QIs all demonstrated significant upgrading with a P-value < 0.05. CONCLUSION: Significant improvements were demonstrated in QI adherence and thus EUS reporting and delivery quality when the 2013-2014 reports were compared to 2009 results. QI implementation facilitates effective high-quality EUS exams by ensuring comprehensive documentation while limiting error. PMID:27114750

  19. Clinical evaluation of new diagnostic modalities of endoscopic ultrasound for pancreaticobiliary diseases.

    PubMed

    Teoh, Anthony Yuen Bun; Tang, Raymond Shing Yan

    2015-04-01

    Endoscopic ultrasonography (EUS) is currently an integral tool for work-up of pancreaticobiliary neoplasms. Tissue acquisition by EUS is possible with fine-needle aspiration (FNA) cytology and histology. However, FNA still carries some limitations and risks of complications. The use of image-enhanced EUS may improve detection and characterization of pancreaticobiliary neoplasms and complement FNA. The present article aims to provide an overview of the current development of contrast-enhanced imaging and elastography in EUS and their potential application in the diagnosis of pancreaticobiliary diseases. PMID:25645516

  20. New developments in endoscopic ultrasound-guided therapies

    PubMed Central

    Bhutani, Manoop S.; Arora, Ayush

    2015-01-01

    Endoscopic ultrasound (EUS) has opened new horizons in minimally invasive therapies for diverse gastrointestinal pathologies. Digestive Disease Weak 2015 held in Washington, DC., USA featured exciting research articles on EUS-guided therapeutic procedures. EUS-guided biliary drainage has been attempted and described for many years. There seems to be a lot of interest among various international groups to compare this technique with other alternatives in terms of efficacy and safety. Similarly, EUS-guided pancreatic drainage of cysts and fluid collections continues to evolve with new stents and devices being developed specifically for deployment under endosonographic guidance. EUS-guided ablation of cystic pancreatic tumors is innovative but not always effective. Combining alcohol ablation with injecting chemotherapeutic agents may improve long-term results regarding efficacy. Similarly, for solid pancreatic tumors there appears to be ongoing interest and continuing efforts in injecting different chemotherapeutic or ablative agents, delivering fiducials for radiation guidance and even attempting ablation with radiofrequency. Gastric variceal treatment and EUS-guided anastomoses also continue to be investigated. This review article is focused on the recent developments in EUS-guided therapies presented at Digestive Disease Week (DDW) 2015. PMID:26643698

  1. Tumors and new endoscopic ultrasound-guided therapies

    PubMed Central

    Carrara, Silvia; Petrone, Maria Chiara; Testoni, Pier Alberto; Arcidiacono, Paolo Giorgio

    2013-01-01

    With the advent of linear echoendoscopes, endoscopic ultrasound (EUS) has become more operative and a new field of oncological application has been opened up. From tumor staging to tissue acquisition under EUS-guided fine-needle aspiration, new operative procedures have been developed on the principle of the EUS-guided puncture. A hybrid probe combining radiofrequency with cryotechnology is now available, to be passed through the operative channel of the echoendoscope into the tumor to create an area of ablation. EUS-guided fine-needle injection is emerging as a method to deliver anti-tumoral agents inside the tumor. Ethanol lavage, with or without paclitaxel, has been proposed for the treatment of cystic tumors in non-resectable cases and complete resolution has been recorded in up to 70%-80%. Many other chemical or biological agents have been investigated for the treatment of pancreatic adenocarcinoma: activated allogenic lymphocyte culture (Cytoimplant), a replication-deficient adenovirus vector carrying the tumor necrosis factor-α gene, or an oncolytic attenuated adenovirus (ONYX-015). The potential advantage of treatment under EUS control is the real-time imaging guidance into a deep target like the pancreas which is extremely difficult to reach by a percutaneous approach. To date there are no randomized controlled trials to confirm the real clinical benefits of these treatments compared to standard therapy so it seems wise to reserve them only for experimental protocols approved by ethics committees. PMID:23596535

  2. A novel fusion imaging system for endoscopic ultrasound

    PubMed Central

    Gruionu, Lucian Gheorghe; Săftoiu, 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 electromagnetic (EM) sensors to co-register the live EUS images with the pre-procedure computed tomography (CT) data with a novel navigation algorithm and catheter. Methods: An experienced gastroenterologist and a novice EUS operator tested the FI system on a GI tract bench top model. Also, the experienced gastroenterologist performed a case series of 20 patients during routine EUS examinations. Results: On the bench top model, the experienced and novice doctors reached the targets in 67 ± 18 s and 150 ± 24 s with a registration error of 6 ± 3 mm and 11 ± 4 mm, respectively. In the case series, the total procedure 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. PMID:26879165

  3. New developments in endoscopic ultrasound-guided therapies.

    PubMed

    Bhutani, Manoop S; Arora, Ayush

    2015-01-01

    Endoscopic ultrasound (EUS) has opened new horizons in minimally invasive therapies for diverse gastrointestinal pathologies. Digestive Disease Weak 2015 held in Washington, DC., USA featured exciting research articles on EUS-guided therapeutic procedures. EUS-guided biliary drainage has been attempted and described for many years. There seems to be a lot of interest among various international groups to compare this technique with other alternatives in terms of efficacy and safety. Similarly, EUS-guided pancreatic drainage of cysts and fluid collections continues to evolve with new stents and devices being developed specifically for deployment under endosonographic guidance. EUS-guided ablation of cystic pancreatic tumors is innovative but not always effective. Combining alcohol ablation with injecting chemotherapeutic agents may improve long-term results regarding efficacy. Similarly, for solid pancreatic tumors there appears to be ongoing interest and continuing efforts in injecting different chemotherapeutic or ablative agents, delivering fiducials for radiation guidance and even attempting ablation with radiofrequency. Gastric variceal treatment and EUS-guided anastomoses also continue to be investigated. This review article is focused on the recent developments in EUS-guided therapies presented at Digestive Disease Week (DDW) 2015. PMID:26643698

  4. Tumors and new endoscopic ultrasound-guided therapies.

    PubMed

    Carrara, Silvia; Petrone, Maria Chiara; Testoni, Pier Alberto; Arcidiacono, Paolo Giorgio

    2013-04-16

    With the advent of linear echoendoscopes, endoscopic ultrasound (EUS) has become more operative and a new field of oncological application has been opened up. From tumor staging to tissue acquisition under EUS-guided fine-needle aspiration, new operative procedures have been developed on the principle of the EUS-guided puncture. A hybrid probe combining radiofrequency with cryotechnology is now available, to be passed through the operative channel of the echoendoscope into the tumor to create an area of ablation. EUS-guided fine-needle injection is emerging as a method to deliver anti-tumoral agents inside the tumor. Ethanol lavage, with or without paclitaxel, has been proposed for the treatment of cystic tumors in non-resectable cases and complete resolution has been recorded in up to 70%-80%. Many other chemical or biological agents have been investigated for the treatment of pancreatic adenocarcinoma: activated allogenic lymphocyte culture (Cytoimplant), a replication-deficient adenovirus vector carrying the tumor necrosis factor-α gene, or an oncolytic attenuated adenovirus (ONYX-015). The potential advantage of treatment under EUS control is the real-time imaging guidance into a deep target like the pancreas which is extremely difficult to reach by a percutaneous approach. To date there are no randomized controlled trials to confirm the real clinical benefits of these treatments compared to standard therapy so it seems wise to reserve them only for experimental protocols approved by ethics committees. PMID:23596535

  5. Endoscopic ultrasound in the papilla and the periampullary region.

    PubMed

    Castillo, Cecilia

    2010-08-16

    Endoscopic ultrasound (EUS) provides relevant information when an ampullary or periampullary tumor is suspected. Early detection, T and N staging and Fine Needle Aspiration plus cithologic confirmation, are some of the expected benefits. Exclusion of benign findings like choledocholithiasis or chronic pancreatitis is also important. A correct understanding of the complex ampullary and periampullary anatomy is needed. Knowledge of the individual clinical history and other previous diagnostic images all contribute to a successful EUS examination. Radial and lineal EUS images are uniquely detailed and, at the moment, it seems to be the best way to exclude or confirm malignant or benign findings. We propose a procedural algorithm, including EUS, for suspected ampullary or periampullary tumors. This review summarizes the vast amount of information to be found spread in the literature, and recognizes this small anatomic area as the origin for a clinical entity with proper clinical presentation, proper imaging and proper therapeutic resolutions. The benefits of performing EUS for its study are highlighted. PMID:21160627

  6. Celiac plexus neurolysis in pancreatic cancer: The endoscopic ultrasound approach

    PubMed Central

    Seicean, Andrada

    2014-01-01

    Pain in pancreatic cancer is often a major problem of treatment. Administration of opioids is frequently limited by side effects or insufficient analgesia. Endoscopic ultrasound-guided celiac plexus neurolysis (EUS-CPN) represents an alternative for the palliative treatment of visceral pain in patients with pancreatic cancer. This review focuses on the indications, technique, outcomes of EUS-CPN and predictors of pain relief. EUS-CPN should be considered as the adjunct method to standard pain management. It moderately reduces pain in pancreatic cancer, without eliminating it. Nearly all patients need to continue opioid use, often at a constant dose. The effect on quality of life is controversial and survival is not influenced. The approach could be done in the central position of the celiac axis, which is easy to perform, or in the bilateral position of the celiac axis, with similar results in terms of pain alleviation. The EUS-CPN with multiple intraganglia injection approach seems to have better results, although extended studies are still needed. Further trials are required to enable more confident conclusions regarding timing, quantity of alcohol injected and the method of choice. Severe complications have rarely been reported, and great care should be taken in choosing the site of alcohol injection. PMID:24415863

  7. The role of endoscopic ultrasound in pancreatic cancer screening

    PubMed Central

    Bhutani, Manoop S.; Koduru, Pramoda; Joshi, Virendra; Saxena, Payal; Suzuki, Rei; Irisawa, Atsushi; Yamao, Kenji

    2016-01-01

    Pancreatic cancer (PC) is a highly lethal cancer. Despite a significant advancement in cancer treatment, the mortality rate of PC is nearly identical to the incidence rates. Early detection of tumor or its precursor lesions with dysplasia may be the most effective approach to improve survival. Screening strategies should include identification of the population at high risk of developing PC, and an intense application of screening tools with adequate sensitivity to detect PC at an early curable stage. Endoscopic ultrasound (EUS) and magnetic resonance imaging (MRI) seem to be the most promising modalities for PC screening based on the data so far. EUS had an additional advantage over MRI by being able to obtain tissue sample during the same examination. Several questions remain unanswered at this time regarding the age to begin screening, frequency of screening, management of asymptomatic pancreatic lesions detected on screening, timing of resection, and extent of surgery and impact of screening on survival. Novel techniques such as needle-based confocal laser endomicroscopy (nCLE), along with biomarkers, may be helpful to identify pancreatic lesions with more aggressive malignant potential. Further studies will hopefully lead to the development of strategies combining EUS with other technological/biological advancements that will be cost-effective and have an impact on survival. PMID:26879161

  8. The effects of fatty deposits on the accuracy of the Fibroscan® liver transient elastography ultrasound system

    NASA Astrophysics Data System (ADS)

    Cournane, S.; Browne, J. E.; Fagan, A. J.

    2012-06-01

    A new generation of ultrasound transient elastography (TE) systems have emerged which exploit the well-known correlation between the liver's pathological and mechanical properties through measurements of the Young's elastic modulus; however, little work has been carried out to examine the effect that fatty deposits may have on the TE measurement accuracy. An investigation was carried out on the effects on the measurement accuracy of a TE ultrasound system, the Fibroscan®, caused by overlaying fat layers of varying thickness on healthy liver-mimicking phantoms, simulating in vivo conditions for obese patients. Furthermore, a steatosis effect similar to that in non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) was simulated to investigate its effect on the TE system. A range of novel elastography fat-mimicking materials were developed using 6-10 wt% poly(vinyl alcohol) cryogel capable of achieving a range of acoustic velocities (1482-1530 m s-1) and attenuation coefficients (0.4-1 dB MHz-1 cm-1) for simulating different liver states. Laboratory-based acoustic velocities and attenuation coefficients were measured while the Young's modulus was established through a gold standard compression testing method. A significant variation of the Young's elastic modulus was measured in healthy phantoms with overlaying fat layers of thicknesses exceeding 45 mm, impinging on the scanners region of interest, overestimating the compression tested values by up to 11 kPa in some cases. Furthermore, Fibroscan® measurements of the steatosis phantoms showed a consistent overestimation (˜54%), which strongly suggests that the speed of sound mismatch between that of liver tissue and that assumed by the scanner is responsible for the high clinical cut-offs established in the case of ALD and NAFLD.

  9. [Endoscopic ultrasound-guided ethanol ablation: an alternative option for the treatment of pancreatic insulinoma].

    PubMed

    Bor, Renáta; Farkas, Klaudia; Bálint, Anita; Molnár, Tamás; Nagy, Ferenc; Valkusz, Zsuzsanna; Sepp, Krisztián; Tiszlavicz, László; Hamar, Sándor; Szepes, Zoltán

    2014-10-12

    Endoscopic ultrasound is the most accurate imaging modality for the diagnosis of pancreatic cancer, and endoscopic ultrasound-guided fine needle injection has already been used for palliative interventions. Surgical resection is currently the standard treatment for pancreatic insulinoma. Medical treatment may be necessary for symptomatic patients with unresectable disease. Case reports have been published about the success of endoscopic ultrasound-guided alcoholic ablation, but it has not been reported previously in Hungarian literature. The authors present the history of an 83-year-old woman who was evaluated because of repeated hypoglycemic coma occurring during the night. Endosonographic image and laboratory findings (elevated serum insulin and chromogranin A) revealed pancreatic insulinoma. Because of severe comorbidities and high risk of surgical resection, the decision was made to ablate the insulinoma by endoscopic ultrasound-guided alcohol injection. A total of 3 mL 95% ethanol was injected into the tumor. Despite the discontinuation of the diazoxide therapy the hypoglycemic episodes disappeared. This case history confirms that endoscopic ultrasound-guided alcoholic ablation is a novel, minimal invasive alternative treatment for patients with pancreatic neuroendocrine tumors in whom surgery is not feasible. PMID:25282110

  10. Ultrasound strain elastography in assessment of cortical mechanical behavior in acute renal vein occlusion: in vivo animal model.

    PubMed

    Gao, Jing; He, Wen; Cheng, Ling-Gang; Li, Xiao-Ya; Zhang, Xiou-Ru; Juluru, Krishna; Al Khori, Noor; Coya, Adrienne; Min, Robert

    2015-01-01

    To assess the correlation of quantitative ultrasound strain parameters with the severity of cortical edema in renal vein occlusion, we prospectively performed ultrasound strain elastography on a canine acute renal vein occlusion model prior to and following 10, 20, and 40min of renal vein ligation. Strain and strain relaxation time representing the deformation and relaxation of the renal cortices and reference soft tissue were produced by the external compression with the ultrasound transducer and estimated using commercially available 2-D speckle tracking software. Cortical thickness was additionally measured. Repeated-measures analysis of variance was used to examine the difference in cortical thickness, strain ratio (mean cortical strain divided by mean reference tissue strain), and strain relaxation time ratio (cortical relaxation time divided by reference tissue relaxation time) prior to and after renal vein ligation. Pearson's correlation coefficient was applied to test the relationship between strain parameters and the time of the renal vein ligation. There was a strong positive correlation between the duration of renal vein ligation and strain (R(2)=0.97) and strain relaxation time (R(2)=0.98) ratios. Significant differences in strain and strain relaxation time ratios were found at all measured timepoints (all P≪.001). Cortical thickness, however, showed no significant difference between timepoints (P=.065). Our result suggest that strain and strain relaxation time ratios may be used as quantitative markers for the assessment of the renal cortical mechanical behavior in subclinical acute renal vein occlusion. PMID:25481219

  11. Comb-push Ultrasound Shear Elastography (CUSE): A Novel Method for Two-dimensional Shear Elasticity Imaging of Soft Tissues

    PubMed Central

    Song, Pengfei; Zhao, Heng; Manduca, Armando; Urban, Matthew W.; Greenleaf, James F.; Chen, Shigao

    2012-01-01

    Fast and accurate tissue elasticity imaging is essential in studying dynamic tissue mechanical properties. Various ultrasound shear elasticity imaging techniques have been developed in the last two decades. However, to reconstruct a full field-of-view 2D shear elasticity map, multiple data acquisitions are typically required. In this paper, a novel shear elasticity imaging technique, comb-push ultrasound shear elastography (CUSE), is introduced in which only one rapid data acquisition (less than 35 ms) is needed to reconstruct a full field-of-view 2D shear wave speed map (40 mm × 38 mm). Multiple unfocused ultrasound beams arranged in a comb pattern (comb-push) are used to generate shear waves. A directional filter is then applied upon the shear wave field to extract the left-to-right (LR) and right-to-left (RL) propagating shear waves. Local shear wave speed is recovered using a time-of-flight method based on both LR and RL waves. Finally a 2D shear wave speed map is reconstructed by combining the LR and RL speed maps. Smooth and accurate shear wave speed maps are reconstructed using the proposed CUSE method in two calibrated homogeneous phantoms with different moduli. Inclusion phantom experiments demonstrate that CUSE is capable of providing good contrast (contrast-to-noise-ratio ≥ 25 dB) between the inclusion and background without artifacts and is insensitive to inclusion positions. Safety measurements demonstrate that all regulated parameters of the ultrasound output level used in CUSE sequence are well below the FDA limits for diagnostic ultrasound. PMID:22736690

  12. Endoscopic Ultrasound-guided Bilio-pancreatic Drainage

    PubMed Central

    Giovannini, Marc; Bories, Erwan; Téllez-Ávila, Félix I.

    2012-01-01

    pancreatic pseudocyst (PPC) puncture combines endos-copy with real time endosonography using an interventional echoendoscope. Several authors have described the use of endoscopic ultrasound (EUS) longitudinal scanners for guidance of transmural puncture and drainage procedures. The same technique could be used to access a dilated pancreatic duct in cases in which the duct cannot be drained by conventional ERCP because of complete obstruction. PMID:24949349

  13. Diagnosis and fine needle aspiration of pancreatic pseudocysts: the role of endoscopic ultrasound.

    PubMed

    Breslin, Niall; Wallace, Michael B

    2002-10-01

    Pseudocysts are localized collections of pancreatic fluid surrounded by nonepithelialized granulation tissue that occur following an insult to the pancreas. High image resolution and the ability sample in real-time by fine needle aspiration permit accurate distinction between various cystic lesions in the pancreas by endoscopic ultrasound (EUS). Other cyst characteristics and background pancreatic changes detectable at EUS assist in the diagnostic process. The use of Doppler flow ultrasound allows diagnosis of important pseudocyst complications such as pseudoaneurysms and varices. Endoscopic approaches to the drainage of symptomatic lesions previously relied on the use of cross-sectional imaging studies such as computed tomography scanning in combination with stent placement using a duodenoscope in the presence of an endoscopically visible cyst bulge. EUS facilitates this process allowing accurate imaging of the lesion prior to stent placement via the echoendoscope and overcomes many of the drawbacks and pitfalls of other endoscopic techniques. PMID:12607787

  14. How to learn and to perform endoscopic ultrasound and endobronchial ultrasound for lung cancer staging: A structured guide and review

    PubMed Central

    Konge, Lars; Colella, Sara; Vilmann, Peter; Clementsen, Paul Frost

    2015-01-01

    The learning of transesophageal ultrasound guided fine needle aspiration (FNA) (endoscopic ultrasound-FNA), and endobronchial ultrasound guided transbronchial needle aspiration (endosonography) should be based on the following steps: Acquiring theoretical knowledge, training on simulators, and supervised performance on patients. Each step should be completed by passing a validated exam before proceeding to the next step. This approach will assure basic competency on all levels, and testing also facilitates learning and improves retention. Competence in endosonography can be based on a systematic an easy principle consisting of 2 times six anatomical landmarks. PMID:25789278

  15. Endoscopic ultrasound-guided biliary drainage as an alternative to percutaneous drainage and surgical bypass.

    PubMed

    Prachayakul, Varayu; Aswakul, Pitulak

    2015-01-16

    Endoscopic retrograde cholangiopancreatography had been a treatment modality of choice for both benign and malignant biliary tract obstruction for more than half century, with a very high clinical success rate and low complications. But in certain circumstances, such as advanced and locally advanced pancreatobiliary malignancies (pancreatic cancer, cholangiocarcinoma, ampullary tumor) and tight benign strictures, endoscopic retrograde cholangiopancreatography (ERCP) fails. Up to this point, the only alternative interventions for these conditions were percutaneous transhepatic biliary drainage or surgery. Endoscopic ultrasound guided interventions was introduced for a couple decades with the better visualization and achievement of the pancreatobiliary tract. And it's still in the process of ongoing development. The inventions of new techniques and accessories lead to more feasibility of high-ended procedures. Endoscopic ultrasound guided biliary drainage was a novel treatment modality for the patient who failed ERCP with the less invasive technique comparing to surgical bypass. The technical and clinical success was high with acceptable complications. Regarded the ability to drain the biliary tract internally without an exploratory laparotomy, this treatment modality became a very interesting procedures for many endosonographers, worldwide, in a short period. We have reviewed the literature and suggest that endoscopic ultrasound-guided biliary drainage is also an option, and one with a high probability of success, for biliary drainage in the patients who failed conventional endoscopic drainage. PMID:25610532

  16. Nonfluoroscopic endoscopic ultrasound-guided transmural drainage of pseudocysts: A pictorial technical review

    PubMed Central

    Rana, Surinder Singh; Bhasin, Deepak Kumar

    2015-01-01

    Pancreatic pseudocysts (PP) are one of the important local complications of pancreatitis and can be treated by surgical, laparoscopic, percutaneous, or endoscopic methods. The endoscopic methods of drainage include transpapillary or transmural drainage or a combination of these two routes. The transmural drainage can be done using conventional duodenoscope without endoscopic ultrasound (EUS) guidance or under EUS guidance. The EUS-guided transmural drainage of PP is done under EUS and fluoroscopic guidance. We have earlier reported nonfluoroscopic EUS-guided transmural drainage of walled-off pancreatic necrosis. In this pictorial technical review, we will discuss in detail this method of nonfluoroscopic EUS-guided drainage of PP. PMID:26020042

  17. Amplitude-modulated ultrasound radiation force combined with phase-sensitive optical coherence tomography for shear wave elastography

    NASA Astrophysics Data System (ADS)

    Nguyen, Thu-Mai; Song, Shaozhen; Arnal, Bastien; Wong, Emily Y.; Shen, Tueng T.; Wang, Ruikang K.; O'Donnell, Matthew

    2015-03-01

    Tissue stiffness can be measured from the propagation speed of shear waves. Acoustic radiation force (ARF) can generate shear waves by focusing ultrasound in tissue for ~100 μs. Safety considerations and electronics abilities limit ultrasound pressures. We previously presented shear wave elastography combining ARF and phase-sensitive optical coherence tomography (PhS-OCT) [1]. Here, we use amplitude-modulated ARF to enhance shear wave signal-to-noise ratio (SNR) at low pressures. Experiments were performed on tissue-mimicking phantoms. ARF was applied using a single-element transducer, driven by a 7.5 MHz, 3-ms, sine wave modulated in amplitude by a linear-swept frequency (1 to 7 kHz). Pressures between 1 to 3 MPa were tested. Displacements were tracked using PhS-OCT and numerically compressed using pulse compression methods detailed in previous work [2]. SNR was compared to that of 200-μs bursts. Stiffness maps were reconstructed using time-of-flight computations. 200-μs bursts give barely detectable displacements at 1 MPa (3.7 dB SNR). Pulse compression gives 36.2 dB at 1.5 MPa. In all cases with detectable displacements, shear wave speeds were determined in 5%-gelatin and 10%-gelatin phantoms and compared to literature values. Applicability to ocular tissues (cornea, intraocular lens) is under investigation.

  18. Monitoring Radiofrequency Ablation Using Ultrasound Envelope Statistics and Shear Wave Elastography in the Periablation Period: An In Vitro Feasibility Study.

    PubMed

    Tsui, Po-Hsiang; Wang, Chiao-Yin; Zhou, Zhuhuang; Wan, Yung-Liang

    2016-01-01

    Radiofrequency ablation (RFA) is a minimally invasive method for treating tumors. Shear wave elastography (SWE) has been widely applied in evaluating tissue stiffness and final ablation size after RFA. However, the usefulness of periablation SWE imaging in assessing RFA remains unclear. Therefore, this study investigated the correlation between periablation SWE imaging and final ablation size. An in vitro porcine liver model was used for experimental validation (n = 36). During RFA with a power of 50 W, SWE images were collected using a clinical ultrasound system. To evaluate the effects of tissue temperature and gas bubbles during RFA, changes in the ablation temperature were recorded, and image echo patterns were measured using B-mode and ultrasound statistical parametric images. After RFA, the gross pathology of each tissue sample was compared with the region of change in the corresponding periablation SWE image. The experimental results showed that the tissue temperature at the ablation site varied between 70°C and 100°C. Hyperechoic regions and changes were observed in the echo amplitude distribution induced by gas bubbles. Under this condition, the confounding effects (including the temperature increase, tissue stiffness increase, and presence of gas bubbles) resulted in artifacts in the periablation SWE images, and the corresponding region correlated with the estimated final ablation size obtained from the gross pathology (r = 0.8). The findings confirm the feasibility of using periablation SWE imaging in assessing RFA. PMID:27603012

  19. DOES ENDOSCOPIC ULTRASOUND IMPROVE DETECTION OF LOCALLY RECURRENT ANAL SQUAMOUS CELL CANCER?

    PubMed Central

    Peterson, Carrie Y.; Weiser, Martin R.; Paty, Philip B.; Guillem, Jose G.; Nash, Garrett M.; Garcia-Aguilar, Julio; Patil, Sujata; Temple, Larissa K.

    2015-01-01

    Background Evaluating patients for recurrent anal cancer after primary treatment can be difficult due to distorted anatomy and scarring. Many institutions incorporate endoscopic ultrasound to improve detection, but the effectiveness is unknown. Objective To compare the effectiveness of digital rectal exam and endoscopic ultrasound during routine follow-up of anal cancer patients in detecting locally recurrent disease. Design Retrospective, single-institution review Settings Oncologic tertiary referral center Patients 175 patients with nonmetastatic anal squamous cell cancer without persistent disease after primary chemoradiotherapy who had at least one post-treatment ultrasound and examination by a colorectal surgeon. Main Outcome Measures First modality to detect local recurrence, concordance, crude cancer detection rate, sensitivity, specificity, and predictive value. Results 855 endoscopic ultrasounds and 873 digital rectal exams were performed during 35 months median follow-up. Overall, ultrasound detected 7 (0.8%) mesorectal and 32 (3.7%) anal canal abnormalities; digital exam detected 69 (7.9%) anal canal abnormalities. Locally recurrent disease was found on biopsy in 8 patients, all detected first or only with digital exam. Four patients did not have an ultrasound at the time of diagnosis of recurrence. The concordance of ultrasound and digital exam in detecting recurrent disease was fair at 0.37 (SE 0.08, 95% CI 0.21-0.54) and there was no difference in crude cancer detection rate, sensitivity, specificity, and negative or positive predictive values. Limitations The heterogeneity of follow-up timing and exams is not standardized in this study but is reflective of general practice. Conclusions Endoscopic ultrasound did not provide any advantage over digital rectal examination in identifying locally recurrent anal cancer, and should not be recommended for routine surveillance. PMID:25585077

  20. Building a virtual simulation platform for quasistatic breast ultrasound elastography using open source software: A preliminary investigation

    PubMed Central

    Wang, Yu; Helminen, Emily; Jiang, Jingfeng

    2015-01-01

    Purpose: Quasistatic ultrasound elastography (QUE) is being used to augment in vivo characterization of breast lesions. Results from early clinical trials indicated that there was a lack of confidence in image interpretation. Such confidence can only be gained through rigorous imaging tests using complex, heterogeneous but known media. The objective of this study is to build a virtual breast QUE simulation platform in the public domain that can be used not only for innovative QUE research but also for rigorous imaging tests. Methods: The main thrust of this work is to streamline biomedical ultrasound simulations by leveraging existing open source software packages including Field II (ultrasound simulator), VTK (geometrical visualization and processing), FEBio [finite element (FE) analysis], and Tetgen (mesh generator). However, integration of these open source packages is nontrivial and requires interdisciplinary knowledge. In the first step, a virtual breast model containing complex anatomical geometries was created through a novel combination of image-based landmark structures and randomly distributed (small) structures. Image-based landmark structures were based on data from the NIH Visible Human Project. Subsequently, an unstructured FE-mesh was created by Tetgen. In the second step, randomly positioned point scatterers were placed within the meshed breast model through an octree-based algorithm to make a virtual breast ultrasound phantom. In the third step, an ultrasound simulator (Field II) was used to interrogate the virtual breast phantom to obtain simulated ultrasound echo data. Of note, tissue deformation generated using a FE-simulator (FEBio) was the basis of deforming the original virtual breast phantom in order to obtain the postdeformation breast phantom for subsequent ultrasound simulations. Using the procedures described above, a full cycle of QUE simulations involving complex and highly heterogeneous virtual breast phantoms can be accomplished for

  1. Ultrasound strain elastography in assessment of resting biceps brachii muscle stiffness in patients with Parkinson's disease: a primary observation.

    PubMed

    Gao, Jing; He, Wen; Du, Li-Juan; Li, Shuo; Cheng, Ling-Gang; Shih, George; Rubin, Jonathan

    2016-01-01

    The aim of this study was to evaluate the feasibility of ultrasound strain elastography (SE) for the assessment of resting biceps brachii muscle (BBM) stiffness in patients with Parkinson's diseases (PD). From May 2014 to December 2014, we prospectively performed SE of BBM in 14 patients with PD and 10 healthy controls. Based on the Unified Parkinson's Disease Rating Scale for scoring muscle rigidity (UPDRS, part III), muscle rigidity scores in 14 patients with PD included 3 patients with high rigidity (UPDRS III-IV) and 11 patients with low rigidity (UPDRS I-II). Ultrasound strain was represented by the deformation of the BBM and subcutaneous soft tissues that was produced by external compression with a sand bag (1.5 kg) tied onto an ultrasound transducer. Deformation was estimated with two-dimensional speckle tracking. The difference in strain ratio (SR, defined as mean BBM strain divided by mean subcutaneous soft tissue strain) between PD and healthy controls was tested by unpaired t test. The correlation between SR and muscle rigidity score was analyzed by Pearson correlation coefficient. The reliability of SR in assessment of BBM stiffness was tested using intraclass correlation coefficient. In our result, the SR in PD and healthy controls measured 2.65±0.36 and 3.30±0.27, respectively. A significant difference in SR was noted between the healthy controls and PD (P=.00011). A negative correlation was found between SR and UPDRS rigidity score (r=-0.78). Our study suggests that the SR of BBM to reference tissue can be used as a quantitative biomarker in assessing resting muscle stiffness associated with muscle rigidity in PD. PMID:27133683

  2. Treatment of a Splenic Artery Pseudoaneurysm by Endoscopic Ultrasound-Guided Thrombin Injection

    SciTech Connect

    Robinson, Mark Richards, Dafydd; Carr, Nicholas

    2007-06-15

    We present a case of a splenic artery pseudoaneurysm secondary to pancreatitis that was successfully treated by transgastric injection of thrombin under endoscopic ultrasound guidance. There has been no recurrence on follow-up CT angiography, and thus complex surgery or endovascular intervention has been avoided.

  3. Endocoil placement after endoscopic ultrasound-guided biliary drainage may prevent a bile leak

    PubMed Central

    van der Merwe, Schalk Willem; Omoshoro-Jones, Jones; Sanyika, Charles

    2013-01-01

    AIM: To further reduce the risk of bleeding or bile leakage. METHODS: We performed endoscopic ultrasound guided biliary drainage in 6 patients in whom endoscopic retrograde cholangiopancreatography (ERCP) had failed. Biliary access of a dilated segment 2 or 3 duct was achieved from the stomach using a 19G needle. After radiologically confirming access a guide wire was placed, a transhepatic tract created using a 6 Fr cystotome followed by balloon dilation of the stricture and antegrade metallic stent placement across the malignant obstruction. This was followed by placement of an endocoil in the transhepatic tract. RESULTS: Dilated segmental ducts were observed in all patients with the linear endoscopic ultrasound scope from the proximal stomach. Transgastric biliary access was obtained using a 19G needle in all patients. Biliary drainage was achieved in all patients. Placement of an endocoil was possible in 5/6 patients. All patients responded to biliary drainage and no complications occurred. CONCLUSION: We show that placing endocoils at the time of endoscopic ultrasound guided biliary stenting is feasible and may reduce the risk of bleeding or bile leakage. PMID:23678378

  4. Utility of endoscopic ultrasound in the diagnosis and management of esophagogastric varices

    PubMed Central

    Wang, An-Jiang; Li, Bi-Min; Zheng, Xue-Lian; Shu, Xu; Zhu, Xuan

    2016-01-01

    Endoscopic ultrasound (EUS) has significantly improved our understanding of the complex vascular structural changes in patients with portal hypertension. At present, EUS is a useful diagnostic tool for the evaluation of esophagogastric varices (EGVs) and guidance of endoscopic therapy. Several studies have employed this new technique for the diagnosis and management of esophageal and gastric varices, respectively. In the present review, we have summarized the current status of EUS for the diagnosis and management of EGVs and clarified the clinical feasibility of this procedure. New indications for EUS can be developed in the future after adequate validation. PMID:27503152

  5. Vision-based endoscope tracking for 3D ultrasound image-guided surgical navigation.

    PubMed

    Yang, L; Wang, J; Ando, T; Kubota, A; Yamashita, H; Sakuma, I; Chiba, T; Kobayashi, E

    2015-03-01

    This work introduces a self-contained framework for endoscopic camera tracking by combining 3D ultrasonography with endoscopy. The approach can be readily incorporated into surgical workflows without installing external tracking devices. By fusing the ultrasound-constructed scene geometry with endoscopic vision, this integrated approach addresses issues related to initialization, scale ambiguity, and interest point inadequacy that may be faced by conventional vision-based approaches when applied to fetoscopic procedures. Vision-based pose estimations were demonstrated by phantom and ex vivo monkey placenta imaging. The potential contribution of this method may extend beyond fetoscopic procedures to include general augmented reality applications in minimally invasive procedures. PMID:25263644

  6. [Endoscopic ultrasound-guided choledocho-duodenostomy in advanced pancreatic cancer with duodenal obstruction].

    PubMed

    Mella, José Manuel; Guidi, Martín; De María, Julio; Hwang, Hui-Jer; Curvale, Cecilia R; Matano, Raúl

    2015-01-01

    Endoscopic retrograde cholangiopancreatography (ERCP) is considered the first-approach for biliary drainage. In cases of ERCP failure, patients are usually referred for percutaneous transhepatic biliary drainage or surgical biliary bypass. In the last decade, the indications of endoscopic ultrasound (EUS) in the management of patients with pancreatic cancer have increased, and numerous cases of EUS-guided biliary drainage have been reported in patients with failures during the ERCP. Our goal is to report a patient with locally advanced pancreatic cancer who presented with painless jaundice and cholestasis with biliary and duodenal obstruction. A EUS-guided choledochoduodenostomy was performed by placement of a self-expanding metal stent. PMID:26502467

  7. Endoscopic Ultrasound-guided Antegrade Stenting in an Occluded Biliary Self-expandable Metal Stent

    PubMed Central

    Almadi, Majid A.; Eltayeb, Mohanned; Thaniah, Salem

    2016-01-01

    Endoscopic ultrasound-guided biliary drainage (EUS-BD) is an attractive option for patients who cannot undergo conventional endoscopic retrograde cholangiopancreatography (ERCP) and do not want surgery or percutaneous drainage procedures. We present the use of EUS-antegrade (EUS-AG) insertion of a self-expandable metal stent (SEMS) in a patient with a common hepatic duct cholangiocarcinoma, as well as a huge gastric lipoma, after recurrent biliary obstruction of a prior SEMS inserted via ERCP in the same session as a duodenal stent insertion for gastric outlet obstruction. PMID:27488330

  8. Cardiac shear-wave elastography using a transesophageal transducer: application to the mapping of thermal lesions in ultrasound transesophageal cardiac ablation

    NASA Astrophysics Data System (ADS)

    Kwiecinski, Wojciech; Bessière, Francis; Constanciel Colas, Elodie; Apoutou N'Djin, W.; Tanter, Mickaël; Lafon, Cyril; Pernot, Mathieu

    2015-10-01

    Heart rhythm disorders, such as atrial fibrillation or ventricular tachycardia can be treated by catheter-based thermal ablation. However, clinically available systems based on radio-frequency or cryothermal ablation suffer from limited energy penetration and the lack of lesion’s extent monitoring. An ultrasound-guided transesophageal device has recently successfully been used to perform High-Intensity Focused Ultrasound (HIFU) ablation in targeted regions of the heart in vivo. In this study we investigate the feasibility of a dual therapy and imaging approach on the same transesophageal device. We demonstrate in vivo that quantitative cardiac shear-wave elastography (SWE) can be performed with the device and we show on ex vivo samples that transesophageal SWE can map the extent of the HIFU lesions. First, SWE was validated with the transesophageal endoscope in one sheep in vivo. The stiffness of normal atrial and ventricular tissues has been assessed during the cardiac cycle (n=11 ) and mapped (n= 7 ). Second, HIFU ablation has been performed with the therapy-imaging transesophageal device in ex vivo chicken breast samples (n  =  3), then atrial (left, n= 2 ) and ventricular (left n=1 , right n=1 ) porcine heart tissues. SWE provided stiffness maps of the tissues before and after ablation. Areas of the lesions were obtained by tissue color change with gross pathology and compared to SWE. During the cardiac cycle stiffness varied from 0.5   ±   0.1 kPa to 6.0   ±   0.3 kPa in the atrium and from 1.3   ±   0.3 kPa to 13.5   ±   9.1 kPa in the ventricles. The thermal lesions were visible on all SWE maps performed after ablation. Shear modulus of the ablated zones increased to 16.3   ±   5.5 kPa (versus 4.4   ±   1.6 kPa before ablation) in the chicken breast, to 30.3   ±   10.3 kPa (versus 12.2   ±   4.3 kPa) in the atria and to 73.8   ±   13

  9. Cardiac shear-wave elastography using a transesophageal transducer: application to the mapping of thermal lesions in ultrasound transesophageal cardiac ablation.

    PubMed

    Kwiecinski, Wojciech; Bessière, Francis; Colas, Elodie Constanciel; N'Djin, W Apoutou; Tanter, Mickaël; Lafon, Cyril; Pernot, Mathieu

    2015-10-21

    Heart rhythm disorders, such as atrial fibrillation or ventricular tachycardia can be treated by catheter-based thermal ablation. However, clinically available systems based on radio-frequency or cryothermal ablation suffer from limited energy penetration and the lack of lesion's extent monitoring. An ultrasound-guided transesophageal device has recently successfully been used to perform High-Intensity Focused Ultrasound (HIFU) ablation in targeted regions of the heart in vivo. In this study we investigate the feasibility of a dual therapy and imaging approach on the same transesophageal device. We demonstrate in vivo that quantitative cardiac shear-wave elastography (SWE) can be performed with the device and we show on ex vivo samples that transesophageal SWE can map the extent of the HIFU lesions. First, SWE was validated with the transesophageal endoscope in one sheep in vivo. The stiffness of normal atrial and ventricular tissues has been assessed during the cardiac cycle (n = 11) and mapped (n = 7). Second, HIFU ablation has been performed with the therapy-imaging transesophageal device in ex vivo chicken breast samples (n  =  3), then atrial (left, n = 2) and ventricular (left n = 1, right n = 1) porcine heart tissues. SWE provided stiffness maps of the tissues before and after ablation. Areas of the lesions were obtained by tissue color change with gross pathology and compared to SWE. During the cardiac cycle stiffness varied from 0.5   ±   0.1 kPa to 6.0   ±   0.3 kPa in the atrium and from 1.3   ±   0.3 kPa to 13.5   ±   9.1 kPa in the ventricles. The thermal lesions were visible on all SWE maps performed after ablation. Shear modulus of the ablated zones increased to 16.3   ±   5.5 kPa (versus 4.4   ±   1.6 kPa before ablation) in the chicken breast, to 30.3   ±   10.3 kPa (versus 12.2   ±   4.3 kPa) in the atria and to 73.8

  10. Characteristic endoscopic ultrasound findings of ampullary lesions that predict the need for surgical excision or endoscopic ampullectomy

    PubMed Central

    Rejeski, Jared J.; Kundu, Sarba; Hauser, Matthew; Conway, Jason D.; Evans, John A.; Pawa, Rishi; Mishra, Girish

    2016-01-01

    Background and Objectives: The management of ampullary lesions has evolved to include endoscopic ampullectomy (EA) as a curative approach to cancers of the ampulla of Vater. With this change comes a need to risk-stratify patients at initial diagnosis. Materials and Methods: Patients with verified ampullary lesions (N = 50) were analyzed in a case-control design. We evaluated endoscopic ultrasound (EUS) data to define characteristics that yield a high sensitivity in selecting candidates for EA. Results: Using data from previously published studies yielded a sensitivity of 0.765 in appropriately identifying the 34 surgical cases. Expanding these characteristics increased the sensitivity of EUS to 0.971 in identifying surgical candidates. Additionally, of advanced disease cases, the expanded characteristics correctly identified these cases with a sensitivity of 1.0-improved over 0.708 using prior published data. Conclusion: EA should be strongly considered if ampullary lesions are found to fit the following characteristics after EUS evaluation: lesion size <2.5 cm, invasion ≤4 mm, pancreatic duct dilatation ≤3 mm, ≤T1 lesion, no lymph nodes present, and no ductal stent in place. Furthermore, EUS data can be used to identify all high-risk lesions. With these characteristics identified, clinicians are better able to risk-stratify patients using EUS as either appropriate for or too high-risk for endoscopic resection. PMID:27386476

  11. Design, development and characterization of cyst phantom for ultrasound elastography applications.

    PubMed

    Kumar, Kishore; Andrews, M E; Jayashankar, V; Mishra, A K; Suresh, S

    2008-01-01

    Polyacrylamide based tissue mimicking phantom with embedded cysts is designed and analyzed for better understanding of cyst elastograms. Cysts filled with different fluids of varying density and bulk moduli are embedded in the phantom. Characterization is done based on parameters measured from the ultrasound B mode and elastogram of the cystic lesions. Such a phantom can serve as tool for better understanding of the elastographic appearance of cysts. Thus simple and complex cysts can be easily distinguished. It can also be used to teach a complex procedure like ultrasound guided fine needle aspiration. PMID:19163330

  12. Urgent endoscopic ultrasound-guided choledochoduodenostomy for acute obstructive suppurative cholangitis-induced sepsis.

    PubMed

    Minaga, Kosuke; Kitano, Masayuki; Imai, Hajime; Yamao, Kentaro; Kamata, Ken; Miyata, Takeshi; Omoto, Shunsuke; Kadosaka, Kumpei; Yoshikawa, Tomoe; Kudo, Masatoshi

    2016-04-28

    Acute obstructive suppurative cholangitis (AOSC) due to biliary lithiasis is a life-threatening condition that requires urgent biliary decompression. Although endoscopic retrograde cholangiopancreatography (ERCP) with stent placement is the current gold standard for biliary decompression, it can sometimes be difficult because of failed biliary cannulation. In this retrospective case series, we describe three cases of successful biliary drainage with recovery from septic shock after urgent endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS) was performed for AOSC due to biliary lithiasis. In all three cases, technical success in inserting the stents was achieved and the patients completely recovered from AOSC with sepsis in a few days after EUS-CDS. There were no procedure-related complications. When initial ERCP fails, EUS-CDS can be an effective life-saving endoscopic biliary decompression procedure that shortens the procedure time and prevents post-ERCP pancreatitis, particularly in patients with AOSC-induced sepsis. PMID:27122677

  13. Urgent endoscopic ultrasound-guided choledochoduodenostomy for acute obstructive suppurative cholangitis-induced sepsis

    PubMed Central

    Minaga, Kosuke; Kitano, Masayuki; Imai, Hajime; Yamao, Kentaro; Kamata, Ken; Miyata, Takeshi; Omoto, Shunsuke; Kadosaka, Kumpei; Yoshikawa, Tomoe; Kudo, Masatoshi

    2016-01-01

    Acute obstructive suppurative cholangitis (AOSC) due to biliary lithiasis is a life-threatening condition that requires urgent biliary decompression. Although endoscopic retrograde cholangiopancreatography (ERCP) with stent placement is the current gold standard for biliary decompression, it can sometimes be difficult because of failed biliary cannulation. In this retrospective case series, we describe three cases of successful biliary drainage with recovery from septic shock after urgent endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS) was performed for AOSC due to biliary lithiasis. In all three cases, technical success in inserting the stents was achieved and the patients completely recovered from AOSC with sepsis in a few days after EUS-CDS. There were no procedure-related complications. When initial ERCP fails, EUS-CDS can be an effective life-saving endoscopic biliary decompression procedure that shortens the procedure time and prevents post-ERCP pancreatitis, particularly in patients with AOSC-induced sepsis. PMID:27122677

  14. Multiple pancreatic metastases from malignant melanoma: Conclusive diagnosis with endoscopic ultrasound-guided fine needle aspiration

    PubMed Central

    Jana, Tanima; Caraway, Nancy P.; Irisawa, Atsushi; Bhutani, Manoop S.

    2015-01-01

    Pancreatic metastases are rare, ranging from 2% to 5% of pancreatic malignancies. Differentiating a primary pancreatic malignancy from a metastasis can be difficult due to similarities on imaging findings, but is crucial to ensure proper treatment. Although transabdominal ultrasound, computed tomography, and magnetic resonance imaging provide useful images, endoscopic ultrasound (EUS) with fine needle aspiration (FNA) is often needed to provide a cytologic diagnosis. Here, we present a unique case of malignant melanoma with pancreatic metastases. It is important for clinicians to recognize the possibility of melanoma metastasizing to the pancreas and the role of EUS with FNA in providing cytological confirmation. PMID:26020050

  15. Multiple pancreatic metastases from malignant melanoma: Conclusive diagnosis with endoscopic ultrasound-guided fine needle aspiration.

    PubMed

    Jana, Tanima; Caraway, Nancy P; Irisawa, Atsushi; Bhutani, Manoop S

    2015-01-01

    Pancreatic metastases are rare, ranging from 2% to 5% of pancreatic malignancies. Differentiating a primary pancreatic malignancy from a metastasis can be difficult due to similarities on imaging findings, but is crucial to ensure proper treatment. Although transabdominal ultrasound, computed tomography, and magnetic resonance imaging provide useful images, endoscopic ultrasound (EUS) with fine needle aspiration (FNA) is often needed to provide a cytologic diagnosis. Here, we present a unique case of malignant melanoma with pancreatic metastases. It is important for clinicians to recognize the possibility of melanoma metastasizing to the pancreas and the role of EUS with FNA in providing cytological confirmation. PMID:26020050

  16. Ultrasound Elastography for Fibrosis Surveillance Is Cost Effective in Patients with Chronic Hepatitis C Virus in the UK

    PubMed Central

    Canavan, C.; Eisenburg, J.; Meng, L.; Corey, K.; Hur, C.

    2014-01-01

    Background Chronic hepatitis C (HCV) is a significant risk factor for cirrhosis and subsequently hepatocellular carcinoma (HCC). HCV patients with cirrhosis are screened for HCC every 6 months. Surveillance for progression to cirrhosis and consequently access to HCC screening is not standardized. Liver biopsy, the usual test to determine cirrhosis, carries a significant risk of morbidity and associated mortality. Transient ultrasound elastography (fibroscan) is a non-invasive test for cirrhosis. Purpose This study assesses the cost effectiveness of annual surveillance for cirrhosis in patients with chronic HCV and the effect of replacing biopsy with fibroscan to diagnose cirrhosis. Method A Markov decision analytic model simulated a hypothetical cohort of 10,000 patients with chronic HCV initially without fibrosis over their lifetime. The cirrhosis surveillance strategies assessed were: no surveillance; current practice; fibroscan in current practice with biopsy to confirm cirrhosis; fibroscan completely replacing biopsy in current practice (definitive); annual biopsy; annual fibroscan with biopsy to confirm cirrhosis; annual definitive fibroscan. Results Our results demonstrate that annual definitive fibroscan is the optimal strategy to diagnose cirrhosis. In our study, it diagnosed 20 % more cirrhosis cases than the current strategy, with 549 extra patients per 10,000 accessing screening over a lifetime and, consequently, 76 additional HCC cases diagnosed. The lifetime cost is £98.78 extra per patient compared to the current strategy for 1.72 additional unadjusted life years. Annual fibroscan surveillance of 132 patients results in the diagnosis one additional HCC case over a lifetime. The incremental cost-effectiveness ratio for an annual definitive fibroscan is £6,557.06/quality-adjusted life years gained. Conclusion Annual definitive fibroscan may be a cost-effective surveillance strategy to identify cirrhosis in patients with chronic HCV, thereby allowing

  17. Non-invasive assessment of human multifidus muscle stiffness using ultrasound shear wave elastography: A feasibility study.

    PubMed

    Moreau, Baptiste; Vergari, Claudio; Gad, Hisham; Sandoz, Baptiste; Skalli, Wafa; Laporte, Sébastien

    2016-08-01

    There is a lack of numeric data for the mechanical characterization of spine muscles, especially in vivo data. The multifidus muscle is a major muscle for the stabilization of the spine and may be involved in the pathogenesis of chronic low back pain (LBP). Supersonic shear wave elastography (SWE) has not yet been used on back muscles. The purpose of this prospective study is to assess the feasibility of ultrasound SWE to measure the elastic modulus of lumbar multifidus muscle in a passive stretching posture and at rest with a repeatable and reproducible method. A total of 10 asymptotic subjects (aged 25.5 ± 2.2 years) participated, 4 females and 6 males. Three operators performed 6 measurements for each of the 2 postures on the right multifidus muscle at vertebral levels L2-L3 and L4-L5. Repeatability and reproducibility have been assessed according to ISO 5725 standard. Intra-class correlation coefficients (ICC) for intra- and inter-observer reliability were rated as both excellent [ICC=0.99 and ICC=0.95, respectively]. Reproducibility was 11% at L2-L3 level and 19% at L4-L5. In the passive stretching posture, shear modulus was significantly higher than at rest (µ < 0.05). This preliminary work enabled to validate the feasibility of measuring the shear modulus of the multifidus muscle with SWE. This kind of measurement could be easily introduces into clinical routine like for the medical follow-up of chronic LBP or scoliosis treatments. PMID:27435466

  18. New ultrasound techniques for lymph node evaluation

    PubMed Central

    Cui, Xin-Wu; Jenssen, Christian; Saftoiu, Adrian; Ignee, Andre; Dietrich, Christoph F

    2013-01-01

    Conventional ultrasound (US) is the recommended imaging method for lymph node (LN) diseases with the advantages of high resolution, real time evaluation and relative low costs. Current indications of transcutaneous ultrasound and endoscopic ultrasound include the detection and characterization of lymph nodes and the guidance for LN biopsy. Recent advances in US technology, such as contrast enhanced ultrasound (CEUS), contrast enhanced endoscopic ultrasound (CE-EUS), and real time elastography show potential to improve the accuracy of US for the differential diagnosis of benign and malignant lymph nodes. In addition, CEUS and CE-EUS have been also used for the guidance of fine needle aspiration and assessment of treatment response. Complementary to size criteria, CEUS could also be used to evaluate response of tumor angiogenesis to anti-angiogenic therapies. In this paper we review current literature regarding evaluation of lymphadenopathy by new and innovative US techniques. PMID:23946589

  19. SU-E-J-76: Incorporation of Ultrasound Elastography in Target Volume Delineation for Partial Breast Radiotherapy Planning: A Comparative Study

    SciTech Connect

    Juneja, P; Harris, E; Bamber, J

    2014-06-01

    Purpose: There is substantial observer variability in the delineation of target volumes for post-surgical partial breast radiotherapy because the tumour bed has poor x-ray contrast. This variability may result in substantial variations in planned dose distribution. Ultrasound elastography (USE) has an ability to detect mechanical discontinuities and therefore, the potential to image the scar and distortion in breast tissue architecture. The goal of this study was to compare USE techniques: strain elastography (SE), shear wave elastography (SWE) and acoustic radiation force impulse (ARFI) imaging using phantoms that simulate features of the tumour bed, for the purpose of incorporating USE in breast radiotherapy planning. Methods: Three gelatine-based phantoms (10% w/v) containing: a stiff inclusion (gelatine 16% w/v) with adhered boundaries, a stiff inclusion (gelatine 16% w/v) with mobile boundaries and fluid cavity inclusion (to mimic seroma), were constructed and used to investigate the USE techniques. The accuracy of the elastography techniques was quantified by comparing the imaged inclusion with the modelled ground-truth using the Dice similarity coefficient (DSC). For two regions of interest (ROI), the DSC measures their spatial overlap. Ground-truth ROIs were modelled using geometrical measurements from B-mode images. Results: The phantoms simulating stiff scar tissue with adhered and mobile boundaries and seroma were successfully developed and imaged using SE and SWE. The edges of the stiff inclusions were more clearly visible in SE than in SWE. Subsequently, for all these phantoms the measured DSCs were found to be higher for SE (DSCs: 0.91–0.97) than SWE (DSCs: 0.68–0.79) with an average relative difference of 23%. In the case of seroma phantom, DSC values for SE and SWE were similar. Conclusion: This study presents a first attempt to identify the most suitable elastography technique for use in breast radiotherapy planning. Further analysis will

  20. Integrated endoscope for real-time 3D ultrasound imaging and hyperthermia: feasibility study.

    PubMed

    Pua, Eric C; Qiu, Yupeng; Smith, S W

    2007-01-01

    The goal of this research is to determine the feasibility of using a single endoscopic probe for the combined purpose of real-time 3D (RT3D) ultrasound imaging of a target organ and the delivery of ultrasound therapy to facilitate the absorption of compounds for cancer treatment. Recent research in ultrasound therapy has shown that ultrasound-mediated drug delivery improves absorption of treatments for prostate, cervical and esophageal cancer. The ability to combine ultrasound hyperthermia and 3D imaging could improve visualization and targeting of cancerous tissues. In this study, numerical modeling and experimental measurements were developed to determine the feasibility of combined therapy and imaging with a 1 cm diameter endoscopic RT3D probe with 504 transmitters and 252 receive channels. This device operates at 5 MHz and has a 6.3 mm x 6.3 mm aperture to produce real time 3D pyramidal scans of 60-120 degrees incorporating 64 x 64 = 4096 image lines at 30 volumes/sec interleaved with a 3D steerable therapy beam. A finite-element mesh was constructed with over 128,000 elements in LS-DYNA to simulate the induced temperature rise from our transducer with a 3 cm deep focus in tissue. Quarter-symmetry of the transducer was used to reduce mesh size and computation time. Based on intensity values calculated in Field II using the transducer's array geometry, a minimum I(SPTA) of 3.6 W/cm2 is required from our endoscope probe in order to induce a temperature rise of 4 degrees C within five minutes. Experimental measurements of the array's power output capabilities were conducted using a PVDF hydrophone placed 3 cm away from the face of the transducer in a watertank. Using a PDA14 Signatec data acquisition board to capture full volumes of transmitted ultrasound data, it was determined that the probe can presently maintain intensity values up to 2.4 W/cm2 over indefinite times for therapeutic applications combined with intermittent 3D scanning to maintain targeting

  1. Contrast-enhanced ultrasound and real-time elastography in the differential diagnosis of malignant and benign thyroid nodules

    PubMed Central

    Sui, Xin; Liu, Huai-Jun; Jia, Hong-Li; Fang, Qin-Mao

    2016-01-01

    The diagnostic value of contrast-enhanced ultrasound (CEUS) or real-time elastography (RTE) alone, as well as a combination of CEUS and RTE, in distinguishing benign from malignant thyroid nodules was investigated. Between August 2012 and June 2014, a total of 97 consecutive patients (50 male and 47 female patients; mean age, 48.6±12.4; age range, 27–70 years) with thyroid nodules referred for surgical treatment were examined by CEUS and RTE. The final diagnosis was obtained based on histological findings. Image analysis of the CEUS and RTE scans was performed. Considering the postoperative pathological results as the golden standard, a receiver operating characteristic (ROC) curve was constructed. Subsequently, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of CEUS alone, RTE alone and CEUS + RTE combination were calculated. Pathological examination showed 66 papillary carcinomas and 43 benign lesions, including 21 adenomas and 22 nodular goiters. The sensitivity, specificity, PPV, NPV and accuracy of CEUS were 81.82, 90.70, 93.10, 90.70 and 85.32%, respectively. In the case of RTE, the sensitivity, specificity, PPV, NPV and accuracy were 80.30, 88.37, 91.38, 88.37 and 83.49%, respectively. Furthermore, the combination of CEUS + RTE had a sensitivity of 95.45%, specificity of 95.35%, PPV of 96.92%, NPV of 95.35% and accuracy of 95.41%. Therefore, the CEUS + RTE combination showed a significantly higher sensitivity and specificity compared with CEUS or RTE alone (all P<0.05). Based on ROC analysis, the area under the curve (AUC) for CEUS, RTE and CEUS + RTE combination was 0.883, 0.863 and 0.959, respectively. The AUC of RTE alone was significantly lower compared with that of the CEUS + RTE combination. In conclusion, our results demonstrate that CEUS + RTE combination significantly increases the diagnostic performance for differential diagnosis of malignant and benign thyroid nodules compared with

  2. Breast Lesions: Quantitative Diagnosis Using Ultrasound Shear Wave Elastography-A Systematic Review and Meta-Analysis.

    PubMed

    Liu, Baoxian; Zheng, Yanling; Huang, Guangliang; Lin, Manxia; Shan, Quanyuan; Lu, Ying; Tian, Wenshuo; Xie, Xiaoyan

    2016-04-01

    The aim of this meta-analysis was to estimate the diagnostic performance of shear wave elastography (SWE) in differentiating malignant from benign breast lesions. A literature search of PubMed, Web of Science and Scopus up to November 2014 was conducted. A summary receiver operating characteristic curve was constructed, and pooled weighted estimates of sensitivity and specificity were calculated using a bivariate mixed-effects regression model. Thirty-three studies, which included a total of 5838 lesions (2093 malignant, 3745 benign) from 5397 patients, were finally analyzed. Summary sensitivity and specificity were 0.886 (95% confidence interval [CI], 0.858-0.909) and 0.866 (95% CI, 0.833-0.894), respectively. The pooled diagnostic odds ratio was 50.410 (95% CI, 34.972-72.664). And the area under the receiver operating characteristic curve of SWE was 0.94 (95% CI, 0.91-0.96). No publication bias existed among these studies (p = 0.245). In the subgroup analysis, sensitivity and specificity were 0.862 (95% CI, 0.811-0.901) and 0.875 (95% CI, 0.793-0.928) among 1552 lesions from 1429 patients in the 12 studies using acoustic radiation force impulse imaging and 0.897 (95% CI, 0.863-0.923) and 0.863 (95% CI, 0.831-0.889) among another 4436 lesions from 4097 patients in the 21 studies using supersonic shear imaging. When analysis confined to 9 studies evaluated the diagnostic performance of combination SWE and conventional ultrasound, the area under the curve was 0.96 (95% CI, 0.94-0.97), yielding a sensitivity of 0.971 (95% CI, 0.941-0.986) and specificity of 0.801 (95% CI, 0.733-0.856). SWE seems to be a good quantitative method for differentiating breast lesions, with promise for integration into routine imaging protocols. PMID:26778289

  3. Endoscopic ultrasound fine needle aspiration: Technique and applications in clinical practice

    PubMed Central

    Tharian, Benjamin; Tsiopoulos, Fotios; George, Nayana; Pietro, Salvatore Di; Attili, Fabia; Larghi, Alberto

    2012-01-01

    Since its initial report in 1992, endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) has now been incorporated into the diagnostic and staging algorithm for the evaluation of benign and malignant diseases of the gastrointestinal tract and of adjacent organs. Its introduction constitutes a major breakthrough in the endoscopic field and has gradually transformed EUS from a pure imaging modality into a more interventional procedure. In addition, the possibility of collecting samples, providing a definitive cytological and/or histological evidence of the presence of malignancy, has strongly contributed to changing EUS from a subjective, highly operator dependant procedure into a more objective one. This article will review the instrumentation, technique and the most important clinical applications of EUS-FNA. PMID:23293723

  4. Advances in endoscopic ultrasound-guided biliary drainage: a comprehensive review.

    PubMed

    Sarkaria, Savreet; Lee, Ho-Su; Gaidhane, Monica; Kahaleh, Michel

    2013-03-01

    Endoscopic retrograde cholangiopancreatography (ERCP) has become the first-line therapy for bile duct drainage. In the hands of experienced endoscopists, conventional ERCP results in a failed cannulation rate of 3% to 5%. This failure can occur more commonly in the setting of altered anatomy or technically difficult cases due to either duodenal or biliary obstruction. In cases of ERCP failure, patients have traditionally been referred for either percutaneous transhepatic biliary drainage (PTBD) or surgery. However, both PTBD and surgery have higher than desirable complication rates. Within the last decade, endoscopic ultrasound-guided biliary drainage (EUS-BD) has become an attractive alternative to PTBD after failed ERCP. Many groups have reported on the feasibility, efficacy and safety of this technique. This article reviews the indications for ERCP and the currently practiced EUS-BD techniques, including EUS-guided rendezvous, EUS-guided choledochoduodenostomy and EUS-guided hepaticogastrostomy. PMID:23560147

  5. Assessment of the accuracy of an ultrasound elastography liver scanning system using a PVA-cryogel phantom with optimal acoustic and mechanical properties

    NASA Astrophysics Data System (ADS)

    Cournane, S.; Cannon, L.; Browne, J. E.; Fagan, A. J.

    2010-10-01

    The accuracy of a transient elastography liver-scanning ultrasound system was assessed using a novel application of PVA-cryogel as a tissue-mimicking material with acoustic and shear elasticity properties optimized to best represent those of liver tissue. Although the liver-scanning system has been shown to offer a safer alternative for diagnosing liver cirrhosis through stiffness measurement, as compared to the liver needle biopsy exam, the scanner's accuracy has not been fully established. Young's elastic modulus values of 5-6 wt% PVA-cryogel phantoms, also containing glycerol and 0.3 µm Al2O3 and 3 µm Al2O3, were measured using a 'gold standard' mechanical testing technique and transient elastography. The mechanically measured values and acoustic velocities of the phantoms ranged between 1.6 and 16.1 kPa and 1540 and 1570 m s-1, respectively, mimicking those observed in liver tissue. The values reported by the transient elastography system overestimated Young's elastic modulus values representative of the progressive stages of liver fibrosis by up to 32%. These results were attributed to the relative rather than absolute nature of the measurement arising from the single-point acoustic velocity calibration of the system, rendering the measurements critically dependent on the speed of sound of the sample under investigation. Given the wide range of acoustic velocities which exist in the liver, spanning healthy tissue to cirrhotic pathology, coupled with the system's assumption that the liver is approximately elastic when it is rather highly viscoelastic, care should be exercised when interpreting the results from this system in patient groups.

  6. Assessment of the accuracy of an ultrasound elastography liver scanning system using a PVA-cryogel phantom with optimal acoustic and mechanical properties.

    PubMed

    Cournane, S; Cannon, L; Browne, J E; Fagan, A J

    2010-10-01

    The accuracy of a transient elastography liver-scanning ultrasound system was assessed using a novel application of PVA-cryogel as a tissue-mimicking material with acoustic and shear elasticity properties optimized to best represent those of liver tissue. Although the liver-scanning system has been shown to offer a safer alternative for diagnosing liver cirrhosis through stiffness measurement, as compared to the liver needle biopsy exam, the scanner's accuracy has not been fully established. Young's elastic modulus values of 5-6 wt% PVA-cryogel phantoms, also containing glycerol and 0.3 µm Al(2)O(3) and 3 µm Al(2)O(3), were measured using a 'gold standard' mechanical testing technique and transient elastography. The mechanically measured values and acoustic velocities of the phantoms ranged between 1.6 and 16.1 kPa and 1540 and 1570 m s(-1), respectively, mimicking those observed in liver tissue. The values reported by the transient elastography system overestimated Young's elastic modulus values representative of the progressive stages of liver fibrosis by up to 32%. These results were attributed to the relative rather than absolute nature of the measurement arising from the single-point acoustic velocity calibration of the system, rendering the measurements critically dependent on the speed of sound of the sample under investigation. Given the wide range of acoustic velocities which exist in the liver, spanning healthy tissue to cirrhotic pathology, coupled with the system's assumption that the liver is approximately elastic when it is rather highly viscoelastic, care should be exercised when interpreting the results from this system in patient groups. PMID:20858913

  7. Liver elastography, comments on EFSUMB elastography guidelines 2013

    PubMed Central

    Cui, Xin-Wu; Friedrich-Rust, Mireen; Molo, Chiara De; Ignee, Andre; Schreiber-Dietrich, Dagmar; Dietrich, Christoph F

    2013-01-01

    Recently the European Federation of Societies for Ultrasound in Medicine and Biology Guidelines and Recommendations have been published assessing the clinical use of ultrasound elastography. The document is intended to form a reference and to guide clinical users in a practical way. They give practical advice for the use and interpretation. Liver disease forms the largest section, reflecting published experience to date including evidence from meta-analyses with shear wave and strain elastography. In this review comments and illustrations on the guidelines are given. PMID:24151351

  8. Placement of multiple metal stents for malignant intrahepatic biliary obstruction via an endoscopic ultrasound-guided choledochoduodenostomy fistula.

    PubMed

    Akiyama, Dai; Hamada, Tsuyoshi; Nakai, Yousuke; Isayama, Hiroyuki; Takagi, Kaoru; Mizuno, Suguru; Koike, Kazuhiko

    2015-01-01

    Endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS) using a fully-covered self-expandable metal stent (SEMS) is increasingly used as an alternative to failed endoscopic retrograde cholangiopancreatography. An EUS-CDS fistula can provide endoscopists with a new approach route for intrahepatic bile ducts. Here, we present successful placement of multiple SEMS for intrahepatic biliary obstruction via an EUS-CDS fistula. PMID:26462843

  9. Needle Fracture during Endoscopic Ultrasound-Guided Fine-Needle Aspiration of Suspicious Thoracic Lymph Nodes

    PubMed Central

    Manière, Thibaut; Déry, Vincent

    2016-01-01

    Endoscopic ultrasound fine-needle aspiration (EUS-FNA) is used to make a cytopathologic diagnosis of suspicious lesions located around the gastrointestinal tract. It is a safe technique with few complications. The most common complications of EUS-FNA are related to pancreatic lesions (pancreatitis, bleeding, and abdominal pain). Rare complications have been noted such as stent malfunction, air embolism, infection, neural and vascular injuries, and tumor cell seeding. There are very few studies examining equipment malfunctions. We report a case of needle fracture during the EUS-FNA of suspicious thoracic lymph nodes in a 79-year-old man investigated for unexplained weight loss. PMID:27555874

  10. Endoscopic ultrasound-guided drainage of an abdominal fluid collection following Whipple's resection.

    PubMed

    Jah, Asif; Jamieson, Neville; Huguet, Emmanuel; Griffiths, William; Carroll, Nicholas; Praseedom, Raaj

    2008-11-28

    Percutaneous aspiration and drainage of post-operative abdominal fluid collections is a well established standard technique. However, some fluid collections are not amenable to percutaneous drainage either due to location or the presence of surrounding visceral structures. Endoscopic Ultrasound (EUS) has been widely used for the drainage of pancreatitis-related abdominal fluid collections. However, there are no reports on the use of this technique in the post-operative setting. We report a case where the EUS-guided technique was used to drain a percutaneously inaccessible post-operative collection which had developed after Whipple's resection. PMID:19058316

  11. Needle Fracture during Endoscopic Ultrasound-Guided Fine-Needle Aspiration of Suspicious Thoracic Lymph Nodes.

    PubMed

    Adamowicz, Bartosz; Manière, Thibaut; Déry, Vincent; Désilets, Étienne

    2016-01-01

    Endoscopic ultrasound fine-needle aspiration (EUS-FNA) is used to make a cytopathologic diagnosis of suspicious lesions located around the gastrointestinal tract. It is a safe technique with few complications. The most common complications of EUS-FNA are related to pancreatic lesions (pancreatitis, bleeding, and abdominal pain). Rare complications have been noted such as stent malfunction, air embolism, infection, neural and vascular injuries, and tumor cell seeding. There are very few studies examining equipment malfunctions. We report a case of needle fracture during the EUS-FNA of suspicious thoracic lymph nodes in a 79-year-old man investigated for unexplained weight loss. PMID:27555874

  12. Enhancing regional lymph nodes from endoscopic ultrasound images

    NASA Astrophysics Data System (ADS)

    Nwogu, Ifeoma; Chaudhary, Vipin

    2008-03-01

    Esophageal ultrasound (EUS) is particularly useful for isolating lymph nodes in the N-staging of esophageal cancer, a disease with very poor overall prognosis. Although EUS is relatively low-cost and real time, and it provides valuable information to the clinician, its usefulness to less trained "users" including opportunities for computer-aided diagnosis is still limited due to the strong presence of spatially correlated interference noise called speckles. To this end, in this paper, we present a technique for enhancing lymph nodes in EUS images by first reducing the spatial correlation of the specular noise and then using a modified structured tensor-based anisotropic filter to complete the speckle reduction process. We report on a measure of the enhancement and also on the extent of automatic processing possible, after the speckle reduction process has taken place. Also, we show the limitations of the enhancement process by extracting relevant lymph node features from the despeckled images. When tested on five representative classes of esophageal lymph nodes, we found the despeckling process to greatly reduce the specularity of the original EUS images, therefore proving very useful for visualization purposes. But it still requires additional work for the complete automation of the lymph node characterizing process.

  13. Co-focused ultrasound and optical coherence elastography system for the study of age-related changes of biomechanical properties of crystalline lens in rabbit eyes

    NASA Astrophysics Data System (ADS)

    Wu, Chen; Han, Zhaolong; Wang, Shang; Li, Jiasong; Singh, Manmohan; Liu, Chih-hao; Aglyamov, Salavat; Emelianov, Stanislav; Manns, Fabrice; Larin, Kirill V.

    2015-03-01

    In this study, we utilize a confocal ultrasound and phase-sensitive optical coherence elastography (OCE) system to assess age-related changes in biomechanical properties of the crystalline lens in intact rabbit eyes in situ. Lowamplitude elastic deformations, induced on the surface of the lens by localized acoustic radiation force, were measured using phase-sensitive OCT. The results demonstrate that the displacements induced in young rabbit lenses are significantly larger than those in the mature lenses. Temporal analyses of the elastic waves are also demonstrated significant difference between young and old lenses, indicating that the stiffness of lens increases with the age. These results demonstrate possibility of OCE for completely noninvasive analysis and quantification of lens biomechanical properties, which could be used in many clinical and basic science applications such as surgeries and studies on lens physiology and function.

  14. Endoscopic Ultrasound-Guided Drainage without Fluoroscopic Guidance for Extraluminal Complicated Cysts

    PubMed Central

    Nam, Hyeong Seok; Kim, Hyung Wook; Kang, Dae Hwan; Choi, Cheol Woong; Park, Su Bum; Kim, Su Jin; Ryu, Dae Gon; Jeon, Joon Ho

    2016-01-01

    Background. Endoscopic ultrasound- (EUS-) guided drainage is generally performed under fluoroscopic guidance. However, improvements in endoscopic and EUS techniques and experience have led to questions regarding the usefulness of fluoroscopy. This study aimed to retrospectively evaluate the safety and efficacy of EUS-guided drainage of extraluminal complicated cysts without fluoroscopic guidance. Methods. Patients who had undergone nonfluoroscopic EUS-guided drainage of extraluminal complicated cysts were enrolled. Drainage was performed via a transgastric, transduodenal, or transrectal approach. Single or double 7 Fr double pigtail stents were inserted. Results. Seventeen procedures were performed in 15 patients in peripancreatic fluid collections (n = 13) and pelvic abscesses (n = 4). The median lesion size was 7.1 cm (range: 2.8–13.0 cm), and the mean time spent per procedure was 26.2 ± 9.8 minutes (range: 16–50 minutes). Endoscopic drainage was successful in 16 of 17 (94.1%) procedures. There were no complications. All patients experienced symptomatic improvement and revealed partial to complete resolution according to follow-up computed tomography findings. Two patients developed recurrent cysts that were drained during repeat procedures, with eventual complete resolution. Conclusion. EUS-guided drainage without fluoroscopic guidance is a technically feasible, safe, and effective procedure for the treatment of extraluminal complicated cysts. PMID:27313606

  15. A navigation system for flexible endoscopes using abdominal 3D ultrasound.

    PubMed

    Hoffmann, R; Kaar, M; Bathia, Amon; Bathia, Amar; Lampret, A; Birkfellner, W; Hummel, J; Figl, M

    2014-09-21

    A navigation system for flexible endoscopes equipped with ultrasound (US) scan heads is presented. In contrast to similar systems, abdominal 3D-US is used for image fusion of the pre-interventional computed tomography (CT) to the endoscopic US. A 3D-US scan, tracked with an optical tracking system (OTS), is taken pre-operatively together with the CT scan. The CT is calibrated using the OTS, providing the transformation from CT to 3D-US. Immediately before intervention a 3D-US tracked with an electromagnetic tracking system (EMTS) is acquired and registered intra-modal to the preoperative 3D-US. The endoscopic US is calibrated using the EMTS and registered to the pre-operative CT by an intra-modal 3D-US/3D-US registration. Phantom studies showed a registration error for the US to CT registration of 5.1 mm±2.8 mm. 3D-US/3D-US registration of patient data gave an error of 4.1 mm compared to 2.8 mm with the phantom. From this we estimate an error on patient experiments of 5.6 mm. PMID:25170913

  16. Forward-viewing linear echoendoscope: a new option in the endoscopic ultrasound armamentarium (with video).

    PubMed

    Fuccio, Lorenzo; Attili, Fabia; Larghi, Alberto

    2015-01-01

    The forward-viewing linear echoendoscope (FV-EUS) has been developed with the aim of overcoming limitations of standard curved linear-array echoendoscopes (CLA-EUS) and to further expand interventional applications of EUS. The main characteristic of the FV-EUS is a shifting in the orientation of both endoscopic and ultrasound views from oblique to forward, with the exit of the working channel at the tip of the instrument. This allows exit of the devices parallel to the longitudinal axis of the endoscope, thus resulting in a more direct and stable access to the lesion while increasing the precision and force applied to the target. Accumulating evidence has shown that the FV-EUS can be used instead of the standard CLA-EUS scope for routine fine needle aspiration, with extremely good performance for subepithelial lesions and for difficult to reach locations. Several areas of use of this echoendoscope are yet to be better defined, such as its potential for therapeutic and interventional procedures, as well as for natural orifice transluminal endoscopic surgery. The current report provides an updated overview of the available evidence for both diagnostic and interventional uses of the FV-EUS. PMID:25345848

  17. Breast Elastography: How We Do It.

    PubMed

    Gkali, Christina A; Chalazonitis, Athanasios N; Feida, Eleni; Sotiropoulou, Maria; Giannos, Aris; Tsigginou, Alexandra; Dimitrakakis, Constantine

    2015-12-01

    In recent years, the use of elastography in addition to sonography has become a routine clinical tool for the characterization of breast masses. Studies have investigated the improvement of specificity in differentiating benign from malignant breast masses. Therefore, additional use of elastography could help reduce the number of unnecessary biopsies in benign breast lesions especially in category IV lesions of the ultrasound breast imaging reporting data system. Ultrasound elastography is a cheap, readily available, useful, quick, noninvasive method, but it needs specific training as well as acknowledging technical and pathological factors, which may influence it. Both strain and acoustic radiation force impulse (ARFI) methods have been evaluated in breast lesions. Whereas strain elastography results in qualitative imaging of tissue stiffness due to induced compression, ARFI elastography displays quantitative and qualitative information of tissue displacement. A standardized imaging protocol is essential for an adequate and effective examination, also helping reduce the dependence from operators. Furthermore, knowledge of pitfalls that can be encountered when ultrasound elastography is performed may help avoid erroneous image interpretation. In this article, we describe a practical examination protocol for both strain and ARFI elastography and demonstrate the elastographic imaging findings in benign and malignant breast lesions. Short video clips displaying the technique are included as supplementary material. PMID:26327432

  18. Evaluation of Elastic Stiffness in Healing Achilles Tendon After Surgical Repair of a Tendon Rupture Using In Vivo Ultrasound Shear Wave Elastography

    PubMed Central

    Zhang, Li-ning; Wan, Wen-bo; Wang, Yue-xiang; Jiao, Zi-yu; Zhang, Li-hai; Luo, Yu-kun; Tang, Pei-fu

    2016-01-01

    Background There has been no published report assessing the mechanical properties of a repaired Achilles tendon after surgery using shear wave elastography (SWE). The aim of this study was to investigate the changes in mechanical properties of the healing Achilles tendon after surgical repair of a tendon rupture using ultrasound SWE and how these changes correlate with tendon function. Material/Methods Twenty-six patients who underwent surgical repair for Achilles tendon rupture were examined with ultrasound SWE coupled with a linear array transducer (4–15 MHz). The elasticity values of the repaired Achilles tendon in a longitudinal view were measured at 12, 24, and 48 weeks postoperatively. Functional outcomes were assessed with the American Orthopedic Foot and Ankle Society (AOFAS) rating system at 12, 24, and 48 weeks postoperatively. General linear regression analysis and correlation coefficients were used to analyze the relationship between elasticity and the AOFAS score. Results There were significant differences with respect to the mean elasticity values and functional scores of the repaired Achilles tendon at 12, 24, and 48 weeks postoperatively (all P<0.05). Tendon function was positively correlated with the elasticity of the repaired Achilles tendon (P=0.0003). Conclusions Our findings suggest that SWE can provide biomechanical information for evaluating the mechanical properties of healing Achilles tendon and predict Achilles tendon function. PMID:27072885

  19. Assessing Age-Related Changes in the Biomechanical Properties of Rabbit Lens Using a Coaligned Ultrasound and Optical Coherence Elastography System

    PubMed Central

    Wu, Chen; Han, Zhaolong; Wang, Shang; Li, Jiasong; Singh, Manmohan; Liu, Chih-hao; Aglyamov, Salavat; Emelianov, Stanislav; Manns, Fabrice; Larin, Kirill V.

    2015-01-01

    Purpose. To evaluate the capability of a novel, coaligned focused ultrasound and phase-sensitive optical coherence elastography (US-OCE) system to assess age-related changes in biomechanical properties of the crystalline lens in situ. Methods. Low-amplitude elastic deformations in young and mature rabbit lenses were measured by an US-OCE system consisting of a spectral-domain optical coherence tomography (OCT) system coaligned with a focused ultrasound system used to produce a transient force on the lens surface. Uniaxial compressional tests were used to validate the OCE data. Results. The OCE measurements showed that the maximum displacements of the young rabbit lenses were significantly larger than those of the mature lenses, indicating a gradual increase of the lens stiffness with age. Temporal analyses of the displacements also demonstrate a similar trend of elastic properties in these lenses. The stress-strain measurements using uniaxial mechanical tests confirmed the results obtained by the US-OCE system. Conclusions. The results demonstrate that the US-OCE system can be used for noninvasive analysis and quantification of lens biomechanical properties in situ and possibly in vivo. PMID:25613945

  20. A Risk Model for Predicting Central Lymph Node Metastasis of Papillary Thyroid Microcarcinoma Including Conventional Ultrasound and Acoustic Radiation Force Impulse Elastography.

    PubMed

    Xu, Jun-Mei; Xu, Hui-Xiong; Li, Xiao-Long; Bo, Xiao-Wan; Xu, Xiao-Hong; Zhang, Yi-Feng; Guo, Le-Hang; Liu, Lin-Na; Qu, Shen

    2016-01-01

    The aim of this prospective study was to propose a new rating system using a risk model including conventional ultrasound (US) and acoustic radiation force impulse (ARFI) elastography for predicting central lymph node metastasis (LNM) in patients with papillary thyroid microcarcinoma (PTMC).A total of 252 patients with PTMCs were enrolled, who were preoperatively evaluated by US and ARFI elastography including virtual touch tissue imaging (VTI) and virtual touch tissue quantification (VTQ). Risk factors of independent variables for central LNM were analyzed by univariate and multivariate analyses. A multivariate analysis was performed to create a predicting model and rating system.Of the 252 patients, 72 (28.6%) had central LNMs. Multivariate analysis revealed that rare internal flow (odds ratio [OR]: 4.454), multiple suspicious foci on US (OR: 5.136), capsule involvement (OR: 20.632), and VTI area ratio (VAR) > 1 (OR: 5.621) were independent risk factors for central LNM. The final predicting model was obtained and the risk score (RS) was defined as 1.5 × (if rare internal flow) + 1.6 × (if multiple suspicious foci on US) + 1.7 × (if VAR > 1) + 3.0 × (if capsule involvement). The rating system was divided into 5 stages. Stage I, <1.5; Stage II, 1.5 to 3.0; Stage III, 3.1 to 4.7; Stage IV, 4.8 to 6.3; and Stage V, 6.4 to 7.8. The risk rates of central LNM were 3.4% (2/59) in Stage I, 13.3% (13/98) in Stage II, 54.2% (39/72) in Stage III, 72.2% (13/18) in Stage IV, and 100% (5/5) in Stage V (P < 0.001).The results indicated that rare internal flow, multiple suspicious foci, capsule involvement on US, and VAR > 1 on ARFI elastography are the risk factors for predicting central LNM. The risk model developed in the study clearly predicts the risk of central LNM in patients with PTMC and thus has a potential to avoid unnecessary central compartment node dissection. PMID:26817907

  1. Endoscopic ultrasound

    MedlinePlus

    ... been put in your digestive tract during the test to move the tube more easily. This may make you feel bloated, but this feeling will go away. When you are fully awake, you can be taken home. Rest that day. You may have fluids and light ... The results depend on what is found during the test. If you do not understand the results, or ...

  2. Pancreatic metastases from ovarian carcinoma--diagnosis by endoscopic ultrasound-guided fine needle aspiration.

    PubMed

    Hadzri, M Hasmoni; Rosemi, Salleh

    2012-04-01

    Pancreatic metastases are very uncommon and originate most commonly from lung, colon, breast and kidney cancer. Ovarian adenocarcinoma has been reported as a primary site of pancreatic metastasis, but its diagnosis has rarely being reported by endoscopic ultrasound guided fine needle aspiration (EUS-FNA). We report a case of multiple metastases to the pancreas from ovarian carcinoma occurring four years after original resection of the primary tumour. Our patient presented with severe epigastric pain which was initially treated as acute pancreatitis. Further imaging modalities showed multiple large pseudocystic lesions in the pancreatic head and body. Subsequent EUS-FNA confirmed that the lesions were metastatic disease from an advanced ovarian carcinoma. She underwent palliative chemotherapy and the pancreatic lesion showed receding size. PMID:22822646

  3. Endoscopic ultrasound-guided fine-needle aspiration in the diagnosis of adrenal lesions

    PubMed Central

    Patil, Rashmee; Ona, Mel A.; Papafragkakis, Charilaos; Duddempudi, Sushil; Anand, Sury; Jamil, Laith H.

    2016-01-01

    The use of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) appears to be a safe and feasible means of confirming or excluding malignancy in the adrenal glands. EUS-FNA with biopsy of suspicious masses in either adrenal gland allows for assessment of these lesions while keeping complications relatively rare. The main advantages of EUS-FNA are that it can be done as an outpatient procedure, with good results, minimal morbidity, and a short hospital stay. Nevertheless, EUS-FNA of adrenal masses should be indicated only in selected cases, in which there is potential to either decrease unnecessary treatment or guide therapy in cancer patients by aiding in either staging of malignancy or treatment of recurrence.v PMID:27366030

  4. Endoscopic Ultrasound-Guided Treatment of Pancreatic Cystic and Solid Masses

    PubMed Central

    2015-01-01

    Pancreatic tumor is one of the most difficult diseases to diagnose and treat because of its anatomical location and characteristics. Recently, there have been several innovative trials on the treatment of pancreatic tumors using endoscopic ultrasound (EUS) because it allows selective access to the difficult to reach target organ along the gastrointestinal tract and can differentiate vessels by color Doppler. Among these trials, several have investigated EUS-guided ethanol lavage with or without paclitaxel for pancreatic cystic tumors. These studies show a 33% to 79% complete resolution rate with a favorable safety profile. Compared to EUS-guided ethanol lavage for pancreatic cystic tumors, EUS-guided radiofrequency ablation is considered a less invasive treatment method for pancreatic cancer. Although there are still several difficulties and concerns about complications, one clinical study reported 72.8% feasibility with favorable safety, and therefore, we anticipate the results of ongoing studies with these new less invasive techniques. PMID:26240804

  5. Endoscopic ultrasound-guided fine-needle aspiration in the diagnosis of adrenal lesions.

    PubMed

    Patil, Rashmee; Ona, Mel A; Papafragkakis, Charilaos; Duddempudi, Sushil; Anand, Sury; Jamil, Laith H

    2016-01-01

    The use of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) appears to be a safe and feasible means of confirming or excluding malignancy in the adrenal glands. EUS-FNA with biopsy of suspicious masses in either adrenal gland allows for assessment of these lesions while keeping complications relatively rare. The main advantages of EUS-FNA are that it can be done as an outpatient procedure, with good results, minimal morbidity, and a short hospital stay. Nevertheless, EUS-FNA of adrenal masses should be indicated only in selected cases, in which there is potential to either decrease unnecessary treatment or guide therapy in cancer patients by aiding in either staging of malignancy or treatment of recurrence.v. PMID:27366030

  6. Role of endoscopic ultrasound in diagnosis and management of hepatocellular carcinoma

    PubMed Central

    Koduru, Pramoda; Suzuki, Rei; Lakhtakia, Sundeep; Ramchandani, Mohan; Makmun, Dadang; Bhutani, Manoop S

    2015-01-01

    Hepatocellular carcinoma (HCC) is an aggressive tumor and a leading cause of cancer-related deaths globally. The mortality rate remains high despite many advances in treatment. HCC is frequently diagnosed late in its course due to lack of classical symptoms at earlier stages. Endoscopic ultrasound (EUS) has emerged as an important diagnostic tool for the diagnostic evaluation, staging, and treatment of gastrointestinal tract disorders. EUS-guided fine needle aspiration has been a valuable addition to EUS by being able to obtain tissue under direct visualization. Here, we review the potential role of EUS in the diagnosis and management of HCC. EUS seems to be a safe and reliable alternative method for obtaining tissue for diagnosis of liver cancer, especially for lesions that are inaccessible by traditional methods. EUS could play an important role in the diagnosis and management of HCC. PMID:27508203

  7. Technical advances in endoscopic ultrasound-guided fiducial placement for the treatment of pancreatic cancer

    PubMed Central

    Chavalitdhamrong, Disaya; DiMaio, Christopher J.; Siersema, Peter D.; Wagh, Mihir S.

    2015-01-01

    Radiation therapy has an important role in the treatment of locally advanced or metastatic pancreatic cancer and can be used alone or in conjunction with surgery and/or systemic chemotherapy. Because of the challenge of delivering an accurate and optimal radiation dose, image-guided radiation therapy can be used to improve targeting. Fiducial markers can be placed in the tumor and used for localization in patients undergoing image-guided radiation therapy. The safety and feasibility of endoscopic ultrasound (EUS)-guided placement of fiducials has been assessed and reported for the management of pancreatic cancer. We herein review the technique, efficacy, and safety profile of EUS-guided fiducial placement. In addition, we highlight recent advances and technological upgrades in EUS-guided fiducial delivery systems for pancreatic cancer most relevant to practicing gastroenterologists and interventional endoscopists. PMID:26355267

  8. Endoscopic ultrasound-guided biliary drainage for right hepatic bile duct obstruction: novel technical tips.

    PubMed

    Ogura, Takeshi; Sano, Tatsushi; Onda, Saori; Imoto, Akira; Masuda, Daisuke; Yamamoto, Kazuhiro; Kitano, Masayuki; Takeuchi, Toshihisa; Inoue, Takuya; Higuchi, Kazuhide

    2015-01-01

    Endoscopic ultrasound (EUS)-guided biliary drainage (EUS-BD) is not normally indicated for an obstructed right intrahepatic bile duct (IHBD). The technical feasibility and clinical efficacy of a novel technique of EUS-BD for right IHBD obstruction were evaluated. A total of 11 patients underwent drainage using either a left or a right biliary access route. The causes of obstructive jaundice were cholangiocarcinoma (n = 6), pancreatic cancer (n = 3), gastric cancer (n = 1), and colon cancer (n = 1). After placement of an uncovered metal stent to bridge the obstruction, a hepaticogastrostomy was completed using a covered stent. Mean procedure time was 33.9 ± 10.0 minutes. Technical and functional success were achieved in all patients, and no adverse events occurred. This novel method appears to be safe and effective for right IHBD obstruction. PMID:25264761

  9. Technical advances in endoscopic ultrasound-guided fiducial placement for the treatment of pancreatic cancer.

    PubMed

    Chavalitdhamrong, Disaya; DiMaio, Christopher J; Siersema, Peter D; Wagh, Mihir S

    2015-08-01

    Radiation therapy has an important role in the treatment of locally advanced or metastatic pancreatic cancer and can be used alone or in conjunction with surgery and/or systemic chemotherapy. Because of the challenge of delivering an accurate and optimal radiation dose, image-guided radiation therapy can be used to improve targeting. Fiducial markers can be placed in the tumor and used for localization in patients undergoing image-guided radiation therapy. The safety and feasibility of endoscopic ultrasound (EUS)-guided placement of fiducials has been assessed and reported for the management of pancreatic cancer. We herein review the technique, efficacy, and safety profile of EUS-guided fiducial placement. In addition, we highlight recent advances and technological upgrades in EUS-guided fiducial delivery systems for pancreatic cancer most relevant to practicing gastroenterologists and interventional endoscopists. PMID:26355267

  10. The role of endoscopic ultrasound in the evaluation of rectal cancer

    PubMed Central

    Siddiqui, Ali A; Fayiga, Yomi; Huerta, Sergio

    2006-01-01

    Accurate staging of rectal cancer is essential for selecting patients who can undergo sphincter-preserving surgery. It may also identify patients who could benefit from neoadjuvant therapy. Clinical staging is usually accomplished using a combination of physical examination, CT scanning, MRI and endoscopic ultrasound (EUS). Transrectal EUS is increasingly being used for locoregional staging of rectal cancer. The accuracy of EUS for the T staging of rectal carcinoma ranges from 80-95% compared with CT (65-75%) and MR imaging (75-85%). In comparison to CT, EUS can potentially upstage patients, making them eligible for neoadjuvant treatment. The accuracy to determine metastatic nodal involvement by EUS is approximately 70-75% compared with CT (55-65%) and MR imaging (60-70%). EUS guided FNA may be beneficial in patients who appear to have early T stage disease and suspicious peri-iliac lymphadenopathy to exclude metastatic disease. PMID:17049086

  11. Therapeutic role of endoscopic ultrasound in pancreaticobiliary disease: A comprehensive review

    PubMed Central

    Meng, Fan-Sheng; Zhang, Zhao-Hong; Ji, Feng

    2015-01-01

    With the development of technology and accessories, the role of endoscopic ultrasound (EUS) has evolved from diagnostics to therapeutics. In order to characterise the therapeutic role of EUS, we searched Web of Knowledge database and reviewed articles associated with therapeutic EUS. There are two modalities for the therapeutic purpose: drainage and fine-needle injection. EUS-guided drainage is a promising procedure for the treatment of peripancreatic fluid collection and biliary obstruction; EUS-guided fine-needle injections such as celiac plexus neurolysis, for the purpose of pain relief for pancreatic cancer and chronic pancreatitis, has emerged as a promising procedure. The aim of the study was to perform a comprehensive and conscientious review on the techniques, complications and clinical outcomes of those EUS-based procedures. PMID:26675538

  12. Current status of endoscopic ultrasound for the upper gastrointestinal tract in Asia.

    PubMed

    Yoshinaga, Shigetaka; Hilmi, Ida Normiha; Kwek, Boon Eu Andrew; Hara, Kazuo; Goda, Kenichi

    2015-04-01

    We summarize the current status of endoscopic ultrasound (EUS) for the upper gastrointestinal (GI) tract solely in Asia, focusing on the staging of superficial cancers and the diagnosis of submucosal tumors (SMT), by analysis of questionnaire responses and a literature review. EUS for assessing the depth of superficial cancers of the upper GI tract is useful; however, evidence is lacking to support that EUS is superior to other modalities. The current status of EUS varies across different Asian countries, and standardization of the methods used both during the procedure and for depth subclassification is necessary to evaluate the diagnostic accuracy. Although EUS alone is limited in the diagnosis of SMT, EUS-guided fine-needle aspiration is an effective and safe diagnostic tool. Although there is a role for EUS, there are still many limitations both technically and in terms of accessibility. PMID:25537645

  13. Therapeutic role of endoscopic ultrasound in pancreaticobiliary disease: A comprehensive review.

    PubMed

    Meng, Fan-Sheng; Zhang, Zhao-Hong; Ji, Feng

    2015-12-14

    With the development of technology and accessories, the role of endoscopic ultrasound (EUS) has evolved from diagnostics to therapeutics. In order to characterise the therapeutic role of EUS, we searched Web of Knowledge database and reviewed articles associated with therapeutic EUS. There are two modalities for the therapeutic purpose: drainage and fine-needle injection. EUS-guided drainage is a promising procedure for the treatment of peripancreatic fluid collection and biliary obstruction; EUS-guided fine-needle injections such as celiac plexus neurolysis, for the purpose of pain relief for pancreatic cancer and chronic pancreatitis, has emerged as a promising procedure. The aim of the study was to perform a comprehensive and conscientious review on the techniques, complications and clinical outcomes of those EUS-based procedures. PMID:26675538

  14. Value of endoscopic ultrasound guided fine needle aspiration biopsy in the diagnosis of solid pancreatic masses

    PubMed Central

    Voss, M; Hammel, P; Molas, G; Palazzo, L; Dancour, A; O'Toole, D; Terris, B; Degott, C; Bernades, P; Ruszniewski, P

    2000-01-01

    AIM—To assess the feasibility and diagnostic accuracy of endoscopic ultrasound guided fine needle biopsy (EUS-FNAB) in patients with solid pancreatic masses.
METHODS—Ninety nine consecutive patients with pancreatic masses were studied. Histological findings obtained by EUS-FNAB were compared with the final diagnosis assessed by surgery, biopsy of other tumour site or at postmortem examination, or by using a combination of clinical course, imaging features, and tumour markers.
RESULTS—EUS-FNAB was feasible in 90 patients (adenocarcinomas, n = 59; neuroendocrine tumours, n = 15; various neoplasms, n = 6; pancreatitis, n = 10), and analysable material was obtained in 73. Tumour size (⩾ or < 25 mm in diameter) did not influence the ability to obtain informative biopsy samples. Diagnostic accuracy was 74.4% (adenocarcinomas, 81.4%; neuroendocrine tumours, 46.7%; other lesions, 75%; p<0.02). Overall, the diagnostic yield in all 99 patients was 68%. Successful biopsies were performed in six patients with portal hypertension. Minor complications (moderate bleeding or pain) occurred in 5% of cases.
CONCLUSIONS—EUS-FNAB is a useful and safe method for the investigation of pancreatic masses, with a high feasibility rate even when lesions are small. Overall diagnostic accuracy of EUS-FNAB seems to depend on the tumour type.


Keywords: pancreas; tumour; endoscopic ultrasound; fine needle aspiration biopsy PMID:10644320

  15. Endoscopic Ultrasound of the Upper Gastrointestinal Tract and Mediastinum: Diagnosis and Therapy

    SciTech Connect

    Prasad, Priyajit; Wittmann, Johannes; Pereira, Stephen P.

    2006-12-15

    Endoscopic ultrasound (EUS) has developed significantly over the last two decades and has had a considerable impact on the imaging and staging of mass lesions within or in close proximity to the gastrointestinal (GI) tract. In conjunction with conventional imaging such as helical computed tomography and magnetic resonance imaging, the indications for EUS include (1) differentiating between benign and malignant lesions of the mediastinum and upper GI tract, (2) staging malignant tumors of the lung, esophagus, stomach, and pancreas prior to surgery or oncological treatment, (3) excluding common bile duct stones before laparoscopic cholecystectomy, thereby avoiding the need for endoscopic retrograde cholangiopancreatography (ERCP) in some patients, and (4) assessing suspected lesions that are either equivocal or not seen on conventional imaging. In recent years, EUS has charted a course similar to that taken by ERCP, evolving from a purely diagnostic modality to one that is interventional and therapeutic. These indications include (5) obtaining a tissue diagnosis by EUS-guided fine-needle aspiration or trucut-type needle biopsy and (6) providing therapy such as coeliac plexus neurolysis and pancreatic pseudocyst drainage-in many cases, more accurately and safely than conventional techniques. Emerging investigational techniques include EUS-guided enteric anastomosis formation and fine-needle injection therapy for malignant disease.

  16. Combining endoscopic ultrasound with Time-Of-Flight PET: The EndoTOFPET-US Project

    NASA Astrophysics Data System (ADS)

    Frisch, Benjamin

    2013-12-01

    The EndoTOFPET-US collaboration develops a multimodal imaging technique for endoscopic exams of the pancreas or the prostate. It combines the benefits of high resolution metabolic imaging with Time-Of-Flight Positron Emission Tomography (TOF PET) and anatomical imaging with ultrasound (US). EndoTOFPET-US consists of a PET head extension for a commercial US endoscope and a PET plate outside the body in coincidence with the head. The high level of miniaturization and integration creates challenges in fields such as scintillating crystals, ultra-fast photo-detection, highly integrated electronics, system integration and image reconstruction. Amongst the developments, fast scintillators as well as fast and compact digital SiPMs with single SPAD readout are used to obtain the best coincidence time resolution (CTR). Highly integrated ASICs and DAQ electronics contribute to the timing performances of EndoTOFPET. In view of the targeted resolution of around 1 mm in the reconstructed image, we present a prototype detector system with a CTR better than 240 ps FWHM. We discuss the challenges in simulating such a system and introduce reconstruction algorithms based on graphics processing units (GPU).

  17. Endoscopic ultrasound-guided treatments: Are we getting evidence based - a systematic review

    PubMed Central

    Fabbri, Carlo; Luigiano, Carmelo; Lisotti, Andrea; Cennamo, Vincenzo; Virgilio, Clara; Caletti, Giancarlo; Fusaroli, Pietro

    2014-01-01

    The continued need to develop less invasive alternatives to surgical and radiologic interventions has driven the development of endoscopic ultrasound (EUS)-guided treatments. These include EUS-guided drainage of pancreatic fluid collections, EUS-guided necrosectomy, EUS-guided cholangiography and biliary drainage, EUS-guided pancreatography and pancreatic duct drainage, EUS-guided gallbladder drainage, EUS-guided drainage of abdominal and pelvic fluid collections, EUS-guided celiac plexus block and celiac plexus neurolysis, EUS-guided pancreatic cyst ablation, EUS-guided vascular interventions, EUS-guided delivery of antitumoral agents and EUS-guided fiducial placement and brachytherapy. However these procedures are technically challenging and require expertise in both EUS and interventional endoscopy, such as endoscopic retrograde cholangiopancreatography and gastrointestinal stenting. We undertook a systematic review to record the entire body of literature accumulated over the past 2 decades on EUS-guided interventions with the objective of performing a critical appraisal of published articles, based on the classification of studies according to levels of evidence, in order to assess the scientific progress made in this field. PMID:25024600

  18. Current endoscopic ultrasound-guided approach to incidental subepithelial lesions: optimal or optional?

    PubMed Central

    Eckardt, Alexander J.; Jenssen, Christian

    2015-01-01

    Subepithelial lesions (SEL) are identified during endoscopic procedures on a regular basis. They can occur anywhere in the gastrointestinal (GI) tract and are located beneath the normal epithelial layer, which explains why a tissue diagnosis is difficult to obtain with routine biopsies. Endoscopic ultrasound (EUS) is used to further characterize these lesions. EUS can distinguish intramural lesion from extramural compression. Furthermore, it allows allocation of intramural lesions to a specific layer of the GI wall and offers additional information as to whether a lesion could be benign or malignant. EUS also assists in choosing the optimal means of tissue acquisition. The choice of tissue acquisition is based on a number of factors, such as tumor size, EUS features, and location within the GI tract or within a specific layer of the GI wall. Furthermore, local expertise and patient factors should be considered when deciding whether tissue acquisition, surgical intervention or follow up is recommended. In this review we offer an EUS-guided approach to the evaluation of incidental SEL based on current evidence and point out areas of uncertainty, which explain why the proposed algorithmic approach may be optional rather than optimal. PMID:25830949

  19. Endoscopic ultrasound-guided placement of AXIOS stent for drainage of pancreatic fluid collections

    PubMed Central

    Patil, Rashmee; Ona, Mel A.; Papafragkakis, Charilaos; Anand, Sury; Duddempudi, Sushil

    2016-01-01

    Pancreatic fluid collections (PFCs) have conventionally been treated with surgery, percutaneous drainage, or with the more recently established endoscopic ultrasound (EUS)-guided drainage modality. Currently, endoscopic plastic or metallic stents are used for PFC drainage. Plastic stents present issues with stent migration and premature occlusion requiring frequent stent exchanges or placement of additional stents. Metallic stents are tubular and may migrate, resulting in inefficient drainage, content leakage, retrieval and replacement, and possible mucosal injury. The aim of this review was to summarize and evaluate the clinical and technical effectiveness of EUS-guided placement of the recently developed AXIOS stent, a lumen-apposing self-expandable metallic stent (LASEMS)for PFC drainage. A literature review was performed to identify the studies describing this technique. In this review article we have summarized case series or reports describing EUS-guided LASEMS placement. The indications, techniques, limitations and complications reported are discussed. A total of 298 patients were included across all studies described thus far in the literature. Overall, a 97% technical success rate and a 96% clinical success rate have been reported. Early and late complications related to the placement or removal of LASEMS have been reported, however few cases have presented life-threatening results. EUS-guided PFC drainage and LASEMS placement can be a safe and effective alternative approach in the management of selected patients. PMID:27065729

  20. Endoscopic ultrasound-guided placement of AXIOS stent for drainage of pancreatic fluid collections.

    PubMed

    Patil, Rashmee; Ona, Mel A; Papafragkakis, Charilaos; Anand, Sury; Duddempudi, Sushil

    2016-01-01

    Pancreatic fluid collections (PFCs) have conventionally been treated with surgery, percutaneous drainage, or with the more recently established endoscopic ultrasound (EUS)-guided drainage modality. Currently, endoscopic plastic or metallic stents are used for PFC drainage. Plastic stents present issues with stent migration and premature occlusion requiring frequent stent exchanges or placement of additional stents. Metallic stents are tubular and may migrate, resulting in inefficient drainage, content leakage, retrieval and replacement, and possible mucosal injury. The aim of this review was to summarize and evaluate the clinical and technical effectiveness of EUS-guided placement of the recently developed AXIOS stent, a lumen-apposing self-expandable metallic stent (LASEMS)for PFC drainage. A literature review was performed to identify the studies describing this technique. In this review article we have summarized case series or reports describing EUS-guided LASEMS placement. The indications, techniques, limitations and complications reported are discussed. A total of 298 patients were included across all studies described thus far in the literature. Overall, a 97% technical success rate and a 96% clinical success rate have been reported. Early and late complications related to the placement or removal of LASEMS have been reported, however few cases have presented life-threatening results. EUS-guided PFC drainage and LASEMS placement can be a safe and effective alternative approach in the management of selected patients. PMID:27065729

  1. Endoscopic ultrasound-guided pancreaticobiliary intervention in patients with surgically altered anatomy and inaccessible papillae: A review of current literature

    PubMed Central

    Martin, Aaron; Kistler, Charles Andrew; Wrobel, Piotr; Yang, Juliana F.; Siddiqui, Ali A.

    2016-01-01

    The management of pancreaticobiliary disease in patients with surgically altered anatomy is a growing problem for gastroenterologists today. Over the years, endoscopic ultrasound (EUS) has emerged as an important diagnostic and therapeutic modality in the treatment of pancreaticobiliary disease. Patient anatomy has become increasingly complex due to advances in surgical resection of pancreaticobiliary disease and EUS has emerged as the therapy of choice when endoscopic retrograde cholangiopancreatography failed cannulation or when the papilla is inaccessible such as in gastric obstruction or duodenal obstruction. The current article gives a comprehensive review of the current literature for EUS-guided intervention of the pancreaticobiliary tract in patients with altered surgical anatomy. PMID:27386471

  2. Endoscopic ultrasound in common bile duct dilatation with normal liver enzymes

    PubMed Central

    De Angelis, Claudio; Marietti, Milena; Bruno, Mauro; Pellicano, Rinaldo; Rizzetto, Mario

    2015-01-01

    In recent years, the description of isolated bile duct dilatation has been increasingly observed in subjects with normal liver function tests and nonspecific abdominal symptoms, probably due to the widespread use of high-resolution imaging techniques. However, there is scant literature about the evolution of this condition and the impact of endoscopic ultrasound (EUS) in the diagnostic work up. When noninvasive imaging tests (transabdominal ultrasound, computed tomography or magnetic resonance cholangiopancreatography) fail to identify the cause of dilatation and clinical or biochemical alarm signs are absent, the probability of having biliary disease is considered low. In this setting, using EUS, the presence of pathologic findings (choledocholithiasis, strictures, chronic pancreatitis, ampullary or pancreatic tumors, cholangiocarcinoma), not always with a benign course, has been observed. The aim of this review has been to evaluate the prevalence of disease among non-jaundiced patients without signs of cytolysis and/or cholestasis and the assessment of EUS yield. Data point out to a promising role of EUS in the identification of a potential biliary pathology. EUS is a low invasive technique, with high accuracy, that could play a double cost-effective role: identifying pathologic conditions with dismal prognosis, in asymptomatic patients with negative prior imaging tests, and excluding pathologic conditions and further follow-up in healthy subjects. PMID:26191344

  3. Contrast-enhanced harmonic endoscopic ultrasound imaging: Basic principles, present situation and future perspectives

    PubMed Central

    Alvarez-Sánchez, María-Victoria; Napoléon, Bertrand

    2014-01-01

    Over the last decade, the development of stabilised microbubble contrast agents and improvements in available ultrasonic equipment, such as harmonic imaging, have enabled us to display microbubble enhancements on a greyscale with optimal contrast and spatial resolution. Recent technological advances made contrast harmonic technology available for endoscopic ultrasound (EUS) for the first time in 2008. Thus, the evaluation of microcirculation is now feasible with EUS, prompting the evolution of contrast-enhanced EUS from vascular imaging to images of the perfused tissue. Although the relevant experience is still preliminary, several reports have highlighted contrast-enhanced harmonic EUS (CH-EUS) as a promising noninvasive method to visualise and characterise lesions and to differentiate benign from malignant focal lesions. Even if histology remains the gold standard, the combination of CH-EUS and EUS fine needle aspiration (EUS-FNA) can not only render EUS more accurate but may also assist physicians in making decisions when EUS-FNA is inconclusive, increasing the yield of EUS-FNA by guiding the puncture with simultaneous imaging of the vascularity. The development of CH-EUS has also opened up exciting possibilities in other research areas, including monitoring responses to anticancer chemotherapy or to ethanol-induced pancreatic tissue ablation, anticancer therapies based on ultrasound-triggered drug and gene delivery, and therapeutic adjuvants by contrast ultrasound-induced apoptosis. Contrast harmonic imaging is gaining popularity because of its efficacy, simplicity and non-invasive nature, and many expectations are currently resting on this technique. If its potential is confirmed in the near future, contrast harmonic imaging will become a standard practice in EUS. PMID:25400439

  4. Real-time ultrasound elastography in 180 axillary lymph nodes: elasticity distribution in healthy lymph nodes and prediction of breast cancer metastases

    PubMed Central

    2012-01-01

    Background To determine the general appearance of normal axillary lymph nodes (LNs) in real-time tissue sonoelastography and to explore the method′s potential value in the prediction of LN metastases. Methods Axillary LNs in healthy probands (n=165) and metastatic LNs in breast cancer patients (n=15) were examined with palpation, B-mode ultrasound, Doppler and sonoelastography (assessment of the elasticity of the cortex and the medulla). The elasticity distributions were compared and sensitivity (SE) and specificity (SP) were calculated. In an exploratory analysis, positive and negative predictive values (PPV, NPV) were calculated based upon the estimated prevalence of LN metastases in different risk groups. Results In the elastogram, the LN cortex was significantly harder than the medulla in both healthy (p=0.004) and metastatic LNs (p=0.005). Comparing healthy and metastatic LNs, there was no difference in the elasticity distribution of the medulla (p=0.281), but we found a significantly harder cortex in metastatic LNs (p=0.006). The SE of clinical examination, B-mode ultrasound, Doppler ultrasound and sonoelastography was revealed to be 13.3%, 40.0%, 14.3% and 60.0%, respectively, and SP was 88.4%, 96.8%, 95.6% and 79.6%, respectively. The highest SE was achieved by the disjunctive combination of B-mode and elastographic features (cortex >3mm in B-mode or blue cortex in the elastogram, SE=73.3%). The highest SP was achieved by the conjunctive combination of B-mode ultrasound and elastography (cortex >3mm in B-mode and blue cortex in the elastogram, SP=99.3%). Conclusions Sonoelastography is a feasible method to visualize the elasticity distribution of LNs. Moreover, sonoelastography is capable of detecting elasticity differences between the cortex and medulla, and between metastatic and healthy LNs. Therefore, sonoelastography yields additional information about axillary LN status and can improve the PPV, although this method is still experimental. PMID

  5. B-Mode Ultrasound Imaging, Doppler Imaging, and Real-Time Elastography in Cutaneous Malignant Melanoma and Lymph Node Metastases

    PubMed Central

    Uematsu, Takayoshi; Kasami, Masako; Kiyohara, Yoshio

    2013-01-01

    Examination by ultrasonography (US) is a rapid, sensitive, cost-effective, and even portable technique for confirming the presence of tumors. However, US is not routinely used worldwide for the diagnostic work-up of cutaneous malignant melanoma. High-resolution US using a 6–14 MHz or 5–13 MHz linear transducer enables the preoperative assessment of tumor size and thickness. Compared with physical examination, US is also very effective in the early detection of lymph node metastases. It can be easily repeated for the follow-up of cutaneous malignant melanoma and lymph node metastases. Ultrasonographic appearance of some lymph nodes may overlap, thus producing diagnostic pitfalls. In such cases with overlapping findings, Doppler imaging and elastography may additionally facilitate the evaluation of cutaneous malignant melanoma and lymph node metastases. US-guided fine needle aspiration cytology (FNAC) finally helps to confirm ultrasonographic results, thus improving the specificity and sensitivity in difficult situations in which US alone gives unclear results in lymph node assessment.

  6. Endoscopic ultrasound characteristics of pancreatic lymphoepithelial cysts: A case series from a large referral center

    PubMed Central

    Dalal, Kunal S.; DeWitt, John M.; Sherman, Stuart; Cramer, Harvey M.; Tirkes, Temel; Al-Haddad, Mohammad A.

    2016-01-01

    Background and Objectives: Lymphoepithelial cysts (LECs) of the pancreas are benign lesions that can mimic cystic neoplasms on imaging. Endoscopic ultrasound (EUS) features have not been well described. We aimed to describe the clinical and EUS characteristics of LECs and the present outcomes of management at a high-volume referral center. Materials and Methods: We identified patients who underwent EUS and were found to have LECs based on fine-needle aspiration (FNA) cytology or surgical pathology from existing databases. EUS features, imaging characteristics, and pathology results were described. Results: Sixteen patients were found to have 17 LECs. The mean size was 33 mm ± 15 mm. Locations within the pancreas included 10 lesions in the tail, 3 in the body, 1 in the uncinate process; the remaining 3 were exophytic. Six lesions were anechoic, 6 were hypoechoic, and 5 had mixed echogenicity. Nine lesions had mixed solid/cystic components, 7 were purely cystic, and 1 was solid. Cyst fluid was thick or viscous in six cases and thin in three. Eleven patients had diagnostic cytopathology. Six patients ultimately underwent surgery due to symptoms, nondiagnostic FNA, or other clinical concerns for malignancy. Conclusions: Pancreatic LECs have variable morphology and echogenicity on EUS, but the appearance of a cyst with variable solid and cystic components combined with the appearance of thick, turbid, and viscous aspirate should raise suspicion for an LEC. The majority of patients with LECs at our center avoided surgery for LECs on the basis of diagnostic EUS-FNA. PMID:27503157

  7. Use of a novel through-the-needle biopsy forceps in endoscopic ultrasound

    PubMed Central

    Shakhatreh, Mohammad H.; Naini, Sohrab Rahimi; Brijbassie, Alan A.; Grider, Douglas J.; Shen, Perry; Yeaton, Paul

    2016-01-01

    Background and aims: Pancreatic cysts are becoming more common. Their differential diagnosis includes benign, premalignant, and malignant lesions. Distinguishing the type of cyst helps in the management decision making. We report on a novel tissue acquisition device for pancreatic cysts. Methods: Data on two patients who underwent endoscopic ultrasound (EUS) – guided fine-needle aspiration with a new micro forceps device are presented. Results: Two patients had large pancreatic cystic lesions in the pancreatic head. Linear EUS was performed, and tissue samples were obtained with the Moray micro forceps through a 19-gauge needle. In both patients, mucinous columnar epithelium lined the cystic walls. One patient underwent surgical resection, and the other elected surveillance. Examination of the surgical specimen from the first patient confirmed the cyst was a side-branch intraductal papillary mucinous neoplasm (IPMN), gastric type. Conclusions: The Moray micro forceps is a new tool that can be used to help determine the nature of pancreatic cysts and aid in their risk stratification and management. PMID:27092324

  8. Endoscopic ultrasound-guided fine needle aspiration: The wet suction technique.

    PubMed

    Villa, Nicolas A; Berzosa, Manuel; Wallace, Michael B; Raijman, Isaac

    2016-01-01

    Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) has become a fundamental tool in obtaining cytopathological diagnosis of pancreatic tumors. When sampling solid lesions of the pancreas, the endosonographer can use two suction techniques to enhance tissue acquisition; the dry and the wet suction techniques. The standard dry suction technique relies on applying negative pressure suction on the proximal end of the needle after the stylet is removed with a pre-vacuum syringe. The wet suction technique relies on pre-flushing the needle with saline to replace the column of air with fluid followed by aspiration the proximal end by using a prefilled syringe with saline. A new modified wet suction technique (hybrid suction technique) relies on preloading the needle with saline, but having continuous negative pressure with a pre-vacuum syringe to avoid manual intermittent suction. Tissue acquisition can be enhanced by applying fluid dynamic principles to the current aspiration techniques, such as the column of water used in the needle of the wet technique. In this review, we will focus on EUS-FNA using the wet suction technique for sampling of pancreatic solid lesions. PMID:26879162

  9. Endoscopic ultrasound comes of age: Mature, established, creative and here to stay!

    PubMed

    Bhutani, Manoop S

    2014-07-01

    Research in endoscopic ultrasound (EUS) is alive and kicking! This paper will present recent interesting developments in EUS based on research presented at the Digestive Disease Week (DDW) held in Chicago in 2014. Endosonographers are looking at various techniques to improve yield of fine needle aspiration and core biopsies, assess circulating tumor cells, apply EUS for personalized medicine and develop devices to ensure the adequacy of sampling. EUS may open new vistas in understanding of neurogastroenterology and gastrointestinal motility disorders as discussed in this paper. EUS guided drainage of pancreatic fluid collections, bile duct and gallbladder is feasible, and many randomized trials are being done to compare different techniques. EUS guided delivery of fiducials, drugs, coils or chemo loaded beads in possible. EUS has come off age, has matured and is here to stay! The DDW in 2014 in Chicago was a very active year for EUS. There were numerous papers on different aspects of EUS, some perfecting and improving old techniques, others dealing with randomized trials and many with novel concepts. In this paper, I will highlight some of the papers that were presented. It is not possible to discuss all the abstracts in detail. I have, therefore, chosen selected papers in different aspects of EUS to give the readers a flavor of the kind of research that was presented at DDW. PMID:25184120

  10. Endoscopic Ultrasound-Guided Fine-Needle Aspiration of the Adrenal Glands: Analysis of 21 Patients

    PubMed Central

    Puri, Rajesh; Choudhary, Narendra S.; Kotecha, Hardik; Misra, Smruti Ranjan; Bhagat, Suraj; Paliwal, Manish; Madan, Kaushal; Saraf, Neeraj; Sarin, Haimanti; Guleria, Mridula; Sud, Randhir

    2015-01-01

    Background/Aims Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) cytology of adrenal masses helps in etiological diagnosis. The aim of this study was to evaluate the diagnostic yield of EUS-FNA of adrenal masses in cases where other imaging methods failed and/or were not feasible. Methods Twenty-one consecutive patients with adrenal masses, in whom adrenal FNA was performed because conventional imaging modalities failed and/or were not feasible, were prospectively evaluated over a period of 3 years. Results Of the 21 patients (mean age, 56±12.2 years; male:female ratio, 2:1), 12 had pyrexia of unknown origin and the other nine underwent evaluation for metastasis. The median lesion size was 2.4×1.6 cm. Ten patients were diagnosed with tuberculosis (shown by the presence of caseating granulomas [n=10] and acid-fast bacilli [n=4]). Two patients had EUS-FNA results suggestive of histoplasmosis. The other patients had metastatic lung carcinoma (n=6), hepatocellular carcinoma (n=1), and adrenal lipoma (n=1) and adrenal myelolipoma (n=1). EUS results were not suggestive of any particular etiology. No procedure-related adverse events occurred. Conclusions EUS-FNA is a safe and effective method for evaluating adrenal masses, and it yields diagnosis in cases where tissue diagnosis is impossible or has failed using conventional imaging modalities. PMID:25844346

  11. Superficial esophageal lesions detected by endoscopic ultrasound enhanced with submucosal edema

    PubMed Central

    Li, Jian-Jun; He, Long-Jun; Shan, Hong-Bo; Wang, Thomas D; Xiong, Huan; Chen, Li-Ming; Xu, Guo-Liang; Li, Xiao-Hai; Huang, Xin-Xin; Luo, Guang-Yu; Li, Yin; Zhang, Rong

    2013-01-01

    AIM: To determine if there is consistency between endoscopic ultrasound (EUS) findings and pathological results for detecting lesions of different depth in the esophageal mucosa. METHODS: A canine (Beagle) model was established in which lesions of different depths were created in the esophageal mucosa by thermal burning. Seventy-two hours later, these lesions and adjacent tissue in the esophagus were examined by EUS. EUS findings including infiltrating depth, strength of echogenicity and homogeneity were recorded. Dogs were sacrificed and tissue specimens were obtained. We then compared the EUS findings with the pathology reports. RESULTS: Thermal burns created at different power settings caused lesions of different depth in the esophageal mucosa. When the echo strength was shifted from high, medium, to low echogenicity, an increase in the infiltrating depth of the lesion was noted, which coincided with results of the pathology examination. Obvious submucosal edema visualized by EUS was also detected by pathology. Furthermore, because of the enhancement caused by the submucosal edema, the lesions invading into the submucosa were easily visualized by EUS. CONCLUSION: There is consistency between EUS findings and pathological results of esophageal lesions with different depths. Submucosal edema can serve as an ultrasonic contrast agent. PMID:24379628

  12. Endoscopic ultrasound comes of age: Mature, established, creative and here to stay!

    PubMed Central

    Bhutani, Manoop S.

    2014-01-01

    Research in endoscopic ultrasound (EUS) is alive and kicking! This paper will present recent interesting developments in EUS based on research presented at the Digestive Disease Week (DDW) held in Chicago in 2014. Endosonographers are looking at various techniques to improve yield of fine needle aspiration and core biopsies, assess circulating tumor cells, apply EUS for personalized medicine and develop devices to ensure the adequacy of sampling. EUS may open new vistas in understanding of neurogastroenterology and gastrointestinal motility disorders as discussed in this paper. EUS guided drainage of pancreatic fluid collections, bile duct and gallbladder is feasible, and many randomized trials are being done to compare different techniques. EUS guided delivery of fiducials, drugs, coils or chemo loaded beads in possible. EUS has come off age, has matured and is here to stay! The DDW in 2014 in Chicago was a very active year for EUS. There were numerous papers on different aspects of EUS, some perfecting and improving old techniques, others dealing with randomized trials and many with novel concepts. In this paper, I will highlight some of the papers that were presented. It is not possible to discuss all the abstracts in detail. I have, therefore, chosen selected papers in different aspects of EUS to give the readers a flavor of the kind of research that was presented at DDW. PMID:25184120

  13. Basic technique in endoscopic ultrasound-guided fine needle aspiration for solid lesions: How many passes?

    PubMed

    Petrone, Maria Chiara; Arcidiacono, Paolo Giorgio

    2014-01-01

    Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has evolved to become an indispensable tool for tissue acquisition in patients with luminal and extra luminal gastrointestinal cancers. Despite the extensive use of EUS-FNA, there still exists a wide variation in the number of samples required to ensure acquisition of diagnostic material from different kind of lesions. There are several factors that may influence the number of fine needle passes made during EUS-FNA, but the main factor seems to be the presence of a Cytopathologist during the EUS procedure. The diagnostic yield of EUS-FNA with rapid on-site evaluation (ROSE) in most studies exceeds 90%. Nevertheless, ROSE is not available in many centers. Various studies have investigated the adequate number of needle passes that should be performed if ROSE is not used. Differences exist based on the nature of the target lesion: Five to seven passes for pancreatic masses, three passes for lymphnodes, only one pass for pancreatic cystic lesions. Consider using a core biopsy needle or a 19-G FNA needle for histology could improve the diagnostic yield. Even though EUS-FNA is widely available, some patients still do not receive conclusive diagnoses upon initial EUS-FNA. One way to maximize the benefits for patients might be to centralize cases to several well-equipped, high-volume centers with experienced endosonographers that have universal availability of ROSE. PMID:24949407

  14. Peripancreatic cystic lymphangioma diagnosed by endoscopic ultrasound/fine-needle aspiration: a rare mesenchymal tumour

    PubMed Central

    Tanimu, Sabo; Rafiullah; Resnick, Jeffrey; Onitilo, Adedayo A

    2013-01-01

    A 73-year-old man presented with a 5-month history of intermittent nausea, vomiting, central abdominal discomfort and a 17-pound weight loss over the past year. Laboratory testing, including a complete blood count with differential, liver function testing, amylase and lipase studies were normal. A CT scan showed a bilobed cystic lesion inferior to the body of the pancreas. An endoscopic ultrasound revealed a 5.3×3.9 cm, anechoic, bilobed cystic lesion, extrinsic to the body of the pancreas with a 1–2 mm septation and a normal pancreas. Fine-needle aspiration revealed a milky-white aspirate with negative cytology. Laboratory assessment of the cystic aspirant revealed carcinoembryonic antigen 1.7 ng/mL, amylase 148 units/L, cholesterol 300 mg/dL, and carbohydrate antigen 19-9 3 units/mL. He underwent resection of the mass, with the histopathology confirming a diagnosis of peripancreatic lymphangioma. He did well after the surgery with interval resolution of his symptoms. PMID:24092605

  15. Endoscopic ultrasound-guided fine needle aspiration: The wet suction technique

    PubMed Central

    Villa, Nicolas A.; Berzosa, Manuel; Wallace, Michael B.; Raijman, Isaac

    2016-01-01

    Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) has become a fundamental tool in obtaining cytopathological diagnosis of pancreatic tumors. When sampling solid lesions of the pancreas, the endosonographer can use two suction techniques to enhance tissue acquisition; the dry and the wet suction techniques. The standard dry suction technique relies on applying negative pressure suction on the proximal end of the needle after the stylet is removed with a pre-vacuum syringe. The wet suction technique relies on pre-flushing the needle with saline to replace the column of air with fluid followed by aspiration the proximal end by using a prefilled syringe with saline. A new modified wet suction technique (hybrid suction technique) relies on preloading the needle with saline, but having continuous negative pressure with a pre-vacuum syringe to avoid manual intermittent suction. Tissue acquisition can be enhanced by applying fluid dynamic principles to the current aspiration techniques, such as the column of water used in the needle of the wet technique. In this review, we will focus on EUS-FNA using the wet suction technique for sampling of pancreatic solid lesions. PMID:26879162

  16. Successful transgastric pancreaticography and endoscopic ultrasound-guided drainage of a disconnected pancreatic tail syndrome

    PubMed Central

    Will, Uwe; Fueldner, Frank; Goldmann, Bernhard; Mueller, Anne-Kathrin; Wanzar, Igor; Meyer, Frank

    2011-01-01

    Objectives: We aim to demonstrate that endoscopic ultrasound (EUS)-guided transgastric pancreaticography/drainage of the pancreatic duct is feasible and successful in healing a persisting pancreaticocutaneous fistula. Methods: By means of a case report, we describe the following alternative therapeutic procedure. A 76-year-old male had: (1) 10 surgical interventions because of necrotizing acute pancreatitis with a persisting pancreaticocutaneous fistula (volume 200–300 ml/day); (2) an unsuccessful attempt of transpapillary drainage (disrupted duct after necrosectomy). He then underwent a EUS-guided transluminal pancreaticography/drainage of the pancreatic duct. A transgastric puncture was performed followed by, insertion of a guide wire into the dilated tail segment, and expansion of the gastropancreaticostomy using a 10-Fr retriever. A 10-Fr Amsterdam prosthesis was then placed through the guide wire. Results: The procedure was both a technical and clinical success as indicated by fistula occlusion and sufficient internal drainage of the pancreatic juice via the gastropancreaticostomy. No severe complications such as bleeding, perforation stent occlusion or migration were observed during the 15-month follow-up. Conclusions: Transgastric pancreaticography and EUS-guided drainage of the enlarged pancreatic duct are elegant and feasible alternative options for the treatment of specific pancreatic lesions such as persisting pancreaticocutaneous fistula (complication after necrotizing pancreatitis), after pancreatic resective surgery, chronic pancreatitis and anomaly of the congenital pancreatic or postoperative gastrointestinal anatomy. Moreover, the procedure may represent a valid tool to avoid surgery and more invasive interventions. PMID:21765865

  17. Endoscopic ultrasound-guided fine-needle aspiration for the diagnosis of kidney lesions: A review.

    PubMed

    Lopes, Roberto Iglesias; Moura, Renata Nobre; Artifon, Everson

    2015-03-16

    Traditionally, treatment of renal lesions is indicated based only on imaging features. Although controversy exists about tissue sampling from small renal masses, renal biopsy is indicated in some cases. In this review, we discuss the rationale for endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) and summarize the recent advances in this field, providing recommendations for the practicing clinician. The use of EUS-FNA appears to be a safe and feasible means of confirming or excluding malignancy. EUS allows assessment and biopsy of masses or lesions within both kidneys and related complications are rare. The main advantages of EUS-FNA are that it can be done as an outpatient procedure, with good results, minimal morbidity and a short hospital stay. Nevertheless, EUS-FNA of renal masses should be indicated only in selected cases, in which there is potential to decrease unnecessary treatment of small renal masses and to best select tumors for active surveillance and minimally invasive ablative therapies. Additionally, some renal lesions may be ineligible for EUS-guided biopsy because of anatomical limitations. EUS-FNA renal biopsy will probably be best applied to central anterior renal masses, while tumors on the posterior aspect of the kidney, percutaneous access will probably be superior. PMID:25789096

  18. Endoscopic ultrasound-guided gastrojejunostomy with a lumen-apposing metal stent: a multicenter, international experience

    PubMed Central

    Tyberg, Amy; Perez-Miranda, Manuel; Sanchez-Ocaña, Ramon; Peñas, Irene; de la Serna, Carlos; Shah, Janak; Binmoeller, Kenneth; Gaidhane, Monica; Grimm, Ian; Baron, Todd; Kahaleh, Michel

    2016-01-01

    Background: Surgical gastrojejunostomy and enteral self-expanding metal stents are efficacious for the management of gastric outlet obstruction but limited by high complication rates and short-term efficacy. Endoscopic ultrasound-guided gastrojejunostomy (EUS-GJ) is a novel alternative option. Patients and methods: Patients who underwent EUS-GJ between March 2014 and September 2015 as part of a prospective multicenter registry at four academic centers in two countries were included. Technical success was defined as successful placement of a gastrojejunal lumen-apposing metal stent. Clinical success was defined as the ability of the patient to tolerate an oral diet. Post-procedural adverse events were recorded. Results: The study included 26 patients, of whom 11 (42 %) were male. Technical success was achieved in 24 patients (92 %). Clinical success was achieved in 22 patients (85 %). Of the 4 patients in whom clinical success was not achieved, 2 had persistent nausea and vomiting despite a patent EUS-GJ and required enteral feeding for nutrition, 1 died before the initiation of an oral diet, and 1 underwent surgery for suspected perforation. Adverse events, including peritonitis, bleeding, and surgery, occurred in 3 patients (11.5 %). Conclusion: EUS-GJ is an emerging procedure that has efficacy and safety comparable with those of current therapies and should hold a place as a new minimally invasive option for patients with gastric outlet obstruction. Clinical trial identification number: NCT01522573 PMID:27004243

  19. Chronic pancreatic pain successfully treated by endoscopic ultrasound-guided pancreaticogastrostomy using fully covered self-expandable metallic stent.

    PubMed

    Chang, Arunchai; Aswakul, Pitulak; Prachayakul, Varayu

    2016-04-16

    One of the most common symptoms presenting in patients with chronic pancreatitis is pancreatic-type pain. Obstruction of the main pancreatic duct in chronic pancreatitis can be treated by a multitude of therapeutic approaches, ranging from pharmacologic, endoscopic and radiologic treatments to surgical interventions. When the conservative treatment approaches fail to resolve symptomatic cases, however, endoscopic retrograde pancreatography with pancreatic duct drainage is the preferred second approach, despite its well-recognized drawbacks. When the conventional transpapillary approach fails to achieve the necessary drainage, the patients may benefit from application of the less invasive endoscopic ultrasound (EUS)-guided pancreatic duct interventions. Here, we describe the case of a 42-year-old man who presented with severe abdominal pain that had lasted for 3 mo. Computed tomography scanning showed evidence of chronic obstructive pancreatitis with pancreatic duct stricture at genu. After conventional endoscopic retrograde pancreaticography failed to eliminate the symptoms, EUS-guided pancreaticogastrostomy (PGS) was applied using a fully covered, self-expandable, 10-mm diameter metallic stent. The treatment resolved the case and the patient experienced no adverse events. EUS-guided PGS with a regular biliary fully covered, self-expandable metallic stent effectively and safely treated pancreatic-type pain in chronic pancreatitis. PMID:27099862

  20. Chronic pancreatic pain successfully treated by endoscopic ultrasound-guided pancreaticogastrostomy using fully covered self-expandable metallic stent

    PubMed Central

    Chang, Arunchai; Aswakul, Pitulak; Prachayakul, Varayu

    2016-01-01

    One of the most common symptoms presenting in patients with chronic pancreatitis is pancreatic-type pain. Obstruction of the main pancreatic duct in chronic pancreatitis can be treated by a multitude of therapeutic approaches, ranging from pharmacologic, endoscopic and radiologic treatments to surgical interventions. When the conservative treatment approaches fail to resolve symptomatic cases, however, endoscopic retrograde pancreatography with pancreatic duct drainage is the preferred second approach, despite its well-recognized drawbacks. When the conventional transpapillary approach fails to achieve the necessary drainage, the patients may benefit from application of the less invasive endoscopic ultrasound (EUS)-guided pancreatic duct interventions. Here, we describe the case of a 42-year-old man who presented with severe abdominal pain that had lasted for 3 mo. Computed tomography scanning showed evidence of chronic obstructive pancreatitis with pancreatic duct stricture at genu. After conventional endoscopic retrograde pancreaticography failed to eliminate the symptoms, EUS-guided pancreaticogastrostomy (PGS) was applied using a fully covered, self-expandable, 10-mm diameter metallic stent. The treatment resolved the case and the patient experienced no adverse events. EUS-guided PGS with a regular biliary fully covered, self-expandable metallic stent effectively and safely treated pancreatic-type pain in chronic pancreatitis. PMID:27099862

  1. Endoscopic ultrasound-guided biliary intervention in patients with surgically altered anatomy

    PubMed Central

    Siripun, Aroon; Sripongpun, Pimsiri; Ovartlarnporn, Bancha

    2015-01-01

    AIM: To evaluate the efficacy of endoscopic ultrasound guided biliary drainage (EUS-BD) in patients with surgically altered anatomies. METHODS: We performed a search of the MEDLINE database for studies published between 2001 to July 2014 reporting on EUS-BD in patients with surgically altered anatomy using the terms “EUS drainage” and “altered anatomy”. All relevant articles were accessed in full text. A manual search of the reference lists of relevant retrieved articles was also performed. Only full-text English papers were included. Data regarding age, gender, diagnosis, method of EUS-BD and intervention, type of altered anatomy, technical success, clinical success, and complications were extracted and collected. Anatomic alterations were categorized as: group 1, Billroth I; group 2, Billroth II; group 4, Roux-en-Y with gastric bypass; and group 3, all other types. RESULTS: Twenty three articles identified in the literature search, three reports were from the same group with different numbers of cases. In total, 101 cases of EUS-BD in patients with altered anatomy were identified. Twenty-seven cases had no information and were excluded. Seventy four cases were included for analysis. Data of EUS-BD in patients categorized as group 1, 2 and 4 were limited with 2, 3 and 6 cases with EUS-BD done respectively. Thirty four cases with EUS-BD were reported in group 3. The pooled technical success, clinical success, and complication rates of all reports with available data were 89.18%, 91.07% and 17.5%, respectively. The results are similar to the reported outcomes of EUS-BD in general, however, with limited data of EUS-BD in patients with altered anatomy rendered it difficult to draw a firm conclusion. CONCLUSION: EUS-BD may be an option for patients with altered anatomy after a failed endoscopic-retrograde-cholangiography in centers with expertise in EUS-BD procedures in a research setting. PMID:25789101

  2. Basic techniques in endoscopic ultrasound-guided fine needle aspiration for solid lesions: Adverse events and avoiding them

    PubMed Central

    Fujii, Larissa L.; Levy, Michael J.

    2014-01-01

    Endoscopic ultrasound (EUS) guided fine-needle aspiration (FNA) is often the preferred technique for tissue acquisition in the diagnosis of suspected intrathoracic and intraabdominal pathology. Although EUS FNA is a safe and accurate procedure, it has been associated with a low risk of adverse events. The unique properties of the echoendoscope and its ability to acquire tissue outside of the gastrointestinal lumen impart risks that are not associated with routine endoscopic procedures. In this review, we discuss the risk of perforation related to the echoendoscope itself and adverse events related to FNA of solid masses including infections, bleeding, pancreatitis and pancreatic duct leak, bile duct leak and tumor seeding. We also provide tips on how to avoid the most common adverse events related to EUS-FNA. PMID:24949409

  3. Development of EndoTOFPET-US, a multi-modal endoscope for ultrasound and time of flight positron emission tomography

    NASA Astrophysics Data System (ADS)

    Pizzichemi, M.

    2014-02-01

    The EndoTOFPET-US project aims at delevoping a multi-modal imaging device that combines Ultrasound with Time-Of-Flight Positron Emission Tomography into an endoscopic imaging device. The goal is to obtain a coincidence time resolution of about 200 ps FWHM and sub-millimetric spatial resolution for the PET head, integrating the components in a very compact detector suitable for endoscopic use. The scanner will be exploited for the clinical test of new bio-markers especially targeted for prostate and pancreatic cancer as well as for diagnostic and surgical oncology. This paper focuses on the status of the Time-Of-Flight Positron Emission Tomograph under development for the EndoTOFPET-US project.

  4. Evaluating the Minimal Specimens From Endoscopic Ultrasound-Guided Fine-Needle Aspiration in Pancreatic Masses

    PubMed Central

    Park, Joo Kyung; Kang, Ki Joo; Oh, Cho Rong; Lee, Jong Kyun; Lee, Kyu Taek; Jang, Kee Taek; Park, Sang-Mo; Lee, Kwang Hyuck

    2016-01-01

    Abstract Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has become one of the most useful diagnostic modalities for the diagnosis of pancreatic mass. The aim of this study was to investigate the role of analyzing the minimal specimens obtained by EUS-FNA for the diagnosis of solid masses of pancreas. This study consisted of retrospective and prospective analyses. The retrospective study was performed on 116 patients who underwent EUS-FNA of solid masses for cytological smear, histological analysis, and combined analysis including immunohistochemical (IHC) staining. In the prospective study, 79 patients were enrolled to evaluate the quality and accuracy of EUS-FNA histological analysis and feasibility of IHC staining. The final diagnoses of all patients included pancreatic cancer (n = 126), nonpancreatic cancer (n = 21), other neoplasm (n = 27), and benign lesions (n = 21). In our retrospective study, the combined analysis was more sensitive than cytological analysis alone (P < 0.01). The overall sensitivity of cytology, histology, and combined analysis was 69.8%, 67.2%, and 81.8%, respectively. In the prospective analysis, 64.2% of all punctures were helpful for determining the diagnosis and 40.7% provided sufficient tissue for IHC staining. Histological analysis was helpful for diagnosis in 74.7% of patients. IHC staining was necessary for a definite diagnosis in 11.4% of patients, especially in the cases of nonmalignant pancreatic mass. Histological analysis and IHC study of EUS-FNA specimens was useful for the accurate diagnosis of pancreatic and peripancreatic lesions. Combined analysis showed significantly higher sensitivity than cytology alone because IHC staining was helpful for a diagnosis in some patients. PMID:27227937

  5. Endoscopic Ultrasound for Preoperative Esophageal Squamous Cell Carcinoma: a Meta-Analysis

    PubMed Central

    Huang, Xin-xin; Shan, Hong-bo; Luo, Guang-yu; Li, Yin; Lin, Shi-yong; Wang, Guo-bao; Zhang, Rong; Xu, Guo-liang; Li, Jian-jun

    2016-01-01

    Background Treatment options and prognosis of esophageal squamous cell carcinoma (ESCC) depend on the primary tumor depth (T-staging) and regional lymph node status (N-staging). Endoscopic ultrasound (EUS) has emerged as a useful staging tool, but studies regarding its benefits have been variable. The objective of this study was to evaluate the diagnostic accuracy of EUS for detecting preoperative ESCC. Methods We included in our meta-analysis studies involving EUS-based staging of preoperative ESCC compared with pathological staging. Using a random-effects model, we performed a meta-analysis of the accuracy of EUS by calculating pooled estimates of sensitivity, specificity and the diagnostic odds ratio. In addition, we created a summary receiver operating characteristic (SROC) curve. Results Forty-four studies (n = 2880) met the inclusion criteria. The pooled sensitivity and specificity of T1 were 77% (95%CI: 73 to 80) and 95% (95%CI: 94 to 96). Among the T1 patients, EUS had a pooled sensitivity in differentiating T1a and T1b of 84% (95%CI: 80 to 88) and 83% (95%CI: 80 to 86), and a specificity of 91% (95%CI: 88 to 94) and 89% (95%CI: 86 to 92). To stage T4, EUS had a pooled sensitivity of 84% (95%CI: 79 to 89) and a specificity of 96% (95%CI: 95 to 97). The overall accuracy of EUS for T-staging was 79% (95%CI: 77 to 80), and for N-staging, 71% (95%CI: 69 to 73). Conclusions EUS has good diagnostic accuracy for staging ESCC, which has better performance in T1 sub-staging (T1a and T1b) and advanced disease (T4). PMID:27387830

  6. Endoscopic ultrasound versus magnetic resonance cholangiopancreatography in suspected choledocholithiasis: A systematic review

    PubMed Central

    De Castro, Vinicius Leite; Moura, Eduardo G.H.; Chaves, Dalton M.; Bernardo, Wanderley M.; Matuguma, Sergio E.; Artifon, Everson L.A.

    2016-01-01

    Background and Objectives: There is a lack of consensus about the optimal noninvasive strategy for patients with suspected choledocholithiasis. Two previous systematic reviews used different methodologies not based on pretest probabilities that demonstrated no statistically significant difference between Endoscopic ultrasound (EUS) and magnetic resonance cholangiopancreatography (MRCP) for the detection of choledocholithiasis. In this article, we made a comparison of the diagnostic ability of EUS and MRCP to detect choledocholithiasis in suspected patients. Methods: We conducted a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations with all published randomized prospective trials. We performed the systemic review using MedLine, EMBASE, Cochrane, LILACS, and Scopus reviews through May 2015. We identified eight randomized, prospective, blinded trials comparing EUS and MRCP. All the patients were submitted to a gold standard method. We calculated the study-specific variables and performed analyses using aggregated variables such as sensitivity, specificity, prevalence, positive predictive value (PPV) and negative predictive value (NPV), and accuracy. Results: Five hundred and thirty eight patients were included in the analysis. The pretest probability for choledocholithiasis was 38.7. The mean sensitivity of EUS and MRCP for detection of choledocholithiasis was 93.7 and 83.5, respectively; the specificity was 88.5 and 91.5, respectively. Regarding EUS and MRCP, PPV was 89 and 87.8, respectively, and NPV was 96.9 and 87.8, respectively. The accuracy of EUS and MRCP was 93.3 and 89.7, respectively. Conclusions: For the same pretest probability of choledocholithiasis, EUS has higher posttest probability when the result is positive and a lower posttest probability when the result is negative compared with MRCP. PMID:27080611

  7. Evaluating the Minimal Specimens From Endoscopic Ultrasound-Guided Fine-Needle Aspiration in Pancreatic Masses.

    PubMed

    Park, Joo Kyung; Kang, Ki Joo; Oh, Cho Rong; Lee, Jong Kyun; Lee, Kyu Taek; Jang, Kee Taek; Park, Sang-Mo; Lee, Kwang Hyuck

    2016-05-01

    Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has become one of the most useful diagnostic modalities for the diagnosis of pancreatic mass. The aim of this study was to investigate the role of analyzing the minimal specimens obtained by EUS-FNA for the diagnosis of solid masses of pancreas.This study consisted of retrospective and prospective analyses. The retrospective study was performed on 116 patients who underwent EUS-FNA of solid masses for cytological smear, histological analysis, and combined analysis including immunohistochemical (IHC) staining. In the prospective study, 79 patients were enrolled to evaluate the quality and accuracy of EUS-FNA histological analysis and feasibility of IHC staining.The final diagnoses of all patients included pancreatic cancer (n = 126), nonpancreatic cancer (n = 21), other neoplasm (n = 27), and benign lesions (n = 21). In our retrospective study, the combined analysis was more sensitive than cytological analysis alone (P < 0.01). The overall sensitivity of cytology, histology, and combined analysis was 69.8%, 67.2%, and 81.8%, respectively. In the prospective analysis, 64.2% of all punctures were helpful for determining the diagnosis and 40.7% provided sufficient tissue for IHC staining. Histological analysis was helpful for diagnosis in 74.7% of patients. IHC staining was necessary for a definite diagnosis in 11.4% of patients, especially in the cases of nonmalignant pancreatic mass.Histological analysis and IHC study of EUS-FNA specimens was useful for the accurate diagnosis of pancreatic and peripancreatic lesions. Combined analysis showed significantly higher sensitivity than cytology alone because IHC staining was helpful for a diagnosis in some patients. PMID:27227937

  8. The Use of Standard Gastrointestinal Endoscopic Ultrasound to Assess Cardiac Anatomy.

    PubMed

    Sentissi, Kinza; Sawhney, Mandeep S; Pleskow, Douglas; Sepe, Paul; Mella, Jose M; Kwittken, Benjamin; Ketwaroo, Gyanprakash; Subramaniam, Balachundhar

    2016-09-01

    In this prospective observational study, conducted at an academic medical center, we evaluated the feasibility of performing a basic transesophageal echocardiography (TEE) examination using endoscopic ultrasound (EUS) technology to determine what cardiac structures could be assessed. This may be potentially beneficial during hemodynamic emergencies in the endoscopy suite resulting from hypovolemia, depressed ventricular function, aortic dissection, pericardial effusions, or aortic stenosis. Of the 20 patients enrolled, 18 underwent EUS with a linear echoendoscope for standard clinical indications followed by a cardiac assessment performed under the guidance of a TEE-certified cardiac anesthesiologist. Eight of the 20 standard views of cardiovascular structures per the 1999 American Society of Echocardiography/Society of Cardiovascular Anesthesiologists guidelines for TEE could be obtained using the linear echoendoscope. The following cardiac valvular structures were visualized: aortic valve (100%), mitral valve (100%), tricuspid valve (33%), and pulmonic valve (11%). Left ventricular and right ventricular systolic function could be assessed in 89% and 67% of patients, respectively. Other structures such as the ascending and descending aorta, pericardium, left atrial appendage, and interatrial septum were identified in 100% of patients. Doppler-dependent functions could not be assessed. Given that the EUS images were not directly compared with TEE in these patients, we cannot comment definitively on the quality of these assessments and further studies would need to be performed to make a formal comparison. Based on this study, EUS technology can consistently assess the mitral valve, aortic valve, aorta, pericardium, and left ventricular function. Given its limitations, EUS technology, although not a substitute for formal echocardiography, could be a helpful early diagnostic tool in an emergency setting. PMID:27541718

  9. Endoscopic Ultrasound in Endocrinology: Imaging of the Adrenals and the Endocrine Pancreas.

    PubMed

    Kann, Peter Herbert

    2016-01-01

    Endoscopic ultrasound (EUS) imaging of adrenal glands and its application to diagnostic procedures of adrenal diseases has been reported since 1998. It can be considered a relevant advantage in the field of adrenal diseases. Indeed, EUS allows the detection of adrenal lesions (even very small ones) and their characterization, the assessment of malignancy criteria, the early detection of neoplastic recurrences, the preoperative identification of morphologically healthy parts of the glands, the differentiation of extra-adrenal from adrenal tumors, and of the pathological entities associated with adrenal insufficiency, and the fine-needle aspiration biopsy (EUS-FNA) of suspicious lesions. At the same time, its clinical relevance depends on the experience of the endosonographer. Moreover, EUS is also by far the best and most sensitive imaging technique to detect and assess the follow-up of pancreatic manifestation of MEN1 disease. It furthermore enables the preoperatively localization of insulinomas and critical structures in their neighborhood, and may be relevant in planning surgical strategy. A positive EUS in a case of insulinoma furthermore confirms the endocrine diagnosis, especially considering the differential diagnosis of hypoglycemia factitia by oral antidiabetics. It can be supplemented by EUS-FNA. Again, it has to be considered that EUS may reveal false positive and false negative results, and the quality of the findings largely depends on the endosonographer's skills and experience. The most important technical details together with the advantages and limitations of EUS, and the pathognomonic characteristic of benign and malignant disorders of the adrenals and pancreas are presented here. PMID:27003412

  10. Efforts to improve the diagnostic accuracy of endoscopic ultrasound-guided fine-needle aspiration for pancreatic tumors

    PubMed Central

    Yamabe, Akane; Irisawa, Atsushi; Bhutani, Manoop S.; Shibukawa, Goro; Fujisawa, Mariko; Sato, Ai; Yoshida, Yoshitsugu; Arakawa, Noriyuki; Ikeda, Tsunehiko; Igarashi, Ryo; Maki, Takumi; Yamamoto, Shogo

    2016-01-01

    Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is widely used to obtain a definitive diagnosis of pancreatic tumors. Good results have been reported for its diagnostic accuracy, with high sensitivity and specificity of around 90%; however, technological developments and adaptations to improve it still further are currently underway. The endosonographic technique can be improved when several tips and tricks useful to overcome challenges of EUS-FNA are known. This review provides various techniques and equipment for improvement in the diagnostic accuracy in EUS-FNA. PMID:27503153

  11. A Prospective Blinded Study Evaluating the Role of Endoscopic Ultrasound before Endoscopic Retrograde Cholangiopancreatography in the Setting of "Positive" Intraoperative Cholangiogram during Cholecystectomy.

    PubMed

    Luthra, Anjuli K; Aggarwal, Vipul; Mishra, Girish; Conway, Jason; Evans, John A

    2016-04-01

    During laparoscopic cholecystectomy, intraoperative cholangiography (IOC) is used to identify common bile duct (CBD) stones. In patients whose IOC is suspicious for stones, endoscopic retrograde cholangiopancreatography (ERCP) is the modality of choice for stone removal. However, IOC has a false positive rate of 30 to 60 per cent, and ERCP adverse events may occur in 11 per cent of patients. Endoscopic ultrasound (EUS) may serve as a noninvasive means of diagnosing suspected CBD stones. This study sought to assess the role of EUS in predicting the likelihood of choledocholithiasis at ERCP in patients found to have a positive IOC. This was a prospective blinded study of EUS before ERCP in patients with a positive IOC. Recruited subjects who underwent cholecystectomy and had an IOC with suspicion for obstruction were referred for ERCP within one month of their procedure. In patients with a positive IOC, EUS had a positive predictive value of 95 per cent in detecting choledocholithiasis. IOC with single or multiple filling defects more often correlated to the presence of CBD stones. At ERCP, choledocholithiasis was present in 65 per cent of patients who had an IOC suspicious for CBD stones. EUS should be used as a noninvasive method to correctly identify retained CBD stones in low-to-moderate risk patients with a positive IOC. PMID:27097628

  12. Endoscopic ultrasound-guided inoculation of transmissible venereal tumor in the colon: A large animal model for colon neoplasia

    PubMed Central

    Bhutani, Manoop S.; Uthamanthil, Rajesh; Suzuki, Rei; Shetty, Anil; Klumpp, Sherry A.; Nau, William; Stafford, Roger Jason

    2016-01-01

    Background: To develop and evaluate the feasibility of emerging interventions, animal models with accurate anatomical environment are required. Objectives: We aimed to establish a clinically relevant colorectal tumor model with canine transmissible venereal tumor (CTVT) utilizing endoscopic ultrasound (EUS) imaging guidance. Design: Survival study using a canine model. Setting: Endoscopic animal research laboratory at a tertiary cancer center. Materials and Methods: This study involved five canines. Interventions: A colorectal tumor model was established and evaluated in five canines under cyclosporine immune suppression. Under endoscopic imaging guidance, saline was injected into the submucosal layer forming a bleb. Subsequently, CTVT was inoculated into the bleb under EUS guidance. Endoscopy was the primary method of assessing tumor growth. Tumors developed in 60-130 days. Upon detection of lesions >1 cm, the animals were euthanized and the tumors were harvested for histopathological characterization. Main outcome measurements: Success rate of tumor growth. The presence or absence of vasculature inside tumors. Results: Colorectal tumor successfully developed in three out of the five animals (60%). Among the ones with tumor growth, average inoculated CTVT volume, incubation time, and tumor size was 1.8 cc, 65.7 days, and 2.0 cm, respectively. The two animals without tumor growth were observed for >100 days. In all the tumors, vascular structure was characterized with CD31 imunohistochemical stain. Limitations: Small number of animals. Conclusion: We succeeded in creating a new colorectal tumor canine model with CTVT utilizing EUS. PMID:27080606

  13. Towards real time 2D to 3D registration for ultrasound-guided endoscopic and laparoscopic procedures

    PubMed Central

    Westin, Carl-Fredrik; Vosburgh, Kirby G.

    2010-01-01

    Purpose A method to register endoscopic and laparoscopic ultrasound (US) images in real time with pre-operative computed tomography (CT) data sets has been developed with the goal of improving diagnosis, biopsy guidance, and surgical interventions in the abdomen. Methods The technique, which has the potential to operate in real time, is based on a new phase correlation technique: LEPART, which specifies the location of a plane in the CT data which best corresponds to the US image. Validation of the method was carried out using an US phantom with cyst regions and with retrospective analysis of data sets from animal model experiments. Results The phantom validation study shows that local translation displacements can be recovered for each US frame with a root mean squared error of 1.56 ± 0.78 mm in less than 5 sec, using non-optimized algorithm implementations. Conclusion A new method for multimodality (preoperative CT and intraoperative US endoscopic images) registration to guide endoscopic interventions was developed and found to be efficient using clinically realistic datasets. The algorithm is inherently capable of being implemented in a parallel computing system so that full real time operation appears likely. PMID:20033331

  14. Endoscopic Ultrasound-Guided Radiofrequency Ablation of the Pancreatic Tumors: A Promising Tool in Management of Pancreatic Tumors

    PubMed Central

    2016-01-01

    Objective. Radiofrequency ablation is a well-established antitumor treatment and is recognized as one of the least invasive therapeutic modalities for pancreatic neoplasm. Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) delivery can be used to treat both pancreatic cancer and asymptomatic premalignant pancreatic neoplasms and may serve as a less invasive alternative to surgical resection. This is an appealing option that may result in less morbidity and mortality. The aim of this review was to summarize and evaluate the clinical and technical effectiveness of EUS-guided RFA of pancreatic neoplasms. Methods. A through literature review was performed to identify the studies describing this novel technique. In this review article, we have summarized human case series. The indications, techniques, limitations, and complications reported are discussed. Results. A total of six studies were included. Overall, a 100% technical success rate was reported in human studies. Complications related to endoscopic ultrasound-guided radiofrequency ablation delivery have been described; however, few cases have presented life-threatening outcomes. Conclusion. We believe that this novel technique can be a safe and effective alternative approach in the management of selected patients. PMID:27478820

  15. Acquisition of Portal Venous Circulating Tumor Cells From Patients With Pancreaticobiliary Cancers by Endoscopic Ultrasound

    PubMed Central

    Catenacci, Daniel V. T.; Chapman, Christopher G.; Xu, Peng; Koons, Ann; Konda, Vani J.; Siddiqui, Uzma D.; Waxman, Irving

    2016-01-01

    BACKGROUND & AIMS Tumor cells circulate in low numbers in peripheral blood; their detection is used predominantly in metastatic disease. We evaluated the feasibility and safety of sampling portal venous blood via endoscopic ultrasound (EUS) to count portal venous circulating tumor cells (CTCs), compared with paired peripheral CTCs, in patients with pancreaticobiliary cancers (PBCs). METHODS In a single-center cohort study, we evaluated 18 patients with suspected PBCs. Under EUS guidance, a 19-gauge EUS fine needle was advanced transhepatically into the portal vein and as many as four 7.5-mL aliquots of blood were aspirated. Paired peripheral blood samples were obtained. Epithelial-derived CTCs were sorted magnetically based on expression of epithelial cell adhesion molecules; only those with a proper morphology and found to be CD45 negative and positive for cytokeratins 8, 18, and/ or 19 and 4′,6-diamidino-2-phenylindole were considered to be CTCs. For 5 samples, CTCs also were isolated by flow cytometry and based on CD45 depletion. ImageStream was used to determine the relative protein levels of P16, SMAD4, and P53. DNA was extracted from CTCs for sequencing of select KRAS codons. RESULTS There were no complications from portal vein blood acquisition. We detected CTCs in portal vein samples from all 18 patients (100%) vs peripheral blood samples from only 4 patients (22.2%). Patients with confirmed PBCs had a mean of 118.4 ± 36.8 CTCs/7.5 mL portal vein blood, compared with a mean of 0.8 ± 0.4 CTCs/7.5 mL peripheral blood (P < .01). The 9 patients with nonmetastatic, resectable, or borderline-resectable PBCs had a mean of 83.2 CTCs/7.5 mL portal vein blood (median, 62.0 CTCs/7.5 mL portal vein blood). In a selected patient, portal vein CTCs were found to carry the same mutations as those detected in a metastatic lymph node and expressed similar levels of P16, SMAD4, and P53 proteins. CONCLUSIONS It is feasible and safe to collect portal venous blood from

  16. Clinical impact of preoperative endoscopic ultrasound-guided fine-needle aspiration for pancreatic ductal adenocarcinoma

    PubMed Central

    Tsutsumi, Hideharu; Hara, Kazuo; Mizuno, Nobumasa; Hijioka, Susumu; Imaoka, Hiroshi; Tajika, Masahiro; Tanaka, Tsutomu; Ishihara, Makoto; Yoshimura, Kenichi; Shimizu, Yasuhiro; Niwa, Yasumasa; Sasaki, Yutaka; Yamao, Kenji

    2016-01-01

    Aim: To reveal the impact of preoperative endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) of pancreatic ductal adenocarcinoma (PDAC). Materials and Methods: We retrospectively reviewed 242 patients who underwent surgery for PDAC at our institution between January 1996 and July 2012. Among them, there were three patients with R2 resection and 30 patients with a follow-up period of less than 1 year, who were excluded because they did not meet the conditions for evaluating recurrence. Consequently, 209 patients were enrolled in the present study. The patients were divided into two groups: 126 patients who underwent preoperative EUS-FNA (FNA group) and 83 patients who did not (non-FNA group) undergo preoperative EUS-FNA. Results: There were no significant differences in baseline characteristics between FNA and non-FNA groups except mean age (66.6 ± 8.9 years vs. 63.5 ± 8.9 years, respectively, P = 0.02) and the administration rate of gemcitabine as adjuvant chemotherapy (42.9% vs. 18.1%, P < 0.01). Sampling adequacy of preoperative EUS-FNA was 99.2% (125/126) and sensitivity for diagnosis was 92.9% (117/126). The rate of complications related to EUS-FNA was 1.6% (2/126); two patients experienced reduction in hemoglobin (≥2.0 g/dL). These two patients did not have any apparent bleeding and could be managed conservatively. No severe complications were seen. We evaluated long-term outcomes of preoperative EUS-FNA, especially disease-free survival, needle-track seeding and recurrence. Kaplan-Meier analysis indicated no significant difference in disease-free survival between the two groups (P = 0.12). The site of recurrence was not significantly different between groups. Needle-track seeding was not observed in this study. Multivariate analysis of recurrence factors showed that preoperative EUS-FNA did not affect postoperative recurrence. Conclusion: Preoperative EUS-FNA for PDAC was shown to be a safe procedure with high diagnostic ability, and not a risk

  17. Role of endoscopic ultrasound-guided fine needle aspiration in the diagnosis of mass lesions

    PubMed Central

    Han, Chaoqun; Lin, Rong; Zhang, Qin; Liu, Jun; Ding, Zhen; Hou, Xiaohua

    2016-01-01

    Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is an accurate technique for sampling the pancreas and mediastinum; however, limited data are available for other mass lesions. The aim of this study was to explore the value of EUS-FNA in the differential diagnosis of all mass lesions. Data from patients who underwent EUS-FNA for the diagnosis of mass lesions, including pancreatic, mediastinal, celiac and retroperitoneal lesions were retrospectively analyzed. The accuracy was calculated by comparing the results of FNA with the results of pathological examination or follow-up surveillances in non-operated cases. A total of 150 cases were included. The location of the mass varied from the pancreas (n=62) to the mediastinum (n=29), gastrointestinal tract (n=36), celiac cavity and retroperitoneum (n=23). The sensitivity and Youdens index of EUS-FNA in the diagnosis of all lesions were 92.97% and 0.93 respectively. The accuracy of diagnosis of pancreatic, mediastinal, gastrointestinal, celiac and retroperitoneal lesions was 85.48, 89.66, 83.33 and 78.23%, respectively. Masses were categorized into parenchymal organs (n=66), luminal organs (n=36) and enlarged lymph nodes (n=33). Lesions in parenchymal organs were likely to be bigger than those in luminal organs (P=0.03) and enlarged lymph nodes (P=0.01). For solid and cystic masses, which constituted 63.3 and 14.7% of the total masses, no significant difference in diagnostic accuracy was observed (P=0.56); however, lesion sizes were significantly different between these two groups (P=0.04) and the majority of cystic masses were identified in women (P=0.03). Malignant lesions were more common in older (P=0.01) and male (P=0.03) patients. In conclusion, EUS-FNA is an effective tool in the diagnosis of unexplained mass lesions; it influences the management of patients by enabling the appropriate treatment to be identified. PMID:27446324

  18. Effectiveness of contrast-enhanced harmonic endoscopic ultrasound for the evaluation of solid pancreatic masses

    PubMed Central

    Park, Jin-Seok; Kim, Hyung Kil; Bang, Byoung Wook; Kim, Sang Gu; Jeong, Seok; Lee, Don Haeng

    2014-01-01

    AIM: To evaluate the usefulness of contrast-enhanced harmonic endoscopic ultrasound (CH-EUS) in differentiating between pancreatic adenocarcinomas and other pancreatic disease. METHODS: This retrospective cohort study evaluated 90 patients who were seen between November 2010 and May 2013. All these patients had solid pancreatic masses that had a hypoechoic appearance on EUS. All patients underwent CH-EUS to evaluate this diagnostic method’s usefulness. The mass lesions observed on CH-EUS were classified into three categories based on their echo intensity: hypoenhanced, isoenhanced, and hyperenhanced lesions. We adjusted the sensitivity and the specificity of each category for detecting malignancies. We also estimated the accuracy of CH-EUS by comparing it to a pathological diagnosis. RESULTS: Of the 90 patients, 62 had a pancreatic adenocarcinoma. Fifty-seven out of 62 pancreatic adenocarcinomas showed a hypoenhanced pattern on CH-EUS. The sensitivity was 92%, the specificity 68% and the accuracy approximately 82%. The area under the curve of the receiver operating characteristic analysis for CH-EUS was 0.799. There is a significant association between the hypoenhanced pattern on CH-EUS and pancreatic duct adenocarcinoma (χ2 = 35.264, P < 0.001). In pathological examinations, the number of specimens for EUS-fine needle aspiration (EUS-FNA) was considered insufficient for diagnosis in three patients, and in two patients, the results were reported to be negative for malignancy. Pancreatic masses in all five patients revealed a hypoenhanced pattern with CH-EUS. Three patients were diagnosed with pancreatic adenocarcinoma based on the pathology results of a biopsy, and the remaining two patients were clinically diagnosed with malignancy. CONCLUSION: CH-EUS is useful for distinguishing between pancreatic adenocarcinoma and other pancreatic disease. When a pancreatic mass shows a hypoenhanced pattern on CH-EUS but involves either insufficient samples or negative

  19. Endoscopic ultrasound guided radiofrequency ablation, for pancreatic cystic neoplasms and neuroendocrine tumors

    PubMed Central

    Pai, Madhava; Habib, Nagy; Senturk, Hakan; Lakhtakia, Sundeep; Reddy, Nageshwar; Cicinnati, Vito R; Kaba, Iyad; Beckebaum, Susanne; Drymousis, Panagiotis; Kahaleh, Michel; Brugge, William

    2015-01-01

    AIM: To outline the feasibility, safety, adverse events and early results of endoscopic ultrasound (EUS)-radiofrequency ablation (RFA) in pancreatic neoplasms using a novel probe. METHODS: This is a multi-center, pilot safety feasibility study. The intervention described was radiofrequency ablation (RF) which was applied with an innovative monopolar RF probe (1.2 mm Habib EUS-RFA catheter) placed through a 19 or 22 gauge fine needle aspiration (FNA) needle once FNA was performed in patients with a tumor in the head of the pancreas. The Habib™ EUS-RFA is a 1 Fr wire (0.33 mm, 0.013”) with a working length of 190 cm, which can be inserted through the biopsy channel of an echoendoscope. RF power is applied to the electrode at the end of the wire to coagulate tissue in the liver and pancreas. RESULTS: Eight patients [median age of 65 (range 27-82) years; 7 female and 1 male] were recruited in a prospective multicenter trial. Six had a pancreatic cystic neoplasm (four a mucinous cyst, one had intraductal papillary mucinous neoplasm and one a microcystic adenoma) and two had a neuroendocrine tumors (NET) in the head of pancreas. The mean size of the cystic neoplasm and NET were 36.5 mm (SD ± 17.9 mm) and 27.5 mm (SD ± 17.7 mm) respectively. The EUS-RFA was successfully completed in all cases. Among the 6 patients with a cystic neoplasm, post procedure imaging in 3-6 mo showed complete resolution of the cysts in 2 cases, whilst in three more there was a 48.4% reduction [mean pre RF 38.8 mm (SD ± 21.7 mm) vs mean post RF 20 mm (SD ± 17.1 mm)] in size. In regards to the NET patients, there was a change in vascularity and central necrosis after EUS-RFA. No major complications were observed within 48 h of the procedure. Two patients had mild abdominal pain that resolved within 3 d. CONCLUSION: EUS-RFA of pancreatic neoplasms with a novel monopolar RF probe was well tolerated in all cases. Our preliminary data suggest that the procedure is straightforward and safe. The

  20. Repeat endoscopic ultrasound fine needle aspiration after a first negative procedure is useful in pancreatic lesions

    PubMed Central

    Téllez-Ávila, Félix I.; Martínez-Lozano, Jorge Adolfo; Rosales-Salinas, Anamaría; Bernal-Méndez, Ambrosio Rafael; Guerrero-Velásquez, Camilo; Ramírez-Luna, Miguel Ángel; Valdovinos-Andraca, Francisco

    2016-01-01

    Background and Objectives: There is no consensus about the ideal method for diagnosis in patients who have already undergone endoscopic ultrasound fine needle aspiration (EUS-FNA), and the inconclusive material is often obtained. The aim was to evaluate the diagnostic yield of the second EUS-FNA of pancreatic lesions. Materials and Methods: A retrospective analysis of prospectively collected data of patients with EUS-FNA of pancreatic lesions is performed. All patients who underwent more than one EUS-FNA for the evaluation of suspected pancreatic cancer over a 7-year period were included in the analysis. Results: A total of 296 EUS-FNAs of the pancreas were performed in 257 patients. The diagnostic yield with the first EUS-FNA was 78.6% (202/257). Thirty-nine (13.3%) FNAs were repeated in 34 patients; 17 (50%) patients were women. The mean ± standard deviation (SD) age was 58.8 ± 16.1 years. The location of the lesions in the pancreatic gland, from which the second biopsies were taken, was head of the pancreas, n = 28 (82.4%), body of the pancreas, n = 3 (8.8%), and tail, n = 3 (8.8%). The mean ± SD of the size of the lesion was 36.3 ± 14.6 mm. The second EUS-FNA was more likely to be positive for diagnosis in patients with an “atypical“ histological result in the first EUS-FNA (odds ratio [OR]: 4.04; 95% confidence interval [CI]: 0.9–18.3), in contrast to patients with a first EUS-FNA reported as “normal” (OR: 0.21; 95% CI: 0.06–0.71). Overall, the diagnostic yield of the second EUS-FNA was 58.8% (20/34) with an increase to 86.3% overall (222/257). Conclusion: Repeat EUS-FNA in pancreatic lesions is necessary in patients with a negative first EUS-FNA because it improves the diagnostic yield. PMID:27503159

  1. Performance characteristic of endoscopic ultrasound-guided fine needle aspiration is unaffected by pancreatic mass size

    PubMed Central

    Ramesh, Jayapal; Kim, Hwasoon; Reddy, Kartika; Eltoum, Isam-Eldin A.

    2016-01-01

    Background and study aims: Despite a well-established tool for diagnosis of pancreatic masses, endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) studies have shown suboptimal diagnostic performance at divergent mass sizes. Since the impact of gold standard follow-up and presence of on-site evaluation on this observation is unknown, we aimed to study the performance characteristics of EUS-FNA under these strict conditions. Patients and methods: EUS-FNA results from pancreatic mass lesions performed between July 2000 and March 2013 were evaluated. All patients with histological follow-up were then stratified into four groups: Group A ( ≤ 10 mm), Group B (11 – 20 mm), Group C (21 – 40 mm), and Group D (> 40 mm). Sensitivity and diagnostic accuracy were calculated for each group and compared. Results: A total of 612 /3832 (16 %) patients with pancreatic masses who underwent EUS-FNA had histology confirmation. Of these, 81 were excluded due to unavailable lesion size, while the rest formed the study cohort. Mean age (SD) was 65.8 years (9.3) with 51.2 % female. The mean number of passes for the entire cohort was 2.9 (SD 1.9; range 1 – 12); patients in group D had a significantly higher number of passes for on-site diagnosis (P = 0.0124). There was no significant difference between the groups for sensitivity (P = 0.1134) or diagnostic accuracy (P = 0.2111). Proportional trend analysis revealed no significant correlation between size and sensitivity (P = 0.6192). The size of lesion measured by EUS was not associated with sensitivity or specificity after adjusting for age, sex, and pancreatic location. Conclusion: In the presence of rapid on-site cytopathology and when final histology is taken as the gold standard, pancreatic mass size does not affect the performance characteristics of EUS-FNA. PMID:27092323

  2. Endoscopic ultrasound (EUS)-guided transhepatic anterograde self-expandable metal stent (SEMS) placement across malignant biliary obstruction.

    PubMed

    Nguyen-Tang, T; Binmoeller, K F; Sanchez-Yague, A; Shah, J N

    2010-03-01

    Endoscopic retrograde cholangiopancreatography (ERCP) with placement of self-expandable metal stents (SEMS) for palliation of malignant obstruction may not be possible in patients with an inaccessible biliary orifice. Endoscopic ultrasound (EUS)-guided drainage methods may be useful in this setting. This study aimed to determine the outcomes of EUS-guided anterograde SEMS placement across malignant strictures in patients with an inaccessible biliary orifice. Over a 2-year period, procedural and outcomes data on all patients undergoing EUS-guided anterograde SEMS drainage after failed ERCP were prospectively entered into a database and reviewed. Five patients underwent EUS-guided anterograde SEMS. Indications included: advanced pancreatic cancer (n = 3), metastatic cancer (n = 1), and anastomotic stricture (n = 1). The biliary orifice could not be reached endoscopically due to duodenal stricture (n = 4) or inaccessible hepaticojejunostomy (n = 1). EUS-guided punctures were performed transgastrically into left intrahepatic ducts (n = 4) or transbulbar into the common bile duct (n = 1). Guide wires were passed and SEMS were successfully deployed across strictures in an anterograde fashion in all patients. Jaundice resolved and serum bilirubin levels decreased in all cases. No procedure-related complications were noted during a mean follow-up of 9.2 months. EUS-guided anterograde SEMS placement appears to be a safe and efficient technique for palliation of biliary obstruction in patients with an endoscopically inaccessible biliary orifice. The procedure can be performed at the time of failed standard ERCP, and provides an alternative drainage option to percutaneous or surgical decompression and to EUS-guided creation of bilioenteric fistulae. PMID:20119894

  3. Sonographic Elastography of the Thyroid Gland

    PubMed Central

    Menzilcioglu, Mehmet Sait; Duymus, Mahmut; Avcu, Serhat

    2016-01-01

    Summary Thyroid gland disorders include benign and malignant thyroid nodules and diffuse thyroid disorders. The incidence of malignant thyroid nodules is low and the prognosis is good. The diagnosis of thyroid cancer and diffuse parenchymal disorders is generally based on clinical manifestations and histopathological evaluation. Ultrasonography has its place in the diagnostics and follow-up of thyroid disorders. Ultrasonographic elastography is a new, developing method that shows increase in clinical practice. In this study, we aimed to review the data on thyroid ultrasound elastography. PMID:27103947

  4. Endoscopic ultrasound-guided fine-needle aspiration with on-site cytopathology versus core biopsy: a comparison of both techniques performed at the same endoscopic session

    PubMed Central

    Lin, Michael; Hair, Clark D.; Green, Linda K.; Vela, Stacie A.; Patel, Kalpesh K.; Qureshi, Waqar A.; Shaib, Yasser H.

    2014-01-01

    Background: Endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) with bedside cytopathology is the gold standard for assessment of pancreatic, subepithelial, and other lesions in close proximity to the gastrointestinal tract, but it is time-consuming, has certain diagnostic limitations, and bedside cytopathology is not widely available. Aims: The goal of this study is to compare the diagnostic yield of EUS-guided FNA with on-site cytopathology and EUS-guided core biopsy. Methods: Twenty-six patients with gastrointestinal mass lesions requiring biopsy at a tertiary medical center were included in this retrospective analysis of a prospective cohort. Two core biopsies were taken using a 22 gauge needle followed by FNA guided by a bedside cytopathologist at the same endoscopic session. The diagnostic yield and test characteristics of EUS core biopsy and EUS FNA with bedside cytopathology were examined. Results: The mean number of passes was 3.2 for FNA, and the mean procedure time was 39.4 minutes. The final diagnosis was malignant in 92.3 %. Sensitivity and specificity were 83 % and 100 %, respectively, for FNA, and 91.7 % and 100 %, respectively, for core biopsy. Diagnostic accuracy was 92.3 % for FNA and 84.6 % for core biopsy. The two approaches were in agreement in 88.4 % with a kappa statistic of 0.66 (95 % confidence interval 0.33 – 0.99). Conclusions: An approach using two passes with a core biopsy needle is comparable to the current gold standard of FNA with bedside cytopathology. The performance of two core biopsies is time-efficient and could represent a good alternative to FNA with bedside cytopathology. PMID:26135096

  5. Endoscopic ultrasound-guided puncture suture device versus metal clip for gastric defect closure after endoscopic full-thickness resection: A randomized, comparative, porcine study

    PubMed Central

    Sun, Beibei; Guo, Jintao; Ge, Nan; Sun, Siyu; Wang, Sheng; Liu, Xiang; Wang, Guoxin; Feng, Linlin

    2016-01-01

    Objective: The secure closure of the wall defect is a critical stage of endoscopic full-thickness resection (EFTR). The aim of this study was to compare the closure of post-EFTR defects using an endoscopic ultrasound-guided puncture suture device (PSD) with the metal clip (MC) technique in a randomized, comparative, porcine study. Methods: We performed a randomized comparative survival study that included 18 pigs. The circular EFTR defects with a diameter of approximately 20 mm were closed with either a PSD or MC. Serum levels of interleukin-6 (IL-6) were determined preoperatively and on a postoperative day (POD) 1, 3, and 7. Three animals from each group were sacrificed at the end of the 7th, 14th, and 30th POD. Tissue samples retrieved from the closure sites were examined macroscopically and microscopically. Results: Resection and closure were performed in 18 pigs (100%) without major perioperative complications. The mean closure time was significantly longer in the MC group than in the PSD group (25.00 ± 3.16 min vs. 1.56 ± 0.39 min; P < 0.05). Preoperative and POD 7 serum levels of IL-6 did not differ between the two groups. However, on POD 1, the IL-6 levels were observed to be significantly greater in the MC group than in the PSD group (P < 0.005). No significant differences between the PSD and MC groups were observed at necropsy. Conclusion: In this in vivo porcine model, PSD is a feasible device that achieves post-EFTR defect closure with a much shorter closure time and with less immunological responses than the MC technique. PMID:27503160

  6. Texture generation in compressional photoacoustic elastography

    NASA Astrophysics Data System (ADS)

    Schmid, J. W.; Zabihian, B.; Widlak, T.; Glatz, T.; Liu, M.; Drexler, W.; Scherzer, O.

    2015-03-01

    Elastography is implemented by applying a mechanical force to a specimen and visualizing the resulting displacement. As a basis of elastographic imaging typically ultrasound, optical coherence tomography or magnetic resonance imaging are used. Photoacoustics has not been viewed as a primary imaging modality for elastography, but only as a complementary method to enhance the contrast in ultrasound elastography. The reason is that photoacoustics is considered speckle free [3], which hinders application of speckle tracking algorithms. However, while conventional ultrasound only uses a single frequency, photoacoustics utilizes a broad frequency spectrum. We are therefore able to generate artificial texture by using a frequency band limited part of the recorded data. In this work we try to assess the applicability of this technique to photoacoustic tomography. We use Agar phantoms with predefined Young's moduli and laterally apply a 50μm static compression. Pre- and post compression data are recorded via a Fabry Pérot interferometer planar sensor setup and reconstructed via a non-uniform-FFT reconstruction algorithm. A displacement vector field, between pre- and post compressed data is then determined via optical flow algorithms. While the implementation of texture generation during post processing reduces image quality overall, it turns out that it improves the detection of moving patterns and is therefore better suited for elastography.

  7. A randomized controlled cross-over trial and cost analysis comparing endoscopic ultrasound fine needle aspiration and fine needle biopsy*

    PubMed Central

    Aadam, A. Aziz; Wani, Sachin; Amick, Ashley; Shah, Janak N.; Bhat, Yasser M.; Hamerski, Christopher M.; Klapman, Jason B.; Muthusamy, V. Raman; Watson, Rabindra R.; Rademaker, Alfred W.; Keswani, Rajesh N.; Keefer, Laurie; Das, Ananya; Komanduri, Srinadh

    2016-01-01

    Background and study aims: Techniques to optimize endoscopic ultrasound-guided tissue acquisition (EUS-TA) in a variety of lesion types have not yet been established. The primary aim of this study was to compare the diagnostic yield (DY) of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) to endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) for pancreatic and non-pancreatic masses. Patients and methods: Consecutive patients referred for EUS-TA underwent randomization to EUS-FNA or EUS-FNB at four tertiary-care medical centers. A maximum of three passes were allowed for the initial method of EUS-TA and patients were crossed over to the other arm based on on-site specimen adequacy. Results: A total of 140 patients were enrolled. The overall DY was significantly higher with specimens obtained by EUS-FNB compared to EUS-FNA (90.0 % vs. 67.1 %, P = 0.002). While there was no difference in the DY between the two groups for pancreatic masses (FNB: 91.7 % vs. FNA: 78.4 %, P = 0.19), the DY of EUS-FNB was higher than the EUS-FNA for non-pancreatic lesions (88.2 % vs. 54.5 %, P = 0.006). Specimen adequacy was higher for EUS-FNB compared to EUS-FNA for all lesions (P = 0.006). There was a significant rescue effect of crossover from failed FNA to FNB in 27 out of 28 cases (96.5 %, P = 0.0003). Decision analysis showed that the strategy of EUS-FNB was cost saving compared to EUS-FNA over a wide range of cost and outcome probabilities. Conclusions: Results of this RCT and decision analysis demonstrate superior DY and specimen adequacy for solid mass lesions sampled by EUS-FNB. PMID:27227104

  8. Breast Ultrasound: Indications and Findings.

    PubMed

    Gundry, Kathleen R

    2016-06-01

    Breast ultrasound is a widely used adjuvant to mammography for the detection of breast cancer. This chapter will review some of the basic ultrasound technical factors and techniques, describe findings on ultrasound with an emphasis on the Breast Imaging Reporting and Data System terminology, and present the indications for breast ultrasound. New innovations in breast ultrasound, such as elastography, ultrasound contrast, 3-dimensional, and automated whole-breast ultrasound, will be reviewed. Ultrasound-guided breast procedures are also presented. PMID:26974219

  9. Endoscopic Ultrasound-Guided Fine-Needle Aspiration of Pancreatic Lesions: A Systematic Review of Technical and Procedural Variables

    PubMed Central

    Jani, Bhairvi S.; Rzouq, Fadi; Saligram, Shreyas; Lim, Diego; Rastogi, Amit; Bonino, John; Olyaee, Mojtaba

    2016-01-01

    Endoscopic ultrasound (EUS)-guided tissue acquisition has emerged over the last decade as an invaluable diagnostic tool in approaching the different pancreatic lesions. Given the safety and minimal invasiveness of this approach combined with the high diagnostic yield, it became the standard of care when dealing with different pancreatic pathologies. However, some variables regarding this procedure remain not fully understood. These can influence the diagnostic yield of the procedure and include the presence of the on-site cytopathologist, the type and size of the needle used as well as obtaining aspiration versus core biopsy, the number of passes and the sampling technique, and the role of suction and stylet use among others. We performed a comprehensive literature search using PubMed, Google Scholar, and Embase for studies that assessed these variables. Eligible studies were analyzed using several parameters such as technique and procedure, with the aim of reviewing results from an evidence-based standpoint. PMID:27011940

  10. Integration of single-fiber reflectance spectroscopy into ultrasound-guided endoscopic lung cancer staging of mediastinal lymph nodes

    NASA Astrophysics Data System (ADS)

    Kanick, Stephen Chad; van der Leest, Cor; Aerts, Joachim G. J. V.; Hoogsteden, Henk C.; Kaščáková, Slávka; Sterenborg, Henricus J. C. M.; Amelink, Arjen

    2010-01-01

    We describe the incorporation of a single-fiber reflectance spectroscopy probe into the endoscopic ultrasound fine-needle aspiration (EUS-FNA) procedure utilized for lung cancer staging. A mathematical model is developed to extract information about the physiological and morphological properties of lymph tissue from single-fiber reflectance spectra, e.g., microvascular saturation, blood volume fraction, bilirubin concentration, average vessel diameter, and Mie slope. Model analysis of data from a clinical pilot study shows that the single-fiber reflectance measurement is capable of detecting differences in the physiology between normal and metastatic lymph nodes. Moreover, the clinical data show that probe manipulation within the lymph node can perturb the in vivo environment, a concern that must be carefully considered when developing a sampling strategy. The data show the feasibility of this novel technique; however, the potential clinical utility has yet to be determined.

  11. Pancreatic Hepatoid Carcinoma Mimicking a Solid Pseudopapillary Neoplasm: A Challenging Case on Endoscopic Ultrasound-guided Fine-needle Aspiration.

    PubMed

    Akimoto, Yutaka; Kato, Hironari; Matsumoto, Kazuyuki; Harada, Ryo; Oda, Shinsuke; Fushimi, Soichiro; Mizukawa, Shou; Yabe, Shuntaro; Uchida, Daisuke; Seki, Hiroyuki; Tomoda, Takeshi; Yamamoto, Naoki; Horiguchi, Shigeru; Tsutsumi, Koichiro; Yagi, Takahito; Okada, Hiroyuki

    2016-01-01

    A 59-year-old man was admitted to our hospital for treatment of a 45 mm pancreatic mass found during a medical examination. Endoscopic ultrasound-guided fine-needle aspiration cytology showed polygonal cells with pseudopapillary structures. The tumor cells were positive for nuclear/cytoplasmic β-catenin and CD10, and negative for chromogranin A. After a tentative diagnosis of a solid pseudopapillary neoplasm, middle pancreatectomy was performed. Histologically, polygonal cells with abundant eosinophilic cytoplasm formed in the trabeculae and were immunohistochemically positive for HepPar1 and protein induced by vitamin K absence or antagonist-II. The tumor was finally diagnosed to be pancreatic hepatoid carcinoma. No recurrence occurred for 12 months, even without adjuvant chemotherapy. PMID:27580541

  12. Endoscopic ultrasound-guided biliary drainage using a lumen-apposing self-expanding metal stent: a case series.

    PubMed

    Brückner, Stefan; Arlt, Alexander; Hampe, Jochen

    2015-09-01

    Endoscopic ultrasound-guided biliary drainage (EUS-BD) might be an alternative to percutaneous or transpapillary biliary drainage in unresectable pancreatic or biliary cancer. A lumen-apposing, fully covered, self-expanding metal stent, which creates a sealed transluminal conduit between the biliary and gastrointestinal tract may offer advantages over conventional plastic and metal stents. In this retrospective, observational, open-label case study, five patients underwent EUS-BD for obstructive jaundice in pancreatic cancer (n = 4) or distal cholangiocarcinoma (n = 1). Technical and functional success was achieved in all patients without complications. The development of specialized stent and delivery systems may render EUS-BD an effective and safe alternative to percutaneous or transpapillary approaches. PMID:26021309

  13. Cell-block procedure in endoscopic ultrasound-guided-fine-needle-aspiration of gastrointestinal solid neoplastic lesions

    PubMed Central

    Ieni, Antonio; Barresi, Valeria; Todaro, Paolo; Caruso, Rosario Alberto; Tuccari, Giovanni

    2015-01-01

    In the present review we have analyzed the clinical applications of endoscopic ultrasound-guided-fine-needle-aspiration (EUS-FNA) and the methodological aspects obtained by cell-block procedure (CBP) in the diagnostic approach to the gastrointestinal neoplastic pathology. CBP showed numerous advantages in comparison to the cytologic routine smears; in particular, better preservation of cell architecture, achievement of routine haematoxylin-eosin staining equivalent to histological slides and possibility to perform immunohistochemistry or molecular analyses represented the most evident reasons to choose this method. Moreover, by this approach, the differential diagnosis of solid gastrointestinal neoplasias may be more easily achieved and the background of contaminant non-neoplastic gastrointestinal avoided. Finally, biological samples collected by EUS-FNA CBP-assisted should be investigated in order to identify and quantify further potential molecular markers. PMID:26322154

  14. Peripancreatic Tuberculous Lymphadenitis with Biliary Obstruction Diagnosed by Endoscopic Ultrasound-guided Fine-needle Aspiration Biopsy.

    PubMed

    Yamada, Reiko; Inoue, Hiroyuki; Yoshizawa, Naohiko; Kitade, Takashi; Tano, Shunsuke; Sakuno, Takashi; Harada, Tetsuro; Nakamura, Misaki; Katsurahara, Masaki; Hamada, Yasuhiko; Tanaka, Kyosuke; Horiki, Noriyuki; Takei, Yoshiyuki

    2016-01-01

    A 57-year-old man with a history of tuberculosis (TB) was found to have a pancreatic head mass, accompanied by stenosis of the common bile duct. Due to the inherent difficulty in differentiating pancreatic carcinoma from an inflammatory mass, endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) was thus performed. The pathological findings confirmed granuloma with caseous necrosis, and the results of the QuantiFERON TB2G test were positive. Accordingly, the patient was diagnosed with peripancreatic TB and thereafter was successfully treated with anti-TB therapy. Based on the findings of this case, we conclude that EUS-FNAB is a useful modality for the diagnosis of pancreatic TB. PMID:27086805

  15. Endoscopic ultrasound-guided forceps biopsy from upper gastrointestinal subepithelial lesions using a forward-viewing echoendoscope

    PubMed Central

    Matsuzaki, Ippei; Miyahara, Ryoji; Hirooka, Yoshiki; Funasaka, Kohei; Yamamura, Takeshi; Ohno, Eizaburo; Nakamura, Masanao; Kawashima, Hiroki; Watanabe, Osamu; Kobayashi, Makoto; Shimoyama, Yoshie; Nakamura, Shigeo; Goto, Hidemi

    2016-01-01

    Background and study aims: Endoscopic tissue acquisition techniques using needle-knife and biopsy forceps allow abundant tissue acquisition from upper gastrointestinal subepithelial lesions; however, these techniques cannot capture real-time intratumor information. The aim of this study was to evaluate the feasibility of endoscopic ultrasound-guided forceps biopsy (EUS-FB) from upper gastrointestinal subepithelial lesions using a forward-viewing echoendoscope. Patients and methods: This study was a prospective case series. After mucosal cuts, several specimens were taken using a hot biopsy forceps under real-time EUS visualization. The incision was closed using hemoclips. Diagnostic yield, rate of diagnosable samples obtained under EUS visualization, procedure time, and adverse events were assessed. Results: Ten patients (median lesion size 16 mm, range 15 – 44 mm) underwent EUS-FB. The overall rate of histological diagnosis by EUS-FB was 100 % (10/10). The rate of diagnosable samples among all cases was 97.6 % (41/42). The median procedure times for EUS-FB and complete closure were 28.5 and 4.5 minutes, respectively. No adverse events occurred. Conclusions: This newly developed EUS-FB is feasible and allowed forceps biopsy from upper gastrointestinal subepithelial lesions. Study registration: UMIN000015364 PMID:27556070

  16. Advances in the Management of Upper Gastrointestinal Subepithelial Tumor: Pathologic Diagnosis Using Endoscopy without Endoscopic Ultrasound-Guided Biopsy

    PubMed Central

    Lee, Hang Lak

    2016-01-01

    Until now, biopsy methods for subepithelial tumors (SETs) have focused on endoscopic ultrasound (EUS)-guided biopsy; however, these methods have several limitations. We devised a simple method for pathologic diagnosis of SETs. SETs are occasionally diagnosed during endoscopy, and lesions are generally small and asymptomatic. It can be challenging to decide on a management plan for large asymptomatic SETs. EUS imaging provides information regarding the size, layer, and echo pattern of the lesions. Patient management plans have traditionally been determined based on EUS images, whereby the endoscopist chooses to either monitor or remove the tumor. However, EUS alone cannot diagnose and evaluate upper gastrointestinal SETs with high accuracy. As sufficient tissue samples are required for the accurate diagnosis of SETs, EUS-guided biopsy techniques such as EUS fine-needle aspiration and trucut biopsy are currently used. However, these methods have a relatively low diagnostic accuracy and do not always provide information upon immunohistochemical staining. Endoscopists can easily detect a submucosal mass after creating an iatrogenic mucosal ulcer, after which tissue sampling is performed by using endoscopic biopsy. Furthermore, pathologic results can differentiate between benign and premalignant lesions. Here, we introduce a simple method for the pathologic diagnosis of SETs. PMID:27246253

  17. What are the current and potential future roles for endoscopic ultrasound in the treatment of pancreatic cancer?

    PubMed Central

    Oh, Stephen Y; Irani, Shayan; Kozarek, Richard A

    2016-01-01

    Pancreatic adenocarcinoma is the fourth leading cause of cancer-related death in the United States. Due to the aggressive tumor biology and late manifestations of the disease, long-term survival is extremely uncommon and the current 5-year survival rate is 7%. Over the last two decades, endoscopic ultrasound (EUS) has evolved from a diagnostic modality to a minimally invasive therapeutic alternative to radiologic procedures and surgery for pancreatic diseases. EUS-guided celiac plexus intervention is a useful adjunct to conventional analgesia for patients with pancreatic cancer. EUS-guided biliary drainage has emerged as a viable option in patients who have failed endoscopic retrograde cholangiopancreatography. Recently, the use of lumen-apposing metal stent to create gastrojejunal anastomosis under EUS and fluoroscopic guidance in patients with malignant gastric outlet obstruction has been reported. On the other hand, anti-tumor therapies delivered by EUS, such as the injection of anti-tumor agents, brachytherapy and ablations are still in the experimental stage without clear survival benefit. In this article, we provide updates on well-established EUS-guided interventions as well as novel techniques relevant to pancreatic cancer. PMID:27076870

  18. What are the current and potential future roles for endoscopic ultrasound in the treatment of pancreatic cancer?

    PubMed

    Oh, Stephen Y; Irani, Shayan; Kozarek, Richard A

    2016-04-10

    Pancreatic adenocarcinoma is the fourth leading cause of cancer-related death in the United States. Due to the aggressive tumor biology and late manifestations of the disease, long-term survival is extremely uncommon and the current 5-year survival rate is 7%. Over the last two decades, endoscopic ultrasound (EUS) has evolved from a diagnostic modality to a minimally invasive therapeutic alternative to radiologic procedures and surgery for pancreatic diseases. EUS-guided celiac plexus intervention is a useful adjunct to conventional analgesia for patients with pancreatic cancer. EUS-guided biliary drainage has emerged as a viable option in patients who have failed endoscopic retrograde cholangiopancreatography. Recently, the use of lumen-apposing metal stent to create gastrojejunal anastomosis under EUS and fluoroscopic guidance in patients with malignant gastric outlet obstruction has been reported. On the other hand, anti-tumor therapies delivered by EUS, such as the injection of anti-tumor agents, brachytherapy and ablations are still in the experimental stage without clear survival benefit. In this article, we provide updates on well-established EUS-guided interventions as well as novel techniques relevant to pancreatic cancer. PMID:27076870

  19. Conversion of Percutaneous Cholecystostomy to Internal Transmural Gallbladder Drainage Using an Endoscopic Ultrasound-Guided, Lumen-Apposing Metal Stent.

    PubMed

    Law, Ryan; Grimm, Ian S; Stavas, Joseph M; Baron, Todd H

    2016-03-01

    Patients with acute cholecystitis sometimes require placement of percutaneous cholecystostomy catheters, either as a bridge to surgery or as primary therapy. In patients who cannot undergo surgery, subsequent removal of the catheter can lead to recurrence of cholecystitis, whereas leaving the drain in place can cause adverse events. We investigated internalization of percutaneous cholecystostomy drainage catheters, using endoscopic ultrasound (EUS)-guided placement of lumen-apposing metal stents (LAMS) as an alternative treatment strategy. Seven patients (median age, 57 years; 6 men) underwent EUS-guided cholecystoenterostomy for internalization of gallbladder drainage with EUS-guided placement of a 10- or 15-mm LAMS. All had initially been treated with placement of a percutaneous cholecystostomy catheter for cholecystitis and were later deemed unfit for cholecystectomy. Technical success was achieved in all patients in 1 endoscopic session, with subsequent removal of all percutaneous drains. Two patients required placement of self-expandable metal stents within the LAMS to successfully bridge the gallbladder and gastrointestinal lumen. No adverse events occurred after a median follow-up of 2.5 months. EUS-guided cholecystoenterostomy using a LAMS is therefore a viable option for internal gallbladder drainage in patients who have a percutaneous cholecystostomy catheter and are poor candidates for cholecystectomy. PMID:26528802

  20. Advances in the Management of Upper Gastrointestinal Subepithelial Tumor: Pathologic Diagnosis Using Endoscopy without Endoscopic Ultrasound-Guided Biopsy.

    PubMed

    Lee, Hang Lak

    2016-05-01

    Until now, biopsy methods for subepithelial tumors (SETs) have focused on endoscopic ultrasound (EUS)-guided biopsy; however, these methods have several limitations. We devised a simple method for pathologic diagnosis of SETs. SETs are occasionally diagnosed during endoscopy, and lesions are generally small and asymptomatic. It can be challenging to decide on a management plan for large asymptomatic SETs. EUS imaging provides information regarding the size, layer, and echo pattern of the lesions. Patient management plans have traditionally been determined based on EUS images, whereby the endoscopist chooses to either monitor or remove the tumor. However, EUS alone cannot diagnose and evaluate upper gastrointestinal SETs with high accuracy. As sufficient tissue samples are required for the accurate diagnosis of SETs, EUS-guided biopsy techniques such as EUS fine-needle aspiration and trucut biopsy are currently used. However, these methods have a relatively low diagnostic accuracy and do not always provide information upon immunohistochemical staining. Endoscopists can easily detect a submucosal mass after creating an iatrogenic mucosal ulcer, after which tissue sampling is performed by using endoscopic biopsy. Furthermore, pathologic results can differentiate between benign and premalignant lesions. Here, we introduce a simple method for the pathologic diagnosis of SETs. PMID:27246253

  1. Prospective international multicenter study on endoscopic ultrasound-guided biliary drainage for patients with malignant distal biliary obstruction after failed endoscopic retrograde cholangiopancreatography

    PubMed Central

    Khashab, Mouen A.; Van der Merwe, Schalk; Kunda, Rastislav; El Zein, Mohamad H.; Teoh, Anthony Y.; Marson, Fernando P.; Fabbri, Carlo; Tarantino, Ilaria; Varadarajulu, Shyam; Modayil, Rani J.; Stavropoulos, Stavros N.; Peñas, Irene; Ngamruengphong, Saowanee; Kumbhari, Vivek; Romagnuolo, Joseph; Shah, Raj; Kalloo, Anthony N.; Perez-Miranda, Manuel; Artifon, Everson L.

    2016-01-01

    Background and aims: Endoscopic ultrasound-guided biliary drainage (EUS-BD) has emerged as an alternative to traditional radiologic and surgical drainage procedures after failed endoscopic retrograde cholangiopancreatography (ERCP). However, prospective multicenter data are lacking. The aims of this study were to prospectively assess the short- and long-term efficacy and safety of EUS-BD in patients with malignant distal biliary obstruction. Patients and methods: Consecutive patients at 12 tertiary centers (5 US, 5 European, 1 Asian, 1 South American) with malignant distal biliary obstruction and failed ERCP underwent EUS-BD. Technical success was defined as successful stent placement in the desired position. Clinical success was defined as a reduction in bilirubin by 50 % at 2 weeks or to below 3 mg/dL at 4 weeks. Adverse events were prospectively tracked and graded according to the American Society for Gastrointestinal Endoscopy (ASGE) lexicon’s severity grading system. Overall survival and duration of stent patency were calculated using Kaplan–Meier analysis. Results: A total of 96 patients (mean age 66 years, female 45 %, pancreatic cancer 55 %) underwent EUS-BD. Stent placement (technical success) was achieved in 92 (95.8 %) patients (metallic stent 84, plastic stent 8). Mean procedure time was 40 minutes. Clinical success was achieved in 86 (89.5 %) patients. A total of 10 (10.5 %) adverse events occurred: pneumoperitoneum (n = 2), sheared wire (n = 1), bleeding (n = 1), bile leak (n = 3), cholangitis (n = 2), and unintentional perforation (n = 1); 4 graded as mild, 4 moderate, 1 severe, and 1 fatal (due to perforation). A total of 38 (44 %) patients died of disease progression during the study period. The median patient survival was 167 days (95 %CI 112 – 221) days. The 6-month stent patency rate was 95 % (95 %CI 94.94 – 95.06 %) and the 1-year stent patency was 86 % (95 %CI 85.74 – 86

  2. Enabling technologies for natural orifice transluminal endoscopic surgery (N.O.T.E.S) using robotically guided elasticity imaging

    NASA Astrophysics Data System (ADS)

    Sen, H. T.; Deshmukh, Nishikant; Goldman, Roger; Kazanzides, Peter; Taylor, Russell H.; Boctor, Emad; Simaan, Nabil

    2012-02-01

    Natural orifice transluminal endoscopic surgery (N.O.T.E.S) is a minimally invasive surgical technique that could benefit greatly from additional methods for intraoperative detection of tissue malignancies (using elastography) along with more precise control of surgical tools. Ultrasound elastography has proven itself as an invaluable imaging modality. However, elasticity images typically suffer from low contrast when imaging organs from the surface of the body. In addition, the palpation motions needed to generate elastography images useful for identifying clinically significant changes in tissue properties are difficult to produce because they require precise axial displacements along the imaging plane. Improvements in elasticity imaging necessitate an approach that simultaneously removes the need for imaging from the body surface while providing more precise palpation motions. As a first step toward performing N.O.T.E.S in-vivo, we integrated a phased ultrasonic micro-array with a flexible snake-like robot. The integrated system is used to create elastography images of a spherical isoechoic lesion (approximately 5mm in cross-section) in a tissue-mimicking phantom. Images are obtained by performing robotic palpation of the phantom at the location of the lesion.

  3. Role of endoscopic ultrasound-guided fine needle aspiration and ultrasound-guided fine-needle aspiration in diagnosis of cystic pancreatic lesions

    PubMed Central

    Okasha, Hussein Hassan; Ashry, Mahmoud; Imam, Hala M. K.; Ezzat, Reem; Naguib, Mohamed; Farag, Ali H.; Gemeie, Emad H.; Khattab, Hani M.

    2015-01-01

    Background and Objective: The addition of fine-needle aspiration (FNA) to different imaging modalities has raised the accuracy for diagnosis of cystic pancreatic lesions. We aim to differentiate benign from neoplastic pancreatic cysts by evaluating cyst fluid carcinoembryonic antigen (CEA), carbohydrate antigen (CA19-9), and amylase levels and cytopathological examination, including mucin stain. Patients and Methods: This prospective study included 77 patients with pancreatic cystic lesions. Ultrasound-FNA (US-FNA) or endoscopic ultrasound-FNA (EUS-FNA) was done according to the accessibility of the lesion. The aspirated specimens were subjected to cytopathological examination (including mucin staining), tumor markers (CEA, CA19-9), and amylase level. Results: Cyst CEA value of 279 or more showed high statistical significance in differentiating mucinous from nonmucinous lesions with sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of 73%, 60%, 50%, 80%, and 65%, respectively. Cyst amylase could differentiate between neoplastic and nonneoplastic cysts at a level of 1043 with sensitivity of 58%, specificity of 75%, PPV of 73%, NPV of 60%, and accuracy of 66%. CA19-9 could not differentiate between neoplastic and nonneoplastic cysts. Mucin examination showed a sensitivity of 85%, specificity of 95%, PPV of 92%, NPV of 91%, and accuracy of 91% in differentiating mucinous from non-mucinous lesions. Cytopathological examination showed a sensitivity of 81%, specificity of 94%, PPV of 94%, NPV of 83%, and accuracy of 88%. Conclusion: US or EUS-FNA with analysis of cyst CEA level, CA19-9, amylase, mucin stain, and cytopathological examination increases the diagnostic accuracy of cystic pancreatic lesions. PMID:26020048

  4. ANTHROPOMORPHIC BREAST PHANTOMS FOR TESTING ELASTOGRAPHY SYSTEMS

    PubMed Central

    Madsen, Ernest L.; Hobson, Maritza A.; Frank, Gary R.; Shi, Hairong; Jiang, Jingfeng; Hall, Timothy J.; Varghese, Tomy; Doyley, Marvin M.; Weaver, John B.

    2006-01-01

    Two equivalent anthropomorphic breast phantoms were constructed, one for use in ultrasound elastography and the other in magnetic resonance (MR) elastography. A complete description of the manufacturing methods is provided. The materials used were oil-in-gelatin dispersions, where the volume percent oil differentiates the materials, primarily according to Young’s moduli. Values of Young’s moduli are in agreement with in vitro ranges for the corresponding normal and abnormal breast tissues. Ultrasound and nuclear magnetic resonance (NMR) properties are reasonably well represented. Phantoms of the type described promise to aid researchers who are developing hardware and software for elastography. Examples of ultrasound and MR elastograms of the phantoms are included to demonstrate the utility of the phantoms. Also, the level of stability of elastic properties of the component materials is quantified over a 15-month period. Such phantoms can serve as performance-assessing intermediaries between simple phantoms (consisting, for example, of homogeneous cylindrical inclusions in a homogeneous background) and a full-scale clinical trial. Thus, premature clinical trials may be avoided. PMID:16785008

  5. Anthropomorphic breast phantoms for testing elastography systems.

    PubMed

    Madsen, Ernest L; Hobson, Maritza A; Frank, Gary R; Shi, Hairong; Jiang, Jingfeng; Hall, Timothy J; Varghese, Tomy; Doyley, Marvin M; Weaver, John B

    2006-06-01

    Two equivalent anthropomorphic breast phantoms were constructed, one for use in ultrasound elastography and the other in magnetic resonance (MR) elastography. A complete description of the manufacturing methods is provided. The materials used were oil-in-gelatin dispersions, where the volume percent oil differentiates the materials, primarily according to Young's moduli. Values of Young's moduli are in agreement with in vitro ranges for the corresponding normal and abnormal breast tissues. Ultrasound and nuclear magnetic resonance (NMR) properties are reasonably well represented. Phantoms of the type described promise to aid researchers who are developing hardware and software for elastography. Examples of ultrasound and MR elastograms of the phantoms are included to demonstrate the utility of the phantoms. Also, the level of stability of elastic properties of the component materials is quantified over a 15-month period. Such phantoms can serve as performance-assessing intermediaries between simple phantoms (consisting, for example, of homogeneous cylindrical inclusions in a homogeneous background) and a full-scale clinical trial. Thus, premature clinical trials may be avoided. PMID:16785008

  6. Efficacy and Safety of Endoscopic Ultrasound-guided Ethanol Ablation Therapy for Pancreatic Neuroendocrine Tumors.

    PubMed

    Matsumoto, Kazuyuki; Kato, Hironari; Tsutsumi, Koichiro; Mizukawa, Sho; Yabe, Syuntaro; Seki, Hiroyuki; Akimoto, Yutaka; Uchida, Daisuke; Tomoda, Takeshi; Yamamoto, Naoki; Horiguchi, Shigeru; Okada, Hiroyuki

    2016-08-01

    Recently, endoscopic ultrasonography (EUS)-guided ethanol ablation for small pancreatic neuroendocrine tumors (p-NETs) has been reported. However, the efficacy and safety of the technique remain unclear. We have launched a prospective pilot study of EUS-guided ethanol ablation for p-NETs. The major eligibility criteria are the presence of a pathologically diagnosed grade (G) 1 or G2 p-NET, a tumor size of 2cm, and being a poor candidate for surgery. A total of 5 patients will be treated. The primary endpoint will be the complete ablation rate at 1 month after treatment. PMID:27549680

  7. Endoscopic Ultrasound-Guided Fine Needle Aspiration versus Percutaneous Ultrasound-Guided Fine Needle Aspiration in Diagnosis of Focal Pancreatic Masses

    PubMed Central

    Okasha, Hussein Hassan; Naga, Mazen Ibrahim; Esmat, Serag; Naguib, Mohamed; Hassanein, Mohamed; Hassani, Mohamed; El-Kassas, Mohamed; Mahdy, Reem Ezzat; El-Gemeie, Emad; Farag, Ali Hassan; Foda, Ayman Mohamed

    2013-01-01

    Objective: Pancreatic carcinoma is one of the leading cancer morbidity and mortality world-wide. Controversy has arisen about whether the percutaneous approach with computed tomography/ultrasonography-guidance fine needle aspiration (US-FNA) or endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is the preferred method to obtain diagnostic tissue. Our purpose of this study is to compare between the diagnostic accuracy of EUS-FNA and percutaneous US-FNA in diagnosis of pancreatic cancer. Patients and Methods: A total of 197 patients with pancreatic masses were included in the study, 125 patients underwent US-FNA (Group 1) and 72 patients underwent EUS-FNA (Group 2). Results: EUS-FNA has nearly the same accuracy (88.9%) as US-FNA (87.2%) in diagnosis of pancreatic cancer. The sensitivity, specificity, positive predictive value and negative predictive value for EUS-FNA was 84%, 100%, 100%, 73.3% respectively. It was 85.5%, 90.4%, 94.7%, 76% respectively for US-FNA. EUS-FNA had a lower complication rate (1.38%) than US-FNA (5.6%). Conclusion: EUS-FNA has nearly the same accuracy as US-FNA of pancreatic masses with a lower complication rate. PMID:24949394

  8. Endoscopic ultrasound (EUS)-guided fiducial placement allows localization of small neuroendocrine tumors during parenchymal-sparing pancreatic surgery

    PubMed Central

    Law, Joanna K.; Singh, Vikesh K.; Khashab, Mouen A.; Hruban, Ralph H.; Canto, Marcia Irene; Shin, Eun Ji; Saxena, Payal; Weiss, Matthew J.; Pawlik, Timothy M.; Wolfgang, Christopher L.

    2014-01-01

    Background Parenchymal-sparing pancreatic surgery is ideal for lesions such as small pancreatic neuroendocrine tumors (PanNET). However, precise localization of these small tumors at surgery can be difficult. The placement of fiducials under endoscopic ultrasound (EUS) guidance (EUS-F) has been used to direct stereotactic radiation therapy for pancreatic adenocarcinoma. This report describes two cases in which placement of fiducials was used to guide surgical resection. This study aimed to assess the feasibility, safety, and efficacy of using EUS-F for intraoperative localization of small PanNETs. Methods A retrospective study analyzed two consecutive patients with small PanNETs who underwent EUS-F followed by enucleation in a tertiary-care referral hospital. The following features were examined: technical success and complication rates of EUS-F, visibility of the fiducial at the time of surgery, and fiducial migration. Results In the study, EUS-F was performed for two female patients with a 7-mm and a 9-mm PanNET respectively in the uncinate process and neck of the pancreas. In both patients, EUS-F was feasible with two Visicoil fiducials (Core Oncology, Santa Barbara, CA, USA) placed either within or adjacent to the tumors using a 22-gauge Cook Echotip needle. At surgery, the fiducials were clearly visible on intraoperative ultrasound, and both the tumor and the fiducials were successfully enucleated in both cases. No complications were associated with EUS-F, and no evidence of pancreatitis was shown either clinically or on surgical pathology. This investigation had the limitations of a small single-center study. Conclusions For patients undergoing enucleation, EUS-F is technically feasible and safe and aids intraoperative localization of small PanNETs. PMID:23636530

  9. Endoscopic ultrasound-guided fine-needle aspiration with an echobronchoscope in undiagnosed mediastinal lymphadenopathy: First experience from India

    PubMed Central

    Dhooria, Sahajal; Aggarwal, Ashutosh Nath; Singh, Navneet; Gupta, Dheeraj; Behera, Digamber; Gupta, Nalini; Agarwal, Ritesh

    2015-01-01

    Background and Aim: Several studies have reported the performance of combining endoscopic ultrasound fine-needle aspiration with an echobronchoscope (EUS-B-FNA), with endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), for the diagnosis of mediastinal lymphadenopathy. Herein we report our initial experience with this technique. Patients and Methods: In this retrospective study, we report the outcome of patients who underwent EUS-B-FNA with or without EBUS-TBNA during the same session. Details of the lymph nodes sampled, number of passes, duration of the procedure, results of the cytological examination, and the final diagnosis of all the patients are presented. Results: Eleven patients underwent EUS-B-FNA during the study period. EUS-B-FNA and EBUS-TBNA together yielded a sensitivity and specificity of 72.7 and 100%, respectively. The number of lymph nodes sampled per patient and the number of passes per lymph node were significantly higher with EBUS-TBNA compared to EUS-B-FNA. The mean duration of procedure was also significantly higher in the EBUS-TBNA group. The most common reason (five patients (45.5%)) for resorting to EUS-B-FNA was the patient being unfit for EBUS-TBNA or the inability of the operator to complete the procedure. Sarcoidosis was the most frequent final diagnosis in the study patients (four cases), followed by bronchogenic carcinoma (three cases). Conclusions: EUS-B-FNA is a useful additional tool for the diagnosis of mediastinal lymphadenopathy. In combination with EBUS-TBNA, it has a fairly good diagnostic yield and is a good alternative in situations where EBUS-TBNA is not feasible. PMID:25624588

  10. A Case of Gastrointestinal Stromal Tumor That Underwent Endoscopic Ultrasound-Guided Aspiration with a 25-Gauge Biopsy Needle

    PubMed Central

    Tomizawa, Minoru; Shinozaki, Fuminobu; Motoyoshi, Yasufumi; Sugiyama, Takao; Yamamoto, Shigenori; Ishige, Naoki

    2016-01-01

    Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is performed to obtain specimens for pathological analysis. For this procedure, 19-gauge (19G), 22-guage (22G), and 25-guage (25G) needles are available. The needles are classified into aspiration type and biopsy type. A 56-year-old woman underwent upper gastrointestinal endoscopy that showed a 38-mm-diameter submucosal tumor. The elevated lesion was diagnosed as a submucosal tumor of the stomach. Contrast-enhanced computed tomography showed a low-density area on the luminal surface of the gastric wall, which was covered with a thin layer of gastric mucosa. EUS showed a hypoechoic lesion in the submucosal layer. Color Doppler image showed a pulsating vascular signal extending into the center of the hypoechoic lesion from the periphery. EUS-FNA was performed with a 25G biopsy needle. The specimen tissue consisted of spindle-shaped cells. The cells were positive for CD117 and CD34. The submucosal tumor was diagnosed as a gastrointestinal stromal tumor.

  11. Recurrence of renal cell carcinoma diagnosed using contralateral adrenal biopsy with endoscopic ultrasound-guided fine-needle aspiration

    PubMed Central

    TANIMOTO, AZUSA; TAKEUCHI, SHINJI; YAEGASHI, HIROSHI; KOTANI, HIROSHI; KITAI, HIDENORI; NANJO, SHIGEKI; EBI, HIROMICHI; YAMASHITA, KANAME; MOURI, HISATSUGU; OHTSUBO, KOUSHIRO; IKEDA, HIROKO; YANO, SEIJI

    2016-01-01

    A 76-year-old female in whom a renal cell carcinoma (RCC) lesion was resected 19 years previously presented to our hospital with cognitive dysfunction. Magnetic resonance imaging and computed tomography revealed nodules in the brain, lung, adrenal gland and a pelvic osteolytic lesion. To identify the primary cancer site, the present study performed endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) of the left adrenal lesion. Consequently, the pathological findings of the tissue obtained by EUS-FNA were similar to those of the previous nephrectomy specimen, revealing that the adrenal lesion was the recurrence of RCC. The majority of the metastatic lesions in the patient were reduced in size by the multiple kinase inhibitor, pazopanib. Contralateral adrenal metastasis of RCC is rare and the use of EUS-FNA in the diagnosis of adrenal lesions remains to be elucidated. This is a rare case of adrenal lesion, diagnosed by EUS-FNA. Therefore, EUS-FNA is considered to be a useful diagnostic modality of adrenal metastases from unidentified primary tumor types. PMID:27073657

  12. Usefulness of strain elastography of the musculoskeletal system

    PubMed Central

    2016-01-01

    Ultrasound elastography is a widely used technique for assessing the mechanical characteristics of tissues. Although there are several ultrasound elastography techniques, strain elastography (SE) is currently the most widely used technique for visualizing an elastographic map in real time. Among its various indications, SE is especially useful in evaluating the musculoskeletal system. In this article, we review the SE techniques for clinical practice and describe the images produced by these techniques in the context of the musculoskeletal system. SE provides information about tissue stiffness and allows real-time visualization of the image; however, SE cannot completely replace gray-scale, color, or power Doppler ultrasonography. SE can increase diagnostic accuracy and may be useful for the follow-up of benign lesions. PMID:26810195

  13. Ultrasound

    MedlinePlus

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

  14. Ultrasound

    MedlinePlus Videos and Cool Tools

    Ultrasound is a useful procedure for monitoring the baby's development in the uterus. Ultrasound uses inaudible sound waves to ... no known risks for ultrasound at present, it is highly recommended that pregnant women consult their physician ...

  15. Endoscopic ultrasound-guided choledochoduodenostomy with a lumen-apposing, self-expandable fully covered metal stent for palliative biliary drainage.

    PubMed

    French, Joshua Blake; Coe, Adam Wesley; Pawa, Rishi

    2016-04-01

    In addition to the poor prognosis associated with pancreatic adenocarcinoma, it can also lead to several other conditions including obstructive jaundice that can affect a patient's quality of life. This is a major concern in non-operative patients where palliation is considered the main therapeutic goal. Traditionally, there are several ways to pursue palliative biliary drainage including endoscopic methods, a variety of surgical procedures, and percutaneous techniques. Generally, endoscopic methods such as endoscopic retrograde cholangiopancreatography (ERCP) with transpapillary stent placement are considered first-line therapies. Unfortunately, ERCP is not always possible due to several potential reasons. Although endoscopic ultrasound-guided biliary puncture has been well described for several years, there are limitations to its usefulness in biliary drainage, in part due to complication concerns. However, more recently a lumen-apposing, self-expandable fully covered metal stent has been employed for such situations. We describe two cases in which this type of stent was used in patients for palliative biliary drainage in pancreatic adenocarcinoma where standard ERCP was not feasible. In both cases, stent deployment was successful without immediate complications related to the procedure or the stent. Furthermore, the main goal of these therapies was palliation and in both cases the patient chose this procedure for quality of life reasons. In the future, randomized trials are needed to better define the long-term effectiveness and safety of these stents compared to more standard therapies. PMID:26956721

  16. The role of endoscopic ultrasound on the preoperative T staging of gastric cancer: A retrospective study.

    PubMed

    Han, Chaoqun; Lin, Rong; Shi, Huiying; Liu, Jun; Qian, Wei; Ding, Zhen; Hou, Xiaohua

    2016-09-01

    Endoscopic ultrasonography (EUS) is used for preoperative assessment of gastric cancer. However, recent studies suggested that EUS staging accuracy is lower than previously thought. We aimed to assess EUS efficacy and image characteristics in preoperative gastric cancer T staging.A retrospective review of clinical and imaging features of 232 gastric carcinoma patients who underwent preoperative EUS assessment of T stage was performed. Only cases with tumor-free resection margin status and no metastases were enrolled. Comparisons of preoperative EUS and postoperative histopathological stagings were also performed to identify vital EUS image features for evaluating gastric carcinoma.EUS accuracy for T staging was 64.2% (149/232) with the highest accuracy for T3 (75.0%). Enlarged lymph nodes, well differentiated histological type and Borrmann IV type were associated with diagnostic accuracy in predicting tumor invasion. Although no factors were associated with overstaging, circumferential lesions ≥1/2, signet ring cell adenocarcinoma, and Borrmann IV type had significantly higher risks of understaging. Gastric wall outer edge irregularity was also an indicator of serosal involvement with a sensitivity of 82.0%. The pancreas and colon were more frequent disease extension sites than previously predicted.Although EUS is likely the best and most accurate option that we have used to stage gastric cancer, the finding that factors including circumferential lesions, signet ring cell adenocarcinoma, and Borrmann IV type carcinoma were more frequently related to incorrect staging warrants attention. PMID:27603347

  17. The Diagnostic Accuracy of Linear Endoscopic Ultrasound for Evaluating Symptoms Suggestive of Common Bile Duct Stones.

    PubMed

    Wang, Min; He, Xu; Tian, Chuan; Li, Jian; Min, Feng; Li, Hong-Yan

    2016-01-01

    Background. In order to assess the diagnostic accuracy of linear EUS for evaluating clinically suggestive CBD stones in high-risk groups. Methods. 202 patients with clinically suggestive CBD stones in high-risk groups who underwent linear EUS examination between January 2012 and January 2015 were retrospectively reviewed. Endoscopic retrograde cholangiopancreatography (ERCP) with stone extraction or surgical choledochoscopy was only performed when a CBD stone was detected by linear EUS. Cases that were negative for CBD stones were followed up for at least 6 months. Results. Of 202 enrolled patients, 126 were positive for CBD stones according to linear EUS findings. 124 patients successfully underwent ERCP, and ERCP failed in 2 who were later successfully treated by surgical intervention. There were 2 false-positive cases with positive findings for CBD stones on ERCP. Among 76 patients without CBD stones, no false-negative cases were identified during the mean 6-month follow-up. Linear EUS had sensitivity, specificity, and positive and negative predictive values for the detection of CBD stones of 100%, 92.88%, 98.21%, and 100%, respectively. Conclusions. Linear EUS is a safe and efficacious diagnostic tool for evaluating clinically suggestive CBD stones with high risk of choledocholithiasis. Performing linear EUS prior to ERCP in patients with symptoms suggestive of CBD stones can reduce unnecessary ERCP procedures. PMID:27610131

  18. Photodynamic therapy (PDT) with endoscopic ultrasound for the treatment of esophageal cancer

    NASA Astrophysics Data System (ADS)

    Woodward, Timothy A.; Wolfsen, Herbert C.

    2000-05-01

    In 1995, PDT was approved for palliative use in patients with esophageal cancer. We report our experience using PDT to treat esophageal cancer patients previously treated with combination chemotherapy and radiation therapy. In our series, nine patients referred for PDT with persistent esophageal cancer after chemo-radiation therapy. We found: (1) All patients were men with a mean age of 63 years and eight out of nine had adenocarcinoma with Barrett's esophagus; (2) All patients required endoscopic dilation after PDT; (3) At a mean follow up of 4 months, two T2N0 patients had no demonstrable tumor and all three T3N0 patients had greater than 50% tumor reduction (the partially responsive T3N0 patients will be offered repeat PDT); (4) Patients with metastatic disease (T3N1 or M1) had effective dysphagia palliation. Thus, PDT is safe and effective in ablating all or most tumor in patients with persistent esophageal cancer after chemotherapy and radiation therapy.

  19. The Diagnostic Accuracy of Linear Endoscopic Ultrasound for Evaluating Symptoms Suggestive of Common Bile Duct Stones

    PubMed Central

    He, Xu; Li, Jian; Min, Feng; Li, Hong-yan

    2016-01-01

    Background. In order to assess the diagnostic accuracy of linear EUS for evaluating clinically suggestive CBD stones in high-risk groups. Methods. 202 patients with clinically suggestive CBD stones in high-risk groups who underwent linear EUS examination between January 2012 and January 2015 were retrospectively reviewed. Endoscopic retrograde cholangiopancreatography (ERCP) with stone extraction or surgical choledochoscopy was only performed when a CBD stone was detected by linear EUS. Cases that were negative for CBD stones were followed up for at least 6 months. Results. Of 202 enrolled patients, 126 were positive for CBD stones according to linear EUS findings. 124 patients successfully underwent ERCP, and ERCP failed in 2 who were later successfully treated by surgical intervention. There were 2 false-positive cases with positive findings for CBD stones on ERCP. Among 76 patients without CBD stones, no false-negative cases were identified during the mean 6-month follow-up. Linear EUS had sensitivity, specificity, and positive and negative predictive values for the detection of CBD stones of 100%, 92.88%, 98.21%, and 100%, respectively. Conclusions. Linear EUS is a safe and efficacious diagnostic tool for evaluating clinically suggestive CBD stones with high risk of choledocholithiasis. Performing linear EUS prior to ERCP in patients with symptoms suggestive of CBD stones can reduce unnecessary ERCP procedures. PMID:27610131

  20. Endoscopic Ultrasound (EUS)-Guided Pancreatic Duct Drainage: The Basics of When and How to Perform EUS-Guided Pancreatic Duct Interventions

    PubMed Central

    Chapman, Christopher G.; Waxman, Irving; Siddiqui, Uzma D.

    2016-01-01

    Despite the advances in endoscopy, endoscopic ultrasound-guided pancreatic duct drainage (EUS-PDD) remains a technically challenging procedure. Technical success rates are greater than 70%; however, the average rate of adverse events is nearly 20%, which increases to 55% when stent migration is included. Until recently, a significant difficulty with this technique was the absence of dedicated devices. Proper patient selection is of utmost importance, and EUS-PDD should be reserved for patients who have failed endoscopic retrograde pancreatography. Furthermore, EUS-PDD must be performed by experienced endoscopists who are familiar with the technique. The most common indications include chronic pancreatitis induced strictures and stones, disconnected pancreatic ducts, inaccessible ampulla, and post-surgical altered anatomy. This manuscript will review the accessories used, techniques employed, and published literature reporting outcomes as well as adverse events regarding EUS-PDD. PMID:27012290

  1. Endoscopic Ultrasound (EUS)-Guided Pancreatic Duct Drainage: The Basics of When and How to Perform EUS-Guided Pancreatic Duct Interventions.

    PubMed

    Chapman, Christopher G; Waxman, Irving; Siddiqui, Uzma D

    2016-03-01

    Despite the advances in endoscopy, endoscopic ultrasound-guided pancreatic duct drainage (EUS-PDD) remains a technically challenging procedure. Technical success rates are greater than 70%; however, the average rate of adverse events is nearly 20%, which increases to 55% when stent migration is included. Until recently, a significant difficulty with this technique was the absence of dedicated devices. Proper patient selection is of utmost importance, and EUS-PDD should be reserved for patients who have failed endoscopic retrograde pancreatography. Furthermore, EUS-PDD must be performed by experienced endoscopists who are familiar with the technique. The most common indications include chronic pancreatitis induced strictures and stones, disconnected pancreatic ducts, inaccessible ampulla, and post-surgical altered anatomy. This manuscript will review the accessories used, techniques employed, and published literature reporting outcomes as well as adverse events regarding EUS-PDD. PMID:27012290

  2. Endoscopic ultrasound-fine needle aspiration: A novel way to diagnose a solitary extramedullary plasmacytoma of the liver.

    PubMed

    Husney, Jack; Guttmann, Steven; Anyadike, Nnaemeka; Mayer, Ira; Rahmani, Rabin

    2016-01-01

    Plasmacytoma is a neoplastic production of a single line of plasma cells, usually forming monoclonal immunoglobulin. It most often occurs in the bone marrow; however, in 3% of the cases, solitary extramedullary plasmacytoma arises, which is a proliferation in the soft tissue, outside the bone marrow. In only 10% of the cases is the gastrointestinal tract involved. A 77-year-old female presented with lethargy, abdominal fullness, bilious vomiting, and clay-colored stools. The patient was anemic with initial laboratory results showing increased total and direct bilirubin with elevated transaminases. Despite conservative management, liver function tests (LFTs) continued to increase. On endoscopic ultrasound (EUS), there was mild diffuse mucosal thickening consistent with possible infiltrative disease of the gastric body without any obvious focal lesions. There was a 1.7 cm × 1.8 cm hypoechoic heterogeneous lesion noted in the porta hepatis and fine needle aspiration (FNA) was performed. Cytology showed infiltrative plasma cells. The patient was then taken for computed tomography (CT)-guided biopsy of the liver. Pathology showed liver involvement by atypical plasma cells in a nodular and sinusoidal pattern. Immunohistochemical staining appropriately identified the solitary extramedullary plasmacytoma. Plasma cell neoplasm is essentially a clonal disease of differentiated B-cells that can encompass a broad spectrum and present as asymptomatic monoclonal gammopathy of undetermined significance to plasma cell neoplasms or multiple myeloma. Five percent of patients with multiple myelomas are diagnosed with extramedullary plasmacytomas, and even less than that are diagnosed as a primary lesion. When the liver is affected, either as a direct diffuse neoplastic plasma cell infiltration, or as a single or multiple space occupying lesion as plasmacytomas, symptomatic features include extrahepatic biliary obstruction, jaundice, or ascites. In our case, the patient was diagnosed

  3. Endoscopic ultrasound-guided fiducial marker placement for image-guided radiation therapy without fluoroscopy: safety and technical feasibility

    PubMed Central

    Dhadham, Gautamy Chitiki; Hoffe, Sarah; Harris, Cynthia L.; Klapman, Jason B.

    2016-01-01

    Background and study aims: Endoscopic ultrasound (EUS)-guided fiducial marker placement for image-guided radiation treatment (IGRT) is becoming more widespread. Most case series report the procedure performed using fluoroscopy for spatial geometry although the benefits of this are unclear. The aim of our study is to report the technical feasibility, safety, and migration rate of fiducial marker placement in a large cohort of patients with gastrointestinal malignancies who underwent EUS-guided fiducial marker placement for IGRT without fluoroscopy. Patients and methods: A retrospective chart review was performed on all patients referred for EUS-guided fiducial marker placement from 08/1/07 to 7/31/14 at Moffitt Cancer Center. Results: During the study period, 514 patients underwent placement of 1093 gold fiducial markers under EUS-guidance. Two hundred and forty patients with esophageal/gastro-esophageal junction cancer had 405 fiducials placed. In 188 patients with pancreatic ancer, 510 fiducials were placed. In 54 patients with rectal cancer, 103 fiducials were placed and 32 patients had 75 fiducials placed into other gastrointestinal tract lesions. Minor bleeding, which resolved spontaneously, occurred in two patients. Technical difficulty in placing fiducials was noted in 18 patients. Intraprocedural fiducial migration was noted in two patients and only 2/1093 fiducials (.002%) in two esophageal patients migrated as noted on simulation computed tomography scan. Conclusions: EUS-guided fiducial marker placement without fluoroscopy is technically feasible and safe. There were minimal intraprocedure/post-procedure complications. Imaging at the time of simulation also revealed the migration rate to be extremely low. These results may allow for more widespread adoption of EUS-guided fiducial marker placement. PMID:27004258

  4. Secondary tumors of the pancreas diagnosed by endoscopic ultrasound-guided fine-needle aspiration: a 10-year experience.

    PubMed

    Waters, Lindsay; Si, Quisheng; Caraway, Nancy; Mody, Dina; Staerkel, Gregg; Sneige, Nour

    2014-09-01

    Determining whether a pancreatic mass is a primary or secondary neoplasm is necessary for appropriate treatment. We reviewed our experience using endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for diagnosis of pancreatic tumors to identify clinical and cytopathologic characteristics of metastatic disease. We reviewed all cases of tumors metastatic to the pancreas evaluated at The University of Texas MD Anderson Cancer Center and The Methodist Hospital in Houston, Texas during the period from 2002 to 2012. The review included cytologic specimens, clinical history, radiologic findings, primary tumor type, and clinical follow-up. We identified 66 patients with disease metastatic to the pancreas for which cytologic material was available: 38 (58%) men and 28 (42%) women, with an average age of 63 years (range, 40-89 years). Most metastases (98%) were single lesions, and nearly half were located in the head of the pancreas (30/66). The most common site of origin for these metastases was kidney (27 [41%] cases). Follow-up information was available for 65 (98%) patients, and duration of follow-up ranged from <1 to 10 years (mean, 2.3 years). Thirty-three patients (50%) were alive at the time of the most recent follow-up contact. Of the 25 patients with metastatic renal cell carcinoma, clear cell type, 19 (76%) were alive at the time of the most recent follow-up. It was concluded that metastases may mimic primary pancreatic carcinomas both clinically and cytologically. Ancillary studies in conjunction with clinical history are necessary for the accurate diagnosis of FNAs of secondary pancreatic tumors. PMID:24554612

  5. Endoscopic ultrasound-fine needle aspiration: A novel way to diagnose a solitary extramedullary plasmacytoma of the liver

    PubMed Central

    Husney, Jack; Guttmann, Steven; Anyadike, Nnaemeka; Mayer, Ira; Rahmani, Rabin

    2016-01-01

    Plasmacytoma is a neoplastic production of a single line of plasma cells, usually forming monoclonal immunoglobulin. It most often occurs in the bone marrow; however, in 3% of the cases, solitary extramedullary plasmacytoma arises, which is a proliferation in the soft tissue, outside the bone marrow. In only 10% of the cases is the gastrointestinal tract involved. A 77-year-old female presented with lethargy, abdominal fullness, bilious vomiting, and clay-colored stools. The patient was anemic with initial laboratory results showing increased total and direct bilirubin with elevated transaminases. Despite conservative management, liver function tests (LFTs) continued to increase. On endoscopic ultrasound (EUS), there was mild diffuse mucosal thickening consistent with possible infiltrative disease of the gastric body without any obvious focal lesions. There was a 1.7 cm × 1.8 cm hypoechoic heterogeneous lesion noted in the porta hepatis and fine needle aspiration (FNA) was performed. Cytology showed infiltrative plasma cells. The patient was then taken for computed tomography (CT)-guided biopsy of the liver. Pathology showed liver involvement by atypical plasma cells in a nodular and sinusoidal pattern. Immunohistochemical staining appropriately identified the solitary extramedullary plasmacytoma. Plasma cell neoplasm is essentially a clonal disease of differentiated B-cells that can encompass a broad spectrum and present as asymptomatic monoclonal gammopathy of undetermined significance to plasma cell neoplasms or multiple myeloma. Five percent of patients with multiple myelomas are diagnosed with extramedullary plasmacytomas, and even less than that are diagnosed as a primary lesion. When the liver is affected, either as a direct diffuse neoplastic plasma cell infiltration, or as a single or multiple space occupying lesion as plasmacytomas, symptomatic features include extrahepatic biliary obstruction, jaundice, or ascites. In our case, the patient was diagnosed

  6. Pathologic evaluation of a new endoscopic ultrasound needle designed to obtain core tissue samples: A pilot study

    PubMed Central

    Adler, Douglas G.; Witt, Benjamin; Chadwick, Barbara; Wells, Jason; Taylor, Linda Jo; Dimaio, Christopher; Schmidt, Robert

    2016-01-01

    Background and Objectives: Standard endoscopic ultrasound-fine-needle aspiration (EUS-FNA) needles are in widespread use. Meaningful differences between the available needles have been difficult to identify. Recently, a new EUS needle (Shark Core®, Covidien, Dublin, Leinster, Ireland), has been introduced in an attempt to improve diagnostic accuracy, tissue yield, and to potentially obtain a core tissue sample. We performed a pilot study prospectively to evaluate this new needle when compared to a standard EUS-FNA needle. Materials and Methods: Analysis of the first 15 patients undergoing EUS-FNA with the Shark Core needle was performed and it was compared to EUS-FNA in 15 patients who underwent EUS-FNA with a standard needle. Results: The Shark Core needle required fewer needle passes to obtain diagnostic adequacy than the standard needle [(χ2(1) = 11.3, P < 0.001]. The Shark Core needle required 1.5 passes to reach adequacy, whereas the standard needle required three passes. For cases with cell blocks, the Shark Core needle produced diagnostic material in 85% of cases [95% confidence interval (CI): 54–98], whereas the standard needle produced diagnostic material in 38% of the cases (95% CI: 9-76). The Shark Core needle produced actual tissue cores 82% of the time (95% CI: 48–98) and the standard needle produced no tissue cores (95% CI: 0-71) (P = 0.03). Conclusion: This pilot study found that the Shark Core needle had a high rate of producing adequate cytologic material for the diagnosis of pancreatic and peri-pancreatic lesions sampled by EUS with fewer passes required to obtain a definitive diagnosis and with a high rate of tissue cores being obtained when compared to a standard FNA needle.

  7. The emerging role of endoscopic ultrasound-guided core biopsy for the evaluation of solid pancreatic masses.

    PubMed

    Bhutani, M; Koduru, P; Lanke, G; Bruno, M; Maitra, A; Giovannini, M

    2015-06-01

    Pancreatic ductal adenocarcinoma is a lethal cancer with a 5-year survival rate of less than 5%. Surgical resection is the only curative treatment but only 20% are eligible for resection at the time of diagnosis. Early detection of cancer is of paramount importance in the management. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is the preferred modality for obtaining tissue diagnosis of pancreatic masses. However, the diagnostic accuracy of EUS-FNA may be limited by several factors like availability of onsite cytopathology, adequacy of tissue core for histology, location of the mass, presence of underlying chronic pancreatitis, and experience of the endoscopist. Modern oncology is focusing on personalizing treatment based on tissue analysis of genetic aberrations and molecular biomarkers which are now available. Core tissue also aids in the diagnosis of disease entities like lymphoma, metastatic tumors, neuroendocrine tumors and autoimmune pancreatitis whose diagnosis rely on preserved tissue architecture and immunohistochemistry. Making accurate diagnosis of solid pancreatic masses is critical to avoid unnecessary resections in patients with benign lesions like focal lesions of chronic pancreatitis and autoimmune pancreatitis which mimic cancer. To overcome the limitations of FNA and to obtain adequate core tissue, a Tru-Cut biopsy needle was developed which met with variable success due to stiffness, cumbersome operation and technical failure using it in the duodenum/pancreatic head. More recently fine needle biopsy needles, with reverse bevel technology have become available in different sizes (19, 22, 25-gauge). The aim of this article was to review the emerging role of core biopsy needles in acquiring tissue in solid pancreatic masses and discuss its potential role in personalized medicine. PMID:25675155

  8. Endoscopic ultrasound-guided fine-needle aspiration diagnosis of secondary tumors involving the pancreas: An institution's experience

    PubMed Central

    Alomari, Almed K.; Ustun, Berrin; Aslanian, Harry R.; Ge, Xinquan; Chhieng, David; Cai, Guoping

    2016-01-01

    Background: Pancreatic masses may seldom represent a metastasis or secondary involvement by lymphoproliferative disorders. Recognition of this uncommon occurrence may help render an accurate diagnosis and avoid diagnostic pitfalls during endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). In this study, we review our experience in diagnosing secondary tumors involving the pancreas. Materials and Methods: The electronic database of cytopathology archives was searched for cases of secondary tumors involving the pancreas at our institution and a total of 31 cases were identified. The corresponding clinical presentations, imaging study findings, cytological diagnoses, the results of ancillary studies, and surgical follow-up, if available, were reviewed. Results: Nineteen of the patients were male and 12 female, with a mean age of 66 years. Twenty-three patients (74%) had a prior history of malignancy, with the latency ranging from 6 months to 19 years. The secondary tumors involving the pancreas included metastatic carcinoma (24 cases), metastatic sarcoma (3 cases), diffuse large B-cell lymphoma (2 cases), and plasma cell neoplasm (2 cases). The most common metastatic tumors were renal cell carcinoma (8 cases) and lung carcinoma (7 cases). Correct diagnoses were rendered in 29 cases (94%). The remaining two cases were misclassified as primary pancreatic carcinoma. In both cases, the patients had no known history of malignancy, and no ancillary studies were performed. Conclusions: Secondary tumors involving the pancreas can be accurately diagnosed by EUS-FNA. Recognizing uncommon cytomorphologic features, knowing prior history of malignancy, and performing ancillary studies are the keys to improve diagnostic performance and avoid diagnostic pitfalls. PMID:26955395

  9. Ultrasound

    MedlinePlus

    Ultrasound uses high-frequency sound waves to make images of organs and structures inside the body. ... An ultrasound machine makes images so that organs inside the body can be examined. The machine sends out high- ...

  10. Sonographic Elastography of Mastitis.

    PubMed

    Sousaris, Nicholas; Barr, Richard G

    2016-08-01

    Sonographic elastography has been shown to be a useful imaging modality in characterizing breast lesions as benign or malignant. However, in preliminary research, mastitis has given false-positive findings on both strain and shear wave elastography. In this article, we review the findings in mastitis with and without abscess formation on both strain and shear wave elastography. The elastographic findings in all cases were suggestive of a malignancy according to published thresholds. In cases of mastitis with abscess formation, there is a characteristic appearance, with a central very soft area (abscess cavity) and a very stiff outer rim (edema and inflammation). This appearance should raise the suspicion of mastitis with abscess formation, since these findings are rare in breast cancers. PMID:27353071

  11. Interobserver agreement among cytopathologists in the evaluation of pancreatic endoscopic ultrasound-guided fine needle aspiration cytology specimens*

    PubMed Central

    Mounzer, Rawad; Yen, Roy; Marshall, Carrie; Sams, Sharon; Mehrotra, Sanjana; Said, Mohamed Sherif; Obuch, Joshua C.; Brauer, Brian; Attwell, Augustin; Fukami, Norio; Shah, Raj; Amateau, Stuart; Hall, Matthew; Hosford, Lindsay; Wilson, Robert; Rastogi, Amit; Wani, Sachin

    2016-01-01

    Background and aims: Endoscopic ultrasound with fine needle aspiration (EUS-FNA) has become the standard of care in the evaluation of solid pancreatic lesions. Limited data exist on interobserver agreement (IOA) among cytopathologists in assessing solid pancreatic EUS-FNA specimens. This study aimed to evaluate IOA among cytopathologists in assessing EUS-FNA cytology specimens of solid pancreatic lesions using a novel standardized scoring system and to assess individual clinical and cytologic predictors of IOA. Methods: Consecutive patients who underwent EUS-FNA of solid pancreatic lesions at a tertiary care referral center were included. EUS-FNA slides were evaluated by four blinded cytopathologists using a standardized scoring system that assessed final cytologic diagnosis and quantitative (number of nucleated/diagnostic cells) and qualitative (bloodiness, inflammation/necrosis, contamination, artifact) cytologic parameters. Final clinical diagnosis was based on final cytology, surgical pathology, or 1-year clinical follow-up. IOA was calculated using multi-rater kappa (κ) statistics. Bivariate analyses were performed comparing cases with and without uniform agreement among the cytopathologists followed by logistic regression with backward elimination to model likelihood of uniform agreement. Results: Ninety-nine patients were included (49 % males, mean age 64 years, mean lesion size 26 mm). IOA for final diagnosis was moderate (κ = 0.45, 95 % confidence interval (CI) 0.4 – 0.49) with minimal improvement when combining suspicious and malignant diagnoses (κ = 0.54, 95 %CI 0.49 – 0.6). The weighted kappa value for overall diagnosis was 0.65 (95 %CI 0.54 – 0.76). IOA was slight to fair (κ = 0.04 – 0.32) for individual cytologic parameters. A final clinical diagnosis of malignancy was the most significant predictor of agreement [OR 3.99 (CI 1.52 – 10.49)]. Conclusions: Interobserver agreement among

  12. Predictors of pain response in patients undergoing endoscopic ultrasound-guided neurolysis for abdominal pain caused by pancreatic cancer

    PubMed Central

    Minaga, Kosuke; Kitano, Masayuki; Sakamoto, Hiroki; Miyata, Takeshi; Imai, Hajime; Yamao, Kentaro; Kamata, Ken; Omoto, Shunsuke; Kadosaka, Kumpei; Sakurai, Toshiharu; Nishida, Naoshi; Chiba, Yasutaka; Kudo, Masatoshi

    2016-01-01

    Background: Interventional endoscopic ultrasound (EUS)-guided procedures such as EUS-guided celiac ganglia neurolysis (EUS-CGN) and EUS-guided broad plexus neurolysis (EUS-BPN) were developed to treat abdominal cancer-associated pain; however, these procedures are not always effective. The aim of this study was to explore predictors of pain response in EUS-guided neurolysis for pancreatic cancer-associated pain. Methods: This was a retrospective analysis of prospectively collected data of 112 consecutive patients who underwent EUS-BPN in our institution. EUS-CGN was added in cases of visible celiac ganglia. The neurolytic-spread area was divided into six sections and evaluated by post-procedural computed tomography scanning. Pain intensity was assessed using a visual analog scale (VAS), and a decrease in VAS scores by ⩾3 points after neurolysis was considered a good pain response. Univariable and multivariable logistic regression analyses were performed to explore predictors of pain response at 1 and 4 weeks, and complications. Results: A good pain response was obtained in 77.7% and 67.9% of patients at 1 and 4 weeks, respectively. In the multivariable analysis of these patients, the combination method (EUS-BPN plus CGN) was a significant positive predictive factor at 1 week (odds ratio = 3.69, p = 0.017) and 4 weeks (odds ratio = 6.37, p = 0.043). The numbers of neurolytic/contrast spread areas (mean ± SD) were 4.98 ± 1.08 and 4.15 ± 1.12 in patients treated with the combination method and single method, respectively (p < 0.001). There was no significant predictor of complications. Conclusions: EUS-BPN in combination with EUS-CGN was a predictor of a good pain response in EUS-guided neurolysis for pancreatic cancer-related pain. The larger number of neurolytic/contrast spread areas may lead to better outcomes in patients receiving combination treatment. PMID:27366217

  13. Copolymer-in-oil phantom materials for elastography.

    PubMed

    Oudry, J; Bastard, C; Miette, V; Willinger, R; Sandrin, L

    2009-07-01

    Phantoms that mimic mechanical and acoustic properties of soft biological tissues are essential to elasticity imaging investigation and to elastography device characterization. Several materials including agar/gelatin, polyvinyl alcohol and polyacrylamide gels have been used successfully in the past to produce tissue phantoms, as reported in the literature. However, it is difficult to find a phantom material with a wide range of stiffness, good stability over time and high resistance to rupture. We aim at developing and testing a new copolymer-in-oil phantom material for elastography. The phantom is composed of a mixture of copolymer, mineral oil and additives for acoustic scattering. The mechanical properties of phantoms were evaluated with a mechanical test instrument and an ultrasound-based elastography technique. The acoustic properties were investigated using a through-transmission water-substituting method. We showed that copolymer-in-oil phantoms are stable over time. Their mechanical and acoustic properties mimic those of most soft tissues: the Young's modulus ranges from 2.2-150 kPa, the attenuation coefficient from 0.4-4.0 dB.cm(-1) and the ultrasound speed from 1420-1464 m/s. Their density is equal to 0.90 +/- 0.04 g/cm3. The results suggest that copolymer-in-oil phantoms are attractive materials for elastography. PMID:19427100

  14. Crawling wave optical coherence elastography.

    PubMed

    Meemon, Panomsak; Yao, Jianing; Chu, Ying-Ju; Zvietcovich, Fernando; Parker, Kevin J; Rolland, Jannick P

    2016-03-01

    Elastography is a technique that measures and maps the local elastic property of biological tissues. Aiming for detection of micron-scale inclusions, various optical elastography, especially optical coherence elastography (OCE), techniques have been investigated over the past decade. The challenges of current optical elastography methods include the decrease in elastographic resolution as compared with its parent imaging resolution, the detection sensitivity and accuracy, and the cost of the overall system. Here we report for the first time, we believe, on an elastography technique-crawling wave optical coherence elastography (CRW-OCE)-which significantly lowers the requirements on the imaging speed and opens the path to high-resolution and high-sensitivity OCE at relatively low cost. Methods of crawling wave excitation, data acquisition, and crawling wave tracking are presented. PMID:26974061

  15. Assessment of liver fibrosis with 2-D shear wave elastography in comparison to transient elastography and acoustic radiation force impulse imaging in patients with chronic liver disease.

    PubMed

    Gerber, Ludmila; Kasper, Daniela; Fitting, Daniel; Knop, Viola; Vermehren, Annika; Sprinzl, Kathrin; Hansmann, Martin L; Herrmann, Eva; Bojunga, Joerg; Albert, Joerg; Sarrazin, Christoph; Zeuzem, Stefan; Friedrich-Rust, Mireen

    2015-09-01

    Two-dimensional shear wave elastography (2-D SWE) is an ultrasound-based elastography method integrated into a conventional ultrasound machine. It can evaluate larger regions of interest and, therefore, might be better at determining the overall fibrosis distribution. The aim of this prospective study was to compare 2-D SWE with the two best evaluated liver elastography methods, transient elastography and acoustic radiation force impulse (point SWE using acoustic radiation force impulse) imaging, in the same population group. The study included 132 patients with chronic hepatopathies, in which liver stiffness was evaluated using transient elastography, acoustic radiation force impulse imaging and 2-D SWE. The reference methods were liver biopsy for the assessment of liver fibrosis (n = 101) and magnetic resonance imaging/computed tomography for the diagnosis of liver cirrhosis (n = 31). No significant difference in diagnostic accuracy, assessed as the area under the receiver operating characteristic curve (AUROC), was found between the three elastography methods (2-D SWE, transient elastography, acoustic radiation force impulse imaging) for the diagnosis of significant and advanced fibrosis and liver cirrhosis in the "per protocol" (AUROCs for fibrosis stages ≥2: 0.90, 0.95 and 0.91; for fibrosis stage [F] ≥3: 0.93, 0.95 and 0.94; for F = 4: 0.92, 0.96 and 0.92) and "intention to diagnose" cohort (AUROCs for F ≥2: 0.87, 0.92 and 0.91; for F ≥3: 0.91, 0.93 and 0.94; for F = 4: 0.88, 0.90 and 0.89). Therefore, 2-D SWE, ARFI imaging and transient elastography seem to be comparably good methods for non-invasive assessment of liver fibrosis. PMID:26116161

  16. Ultrasound annual, 1986

    SciTech Connect

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

    1986-01-01

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

  17. Endoscopic neurosurgery.

    PubMed

    Auer, L M; Holzer, P; Ascher, P W; Heppner, F

    1988-01-01

    This paper describes an ultrasound-guided, laser-assisted, and TV-controlled endoscopic technique which has been used so far in 133 patients for a variety of intracranial lesions. Following CT or MRI image reconstruction, and a decision on the placement of a 1 cm or a 2 cm burrhole, a 1 cm 5.0 mHz or 7.5 mHz intraoperative ultrasound probe is used to direct the endoscope from the burrhole to the target area. A 22.5 cm long rigid endoscope tube with an outer diameter of 6 mm with an inbuilt suction irrigation system, Neodymium Yag laser with 600 micron Quartz glass-fibre and an inlet for various microinstruments is then introduced. The attachment of a TV camera to the ocular lens allows the operator to control further surgical steps in the target area via the TV screen and thus warrants sterility in the operating field. The technique has been used for evacuation of 77 spontaneous intracerebral haematomas (lobar, putaminal, thalamic), 8 traumatic intracerebral haematomas, 13 ventricular haematomas, 8 cerebellar haematomas and 1 brainstem haematoma. Total or subtotal evacuation was achieved in 33% of intracerebral haematomas, removal of more than 50% of the clot in 55%. Twenty-four brain tumours (12 ventricular, 12 cystic cerebral or cerebellar tumours) were operated on for biopsy, evacuation of cyst, resection or removal of the cyst wall and/or laser irradiation of solid tumour or the inner cyst wall of cystic tumours. The complication rate probably related to surgery was 1.6%, morbidity 1.6%, mortality 0%. This high-tec endoscopic technique with its minimal surgical trauma and short operation time can be recommended as a low-risk alternative to conventional neurosurgical techniques. PMID:3278501

  18. In vivo cytological observation of liver and spleen by using high-resolution microendoscopy system under endoscopic ultrasound guidance: A preliminary study using a swine model

    PubMed Central

    Suzuki, Rei; Shin, Dongsuk; Richards-Kortum, Rebecca; Coghlan, Lezlee; Bhutani, Manoop S.

    2016-01-01

    Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is useful to obtain specimens from lesions underlying deep parts of the liver and spleen. However, the development of novel ancillary techniques must be explored to reduce the number of needle passes and potential adverse effects during this procedure. We conducted an animal study using a swine to demonstrate technical feasibility of in vivo cytological observation of liver and spleen using the high-resolution microendoscopy (HRME) system under EUS guidance. We successfully performed the study. No significant acute adverse events occurred during the procedure. The HRME system could obtain clear images representing cytology-level morphology of spleen and liver. Hence, it is found out that in vivo cytological observation of liver and spleen using the HRME system under EUS guidance is technically feasible. PMID:27503155

  19. [A Case of Intra-abdominal Paragonimiasis Mimicking Metastasis of Lung Cancer Diagnosed by Endoscopic Ultrasound-guided Fine Needle Aspiration].

    PubMed

    Oh, Cho Rong; Kim, Mi Jin; Lee, Kwang Hyuck

    2015-07-01

    Paragonimiasis has been continuously decreasing in Korea. However, it still occurs by ingesting raw or incompletely cooked fresh water crab or crayfish. The diagnosis of paragonimiasis is challenging because of its rarity. It may be confused with other inflammatory disease or carcinomatosis. Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) has lower risk of complications such as bleeding, perforation than percutaneous fine needle aspiration. EUS-FNA is more accurate and popular method to find mucosal or submucosal tumors and the lesions of several organs. Benign and malignant tumors, infectious diseases have been diagnosed by EUS-FNA, but there was no report describing the use of EUS-FNA for diagnosing paragonimiasis. Herein, we present a 47-year-old male patient with paragonimiasis diagnosed by EUS-FNA. Imaging studies revealed mass lesions in the lung and peritoneal cavity, which was eventually confirmed as paragonimiasis using EUS-FNA. PMID:26194128

  20. Endoscopic ultrasound-guided placement of the lumen-apposing self-expandable metallic stent for gallbladder drainage: a promising technique

    PubMed Central

    Patil, Rashmee; Ona, Mel A.; Papafragkakis, Charilaos; Anand, Sury; Duddempudi, Sushil

    2016-01-01

    Acute cholecystitis and other clinical problems requiring gallbladder removal or drainage have conventionally been treated with surgery, endoscopic retrograde cholangiopancreatography or percutaneous transhepatic drainage of the gallbladder and/or extrahepatic bile duct. Patients unable to undergo these procedures due to functional status or anatomical anomalies are candidates for endoscopic ultrasound (EUS)-guided gallbladder drainage with stent placement. The aim of this review was to evaluate the technical feasibility and efficacy of EUS-guided placement of the recently developed lumen-apposing self-expandable metallic stent (LASEMS). A literature review was performed to identify the studies describing this technique. In this review article we have summarized case series or reports describing EUS-guided LASEMS placement. The indications, techniques, limitations and complications reported are discussed. A total of 78 patients were included across all studies described thus far in the literature. Studies have reported near 100% technical and clinical success rates in selected cases. No major complications were reported. EUS-guided gallbladder drainage and LASEMS placement can be a safe and effective alternative approach in the management of selected patients. PMID:27065728

  1. Endoscopic ultrasound-guided placement of the lumen-apposing self-expandable metallic stent for gallbladder drainage: a promising technique.

    PubMed

    Patil, Rashmee; Ona, Mel A; Papafragkakis, Charilaos; Anand, Sury; Duddempudi, Sushil

    2016-01-01

    Acute cholecystitis and other clinical problems requiring gallbladder removal or drainage have conventionally been treated with surgery, endoscopic retrograde cholangiopancreatography or percutaneous transhepatic drainage of the gallbladder and/or extrahepatic bile duct. Patients unable to undergo these procedures due to functional status or anatomical anomalies are candidates for endoscopic ultrasound (EUS)-guided gallbladder drainage with stent placement. The aim of this review was to evaluate the technical feasibility and efficacy of EUS-guided placement of the recently developed lumen-apposing self-expandable metallic stent (LASEMS). A literature review was performed to identify the studies describing this technique. In this review article we have summarized case series or reports describing EUS-guided LASEMS placement. The indications, techniques, limitations and complications reported are discussed. A total of 78 patients were included across all studies described thus far in the literature. Studies have reported near 100% technical and clinical success rates in selected cases. No major complications were reported. EUS-guided gallbladder drainage and LASEMS placement can be a safe and effective alternative approach in the management of selected patients. PMID:27065728

  2. Ultrasound

    MedlinePlus

    ... please enable JavaScript. Ultrasound uses high-frequency sound waves to make images of organs and structures inside ... examined. The machine sends out high-frequency sound waves, which reflect off body structures. A computer receives ...

  3. Optical Coherence Elastography

    NASA Astrophysics Data System (ADS)

    Kennedy, Brendan F.; Kennedy, Kelsey M.; Oldenburg, Amy L.; Adie, Steven G.; Boppart, Stephen A.; Sampson, David D.

    The mechanical properties of tissue are pivotal in its function and behavior, and are often modified by disease. From the nano- to the macro-scale, many tools have been developed to measure tissue mechanical properties, both to understand the contribution of mechanics in the origin of disease and to improve diagnosis. Optical coherence elastography is applicable to the intermediate scale, between that of cells and whole organs, which is critical in the progression of many diseases and not widely studied to date. In optical coherence elastography, a mechanical load is imparted to a tissue and the resulting deformation is measured using optical coherence tomography. The deformation is used to deduce a mechanical parameter, e.g., Young's modulus, which is mapped into an image, known as an elastogram. In this chapter, we review the development of optical coherence elastography and report on the latest developments. We provide a focus on the underlying principles and assumptions, techniques to measure deformation, loading mechanisms, imaging probes and modeling, including the inverse elasticity problem.

  4. Is Strain Elastography (IO-SE) Sufficient for Characterization of Liver Lesions before Surgical Resection—Or Is Contrast Enhanced Ultrasound (CEUS) Necessary?

    PubMed Central

    Jung, Ernst Michael; Platz Batista da Silva, Natascha; Jung, Wolfgang; Farkas, Stefan; Stroszczynski, Christian; Rennert, Janine

    2015-01-01

    Aim To evaluate the diagnostic accuracy of IO-SE in comparison to IO-CEUS for the differentiation between malignant and benign liver lesions. Material and Methods In a retrospective diagnostic study IO-CEUS and SE examinations of 49 liver lesions were evaluated and compared to histopathological examinations. Ultrasound was performed using a multifrequency linear probe (6–9 MHz). The loops of CEUS were evaluated up to 5 min. The qualitative characterization of IO-SE was based on a color coding system (blue = hard, red = soft). Stiffness of all lesions was quantified by a specific scaling of 0–6 (0 = low, 6 = high) using 7 ROIs (2 central, 5 peripheral). Results All malignant lesions displayed a characteristic portal venous washout and could be diagnosed correctly by IO-CEUS. 3/5 benign lesions could not be characterized properly either by IO-CEUS or IO-SE prior to resection. Thus for IO-CEUS sensitivity, specificity, positive and negative predictive value and accuracy were 100%, 40%, 94%, 100% and 94%. Lesion sizes were between 8 and 59 mm in diameter. Regarding the IO-SE, malignant lesions showed a marked variability. In qualitative analysis, 31 of the malignant lesions were blue colored denoting overall induration. Thirteen malignant lesions showed an inhomogenous color pattern with partial indurations. Two of the benign lesions also displayed overall induration. The other benign lesions showed an inhomogenous color mapping. Calculated sensitivity of the SE was 70.5%, specificity 60%, PPV 94%, NPV 18.75%, and accuracy 69%. Conclusion IO-CEUS is useful for localization and characterization of liver lesions prior to surgical resection whereas IO-SE provided correct characterization only for a limited number of lesions. PMID:26114286

  5. Development of a training phantom for compression breast elastography-comparison of various elastography systems and numerical simulations.

    PubMed

    Manickam, Kavitha; Reddy, Machireddy Ramasubba; Seshadri, Suresh; Raghavan, Bagyam

    2015-10-01

    The elastic properties of tissue are related to tissue composition and pathological changes. It has been observed that many pathological processes increase the elastic modulus of soft tissue compared to normal. Ultrasound compression elastography is a method of characterization of elastic properties that has been the focus of many research efforts in the last two decades. In medical radiology, compression elastography is provided as an additional tool with ultrasound B-mode in the existing scanners, and the combined features of elastography and echography act as a promising diagnostic method in breast cancer detection. However, the full capability of the ultrasound elastography technique together with B-mode has not been utilized by novice radiologists due to the nonavailability of suitable, appropriately designed tissue-mimicking phantoms. Since different commercially available ultrasound elastographic scanners follow their own unique protocols, training novice radiologists is becoming cumbersome. The main focus of this work is to develop a tissue-like agar-based phantom, which mimics breast tissue with common abnormal lesions like fibroadenoma and invasive ductal carcinoma in a clinically perceived way and compares the sonographic and elastographic appearances using different commercially available systems. In addition, the developed phantoms are simulated using the finite-element method, and ideal strain images are generated. Strain images from experiment and simulation are compared based on image contrast parameters, namely contrast transfer efficiency (CTE) and observed strain, and they are in good agreement. The strain image contrast of malignant inclusions is significantly improved compared to benign inclusions, and the trend of CTE is similar for all elastographic scanners under investigation. PMID:26697511

  6. The potential role of elastography in differentiating between endometrial polyps and submucosal fibroids: a preliminary study

    PubMed Central

    2015-01-01

    Endometrial polyps and submucosal fibroids are common causes of abnormal uterine bleeding (AUB) and less commonly infertility. The prevalence of such intrauterine lesions increases with age during the reproductive years, and usually decreases after menopause. The first-line imaging examination in the diagnosis of endometrial polyps as well as submucosal fibroidsis ultrasound, but its accuracy is not obvious. Elastography is an ultrasound-based imaging modality that is used to assess the stiffness of examined tissues. Considering the fact that endometrial polyps derive from soft endometrial tissue and submucosal fibroids are made of hard muscle tissue, elastography seems a perfect tool to differentiate between such lesions. I present two groups of patients with AUB and intrauterine lesions suspected on ultrasound. In the first group of patients, elastography showed that the stiffness of the lesion was similar to the endometrium and softer than the myometrium. During hysteroscopies endometrial polyps were removed. In the second group of patients, elastography showed that the stiffness of the lesion was similar to the myometrium and harder than the endometrium. During hysteroscopies submucosal fibroids were removed. In both groups, the diagnosis was confirmed by the pathological examination in all cases. It was demonstrated that with the use of elastography it is possible to assess the stiffness of intrauterine lesions, which may be useful in differentiating between endometrial polyps and submucosal fibroids. PMID:26327901

  7. The potential role of elastography in differentiating between endometrial polyps and submucosal fibroids: a preliminary study.

    PubMed

    Woźniak, Sławomir

    2015-06-01

    Endometrial polyps and submucosal fibroids are common causes of abnormal uterine bleeding (AUB) and less commonly infertility. The prevalence of such intrauterine lesions increases with age during the reproductive years, and usually decreases after menopause. The first-line imaging examination in the diagnosis of endometrial polyps as well as submucosal fibroidsis ultrasound, but its accuracy is not obvious. Elastography is an ultrasound-based imaging modality that is used to assess the stiffness of examined tissues. Considering the fact that endometrial polyps derive from soft endometrial tissue and submucosal fibroids are made of hard muscle tissue, elastography seems a perfect tool to differentiate between such lesions. I present two groups of patients with AUB and intrauterine lesions suspected on ultrasound. In the first group of patients, elastography showed that the stiffness of the lesion was similar to the endometrium and softer than the myometrium. During hysteroscopies endometrial polyps were removed. In the second group of patients, elastography showed that the stiffness of the lesion was similar to the myometrium and harder than the endometrium. During hysteroscopies submucosal fibroids were removed. In both groups, the diagnosis was confirmed by the pathological examination in all cases. It was demonstrated that with the use of elastography it is possible to assess the stiffness of intrauterine lesions, which may be useful in differentiating between endometrial polyps and submucosal fibroids. PMID:26327901

  8. Prospective Study for Comparison of Endoscopic Ultrasound-Guided Tissue Acquisition Using 25- and 22-Gauge Core Biopsy Needles in Solid Pancreatic Masses

    PubMed Central

    Lee, Sang Hoon; Lee, Hee Seung; Lee, Hyun Jik; Park, Jeong Yup; Park, Seung Woo; Song, Si Young; Kim, Hoguen; Chung, Jae Bock; Bang, Seungmin

    2016-01-01

    Background and Aims Although thicker needles theoretically allow more tissue to be collected, their decreased flexibility can cause mechanical damage to the endoscope, technical failure, and sample blood contamination. The effects of needle gauge on diagnostic outcomes of endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) of pancreatic mass lesions remain unknown. This study compared procurement rates of histologic cores obtained from EUS-FNB of pancreatic masses using 25- and 22-gauge core biopsy needles. Patients and Methods From March 2014 to July 2014, 66 patients with solid pancreatic mass underwent EUS-FNB with both 25- and 22-gauge core biopsy needles. Among them, 10 patients were excluded and thus 56 patients were eligible for the analyses. Needle sequences were randomly assigned, and two passes were made with each needle, consisting of 10 uniform to-and-fro movements on each pass with 10 mL syringe suction. A pathologist blinded to needle sequence evaluated specimens for the presence of histologic core. Results The mean patient age was 65.8 ± 9.5 years (range, 44–89 years); 35 patients (62.5%) were men. The mean pancreatic mass size was 35.3 ± 17.1 mm (range 14–122.3 mm). Twenty-eight patients (50%) had tumors at the pancreas head or uncinate process. There were no significant differences in procurement rates of histologic cores between 25-gauge (49/56, 87.5%) and 22-gauge (46/56, 82.1%, P = 0.581) needles or diagnostic accuracy using only histologic cores (98% and 95%). There were no technical failures or procedure-related adverse events. Conclusions The 25-gauge core biopsy needle could offer acceptable and comparable outcomes regarding diagnostic performance including histologic core procurement rates compared to the 22-gauge core biopsy needle, although the differences were not statistically significant. Trial Registration ClinicalTrials.gov NCT01795066 PMID:27149404

  9. The integration of 18-fluoro-deoxy-glucose positron emission tomography and endoscopic ultrasound in the treatment-planning process for esophageal carcinoma

    SciTech Connect

    Konski, Andre . E-mail: a_konski@fccc.edu; Doss, Mohan; Milestone, Barton; Haluszka, Oleh; Hanlon, Alexandra; Freedman, Gary; Adler, Lee

    2005-03-15

    Purpose: Accurate delineation of the gross tumor volume (GTV) is important in radiation therapy treatment planning. We evaluated the impact of PET and endoscopic ultrasound (EUS) compared with CT simulation in the planning of radiation fields for patients with esophageal carcinoma. Material and methods: Twenty-five patients presenting with esophageal carcinoma for radiation therapy underwent PET scans in the treatment position after conventional CT simulation. Patients underwent PET/CT scanning after being injected with 10 to 20 mCi of [F-18]-2-deoxy-2-fluro-D-glucose. The length of the abnormality seen on the CT portion of the PET/CT scan vs. the PET scan alone was determined independently by 2 separate investigators. The length of the GTV and detection of regional adenopathy by PET was also correlated with EUS in 18 patients. Of the 18 patients who had EUS, 2 had T2 tumors and 16 had T3 tumors. Eighteen patients had adenocarcinoma and 7 had squamous cell carcinoma. Nine tumors were located at the gastroesophageal junction, 8 at the lower esophagus, 7 in the middle esophagus, and 1 in the cervical esophagus. The PET scans were reviewed to determine the length of the abnormality by use of a standard uptake value (SUV) of 2.5 to delineate the tumor extent. Results: The mean length of the cancer was 5.4 cm (95% CI 4.4-6.4 cm) as determined by PET scan, 6.77 cm (95% CI, 5.6-7.9 cm) as determined by CT scan, and 5.1 cm (95% CI, 4.0-6.1 cm) for the 22 patients who had endoscopy. The length of the tumors was significantly longer as measured by CT scans compared with PET scans (p = 0.0063). EUS detected significantly more patients with periesophageal and celiac lymphadenopathy compared to PET and CT. The SUV of the esophageal tumors was higher in patients with peri-esophageal lymphadenopathy identified on PET scans. Conclusion: Endoscopic ultrasound and PET scans can add additional information to aid the radiation oncologist's ability to precisely identify the GTV in

  10. Spatial Angular Compounding for Elastography without the Incompressibility Assumption

    PubMed Central

    Rao, Min; Varghese, Tomy

    2007-01-01

    Spatial-angular compounding is a new technique that enables the reduction of noise artifacts in ultrasound elastography. Previous results using spatial angular compounding, however, were based on the use of the tissue incompressibility assumption. Compounded elastograms were obtained from a spatially-weighted average of local strain estimated from radiofrequency echo signals acquired at different insonification angles. In this paper, we present a new method for reducing the noise artifacts in the axial strain elastogram utilizing a least-squares approach on the angular displacement estimates that does not use the incompressibility assumption. This method produces axial strain elastograms with higher image quality, compared to noncompounded axial strain elastograms, and is referred to as the least-squares angular-compounding approach for elastography. To distinguish between these two angular compounding methods, the spatial-angular compounding with angular weighting based on the tissue incompressibility assumption is referred to as weighted compounding. In this paper, we compare the performance of the two angular-compounding techniques for elastography using beam steering on a linear-array transducer. Quantitative experimental results demonstrate that least-squares compounding provides comparable but smaller improvements in both the elastographic signal-to-noise ratio and the contrast-to-noise ratio, as compared to the weighted-compounding method. Ultrasound simulation results suggest that the least-squares compounding method performs better and provide accurate and robust results when compared to the weighted compounding method, in the case where the incompressibility assumption does not hold. PMID:16761786

  11. Successful endoscopic ultrasound-guided overstenting biliary drainage through a pre-existing proximal migrated metal biliary stent.

    PubMed

    Artifon, E L A; Takada, J; Okawa, L; Ferreira, F; Santos, M; Moura, E G H; Otoch, J P; Sakai, P

    2011-01-01

    Biliary endoscopic drainage using metallic self-expanded stents has become a well-established method for palliative treatment of malignant biliary obstruction. However, its occlusion, mainly by tumor overgrowth, is still the main complication without a standard treatment. We here describe a new method of treatment for biliary metallic stent occlusion, through the echo guided biliary drainage. We present a 68-year-old patient with metastatic pancreatic cancer previously treated for jaundice with ERCP and self-expandable metallic stent insertion. Four weeks later, the patient developed jaundice and symptoms of gastric outlet obstruction. A new ERCP confirmed obstruction of the second portion of the duodenum, due to diffuse tumor growth. EUS was performed, and the previous metal biliary stent was seen occluded at the distal portion in the common bile duct. A EUS-guided choledocododenostomy was performed and then, an overlapping self-expanding metal enteral stent was placed through the malignant obstruction. There were no early complications and the procedure was also clinically effective in relieving jaundice and gastric outlet obstruction symptoms. If ERCP fails in the management of occluded biliary metallic stents, EUS biliary drain can provide effective biliary decompression and should be considered an alternative to other endoscopic techniques. PMID:22041320

  12. Elastography for Muscle Biomechanics: Toward the Estimation of Individual Muscle Force.

    PubMed

    Hug, François; Tucker, Kylie; Gennisson, Jean-Luc; Tanter, Mickaël; Nordez, Antoine

    2015-07-01

    Estimation of individual muscle force remains one of the main challenges in biomechanics. This review presents a series of experiments that used ultrasound shear wave elastography to support the hypothesis that muscle stiffness is linearly related to both active and passive muscle forces. Examples of studies that used measurement of muscle stiffness to estimate changes in muscle force are presented. PMID:25906424

  13. Evaluation of levator ani with no defect on elastography in women with POP

    PubMed Central

    Xie, Meng; Zhang, Xuyin; Liu, Jia; Ding, Jingxin; Ren, Yunyun; Hua, Keqin

    2015-01-01

    Objective: It is difficult to evaluate the function of levator ani with no defect encountered in routine practice. Elastography is a new adjunct to real-time ultrasound imaging that overlays traditional B-mode imaging with a color graphic representation of tissue elasticity. The aim of this study is to specifically evaluate the function of levator ani with no defect by ES (elastography). Methods: This was a prospective, observational study. All patients were examined by MRI and the cases with levator ani defect were excluded. The included cases underwent conventional translabial ultrasound, and then ultrasound ES. A little levator ani were biopsied for immunohistochemistry check in the patients who underwent surgery. Results: Of the 52 cases with no levator ani defects, 22 had an elastography score of 1, 20 had a score of 2, 8 had a score of 3 and 2 had a score of 4 in levator ani. Cases of ES1 and ES2 were more than ES3 and ES4 (P = 0.004). The immunohistochemistry check indicated that 12 patients who underwent surgery showed weak expression and the other 4 patients showed moderate expression of collagen type I in levator ani, compared with 2 controls showing strong expressions. Conclusions: Elastography can assess the change of elasticity function of levator ani though the structure has no defect which was detected by MRI and conventional ultrasound. And probably the change of function of levator ani was earlier than structure abnormity in POP. PMID:26309719

  14. Analisys of pectoralis major tendon in weightlifting athletes using ultrasonography and elastography

    PubMed Central

    Pochini, Alberto de Castro; Ferretti, Mario; Kawakami, Eduardo Felipe Kin Ito; Fernandes, Artur da Rocha Corrêa; Yamada, Andre Fukunishi; de Oliveira, Gabriela Clemente; Cohen, Moisés; Andreoli, Carlos Vicente; Ejnisman, Benno

    2015-01-01

    ABSTRACT Objective To evaluate tendinopathy of the pectoralis major muscle in weightlifting athletes using ultrasound and elastography. Methods This study included 20 patients, 10 with rupture of the pectoralis major muscle and 10 control patients. We evaluated pectoralis major muscle contralateral tendon with ultrasonographic and elastography examinations. The ultrasonographic examinations were performed using a high-resolution B mode ultrasound device. The elastography evaluation was classified into three patterns: (A), if stiff (more than 50% area with blue staining); (B), if intermediate (more than 50% green); and (C), if softened (more than 50% red). Results Patients’ mean age was 33±5.3 years. The presence of tendinous injury measured by ultrasound had a significant different (p=0.0055), because 80% of cases had tendinous injury versus 10% in the Control Group. No significant differences were seen between groups related with change in elastography (p=0.1409). Conclusion Long-term bodybuilders had ultrasound image with more tendinous injury than those in Control Group. There was no statistical significance regarding change in tendon elasticity compared with Control Group. PMID:26761551

  15. Elastography in the differential diagnosis of thyroid nodules.

    PubMed

    Çakal, Erman; Şahin, Mustafa; Ünsal, İlknur Öztürk; Güngüneş, Aşkın; Akkaymak, Esra; Özkaya, Evrim Çakır; Bozkurt, Nujen Çolak; Özbek, Mustafa; Delibaşı, Tuncay

    2015-07-01

    Despite the publication of a recent meta-analysis of elastography in thyroid nodules, further work is necessary on this issue in different populations. In this study, we aimed to evaluate the clinical value of elastography on nodular goiters in mild iodine-deficient regions without excluding patients according to nodule characteristics. This prospective study was conducted between April 2010 and December 2011 in Yıldırım Beyazıt Dıskapı Research Hospital Endocrinology outpatient clinic. Five hundred twenty-eight nodular goiter patients who underwent thyroid fine-needle aspiration biopsy were included in our study. Elastography scores and indexes were measured with real-time ultrasound elastography (Hitachi® EUB 7000 HV machine with 13 MHz linear transducer). There were 471 females and 57 males and their ages ranged from 45 years to 78 years. A total of 601 nodules were evaluated in these patients. The area under the curve (AUC) for the elasto score was 0.91 (p < 0.0001) and AUC for the strain index (SI) was 0.96 (p < 0.0001). We suggest that the SI reflects malignancy better than the elasto score. We conclude that elastography scores greater than 3 have 76% sensitivity and 96% specificity for diagnosing malignancy. For SI, we conclude that 3.75 (83% sensitivity and 95% specificity) is the cutoff point. Elasto score and SI measurements of thyroid nodules in our population are efficient and increase the diagnostic performance of the sonography. PMID:25161183

  16. Comparing cost-effectiveness between endoscopic ultrasound and endoscopic retrograde cholangiopancreatography in diagnosis of common bile duct stone in patients with predefined risks: A study from a developing country

    PubMed Central

    Netinatsunton, Nisa; Attasaranya, Siriboon; Sottisuporn, Jaksin; Witeerungrot, Teepawit; Jongboonyanuparp, Theeratus; Piratvisuth, Teerha; Ovartlarnporn, Bancha

    2016-01-01

    Background and Objectives: Endoscopic ultrasound (EUS) achieves results comparable to endoscopic retrograde cholangiopancreatography (ERCP) in the diagnosis of common bile duct (CBD) stone, but studies from the western have shown EUS to be less expensive in patients with intermediate risk for CBD stones. The aim of this study was to compare the costs of EUS and ERCP in the diagnosis of CBD stones in a developing country. Materials and Methods: A prospective study was done with 141 patients with suspected CBD stones, categorized as having high or intermediate risk for CBD stone. All underwent EUS, and the high-risk patients had ERCP after the EUS. For intermediate-risk patients, an ERCP was done at the discretion of the attending physician. The CBD stone was confirmed by ERCP in patients who underwent both EUS and ERCP. Patients who received EUS only were followed up every 3 months for 1 year. The false negative rate in patients with EUS and ERCP was estimated in the clinical follow-up. Result: One hundred and forty-one patients (141: 83 females, 58 males) with a mean age ± standard deviation (SD) of 55.71 ±18.68 years were recruited. Ninety-four (94) patients underwent both EUS and ERCP. ERCP confirmed the diagnosis in 83 of 85 patients (97.6%) with CBD stone detected by EUS. Forty-seven (47) patients with a negative EUS and no ERCP done were symptom-free during the follow-up. The overall sensitivity, specificity, positive predictive value, and negative predictive value of EUS were 97.6%, 80%, 97.6%, and 80% respectively. An EUS-based strategy for high-risk patients was 15% more expensive than an ERCP-based strategy, but the EUS-based strategy reduced the cost to 37.78% less than the ERCP-based strategy in intermediate-risk patients. The EUS-based strategy was cost-saving when the CBD stone prevalence was less than 52.5%. Conclusion: EUS is safer and less costly than ERCP for CBD stone diagnosis in patients with intermediate risk. PMID:27386473

  17. Endoscopic ultrasound-guided fine needle core biopsy for the diagnosis of pancreatic malignant lesions: a systematic review and Meta-Analysis

    PubMed Central

    Yang, Yongtao; Li, Lianyong; Qu, Changmin; Liang, Shuwen; Zeng, Bolun; Luo, Zhiwen

    2016-01-01

    Endoscopic ultrasound-guided fine needle core biopsy (EUS-FNB) has been used as an effective method of diagnosing pancreatic malignant lesions. It has the advantage of providing well preserved tissue for histologic grading and subsequent molecular biological analysis. In order to estimate the diagnostic accuracy of EUS-FNB for pancreatic malignant lesions, studies assessing EUS-FNB to diagnose solid pancreatic masses were selected via Medline. Sixteen articles published between 2005 and 2015, covering 828 patients, met the inclusion criteria. The summary estimates for EUS-FNB differentiating malignant from benign solid pancreatic masses were: sensitivity 0.84 (95% confidence interval (CI), 0.82–0.87); specificity 0.98 (95% CI, 0.93–1.00); positive likelihood ratio 8.0 (95% CI 4.5–14.4); negative likelihood ratio 0.17 (95% CI 0.10–0.26); and DOR 64 (95% CI 30.4–134.8). The area under the sROC curve was 0.96. Subgroup analysis did not identify other factors that could substantially affect the diagnostic accuracy, such as the study design, location of study, number of centers, location of lesion, whether or not a cytopathologist was present, and so on. EUS-FNB is a reliable diagnostic tool for solid pancreatic masses and should be especially considered for pathology where histologic morphology is preferred for diagnosis. PMID:26960914

  18. Randomized Trial Comparing the Flexible 19G and 25G Needles for Endoscopic Ultrasound-Guided Fine Needle Aspiration of Solid Pancreatic Mass Lesions

    PubMed Central

    Ramesh, Jayapal; Bang, Ji Young; Hebert-Magee, Shantel; Trevino, Jessica; Eltoum, Isam; Frost, Andra; Hasan, Muhammad K.; Logue, Amy; Hawes, Robert; Varadarajulu, Shyam

    2015-01-01

    Objectives Although a large gauge needle can procure more tissue at endoscopic ultrasound-guided fine needle aspiration (EUS-FNA), its advantage over smaller needles is unclear. This study compared flexible 19G and 25G needles for EUS-FNA of solid pancreatic masses. Methods This was a randomized trial of patients undergoing EUS-FNA of pancreatic masses using flexible 19G or 25G needle. Main outcome measure was to compare median number of passes for on-site diagnosis. Secondary measures were to compare specimen bloodiness, complications, technical failures, and histological core tissue procurement. Results One hundred patients were randomized to EUS-FNA using flexible 19G or 25G needle. Median of 1 pass was required to achieve on-site diagnosis of 96% and 92% (P = 0.68) in 19G and 25G cohorts. There was no significant difference in technical failure (0% vs 2%, P = 0.99) or adverse events (2% vs 0%, P = 0.99) between 19G and 25G cohorts. Although histological core tissue procurement was significantly better with flexible 19G needle (88% vs 44%, P < 0.001), specimens were bloodier (severe bloodiness, 36% vs 4%; P < 0.001). Conclusions As there is no significant difference in the performance of flexible 19G and 25G needles, needle choice for sampling pancreatic masses should be based on endoscopist preference and need for histology. PMID:25232713

  19. Assessment of Factors Affecting the Usefulness and Diagnostic Yield of Core Biopsy Needles with a Side Hole in Endoscopic Ultrasound-Guided Fine-Needle Aspiration

    PubMed Central

    Inoue, Tadahisa; Okumura, Fumihiro; Mizushima, Takashi; Nishie, Hirotada; Iwasaki, Hiroyasu; Anbe, Kaiki; Ozeki, Takanori; Kachi, Kenta; Fukusada, Shigeki; Suzuki, Yuta; Sano, Hitoshi

    2016-01-01

    Background/Aims A barbed puncture needle with a side hole was recently developed to improve sample quality and quantity in endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). In this study, we retrospectively assessed the usefulness of this puncture needle. Methods Factors affecting diagnostic yield, safety, and diagnostic accuracy were investigated in 76 patients who consecutively underwent EUS-FNA for neoplastic lesions at our hospital between January and December 2013. Results The procedure was successful in all cases; the rates of sample collection and determination of the correct diagnosis were 92.1% and 89.5%, respectively. The mean number of needle passes required for diagnosis was 1.1. Complications included mild intraluminal bleeding in two patients (2.6%). Multivariate analysis revealed that lesion size (≤20 mm) was significantly associated with a decreased chance of determining the correct diagnosis. Conclusions Core biopsy needles with a side hole are safe and provide a satisfactory diagnostic yield. However, the side hole may potentially reduce the rate of making the correct diagnosis in small lesions. PMID:25963081

  20. Confocal acoustic radiation force optical coherence elastography using a ring ultrasonic transducer

    SciTech Connect

    Qi, Wenjuan; Li, Rui; Ma, Teng; Kirk Shung, K.; Zhou, Qifa; Chen, Zhongping

    2014-03-24

    We designed and developed a confocal acoustic radiation force optical coherence elastography system. A ring ultrasound transducer was used to achieve reflection mode excitation and generate an oscillating acoustic radiation force in order to generate displacements within the tissue, which were detected using the phase-resolved optical coherence elastography method. Both phantom and human tissue tests indicate that this system is able to sense the stiffness difference of samples and quantitatively map the elastic property of materials. Our confocal setup promises a great potential for point by point elastic imaging in vivo and differentiation of diseased tissues from normal tissue.

  1. How to improve the success of endoscopic ultrasound guided fine needle aspiration cytology in the diagnosis of pancreatic lesions.

    PubMed

    Gimeno-García, Antonio Z; Elwassief, Ahmed

    2012-01-01

    Endoscopic ultrasonography (EUS) is highly accurate for assessing the pancreatic parenchyma and ductal system. Currently, it is the most sensitive imaging procedure for detecting small solid pancreatic masses. EUS-guided fine needle aspiration cytology (EUS-FNA) is a safe and highly accurate tool for the diagnosis of pancreatic malignancy. Prior to perform an EUS-FNA one should wonder whether the benefits outweigh the potential risks of the procedure. Therefore, it is important to take into account whether the procedure will influence patient management. The diagnostic yield and success rate of EUS-FNA in pancreatic lesions varies greatly depending on many factors including: the characteristics of the lesion itself (location of the mass and consistency of the lesion), technical factors (type of needle size, use of stylet, use of suction and number of needle passes performed) and the availability of immediate cytological assessment of the specimen. The aim of this review is to analyze all these factors for optimizing specimen collection and diagnostic efficiency in dealing with solid pancreatic masses. PMID:22586548

  2. Synthetic aperture elastography: a GPU based approach

    NASA Astrophysics Data System (ADS)

    Verma, Prashant; Doyley, Marvin M.

    2014-03-01

    Synthetic aperture (SA) ultrasound imaging system produces highly accurate axial and lateral displacement estimates; however, low frame rates and large data volumes can hamper its clinical use. This paper describes a real-time SA imaging based ultrasound elastography system that we have recently developed to overcome this limitation. In this system, we implemented both beamforming and 2D cross-correlation echo tracking on Nvidia GTX 480 graphics processing unit (GPU). We used one thread per pixel for beamforming; whereas, one block per pixel was used for echo tracking. We compared the quality of elastograms computed with our real-time system relative to those computed using our standard single threaded elastographic imaging methodology. In all studies, we used conventional measures of image quality such as elastographic signal to noise ratio (SNRe). Specifically, SNRe of axial and lateral strain elastograms computed with real-time system were 36 dB and 23 dB, respectively, which was numerically equal to those computed with our standard approach. We achieved a frame rate of 6 frames per second using our GPU based approach for 16 transmits and kernel size of 60 × 60 pixels, which is 400 times faster than that achieved using our standard protocol.

  3. Endoscopic ultrasound-guided fine-needle aspiration cytology diagnosis of solid pseudopapillary tumor of the pancreas: a case report and literature review.

    PubMed

    Salla, Charitini; Chatzipantelis, Paschalis; Konstantinou, Panagiotis; Karoumpalis, Ioannis; Pantazopoulou, Akrivi; Dappola, Victoria

    2007-10-14

    We describe the clinical, imaging and cytopathological features of solid pseudopapillary tumor of the pancreas (SPTP) diagnosed by endoscopic ultrasound-guided (EUS-guided) fine-needle aspiration (FNA). A 17-year-old woman was admitted to our hospital with complaints of an unexplained episodic abdominal pain for 2 mo and a short history of hypertension in the endocrinology clinic. Clinical laboratory examinations revealed polycystic ovary syndrome, splenomegaly and low serum amylase and carcinoembryonic antigen (CEA) levels. Computed tomography (CT) analysis revealed a mass of the pancreatic tail with solid and cystic consistency. EUS confirmed the mass, both in body and tail of the pancreas, with distinct borders, which caused dilation of the peripheral part of the pancreatic duct (major diameter 3.7 mm). The patient underwent EUS-FNA. EUS-FNA cytology specimens consisted of single cells and aggregates of uniform malignant cells, forming microadenoid structures, branching, papillary clusters with delicate fibrovascular cores and nuclear overlapping. Naked capillaries were also seen. The nuclei of malignant cells were round or oval, eccentric with fine granular chromatin, small nucleoli and nuclear grooves in some of them. The malignant cells were periodic acid Schiff (PAS)-Alcian blue (+) and immunocytochemically they were vimentin (+), CA 19.9 (+), synaptophysin (+), chromogranin (-), neuro-specific enolase (-), a1-antitrypsin and a1-antichymotrypsin focal positive. Cytologic findings were strongly suggestive of SPTP. Biopsy confirmed the above cytologic diagnosis. EUS-guided FNA diagnosis of SPTP is accurate. EUS findings, cytomorphologic features and immunostains of cell block help distinguish SPTP from pancreatic endocrine tumors, acinar cell carcinoma and papillary mucinous carcinoma. PMID:17876886

  4. Shear Wave Elastography and Cervical Lymph Nodes: Predicting Malignancy.

    PubMed

    Azizi, Ghobad; Keller, James M; Mayo, Michelle L; Piper, Kelé; Puett, David; Earp, Karly M; Malchoff, Carl D

    2016-06-01

    This prospective study evaluates the accuracy of virtual touch imaging quantification (VTIQ), a non-invasive shear wave elastography method for measuring cervical lymph nodes (LN) stiffness in differentiating benign from malignant LN. The study evaluated 270 LN in 236 patients with both conventional B-mode ultrasound and VTIQ shear wave elastography before fine-needle aspiration biopsy (FNAB). LN stiffness was measured as shear wave velocity (SWV) in m/s. Surgical resection was advised for FNAB results that were not clearly benign. Surgical pathology confirmed 54 malignant LN. The receiver operating curve (ROC) identified a single cut-off value of 2.93 m/s as the maximum SWV for predicting a malignant cervical LN. The sensitivity and specificity were 92.59% and 75.46%, respectively. Positive predictive value (PPV) was 48.54% and negative predictive value (NPV) was 97.60%. LN stiffness measured by VTIQ-generated shear wave elastography is an independent predictor of malignancy. PMID:26976785

  5. Effect of the time of day and queue position in the endoscopic schedule on the performance characteristics of endoscopic ultrasound-guided fine-needle aspiration for diagnosing pancreatic malignancies

    PubMed Central

    Korenblit, Jason; Tholey, Danielle M.; Tolin, Joanna; Loren, David; Kowalski, Thomas; Adler, Douglas G.; Davolos, Julie; Siddiqui, Ali A.

    2016-01-01

    Background and Objectives: Recent reports have indicated that the time of day may impact the detection rate of abnormal cytology on gynecologic cytology samples. The aim of this study was to determine if procedure time or queue position affected the performance characteristics of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) for diagnosing solid pancreatic malignancies. Patients and Methods: We conducted a retrospective study evaluating patients with solid pancreatic lesions in whom EUS-FNA was performed. Three timing variables were evaluated as surrogate markers for endoscopist fatigue: Procedure start times, morning versus afternoon procedures, and endoscopy queue position. Statistical analyses were performed to determine whether the timing variables predicted performance characteristics of EUS-FNA. Results: We identified 609 patients (mean age: 65.8 years, 52.1% males) with solid pancreatic lesions who underwent EUS-FNA. The sensitivity of EUS-FNA was 100% for procedures that started at 7 AM while cases that started at 4 PM had a sensitivity of 81%. Using start time on a continuous scale, each elapsed hour was associated with a 1.9% decrease in EUS-FNA sensitivity (P = 0.003). Similarly, a 10% reduction in EUS-FNA sensitivity was detected between morning and afternoon procedures (92% vs. 82% respectively, P = 0.0006). A linear regression comparing the procedure start time and diagnostic accuracy revealed a decrease of approximately 1.7% in procedure accuracy for every hour later a procedure was started. A 16% reduction in EUS-FNA accuracy was detected between morning and afternoon procedures (100% vs. 84% respectively, P = 0.0009). When the queue position was assessed, a 2.4% reduction in accuracy was noted for each increase in the queue position (P = 0.013). Conclusion: Sensitivity and diagnostic accuracy of EUS-FNA for solid pancreatic lesions decline with progressively later EUS starting times and increasing numbers of procedures before a

  6. Correlation of Strain Elastography with Conventional Sonography and FNAC/Biopsy

    PubMed Central

    Sardessai, Sanjay; Furtado, Renny; Sardessai, Mahesh

    2016-01-01

    Introduction Elastography is a new promising technique that can be especially helpful when used as an adjunct to conventional B-mode ultrasound in evaluating breast lesions. Aim To evaluate the diagnostic performance of four interpretation criteria for elastography and to compare the diagnostic performance of sonoelastography with that of conventional sonography in characterising breast lesions as benign or malignant with FNAC/biopsy correlation. Materials and Methods One hundred breast lesions were prospectively evaluated by ultrasound as well as by strain elastography followed by FNAC/ biopsy correlation. The criteria used were Elastography Score, Strain Ratio, Distance Ratio and Area Ratio. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value were calculated for each modality. The best cut-off point was calculated for each of the interpretation criteria using the MedCalc version 10.1 software. The diagnostic performance of the interpretation criteria was compared with that of conventional sonography by the area under the receiver operating characteristic curve using SPSS software. Results The elastography score was found to have the best performance among the 4 criteria used with a sensitivity and specificity of 100% and 82.66%, respectively at the best cut-off point between 3 and 4. At a best cut-off point for conventional sonography between BI-RADS categories 4A and 4B, the sensitivity and specificity were found to be 96% and 92% respectively. The area under the curve value was slightly greater for conventional sonography (0.980) than for the elastography score (0.913) using receiver operating characteristic curve analysis. Conclusion While all interpretation criteria were able to differentiate benign and malignant lesions with statistical significance, the elastography score was found to be the most accurate. While conventional ultrasound remains the primary modality for the characterization of breast masses

  7. Spectroscopic optical coherence elastography

    PubMed Central

    Adie, Steven G.; Liang, Xing; Kennedy, Brendan F.; John, Renu; Sampson, David D.; Boppart, Stephen A.

    2010-01-01

    We present an optical technique to image the frequency-dependent complex mechanical response of a viscoelastic sample. Three-dimensional hyperspectral data, comprising two-dimensional B-mode images and a third dimension corresponding to vibration frequency, were acquired from samples undergoing external mechanical excitation in the audio-frequency range. We describe the optical coherence tomography (OCT) signal when vibration is applied to a sample and detail the processing and acquisition techniques used to extract the local complex mechanical response from three-dimensional data that, due to a wide range of vibration frequencies, possess a wide range of sample velocities. We demonstrate frequency-dependent contrast of the displacement amplitude and phase of a silicone phantom containing inclusions of higher stiffness. Measurements of an ex vivo tumor margin demonstrate distinct spectra between adipose and tumor regions, and images of displacement amplitude and phase demonstrated spatially-resolved contrast. Contrast was also observed in displacement amplitude and phase images of a rat muscle sample. These results represent the first demonstration of mechanical spectroscopy based on B-mode OCT imaging. Spectroscopic optical coherence elastography (S-OCE) provides a high-resolution imaging capability for the detection of tissue pathologies that are characterized by a frequency-dependent viscoelastic response. PMID:21164898

  8. Spectroscopic optical coherence elastography.

    PubMed

    Adie, Steven G; Liang, Xing; Kennedy, Brendan F; John, Renu; Sampson, David D; Boppart, Stephen A

    2010-12-01

    We present an optical technique to image the frequency-dependent complex mechanical response of a viscoelastic sample. Three-dimensional hyperspectral data, comprising two-dimensional B-mode images and a third dimension corresponding to vibration frequency, were acquired from samples undergoing external mechanical excitation in the audio-frequency range. We describe the optical coherence tomography (OCT) signal when vibration is applied to a sample and detail the processing and acquisition techniques used to extract the local complex mechanical response from three-dimensional data that, due to a wide range of vibration frequencies, possess a wide range of sample velocities. We demonstrate frequency-dependent contrast of the displacement amplitude and phase of a silicone phantom containing inclusions of higher stiffness. Measurements of an ex vivo tumor margin demonstrate distinct spectra between adipose and tumor regions, and images of displacement amplitude and phase demonstrated spatially-resolved contrast. Contrast was also observed in displacement amplitude and phase images of a rat muscle sample. These results represent the first demonstration of mechanical spectroscopy based on B-mode OCT imaging. Spectroscopic optical coherence elastography (S-OCE) provides a high-resolution imaging capability for the detection of tissue pathologies that are characterized by a frequency-dependent viscoelastic response. PMID:21164898

  9. Damping models in elastography

    NASA Astrophysics Data System (ADS)

    McGarry, Matthew D. J.; Berger, Hans-Uwe; Van Houten, Elijah E. W.

    2007-03-01

    Current optimization based Elastography reconstruction algorithms encounter difficulties when the motion approaches resonant conditions, where the model does a poor job of approximating the real behavior of the material. Model accuracy can be improved through the addition of damping effects. These effects occur in-vivo due to the complex interaction between microstructural elements of the tissue; however reconstruction models are typically formulated at larger scales where the structure can be treated as a continuum. Attenuation behavior in an elastic continuum can be described as a mixture of inertial and viscoelastic damping effects. In order to develop a continuum damping model appropriate for human tissue, the behavior of each aspect of this proportional, or Rayleigh damping needs to be characterized. In this paper we investigate the nature of these various damping representations with a goal of best describing in-vivo behavior of actual tissue in order to improve the accuracy and performance of optimization based elastographic reconstruction. Inertial damping effects are modelled using a complex density, where the imaginary part is equivalent to a damping coefficient, and the effects of viscoelasticity are modelled through the use of complex shear moduli, where the real and imaginary parts represent the storage and loss moduli respectively. The investigation is carried out through a combination of theoretical analysis, numerical experiment, investigation of gelatine phantoms and comparison with other continua such as porous media models.

  10. Magnetic Resonance Elastography

    PubMed Central

    Litwiller, Daniel V.; Mariappan, Yogesh K.; Ehman, Richard L.

    2015-01-01

    Often compared to the practice of manual palpation, magnetic resonance elastography is an emerging technology for quantitatively assessing the mechanical properties of tissue as a basis for characterizing disease. The potential of MRE as a diagnostic tool is rooted in the fact that normal and diseased tissues often differ significantly in terms of their intrinsic mechanical properties. MRE uses magnetic resonance imaging (MRI) in conjunction with the application of mechanical shear waves to probe tissue mechanics. This process can be broken down into three essential steps: inducing shear waves in the tissue,imaging the propagating shear waves with MRI, andanalyzing the wave data to generate quantitative images of tissue stiffness MRE has emerged as a safe, reliable and noninvasive method for staging hepatic liver fibrosis, and is now used in some locations as an alternative to biopsy. MRE is also being used in the ongoing investigations of numerous other organs and tissues, including, for example, the spleen, kidney, pancreas, brain, heart, breast, skeletal muscle, prostate, vasculature, lung, spinal cord, eye, bone, and cartilage. In the article that follows, some fundamental techniques and applications of MRE are summarized. PMID:26361467

  11. Spectral estimators in elastography.

    PubMed

    Konofagou, E E; Varghese, T; Ophir, J

    2000-03-01

    Like velocity, strain induces a time delay and a time scaling to the received signal. Elastography typically uses time delay techniques to indirectly (i.e. via the displacement estimate) measure tissue strain induced by an applied compression, and considers time scaling as a source of distortion. More recently, we have shown that the time scaling factor can also be spectrally estimated and used as a direct measure of strain. Strain causes a Doppler-like frequency shift and a change in bandwidth of the bandpass power spectrum of the echo signal. Two frequency shift strain estimators are described that have been proven to be more robust but less precise when compared to time delay estimators, both in simulations and experiments. The increased robustness is due to the insensitivity of the spectral techniques to phase decorrelation noise. In this paper we discuss and compare the theoretical and experimental findings obtained with traditional time delay estimators and with the newly proposed spectral methods. PMID:10829698

  12. Endoscopic Management of Portal Hypertension

    PubMed Central

    Al-Busafi, Said A.; Ghali, Peter; Wong, Philip; Deschenes, Marc

    2012-01-01

    Cirrhosis is the leading cause of portal hypertension worldwide, with the development of bleeding gastroesophageal varices being one of the most life-threatening consequences. Endoscopy plays an indispensible role in the diagnosis, staging, and prophylactic or active management of varices. With the expected future refinements in endoscopic technology, capsule endoscopy may one day replace traditional gastroscopy as a diagnostic modality, whereas endoscopic ultrasound may more precisely guide interventional therapy for gastric varices. PMID:22830037

  13. Endoscopic resection of subepithelial tumors

    PubMed Central

    Schmidt, Arthur; Bauder, Markus; Riecken, Bettina; Caca, Karel

    2014-01-01

    Management of subepithelial tumors (SETs) remains challenging. Endoscopic ultrasound (EUS) has improved differential diagnosis of these tumors but a definitive diagnosis on EUS findings alone can be achieved in the minority of cases. Complete endoscopic resection may provide a reasonable approach for tissue acquisition and may also be therapeutic in case of malignant lesions. Small SET restricted to the submucosa can be removed with established basic resection techniques. However, resection of SET arising from deeper layers of the gastrointestinal wall requires advanced endoscopic methods and harbours the risk of perforation. Innovative techniques such as submucosal tunneling and full thickness resection have expanded the frontiers of endoscopic therapy in the past years. This review will give an overview about endoscopic resection techniques of SET with a focus on novel methods. PMID:25512768

  14. Endoscopic Therapy in Chronic Pancreatitis

    PubMed Central

    Tan, Damien Meng Yew

    2011-01-01

    Chronic pancreatitis (CP) is a debilitating disease that can result in chronic abdominal pain, malnutrition, and other related complications. The main aims of treatment are to control symptoms, prevent disease progression, and correct any complications. A multidisciplinary approach involving medical, endoscopic, and surgical therapy is important. Endoscopic therapy plays a specific role in carefully selected patients as primary interventional therapy when medical measures fail or in patients who are not suitable for surgery. Endoscopic therapy is also used as a bridge to surgery or as a means to assess the potential response to pancreatic surgery. This review addresses the role of endoscopic therapy in relief of obstruction of the pancreatic duct (PD) and bile du ct, closure of PD leaks, and drainage of pseudocysts in CP. The role of endoscopic ultrasound-guided celiac plexus block for pain in chronic pancreatitis is also discussed. PMID:22205838

  15. From supersonic shear wave imaging to full-field optical coherence shear wave elastography

    NASA Astrophysics Data System (ADS)

    Nahas, Amir; Tanter, Mickaël; Nguyen, Thu-Mai; Chassot, Jean-Marie; Fink, Mathias; Claude Boccara, A.

    2013-12-01

    Elasticity maps of tissue have proved to be particularly useful in providing complementary contrast to ultrasonic imaging, e.g., for cancer diagnosis at the millimeter scale. Optical coherence tomography (OCT) offers an endogenous contrast based on singly backscattered optical waves. Adding complementary contrast to OCT images by recording elasticity maps could also be valuable in improving OCT-based diagnosis at the microscopic scale. Static elastography has been successfully coupled with full-field OCT (FF-OCT) in order to realize both micrometer-scale sectioning and elasticity maps. Nevertheless, static elastography presents a number of drawbacks, mainly when stiffness quantification is required. Here, we describe the combination of two methods: transient elastography, based on speed measurements of shear waves induced by ultrasonic radiation forces, and FF-OCT, an en face OCT approach using an incoherent light source. The use of an ultrafast ultrasonic scanner and an ultrafast camera working at 10,000 to 30,000 images/s made it possible to follow shear wave propagation with both modalities. As expected, FF-OCT is found to be much more sensitive than ultrafast ultrasound to tiny shear vibrations (a few nanometers and micrometers, respectively). Stiffness assessed in gel phantoms and an ex vivo rat brain by FF-OCT is found to be in good agreement with ultrasound shear wave elastography.

  16. Mapping tissue shear modulus on Thiel soft-embalmed mouse skin with shear wave optical coherence elastography

    NASA Astrophysics Data System (ADS)

    Song, Shaozhen; Joy, Joyce; Wang, Ruikang K.; Huang, Zhihong

    2015-03-01

    A quantitative measurement of the mechanical properties of biological tissue is a useful assessment of its physiologic conditions, which may aid medical diagnosis and treatment of, e.g., scleroderma and skin cancer. Traditional elastography techniques such as magnetic resonance elastography and ultrasound elastography have limited scope of application on skin due to insufficient spatial resolution. Recently, dynamic / transient elastography are attracting more applications with the advantage of non-destructive measurements, and revealing the absolute moduli values of tissue mechanical properties. Shear wave optical coherence elastography (SW-OCE) is a novel transient elastography method, which lays emphasis on the propagation of dynamic mechanical waves. In this study, high speed shear wave imaging technique was applied to a range of soft-embalmed mouse skin, where 3 kHz shear waves were launched with a piezoelectric actuator as an external excitation. The shear wave velocity was estimated from the shear wave images, and used to recover a shear modulus map in the same OCT imaging range. Results revealed significant difference in shear modulus and structure in compliance with gender, and images on fresh mouse skin are also compared. Thiel embalming technique is also proven to present the ability to furthest preserve the mechanical property of biological tissue. The experiment results suggest that SW-OCE is an effective technique for quantitative estimation of skin tissue biomechanical status.

  17. Endoscopic and endosonography guided fine-needle aspiration.

    PubMed

    Antillon, M R; Chang, K J

    2000-10-01

    Endoscopic ultrasound-guided fine-needle aspiration is emerging as the preferred technique for the cytologic diagnosis of various gastrointestinal lesions. This technique may not be routinely available, but there is still a role for endoscopic or endoscopic ultrasound-assisted fine-needle aspiration. This article provides an overview of the evolution of these various techniques and discusses the advantages, disadvantages, indications, and contraindications of each. PMID:11036536

  18. Feasibility of monitoring HIFU prostate cancer therapy using elastography

    NASA Astrophysics Data System (ADS)

    Souchon, Remi; Chapelon, Jean Y.; Bertrand, Michel J.; Kallel, Faouzi; Ophir, Jonathan

    2001-05-01

    The objective of this study is to investigate the feasibility of elastographic monitoring of High Intensity Focused Ultrasound (HIFU) therapy of prostate cancer. Elastography is an imaging technique based on strain estimation in soft tissues under quasi-static compression. Since pathological tissues and HIFU-induced lesions exhibit different elastic properties than normal tissues, elastography is potentially able to achieve these goals. An ultrasound scanner was connected to a PC to acquire RF images. This setup is compatible with a HIFU device used for prostate cancer therapy by transrectal route. The therapy transducer and the biplane-imaging probe are covered with a balloon filled with a coupling liquid. Compression of the prostate is applied by inflating the balloon, while imaging sector scans of the prostate. In-vivo elastograms of the prostate were acquired before HIFU treatment. Problems inherent to in-vivo acquisitions are reported, such as undesired tangential displacements during the radial compression. This study shows the potential for in-vivo elastogram acquisition of HIFU-induced lesions in the human prostate.

  19. Diagnostic Value of Elastography in the Diagnosis of Intermetatarsal Neuroma.

    PubMed

    Ormeci, Tugrul; Güler, Olcay; Malkoc, Melih; Keskinbora, Mert; Güngören, Fatma Zeynep; Mahirogulları, Mahir

    2016-01-01

    The objective of the present study was to characterize the ultrasound and elastographic properties of intermetatarsal neuroma (interdigital neuroma) and their contribution to diagnosis. Eighteen patients with metatarsalgia, who had presented to an orthopedic clinic from April 2013 to February 2015, were diagnosed with 25 intermetatarsal neuromas (11 unilateral [61.11%], 7 bilateral [38.89%]). These patients underwent evaluation with ultrasonography and simultaneous ultrasound strain elastography to assess the elastographic properties of the tissues in the intermetatarsal space. The intermetatarsal neuroma diagnosis was confirmed by histopathologic inspection. The lesion contours, localization, dimensions, and vascularization were evaluated before surgical excision. The elasticity and strain ratio values were compared between the neuroma and adjacent healthy intermetatarsal space. Of the 25 intermetatarsal neuromas, 1 (4%) was not detected by ultrasonography (incidence of detection of 96%). The mean neuroma width was 6.35 (range 3.7 to 13) mm in the coronal plane, and the mean elasticity and strain ratio values were 3.44 (range 1.1 to 5.1) and 9.47 (range 2.3 to 19.3), respectively. The elasticity and strain ratio values were significantly greater in the presence of an interdigital neuroma than in the adjacent healthy intermetatarsal spaces (Z = -3.964, p = .0001 and Z = -3.927, p = .0001, respectively). The diagnostic cutoff values were calculated as 2.52 for elasticity and 6.1 for the strain ratio. Four neuromas (16%) were not demarcated, and the elasticity and strain ratio values for these were lower than those for neuromas with demarcated contours but were greater than those for healthy intermetatarsal spaces (p < .006 and p < .005, respectively). Patients with clinically suspected intermetatarsal neuromas that do not show demarcation and with smaller lesions might benefit from the use of ultrasound elastography for diagnosis. PMID:26964696

  20. Ultrasound elastographic techniques in focal liver lesions

    PubMed Central

    Conti, Clara Benedetta; Cavalcoli, Federica; Fraquelli, Mirella; Conte, Dario; Massironi, Sara

    2016-01-01

    Elastographic techniques are new ultrasound-based imaging techniques developed to estimate tissue deformability/stiffness. Several ultrasound elastographic approaches have been developed, such as static elastography, transient elastography and acoustic radiation force imaging methods, which include point shear wave and shear wave imaging elastography. The application of these methods in clinical practice aims at estimating the mechanical tissues properties. One of the main settings for the application of these tools has been liver stiffness assessment in chronic liver disease, which has been studied mainly using transient elastography. Another field of application for these techniques is the assessment of focal lesions, detected by ultrasound in organs such as pancreas, prostate, breast, thyroid, lymph nodes. Considering the frequency and importance of the detection of focal liver lesions through routine ultrasound, some studies have also aimed to assess the role that elestography can play in studying the stiffness of different types of liver lesions, in order to predict their nature and thus offer valuable non-invasive methods for the diagnosis of liver masses. PMID:26973405

  1. The Avaibility of Strain Elastography in a Hydatid Cyst – Interobserver Study

    PubMed Central

    Duymuş, Mahmut; Menzilcioğlu, Mehmet Sait; Gök, Mustafa; Erdem, Ahmet; Avcu, Serhat; Kırış, Adem

    2016-01-01

    Summary Background To differentiate the hydatid cyst (HC) types by ultrasound elastography using two different sizes (4 mm and 8 mm) of the region of interest (ROI) and asking two different radiologists (interobserver) for their opinion. Material/Methods Patients with HC were evaluated by USG elastography. The statistical anayses were performed using Strain index (SI) which is the unit of strain elastography. Results A total of 26 out of 33 patients were female, and 7 were male. The mean age was 38.85±17.62 (range from 10 to 72 years). Type I: 6, Type 2: 6, Type III: 6, Type IV: 11, Type V: 4. There was no significant difference in HC SI (regardless of types) between O1 and O2, and 4-mm and 8-mm ROI (p>0.05). There was no statistically significant difference between SI of HC types of interobservers (O1–O2) and ROI sizes (4–8 mm) (p>0.05 for all parameters). The highest correlation between HC types and ROI sizes was in ROI size of 4 mm. Conclusions The correlation between SI and types was reliable in standard-applied 4-mm ROI. There was no statistically significant difference between interobservers in SI values. Thus, elastography tecnhnique is objective for HC but not appropriate to differentiate the types. PMID:27429674

  2. A novel shape similarity based elastography system for prostate cancer assessment

    NASA Astrophysics Data System (ADS)

    Wang, Haisu; Mousavi, Seyed Reza; Samani, Abbas

    2012-03-01

    Prostate cancer is the second common cancer among men worldwide and remains the second leading cancer-related cause of death in mature men. The disease can be cured if it is detected at early stage. This implies that prostate cancer detection at early stage is very critical for desirable treatment outcome. Conventional techniques of prostate cancer screening and detection, such as Digital Rectal Examination (DRE), Prostate-Specific Antigen (PSA) and Trans Rectal Ultra-Sonography (TRUS), are known to have low sensitivity and specificity. Elastography is an imaging technique that uses tissue stiffness as contrast mechanism. As the association between the degree of prostate tissue stiffness alteration and its pathology is well established, elastography can potentially detect prostate cancer with a high degree of sensitivity and specificity. In this paper, we present a novel elastography technique which, unlike other elastography techniques, does not require displacement data acquisition system. This technique requires the prostate's pre-compression and postcompression transrectal ultrasound images. The conceptual foundation of reconstructing the prostate's normal and pathological tissues elastic moduli is to determine these moduli such that the similarity between calculated and observed shape features of the post compression prostate image is maximized. Results indicate that this technique is highly accurate and robust.

  3. Pediatric Cardiac Shear Wave Elastography for Quantitative Assessment of Myocardial Stiffness: A Pilot Study in Healthy Controls.

    PubMed

    Song, Pengfei; Bi, Xiaojun; Mellema, Daniel C; Manduca, Armando; Urban, Matthew W; Pellikka, Patricia A; Chen, Shigao; Greenleaf, James F

    2016-08-01

    The long-term goal of this study is to assess chemotherapy-induced cardiotoxicity for pediatric cancer patients using cardiac ultrasound shear wave (SW) elastography. This pilot study aimed to systematically investigate the feasibility of using cardiac SW elastography in children and provide myocardial stiffness control data for cancer patients. Twenty healthy volunteers (ages 5-18) were recruited. A novel cardiac SW elastography sequence with pulse-inversion harmonic imaging and time-aligned sequential tracking was developed for this study. Cardiac SW elastography produces and detects transient SWs propagating in the myocardium in late-diastole, which can be used to quantify myocardial stiffness. The parasternal long-axis (L-A) and short-axis (S-A) views of the interventricular septum (IVS) were feasible for pediatric cardiac SW elastography. The L-A and S-A views of the basal and mid IVS provided better success rates than those of the apical IVS. Success rates decreased with increased body mass index (BMI), but did not differ with age or gender. Two-dimensional SW speed measurements were 1.26, 1.22, 1.71 and 1.67 m/s for L-A base, L-A mid, S-A base and S-A mid IVS, respectively. All S-A SW speed values were significantly higher (p < 0.01) than L-A values due to myocardial anisotropy. No SW speed difference was observed for different ages and genders. This pilot study demonstrated, for the first time, the feasibility of using cardiac SW elastography to measure quantitative myocardial stiffness in children, and established control SW speed values for using SW elastography to assess chemo-induced cardiotoxicity for pediatric cancer patients. The results showed that the myocardial anisotropy needs to be accounted for when comparing SW speed from different imaging axes. PMID:27140522

  4. In vivo time-harmonic multifrequency elastography of the human liver

    NASA Astrophysics Data System (ADS)

    Tzschätzsch, Heiko; Ipek-Ugay, Selcan; Guo, Jing; Streitberger, Kaspar-Josche; Gentz, Enno; Fischer, Thomas; Klaua, Robert; Schultz, Michael; Braun, Jürgen; Sack, Ingolf

    2014-04-01

    Elastography is capable of noninvasively detecting hepatic fibrosis by imposing mechanical stress and measuring the viscoelastic response in the liver. Magnetic resonance elastography (MRE) relies on time-harmonic vibrations, while most dynamic ultrasound elastography methods employ transient stimulation methods. This study attempts to benefit from the advantages of time-harmonic tissue stimulation, i.e. relative insensitivity to obesity and ascites and mechanical approachability of the entire liver, and the advantages of ultrasound, i.e. time efficiency, low costs, and wide availability, by introducing in vivo time-harmonic elastography (THE) of the human liver using ultrasound and a broad range of harmonic stimulation frequencies. THE employs continuous harmonic shear vibrations at 7 frequencies from 30 to 60 Hz in a single examination and determines the elasticity and the viscosity of the liver from the dispersion of the shear wave speed within the applied frequency range. The feasibility of the method is demonstrated in the livers of eight healthy volunteers and a patient with cirrhosis. Multifrequency MRE at the same drive frequencies was used as elastographic reference method. Similar values of shear modulus and shear viscosity according the Kelvin-Voigt model were obtained by MRE and THE, indicating that the new method is suitable for in vivo quantification of the shear viscoelastic properties of the liver, however, in real-time and at a fraction of the costs of MRE. In conclusion, THE may provide a useful tool for fast assessment of the viscoelastic properties of the liver at low costs and without limitations in obesity, ascites or hemochromatosis.

  5. In vivo time-harmonic multifrequency elastography of the human liver.

    PubMed

    Tzschätzsch, Heiko; Ipek-Ugay, Selcan; Guo, Jing; Streitberger, Kaspar-Josche; Gentz, Enno; Fischer, Thomas; Klaua, Robert; Schultz, Michael; Braun, Jürgen; Sack, Ingolf

    2014-04-01

    Elastography is capable of noninvasively detecting hepatic fibrosis by imposing mechanical stress and measuring the viscoelastic response in the liver. Magnetic resonance elastography (MRE) relies on time-harmonic vibrations, while most dynamic ultrasound elastography methods employ transient stimulation methods. This study attempts to benefit from the advantages of time-harmonic tissue stimulation, i.e. relative insensitivity to obesity and ascites and mechanical approachability of the entire liver, and the advantages of ultrasound, i.e. time efficiency, low costs, and wide availability, by introducing in vivo time-harmonic elastography (THE) of the human liver using ultrasound and a broad range of harmonic stimulation frequencies. THE employs continuous harmonic shear vibrations at 7 frequencies from 30 to 60 Hz in a single examination and determines the elasticity and the viscosity of the liver from the dispersion of the shear wave speed within the applied frequency range. The feasibility of the method is demonstrated in the livers of eight healthy volunteers and a patient with cirrhosis. Multifrequency MRE at the same drive frequencies was used as elastographic reference method. Similar values of shear modulus and shear viscosity according the Kelvin-Voigt model were obtained by MRE and THE, indicating that the new method is suitable for in vivo quantification of the shear viscoelastic properties of the liver, however, in real-time and at a fraction of the costs of MRE. In conclusion, THE may provide a useful tool for fast assessment of the viscoelastic properties of the liver at low costs and without limitations in obesity, ascites or hemochromatosis. PMID:24614751

  6. Endoscopic mediastinal staging of lung cancer.

    PubMed

    Khoo, Kay-Leong; Ho, Khek-Yu

    2011-04-01

    The advent of endoscopic ultrasound-guided sampling procedures such as endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has lead to significant advances in the mediastinal diagnosis and staging of lung cancer. These endoscopic techniques can be performed in the outpatient setting under conscious sedation and local anesthesia, in contrast to the surgical standard, mediastinoscopy (MS), which requires operating theatre time and general anesthesia. Proponents of mediastinoscopy have always emphasized the advantages of mediastinoscopy, namely its sensitivity even with a low prevalence of mediastinal metastases and its low false negative rate. Newer endoscopic techniques such as EBUS-TBNA are showing sensitivities exceeding that of mediastinoscopy, even in the setting of an equally low prevalence of mediastinal metastases. However, endoscopic techniques have double the false negative rate of mediastinoscopy. As the tracheobronchial route and esophageal route provide almost complete access to mediastinal lymph nodes, these endoscopic techniques are complementary rather than competing. When used in combination, it is possible mediastinoscopy may be superseded. The challenge however, is how best to select the appropriate endoscopic procedures to accurately stage lung cancer in the most cost-effective manner. PMID:21130638

  7. Duplex ultrasound

    MedlinePlus

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

  8. Real-time two-dimensional shear wave ultrasound elastography of the liver is a reliable predictor of clinical outcomes and the presence of esophageal varices in patients with compensated liver cirrhosis

    PubMed Central

    Grgurević, Ivica; Bokun, Tomislav; Mustapić, Sanda; Trkulja, Vladimir; Heinzl, Renata; Banić, Marko; Puljiz, Željko; Lukšić, Boris; Kujundžić, Milan

    2015-01-01

    Aim Primary: to evaluate predictivity of liver stiffness (LS), spleen stiffness (SS), and their ratio assessed by real-time 2D shear wave elastography (RT-2D-SWE) for adverse outcomes (hepatic decompensation, hepatocellular carcinoma or death; “event”) in compensated liver cirrhosis (LC) patients. Secondary: to evaluate ability of these measures to discriminate between cirrhotic patients with/without esophageal varices (EV). Methods Predictivity of LS, SS, and LS/SS was assessed in a retrospectively analyzed cohort of compensated LC patients (follow-up cohort) and through comparison with incident patients with decompensated cirrhosis (DC) (cross-sectional cohort). Both cohorts were used to evaluate diagnostic properties regarding EV. Results In the follow-up cohort (n = 44) 18 patients (40.9%) experienced an “event” over a median period of 28 months. LS≥21.5 kPa at baseline was independently associated with 3.4-fold (95% confidence interval [CI] 1.16-10.4, P = 0.026) higher risk of event. Association between SS and outcomes was weaker (P = 0.056), while there was no association between LS/SS ratio and outcomes. Patients with DC (n = 43) had higher LS (35.3 vs 18.3 kPa, adjusted difference 65%, 95% CI 43%-90%; P < 0.001) than compensated patients at baseline. Adjusted odds of EV increased by 13% (95% CI 7.0%-20.0%; P < 0.001) with 1 kPa increase in LS. At cut-offs of 19.7 and 30.3 kPa, LS and SS had 90% and 86.6% negative predictive value, respectively, to exclude EV in compensated patients. Conclusion This is the first evaluation of RT-2D-SWE as a prognostic tool in LC. Although preliminary and gathered in a limited sample, our data emphasize the potential of LS to be a reliable predictor of clinical outcomes and the presence of EV in LC patients. PMID:26526884

  9. Acoustic Radiation Force Impulse Elastography in the Diagnosis of Thyroid Nodules: Useful or Not Useful?

    PubMed

    Zhang, Yi-Feng; Xu, Hui-Xiong; Xu, Jun-Mei; Liu, Chang; Guo, Le-Hang; Liu, Lin-Na; Zhang, Jing; Xu, Xiao-Hong; Qu, Shen; Xing, Mingzhao

    2015-10-01

    The goal of this study is to evaluate the diagnostic performance of acoustic radiation force impulse (ARFI) elastography for differentiating benign from malignant thyroid nodules. One hundred and seventy-four pathologically proven thyroid nodules (139 benign, 35 malignant) in 154 patients (mean age: 49.2 ± 12.1 y; range: 16-72 y) were included in this study. Conventional ultrasound (US) and ARFI elastography using virtual touch tissue imaging (VTI) and virtual touch tissue quantification (VTQ) were performed to examine the thyroid nodules. Two blinded readers with different amounts of experience independently scored the likelihood of malignancy on the basis of a five-point scale in three different image-reading sets. The diagnostic performances among different image-reading sets and between the two readers were compared. The diagnostic specificity of both readers improved significantly after reading the VTI images or both VTI and VTQ images (all p < 0.05). After review of the results of both VTI and VTQ, the numbers of correctly diagnosed nodules increased in nodules <1.0 cm for both readers and in both nodular goiter and papillary thyroid carcinoma for the junior reader (p < 0.05). The nodules with definite diagnoses (i.e., confidence levels including definite benign and definite malignant cases) increased after review of VTI and VTQ images versus conventional US for the senior reader (p < 0.05). In conclusion, adding ARFI elastography improves the specificity in diagnosing malignant thyroid nodules compared with conventional US on its own. ARFI elastography particularly facilitates the specific diagnosis for thyroid nodules smaller than 1.0 cm. ARFI elastography is also able to increase the diagnostic confidence of the readers. PMID:26119458

  10. Advanced endoscopic imaging of indeterminate biliary strictures

    PubMed Central

    Tabibian, James H; Visrodia, Kavel H; Levy, Michael J; Gostout, Christopher J

    2015-01-01

    Endoscopic evaluation of indeterminate biliary strictures (IDBSs) has evolved considerably since the development of flexible fiberoptic endoscopes over 50 years ago. Endoscopic retrograde cholangiography pancreatography (ERCP) was introduced nearly a decade later and has since become the mainstay of therapy for relieving obstruction of the biliary tract. However, longstanding methods of ERCP-guided tissue acquisition (i.e., biliary brushings for cytology and intraductal forceps biopsy for histology) have demonstrated disappointing performance characteristics in distinguishing malignant from benign etiologies of IDBSs. The limitations of these methods have thus helped drive the search for novel techniques to enhance the evaluation of IDBSs and thereby improve diagnosis and clinical care. These modalities include, but are not limited to, endoscopic ultrasound, intraductal ultrasound, cholangioscopy, confocal endomicroscopy, and optical coherence tomography. In this review, we discuss established and emerging options in the evaluation of IDBSs. PMID:26675379

  11. Swept-source anatomic optical coherence elastography of porcine trachea

    NASA Astrophysics Data System (ADS)

    Bu, Ruofei; Price, Hillel; Mitran, Sorin; Zdanski, Carlton; Oldenburg, Amy L.

    2016-02-01

    Quantitative endoscopic imaging is at the vanguard of novel techniques in the assessment upper airway obstruction. Anatomic optical coherence tomography (aOCT) has the potential to provide the geometry of the airway lumen with high-resolution and in 4 dimensions. By coupling aOCT with measurements of pressure, optical coherence elastography (OCE) can be performed to characterize airway wall stiffness. This can aid in identifying regions of dynamic collapse as well as informing computational fluid dynamics modeling to aid in surgical decision-making. Toward this end, here we report on an anatomic optical coherence tomography (aOCT) system powered by a wavelength-swept laser source. The system employs a fiber-optic catheter with outer diameter of 0.82 mm deployed via the bore of a commercial, flexible bronchoscope. Helical scans are performed to measure the airway geometry and to quantify the cross-sectional-area (CSA) of the airway. We report on a preliminary validation of aOCT for elastography, in which aOCT-derived CSA was obtained as a function of pressure to estimate airway wall compliance. Experiments performed on a Latex rubber tube resulted in a compliance measurement of 0.68+/-0.02 mm2/cmH2O, with R2=0.98 over the pressure range from 10 to 40 cmH2O. Next, ex vivo porcine trachea was studied, resulting in a measured compliance from 1.06+/-0.12 to 3.34+/-0.44 mm2/cmH2O, (R2>0.81). The linearity of the data confirms the elastic nature of the airway. The compliance values are within the same order-of-magnitude as previous measurements of human upper airways, suggesting that this system is capable of assessing airway wall compliance in future human studies.

  12. Endoscopic management of chronic pancreatitis

    PubMed Central

    Oza, Veeral M; Kahaleh, Michel

    2013-01-01

    Chronic pancreatitis (CP) is a common gastrointestinal illness, which affects the quality of life with substantial morbidity and mortality. The management includes medical, endoscopic and surgical approaches with the need for interaction between various specialties, calling for a concerted multidisciplinary approach. However, at the time of this publication, guidelines to establish care of these patients are lacking. This review provides the reader with a comprehensive overview of the studies summarizing the various treatment options available, including medical, surgical and endoscopic options. In addition, technological advances such as endoscopic retrograde cholangiopancreatogrophy, endoscopic shock wave lithotripsy and endoscopic ultrasound can now be offered with reasonable success for pancreatic decompression, stricture dilatation with stent placement, stone fragmentation, pseudocyst drainage, and other endoscopic interventions such as celiac plexus block for pain relief. We emphasize the endoscopic options in this review, and attempt to extract the most up to date information from the current literature. The treatment of CP and its complications are discussed extensively. Complications such as biliary strictures. pancreatic pseudocysts, and chronic pain are common issues that arise as long-term complications of CP. These often require endoscopic or surgical management and possibly a combination of approaches, however choosing amongst the various therapeutic and palliative modalities while weighing the risks and benefits, makes the management of CP challenging. Treatment goals should be not just to control symptoms but also to prevent disease progression. Our aim in this paper is to advocate and emphasize an evidence based approach for the management of CP and associated long term complications. PMID:23330050

  13. Endoscopic management of hilar biliary strictures

    PubMed Central

    Singh, Rajiv Ranjan; Singh, Virendra

    2015-01-01

    Hilar biliary strictures are caused by various benign and malignant conditions. It is difficult to differentiate benign and malignant strictures. Postcholecystectomy benign biliary strictures are frequently encountered. Endoscopic management of these strictures is challenging. An endoscopic method has been advocated that involves placement of increasing number of stents at regular intervals to resolve the stricture. Malignant hilar strictures are mostly unresectable at the time of diagnosis and only palliation is possible.Endoscopic palliation is preferred over surgery or radiological intervention. Magnetic resonance cholangiopancreaticography is quite important in the management of these strictures. Metal stents are superior to plastic stents. The opinion is divided over the issue of unilateral or bilateral stenting.Minimal contrast or no contrast technique has been advocated during endoscopic retrograde cholangiopancreatography of these patients. The role of intraluminal brachytherapy, intraductal ablation devices, photodynamic therapy, and endoscopic ultrasound still remains to be defined. PMID:26191345

  14. Endoscopic management of hilar biliary strictures.

    PubMed

    Singh, Rajiv Ranjan; Singh, Virendra

    2015-07-10

    Hilar biliary strictures are caused by various benign and malignant conditions. It is difficult to differentiate benign and malignant strictures. Postcholecystectomy benign biliary strictures are frequently encountered. Endoscopic management of these strictures is challenging. An endoscopic method has been advocated that involves placement of increasing number of stents at regular intervals to resolve the stricture. Malignant hilar strictures are mostly unresectable at the time of diagnosis and only palliation is possible.Endoscopic palliation is preferred over surgery or radiological intervention. Magnetic resonance cholangiopancreaticography is quite important in the management of these strictures. Metal stents are superior to plastic stents. The opinion is divided over the issue of unilateral or bilateral stenting.Minimal contrast or no contrast technique has been advocated during endoscopic retrograde cholangiopancreatography of these patients. The role of intraluminal brachytherapy, intraductal ablation devices, photodynamic therapy, and endoscopic ultrasound still remains to be defined. PMID:26191345

  15. Magnetic resonance elastography of abdomen.

    PubMed

    Venkatesh, Sudhakar Kundapur; Ehman, Richard L

    2015-04-01

    Many diseases cause substantial changes in the mechanical properties of tissue, and this provides motivation for developing methods to noninvasively assess the stiffness of tissue using imaging technology. Magnetic resonance elastography (MRE) has emerged as a versatile MRI-based technique, based on direct visualization of propagating shear waves in the tissues. The most established clinical application of MRE in the abdomen is in chronic liver disease. MRE is currently regarded as the most accurate noninvasive technique for detection and staging of liver fibrosis. Increasing experience and ongoing research is leading to exploration of applications in other abdominal organs. In this review article, the current use of MRE in liver disease and the potential future applications of this technology in other parts of the abdomen are surveyed. PMID:25488346

  16. Quantitative photoacoustic elastography in humans

    NASA Astrophysics Data System (ADS)

    Hai, Pengfei; Zhou, Yong; Gong, Lei; Wang, Lihong V.

    2016-06-01

    We report quantitative photoacoustic elastography (QPAE) capable of measuring Young's modulus of biological tissue in vivo in humans. By combining conventional PAE with a stress sensor having known stress-strain behavior, QPAE can simultaneously measure strain and stress, from which Young's modulus is calculated. We first demonstrate the feasibility of QPAE in agar phantoms with different concentrations. The measured Young's modulus values fit well with both the empirical expectation based on the agar concentrations and those measured in an independent standard compression test. Next, QPAE was applied to quantify the Young's modulus of skeletal muscle in vivo in humans, showing a linear relationship between muscle stiffness and loading. The results demonstrated the capability of QPAE to assess the absolute elasticity of biological tissue noninvasively in vivo in humans, indicating its potential for tissue biomechanics studies and clinical applications.

  17. Magnetic Resonance Elastography of Abdomen

    PubMed Central

    Venkatesh, Sudhakar K.; Ehman, Richard L.

    2015-01-01

    Many diseases cause substantial changes in the mechanical properties of tissue and this provides motivation for developing methods to non-invasively assess the stiffness of tissue using imaging technology. Magnetic resonance elastography (MRE) has emerged as a versatile MRI-based technique, based on direct visualization of propagating shear waves in the tissues. The most established clinical application of MRE in the abdomen is in chronic liver disease. MRE is currently regarded as the most accurate non-invasive technique for detection and staging of liver fibrosis. Increasing experience and ongoing research is leading to exploration of applications in other abdominal organs. In this review article, the current use of MRE in liver disease and the potential future applications of this technology in other parts of the abdomen are surveyed. PMID:25488346

  18. Fabrication and Performance of Endoscopic Ultrasound Radial Arrays Based on PMN-PT Single Crystal/Epoxy 1-3 Composite

    PubMed Central

    Zhou, Dan; Cheung, Kwok Fung; Chen, Yan; Lau, Sien Ting; Zhou, Qifa; Shung, K. Kirk; Luo, Hao Su; Dai, Jiyan; Chan, Helen Lai Wa

    2011-01-01

    In this paper, 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (PMN-PT) single crystal/epoxy 1–3 composite was used as the active material of the endoscopic ultrasonic radial array transducer, because this composite exhibited ultrahigh electromechanical coupling coefficient (kt = 0.81%), very low mechanical quality factor (Qm = 11) and relatively low acoustic impedance (Zt = 12 MRayls). A 6.91 MHz PMN-PT/epoxy 1–3 composite radial array transducer with 64 elements was tested in a pulse-echo response measurement. The −6-dB bandwidth of the composite array transducer was 102%, which was ~30% larger than that of traditional lead zirconate titanate array transducer. The two-way insertion loss was found to be −32.3 dB. The obtained results show that this broadband array transducer is promising for acquiring high-resolution endoscopic ultrasonic images in many clinical applications. PMID:21342833

  19. Clinical utility of endoscopic ultrasound-guided fine-needle aspiration in mixed adenoneuroendocrine carcinoma with signet-ring cells of the pancreas: a case report and review of the literature.

    PubMed

    Kaji, Kiichiro; Seishima, Jun; Yamato, Masatoshi; Miyazawa, Masaki; Komura, Takuya; Marukawa, Yohei; Ohta, Hajime; Kasashima, Satomi; Kawashima, Atsuhiro; Yano, Masaaki; Unoura, Masashi

    2016-02-01

    A man in his 60s visited our hospital because of a pancreatic head tumor. Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) revealed that the tumor consisted of a neuroendocrine carcinoma (NEC) and adenocarcinoma, including signet-ring cell carcinoma, and that the ratio of these components was approximately 50:50. Therefore, he was diagnosed with mixed adenoneuroendocrine carcinoma (MANEC). Because of liver and lymph node metastases, systemic chemotherapy was initiated using a regimen for the NEC component based on an increase in neuron-specific enolase (NSE). Although the patient achieved stable disease after two chemotherapy cycles, the tumor increased in size after three cycles, which was associated with a gradual increase in carcinoembryonic antigen and a decrease in NSE level. An EUS-FNA reexamination revealed that the adenocarcinoma component accounted for 90 % of the tumor. Thus, an adenocarcinoma chemotherapy regimen was started, and a slight reduction in tumor size was observed. Here, we report an extremely rare and remarkable case of MANEC of the pancreas that demonstrates the effectiveness of EUS-FNA for helping to decide the chemotherapy regimen. PMID:26848585

  20. Tabletop magnetic resonance elastography for the measurement of viscoelastic parameters of small tissue samples

    NASA Astrophysics Data System (ADS)

    Ipek-Ugay, Selcan; Drießle, Toni; Ledwig, Michael; Guo, Jing; Hirsch, Sebastian; Sack, Ingolf; Braun, Jürgen

    2015-02-01

    We demonstrate the feasibility of low-cost tabletop MR elastography (MRE) for quantifying the complex shear modulus G∗ of small soft biological tissue samples as provided by pathologists. The MRE system was developed based on a tabletop MRI scanner equipped with a 0.5 T permanent magnet and a tissue sample holder mounted to a loudspeaker. A spin echo sequence was enhanced with motion-encoding gradients of 250 mT/m amplitude synchronized to acoustic vibration frequencies. Shear wave images suitable for elastography were acquired between vibration frequencies of 0.5 and 1 kHz in agarose, ultrasound gel, porcine liver, porcine skeletal muscle, and bovine heart with a spatial resolution of 234 μm pixel edge length. The measured frequency dependence of G∗ agreed well with previous work based on high-field MR systems. The ratio between loss and storage moduli was highest in liver and ultrasound gel, followed by muscle tissue and agarose gel while ultrasound gel and liver showed similarly low storage moduli compared to the other samples. The shear wave to noise ratio is an important imaging criteria for MRE and was about 4.2 times lower for the preliminary setup of the 0.5 T tabletop system compared to a 7 T animal scanner. In the future, the new tabletop MRE system may serve as a low cost device for preclinical research on the correlation of viscoelastic parameters with histopathology of biological samples.

  1. Tabletop magnetic resonance elastography for the measurement of viscoelastic parameters of small tissue samples.

    PubMed

    Ipek-Ugay, Selcan; Drießle, Toni; Ledwig, Michael; Guo, Jing; Hirsch, Sebastian; Sack, Ingolf; Braun, Jürgen

    2015-02-01

    We demonstrate the feasibility of low-cost tabletop MR elastography (MRE) for quantifying the complex shear modulus G(∗) of small soft biological tissue samples as provided by pathologists. The MRE system was developed based on a tabletop MRI scanner equipped with a 0.5 T permanent magnet and a tissue sample holder mounted to a loudspeaker. A spin echo sequence was enhanced with motion-encoding gradients of 250 mT/m amplitude synchronized to acoustic vibration frequencies. Shear wave images suitable for elastography were acquired between vibration frequencies of 0.5 and 1 kHz in agarose, ultrasound gel, porcine liver, porcine skeletal muscle, and bovine heart with a spatial resolution of 234 μm pixel edge length. The measured frequency dependence of G(∗) agreed well with previous work based on high-field MR systems. The ratio between loss and storage moduli was highest in liver and ultrasound gel, followed by muscle tissue and agarose gel while ultrasound gel and liver showed similarly low storage moduli compared to the other samples. The shear wave to noise ratio is an important imaging criteria for MRE and was about 4.2 times lower for the preliminary setup of the 0.5 T tabletop system compared to a 7 T animal scanner. In the future, the new tabletop MRE system may serve as a low cost device for preclinical research on the correlation of viscoelastic parameters with histopathology of biological samples. PMID:25554945

  2. Maximum likelihood estimation of shear wave speed in transient elastography.

    PubMed

    Audière, Stéphane; Angelini, Elsa D; Sandrin, Laurent; Charbit, Maurice

    2014-06-01

    Ultrasonic transient elastography (TE), enables to assess, under active mechanical constraints, the elasticity of the liver, which correlates with hepatic fibrosis stages. This technique is routinely used in clinical practice to assess noninvasively liver stiffness. The Fibroscan system used in this work generates a shear wave via an impulse stress applied on the surface of the skin and records a temporal series of radio-frequency (RF) lines using a single-element ultrasound probe. A shear wave propagation map (SWPM) is generated as a 2-D map of the displacements along depth and time, derived from the correlations of the sequential 1-D RF lines, assuming that the direction of propagation (DOP) of the shear wave coincides with the ultrasound beam axis (UBA). Under the assumption of pure elastic tissue, elasticity is proportional to the shear wave speed. This paper introduces a novel approach to the processing of the SWPM, deriving the maximum likelihood estimate of the shear wave speed when comparing the observed displacements and the estimates provided by the Green's functions. A simple parametric model is used to interface Green's theoretical values of noisy measures provided by the SWPM, taking into account depth-varying attenuation and time-delay. The proposed method was evaluated on numerical simulations using a finite element method simulator and on physical phantoms. Evaluation on this test database reported very high agreements of shear wave speed measures when DOP and UBA coincide. PMID:24835213

  3. Thyroid Nodules and Shear Wave Elastography: A New Tool in Thyroid Cancer Detection.

    PubMed

    Azizi, Ghobad; Keller, James M; Mayo, Michelle L; Piper, Kelé; Puett, David; Earp, Karly M; Malchoff, Carl D

    2015-11-01

    This study determines the performance of virtual touch imaging quantification (VTIQ), a non-invasive shear wave elastography method for measuring thyroid nodule (TN) stiffness, in distinguishing benign from malignant TNs. This prospective study evaluates 707 TNs in 676 patients with fine-needle aspiration biopsy (FNAB). Before FNAB, both conventional B-mode ultrasound and shear wave elastography were performed. Surgical resection was recommended for FNAB results that were not clearly benign. Surgical pathology confirmed 82 malignant TNs. The receiver operating curve identified a single cut-off of 3.54 m/s as the maximum shear wave velocity (SWV) for predicting thyroid cancer (TC). The sensitivity and specificity were 79.27% and 71.52%, respectively. Positive predictive value (PPV) was 26.75% and negative predictive value (NPV) was 96.34%. Compared with B-mode US features for predicting malignancy, SWV ≥3.54 m/s has a higher sensitivity, specificity, PPV and NPV. TN stiffness measured by VTIQ-generated shear wave elastography is an independent predictor of TC. PMID:26277203

  4. The Shear Wave Velocity on Elastography Correlates with the Clinical Symptoms and Histopathological Features of Keloids

    PubMed Central

    Yamawaki, Satoko; Yoshikawa, Katsuhiro; Katayama, Yasuhiro; Enoshiri, Tatsuki; Naitoh, Motoko; Suzuki, Shigehiko

    2015-01-01

    Background: Keloids present as red, painful lesions causing serious functional and cosmetic problems; however, there is no consensus regarding tools for objectively evaluating keloids. To demonstrate the utility of shear wave elastography in keloids, we investigated the correlations between clinical symptoms, ultrasound shear wave velocity, and histopathological findings. Methods: Three patients with keloids containing both red hypertrophic and mature areas were evaluated using the shear wave velocity and histopathological findings. Results: The results indicate that the shear wave velocity is high in active hypertrophic areas and low in mature areas. The areas with high elastography values exhibited numerous fibrillar collagenous matrices forming a whorled pattern with hyalinized tissue on hematoxylin-eosin staining corresponding with metachromasia on toluidine blue staining. In the mature area, the collagen fibers were oriented parallel to each other without metachromasia. Conclusions: Shear wave elastography provides quantitative estimates of tissue stiffness that correlate with the clinical symptoms and histopathological findings of the keloid lesions and can be used to assess the activity of keloids. PMID:26301153

  5. Nondestructive inspection for internal defects of rail based on photoacoustic elastography

    NASA Astrophysics Data System (ADS)

    Sun, Mingjian; Fu, Ying; Liu, Ting; Cheng, Xingzhen; Leng, Guanji; Feng, Naizhang

    2015-11-01

    Laser ultrasonic technique is used for the nondestructive testing technology of surface damage, but ignores the density variation in the sample. Photoacoustic elastography is adopted to obtain more rail information (such as the internal defects, the variation of sample's interior density) of the sample by collecting Rayleigh wave on rail surface and shear wave within the rail. In this paper, it is proved that the internal defects and the variation of density can be detected by photoacoustic elastography, using finite element analysis (FEA). We first use FEA to simulate the ultrasound excitation on the steel material surface excited by the laser source. Two cases of sample are modeled and analyzed, one is with defects of different depth and the other is with different density. Then, an isotropic model using ANSYS is employed and shear wave propagation is modeled. The preliminary results successfully recapitulate the trend of the change of shear wave's velocities, which shows that the defects can enhance the amplitude of shear wave. In addition, the velocities of shear wave would increase when the density of the sample enlarges. Results from computer simulations demonstrate the effectiveness of photoacoustic elastography with application to quantitative analysis for the structures of sample.

  6. A class of kernel based real-time elastography algorithms.

    PubMed

    Kibria, Md Golam; Hasan, Md Kamrul

    2015-08-01

    In this paper, a novel real-time kernel-based and gradient-based Phase Root Seeking (PRS) algorithm for ultrasound elastography is proposed. The signal-to-noise ratio of the strain image resulting from this method is improved by minimizing the cross-correlation discrepancy between the pre- and post-compression radio frequency signals with an adaptive temporal stretching method and employing built-in smoothing through an exponentially weighted neighborhood kernel in the displacement calculation. Unlike conventional PRS algorithms, displacement due to tissue compression is estimated from the root of the weighted average of the zero-lag cross-correlation phases of the pair of corresponding analytic pre- and post-compression windows in the neighborhood kernel. In addition to the proposed one, the other time- and frequency-domain elastography algorithms (Ara et al., 2013; Hussain et al., 2012; Hasan et al., 2012) proposed by our group are also implemented in real-time using Java where the computations are serially executed or parallely executed in multiple processors with efficient memory management. Simulation results using finite element modeling simulation phantom show that the proposed method significantly improves the strain image quality in terms of elastographic signal-to-noise ratio (SNRe), elastographic contrast-to-noise ratio (CNRe) and mean structural similarity (MSSIM) for strains as high as 4% as compared to other reported techniques in the literature. Strain images obtained for the experimental phantom as well as in vivo breast data of malignant or benign masses also show the efficacy of our proposed method over the other reported techniques in the literature. PMID:25929595

  7. Acoustic radiation force impulse induced strain elastography and point shear wave elastography for evaluation of thyroid nodules

    PubMed Central

    Huang, Xian; Guo, Le-Hang; Xu, Hui-Xiong; Gong, Xue-Hao; Liu, Bo-Ji; Xu, Jun-Mei; Zhang, Yi-Feng; Li, Xiao-Long; Li, Dan-Dan; Qu, Shen; Fang, Lin

    2015-01-01

    The aim of the study was to evaluate the diagnostic performance of acoustic radiation force impulse (ARFI) induced strain elastography (SE), point shear wave elastography (p-SWE), and their combined use in differentiating thyroid nodules. This retrospective study included 155 thyroid nodules (94 benign and 61 malignant) in 136 patients. Ultrasound, ARFI-induced SE and p-SWE were performed on each nodule. Receiver operating characteristic curve (ROC) analyses were performed to assess the diagnostic efficacy of ARFI-induced SE, p-SWE and their combined use to distinguish benign from malignant thyroid nodules with histological results used as the reference standard. The areas under the ROC for ARFI-induced SE, p-SWE, and their combined use were 0.828, 0.829, and 0.840, respectively (both P > 0.05). The specificity of ARFI-induced SE was higher than that of p-SWE as well as their combined use (both P < 0.05). The combination of the two methods significantly improved the diagnostic sensitivity and NPV compared with either ARFI-induced SE or p-SWE alone (both P < 0.05). For nodules ≤ 10 mm, the combination of the two methods significantly improved the diagnostic sensitivity only. For nodules > 10 mm, there were no significant differences in sensitivity and NPV among the three methods in differentiating thyroid nodules (all P > 0.05). In conclusions, ARFI-induced SE and p-SWE are both valuable tools for detecting malignant thyroid nodules. The combined use of ARFI-induced SE and p-SWE improves the diagnostic sensitivity and NPV significantly whereas ARFI-induced SE alone achieves the highest specificity. PMID:26379890

  8. MAGNETIC RESONANCE ELASTOGRAPHY: A REVIEW

    PubMed Central

    Mariappan, Yogesh K; Glaser, Kevin J; Ehman, Richard L

    2011-01-01

    Magnetic Resonance Elastography (MRE) is a rapidly developing technology for quantitatively assessing the mechanical properties of tissue. The technology can be considered to be an imaging-based counterpart to palpation, commonly used by physicians to diagnose and characterize diseases. The success of palpation as a diagnostic method is based on the fact that the mechanical properties of tissues are often dramatically affected by the presence of disease processes such as cancer, inflammation, and fibrosis. MRE obtains information about the stiffness of tissue by assessing the propagation of mechanical waves through the tissue with a special magnetic resonance imaging (MRI) technique. The technique essentially involves three steps: generating shear waves in the tissue,acquiring MR images depicting the propagation of the induced shear waves andprocessing the images of the shear waves to generate quantitative maps of tissue stiffness, called elastograms. MRE is already being used clinically for the assessment of patients with chronic liver diseases and is emerging as a safe, reliable and noninvasive alternative to liver biopsy for staging hepatic fibrosis. MRE is also being investigated for application to pathologies of other organs including the brain, breast, blood vessels, heart, kidneys, lungs and skeletal muscle. The purpose of this review article is to introduce this technology to clinical anatomists and to summarize some of the current clinical applications that are being pursued. PMID:20544947

  9. Endoscopic Sinus Surgery

    MedlinePlus

    ... The nasal endoscope is a small, lighted metal telescope placed into the nostril. The endoscope allows the ... sinus surgery involves the use of a small telescope (nasal endoscope) that is inserted through the nostril ...

  10. Multimodal classification of prostate tissue: a feasibility study on combining multiparametric MRI and ultrasound

    NASA Astrophysics Data System (ADS)

    Ashab, Hussam Al-Deen; Haq, Nandinee Fariah; Nir, Guy; Kozlowski, Piotr; Black, Peter; Jones, Edward C.; Goldenberg, S. Larry; Salcudean, Septimiu E.; Moradi, Mehdi

    2015-03-01

    The common practice for biopsy guidance is through transrectal ultrasound, with the fusion of ultrasound and MRI-based targets when available. However, ultrasound is only used as a guidance modality in MR-targeted ultrasound-guided biopsy, even though previous work has shown the potential utility of ultrasound, particularly ultrasound vibro-elastography, as a tissue typing approach. We argue that multiparametric ultrasound, which includes B-mode and vibro-elastography images, could contain information that is not captured using multiparametric MRI (mpMRI) and therefore play a role in refining the biopsy and treatment strategies. In this work, we combine mpMRI with multiparametric ultrasound features from registered tissue areas to examine the potential improvement in cancer detection. All the images were acquired prior to radical prostatectomy and cancer detection was validated based on 36 whole mount histology slides. We calculated a set of 24 texture features from vibro-elastography and B-mode images, and five features from mpMRI. Then we used recursive feature elimination (RFE) and sparse regression through LASSO to find an optimal set of features to be used for tissue classification. We show that the set of these selected features increases the area under ROC curve from 0.87 with mpMRI alone to 0.94 with the selected mpMRI and multiparametric ultrasound features, when used with support vector machine classification on features extracted from peripheral zone. For features extracted from the whole-gland, the area under the curve was 0.75 and 0.82 for mpMRI and mpMRI along with ultrasound, respectively. These preliminary results provide evidence that ultrasound and ultrasound vibro-elastography could be used as modalities for improved cancer detection in combination with MRI.

  11. Developments in flexible endoscopic surgery: a review

    PubMed Central

    Feussner, Hubertus; Becker, Valentin; Bauer, Margit; Kranzfelder, Michael; Schirren, Rebekka; Lüth, Tim; Meining, Alexander; Wilhelm, Dirk

    2015-01-01

    Flexible endoscopy is increasingly developing into a therapeutic instead of a purely diagnostic discipline. Improved visualization makes early lesions easily detectable and allows us to decide ad hoc on the required treatment. Deep enteroscopy allows the exploration of even the small bowel – for long a “white spot” for gastrointestinal endoscopy – and to perform direct treatment. Endoscopic submucosal dissection is a considerable step forward in oncologically correct endoscopic treatment of (early) malignant lesions. Though still technically challenging, it is increasingly facilitated by new manipulation techniques and tools that are being steadily optimized. Closure of wall defects and hemostasis could be improved significantly. Even the anatomy beyond the gastrointestinal wall is being explored by the therapeutic use of endoluminal ultrasound. Endosonographic-guided surgery is not only a suitable fallback solution if conventional endoscopic retrograde cholangiopancreatography fails, but even makes necrosectomy procedures, abscess drainage, and neurolysis feasible for the endoscopist. Newly developed endoscopic approaches aim at formerly distinctive surgical domains like gastroesophageal reflux disease, appendicitis, and cholecystitis. Combined endoscopic/laparoscopic interventional techniques could become the harbingers of natural orifice transluminal endoscopic surgery, whereas pure natural orifice transluminal endoscopic surgery is currently still in its beginnings. PMID:25565878

  12. Endoscopic Gallbladder Drainage for Acute Cholecystitis

    PubMed Central

    Widmer, Jessica; Alvarez, Paloma; Sharaiha, Reem Z.; Gossain, Sonia; Kedia, Prashant; Sarkaria, Savreet; Sethi, Amrita; Turner, Brian G.; Millman, Jennifer; Lieberman, Michael; Nandakumar, Govind; Umrania, Hiren; Gaidhane, Monica

    2015-01-01

    Background/Aims Surgery is the mainstay of treatment for cholecystitis. However, gallbladder stenting (GBS) has shown promise in debilitated or high-risk patients. Endoscopic transpapillary GBS and endoscopic ultrasound-guided GBS (EUS-GBS) have been proposed as safe and effective modalities for gallbladder drainage. Methods Data from patients with cholecystitis were prospectively collected from August 2004 to May 2013 from two United States academic university hospitals and analyzed retrospectively. The following treatment algorithm was adopted. Endoscopic retrograde cholangiopancreatography (ERCP) with sphincterotomy and cystic duct stenting was initially attempted. If deemed feasible by the endoscopist, EUS-GBS was then pursued. Results During the study period, 139 patients underwent endoscopic gallbladder drainage. Among these, drainage was performed in 94 and 45 cases for benign and malignant indications, respectively. Successful endoscopic gallbladder drainage was defined as decompression of the gallbladder without incidence of cholecystitis, and was achieved with ERCP and cystic duct stenting in 117 of 128 cases (91%). Successful endoscopic gallbladder drainage was also achieved with EUS-guided gallbladder drainage using transmural stent placement in 11 of 11 cases (100%). Complications occurred in 11 cases (8%). Conclusions Endoscopic gallbladder drainage techniques are safe and efficacious methods for gallbladder decompression in non-surgical patients with comorbidities. PMID:26473125

  13. The integration of single fiber reflectance (SFR) spectroscopy during endoscopic ultrasound-guided fine needle aspirations (EUS-FNA) in pancreatic masses: a feasibility study

    NASA Astrophysics Data System (ADS)

    Stegehuis, Paulien L.; Boogerd, Leonora S. F.; Inderson, Akin; Veenendaal, Roeland A.; Bonsing, Bert A.; Amelink, Arjen; Vahrmeijer, Alexander L.; Dijkstra, Jouke; Robinson, Dominic J.

    2016-03-01

    EUS-FNA can be used for pathological confirmation of a suspicious pancreatic mass. However, performance depends on an on-site cytologist and time between punction and final pathology results can be long. SFR spectroscopy is capable of extracting biologically relevant parameters (e.g. oxygenation and blood volume) in real-time from a very small tissue volume at difficult locations. In this study we determined feasibility of the integration of SFR spectroscopy during EUSFNA procedures in pancreatic masses. Patients with benign and malignant pancreatic masses who were scheduled for an EUS-FNA were included. The working guide wire inside the 19 gauge endoscopic biopsy needle was removed and the sterile single fiber (300 μm core and 700 μm outer diameter, wide-angle beam, NA 0.22) inserted through the needle. Spectroscopy measurements in the visiblenear infrared wavelength region (400-900 nm) and autofluorescence measurements (excitation at 405 nm) were taken three times, and subsequently cytology was obtained. Wavelength dependent optical properties were compared to cytology results. We took measurements in 13 patients with corresponding cytology results (including mucinous tumor, ductal adenocarcinoma, neuroendocrine tumor, and pancreatitis). In this paper we show the first analyzed results comparing normal pancreatic tissue with cancerous tissue in the same patient. We found a large difference in blood volume fraction, and blood oxygenation was higher in normal tissue. Integration of SFR spectroscopy is feasible in EUS-FNA procedures, the workflow hardly requires changes and it takes little time. The first results differentiating normal from tumor tissue are promising.

  14. Endoscopic cyclophotocoagulation.

    PubMed

    Seibold, Leonard K; SooHoo, Jeffrey R; Kahook, Malik Y

    2015-01-01

    In recent years, many new procedures and implants have been introduced as safer alternatives for the surgical treatment of glaucoma. The majority of these advances are implant-based with a goal of increased aqueous drainage to achieve lower intraocular pressure (IOP). In contrast, endoscopic cyclophotocoagulation (ECP) lowers IOP through aqueous suppression. Although ciliary body ablation is a well-established method of aqueous suppression, the novel endoscopic approach presents a significant evolution of this treatment with marked improvement in safety. The endoscope couples a light source, video imaging, and diode laser to achieve direct visualization of the ciliary processes during controlled laser application. The result is an efficient and safe procedure that can achieve a meaningful reduction in IOP and eliminate or reduce glaucoma medication use. From its initial use in refractory glaucoma, the indications for ECP have expanded broadly to include many forms of glaucoma across the spectrum of disease severity. The minimally-invasive nature of ECP allows for easy pairing with phacoemulsification in patients with coexisting cataract. In addition, the procedure avoids implant or device-related complications associated with newer surgical treatments. In this review, we illustrate the differences between ECP and traditional cyclophotocoagulation, then describe the instrumentation, patient selection, and technique for ECP. Finally, we summarize the available clinical evidence regarding the efficacy and safety of this procedure. PMID:25624669

  15. Endoscopic Cyclophotocoagulation

    PubMed Central

    Seibold, Leonard K.; SooHoo, Jeffrey R.; Kahook, Malik Y.

    2015-01-01

    In recent years, many new procedures and implants have been introduced as safer alternatives for the surgical treatment of glaucoma. The majority of these advances are implant-based with a goal of increased aqueous drainage to achieve lower intraocular pressure (IOP). In contrast, endoscopic cyclophotocoagulation (ECP) lowers IOP through aqueous suppression. Although ciliary body ablation is a well-established method of aqueous suppression, the novel endoscopic approach presents a significant evolution of this treatment with marked improvement in safety. The endoscope couples a light source, video imaging, and diode laser to achieve direct visualization of the ciliary processes during controlled laser application. The result is an efficient and safe procedure that can achieve a meaningful reduction in IOP and eliminate or reduce glaucoma medication use. From its initial use in refractory glaucoma, the indications for ECP have expanded broadly to include many forms of glaucoma across the spectrum of disease severity. The minimally-invasive nature of ECP allows for easy pairing with phacoemulsification in patients with coexisting cataract. In addition, the procedure avoids implant or device-related complications associated with newer surgical treatments. In this review, we illustrate the differences between ECP and traditional cyclophotocoagulation, then describe the instrumentation, patient selection, and technique for ECP. Finally, we summarize the available clinical evidence regarding the efficacy and safety of this procedure. PMID:25624669

  16. The usefulness of S100P, mesothelin, fascin, prostate stem cell antigen, and 14-3-3 sigma in diagnosing pancreatic adenocarcinoma in cytological specimens obtained by endoscopic ultrasound guided fine-needle aspiration.

    PubMed

    Dim, Daniel C; Jiang, Feng; Qiu, Qi; Li, Ting; Darwin, Peter; Rodgers, William H; Peng, Hong Qi

    2014-03-01

    Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) of the pancreas is an efficient and minimally invasive procedure for the diagnosis and staging of pancreatic adenocarcinoma. Because of some limitations of EUS-FNA in diagnosis of well-differentiated or early stage cancers, the purpose of this study is to assess the added benefit of immunohistochemistry. We studied five proteins overexpressed in pancreatic adenocarcinoma, namely, prostate stem cell antigen, fascin, 14-3-3 sigma, mesothelin and S100P utilizing immunohistochemistry on paraffin sections from cellblocks obtained by EUS-FNA. Sixty-two cases of EUS-FNA of the pancreas that had follow-up histological and/or clinical diagnosis and sufficient material in cell blocks were included. Using histological diagnosis and/or clinical outcome as the reference standard, EUS-FNA shows the highest sensitivity (95%) and specificity (91%) and is superior to any marker in this study. Among five antibodies, S100P reveals the best diagnostic characters showing 90% of sensitivity and 67% of specificity. Fascin shows high specificity (92%) but low sensitivity (38%). Mesothelin has a moderate sensitivity (74%) and low specificity (33%), PSCA and 14-3-3 show high sensitivity but zero specificity. S100P and mesothelin were useful in nine indeterminate cases. S100P correctly predicted six of seven cancers and one of one without cancer and mesothelin correctly diagnosed five of seven cancers and one of two noncancers in this group. EUS-FNA cytomorphology is superior to any of the immunohistochemical markers used in this study. Use of S100P and mesothelin in cytologically borderline cases can increase the diagnostic accuracy in this group. PMID:21538952

  17. Investigation of the effects of myocardial anisotropy for shear wave elastography using impulsive force and harmonic vibration

    NASA Astrophysics Data System (ADS)

    Urban, Matthew W.; Qiang, Bo; Song, Pengfei; Nenadic, Ivan Z.; Chen, Shigao; Greenleaf, James F.

    2016-01-01

    The myocardium is known to be an anisotropic medium where the muscle fiber orientation changes through the thickness of the wall. Shear wave elastography methods use propagating waves which are measured by ultrasound or magnetic resonance imaging (MRI) techniques to characterize the mechanical properties of various tissues. Ultrasound- or MR-based methods have been used and the excitation frequency ranges for these various methods cover a large range from 24-500 Hz. Some of the ultrasound-based methods have been shown to be able to estimate the fiber direction. We constructed a model with layers of elastic, transversely isotropic materials that were oriented at different angles to simulate the heart wall in systole and diastole. We investigated the effect of frequency on the wave propagation and the estimation of fiber direction and wave speeds in the different layers of the assembled models. We found that waves propagating at low frequencies such as 30 or 50 Hz showed low sensitivity to the fiber direction but also had substantial bias in estimating the wave speeds in the layers. Using waves with higher frequency content (>200 Hz) allowed for more accurate fiber direction and wave speed estimation. These results have particular relevance for MR- and ultrasound-based elastography applications in the heart.

  18. Analysis of elastography methods using mathematical and ex vivo data

    NASA Astrophysics Data System (ADS)

    Byram, Brett C.; Wahl, Michael R.; Holmes, David R., III; Lerman, Amir; Robb, Richard A.

    2003-05-01

    Intravascular ultrasound (IVUS) currently has a limited ability to characterize endovascular anatomic properties. IVUS elastography enhances the ability to characterize the biomechanical properties of arterial walls. A mathematical phantom generator was developed based on the characteristics of 30MHz, 64 element IVUS catheter images from excised canine femoral arteries. The difference between high and low-pressure intra-arterial images was modeled using phase shifts. The increase in phase shift occurred randomly, generally at every three pixels in our images. Using mathematical phantoms, different methods for calculating elastograms were quantitatively analyzed. Specifically, the effect of standard cross correlation versus cross correlation of the integral of the inflection characteristics for a given set of data, and the effect of an algorithm utilizing a non-constant kernel, were assessed. The specific methods found to be most accurate on the mathematical phantom data were then applied to ex vivo canine data of a scarred and a healthy artery. The algorithm detected significant differences between these two sets of arterial data. It will be necessary to obtain and analyze several more sets of canine arterial data in order to determine the accuracy and reproducibility of the algorithm.

  19. Endoscopic diagnostic of chronic pancreatitis.

    PubMed

    Cubranić, Aleksandar; Dintinjana, Renata Dobrila; Vanis, Nenad

    2014-12-01

    Chronic pancreatitis is defined as a continuous inflammatory pancreatic disease, one characterized by irreversible morphological changes, often associates with pain and sometimes with the loss of endocrine and exocrine function. As a histological confirmation of chronic pancreatitis is often unavailable, the diagnosis is traditionally based on imaging methods such as computerized tomography (CT) or endoscopic retrograde cholangiopancreatography (ERCP), and recently magnetic resonance cholangiopancreatography (MRCP) as a noninvasive alternative to ERCP. Developments in the classification system of CP include the Marseille classification of 1963 which offered histopathologic criteria for CP, the Cambridge classification of 1984 which introduced imaging features of computed tomography (CT), transabdominal ultrasound (TUS) and endoscopic retrograde cholangiopancreatography (ERCP) for classification of CP as well as Rosemont classification system of 2007 which presented the endoscopic ultrasonography diagnosis of CP. Endoscopic ultra-sonography (EUS) was first introduced as a diagnostic method for evaluation of pancreatic disease in 1986. It has experienced significant improvements since then and allowed for an alternative approach in diagnosing patients with pancreatic diseases. In patients with suspected pancreatic masses EUS-guided fine needle aspiration (EUS-FNA) is the best method for obtaining tissue diagnosis and differentiating CP from pancreatic carcinoma. The recent studies indicate that EUS is the method of choice when compared with other imaging methods such as ERCP because it frequently provides more accurate diagnostics. The aim of this review is to discuss the findings in endoscopic diagnostics up to the present moment and to indicate advantages, limitations and possible complications along with the current recommendations in CP diagnostics. PMID:25842773

  20. Validation of Shear Wave Elastography in Skeletal Muscle

    PubMed Central

    Eby, Sarah F.; Song, Pengfei; Chen, Shigao; Chen, Qingshan; Greenleaf, James F.; An, Kai-Nan

    2013-01-01

    Skeletal muscle is a very dynamic tissue, thus accurate quantification of skeletal muscle stiffness throughout its functional range is crucial to improve the physical functioning and independence following pathology. Shear wave elastography (SWE) is an ultrasound-based technique that characterizes tissue mechanical properties based on the propagation of remotely induced shear waves. The objective of this study is to validate SWE throughout the functional range of motion of skeletal muscle for three ultrasound transducer orientations. We hypothesized that combining traditional materials testing (MTS) techniques with SWE measurements will show increased stiffness measures with increasing tensile load, and will correlate well with each other for trials in which the transducer is parallel to underlying muscle fibers. To evaluate this hypothesis, we monitored the deformation throughout tensile loading of four porcine brachialis whole-muscle tissue specimens, while simultaneously making SWE measurements of the same specimen. We used regression to examine the correlation between Young's modulus from MTS and shear modulus from SWE for each of the transducer orientations. We applied a generalized linear model to account for repeated testing. Model parameters were estimated via generalized estimating equations. The regression coefficient was 0.1944, with a 95% confidence interval of (0.1463 – 0.2425) for parallel transducer trials. Shear waves did not propagate well for both the 45° and perpendicular transducer orientations. Both parallel SWE and MTS showed increased stiffness with increasing tensile load. This study provides the necessary first step for additional studies that can evaluate the distribution of stiffness throughout muscle. PMID:23953670

  1. Endoscopic Microscopy

    PubMed Central

    Sokolov, Konstantin; Sung, Kung-Bin; Collier, Tom; Clark, Anne; Arifler, Dizem; Lacy, Alicia; Descour, Michael; Richards-Kortum, Rebecca

    2002-01-01

    In vivo endoscopic optical microscopy provides a tool to assess tissue architecture and morphology with contrast and resolution similar to that provided by standard histopathology – without need for physical tissue removal. In this article, we focus on optical imaging technologies that have the potential to dramatically improve the detection, prevention, and therapy of epithelial cancers. Epithelial pre-cancers and cancers are associated with a variety of morphologic, architectural, and molecular changes, which currently can be assessed only through invasive, painful biopsy. Optical imaging is ideally suited to detecting cancer-related alterations because it can detect biochemical and morphologic alterations with sub-cellular resolution throughout the entire epithelial thickness. Optical techniques can be implemented non-invasively, in real time, and at low cost to survey the tissue surface at risk. Our manuscript focuses primarily on modalities that currently are the most developed: reflectance confocal microscopy (RCM) and optical coherence tomography (OCT). However, recent advances in fluorescence-based endoscopic microscopy also are reviewed briefly. We discuss the basic principles of these emerging technologies and their current and potential applications in early cancer detection. We also present research activities focused on development of exogenous contrast agents that can enhance the morphological features important for cancer detection and that have the potential to allow vital molecular imaging of cancer-related biomarkers. In conclusion, we discuss future improvements to the technology needed to develop robust clinical devices. PMID:14646041

  2. Transoral endoscopic thyroidectomy: A case report

    PubMed Central

    Pai, Vishwanath M.; Muthukumar, Pari; Prathap, Apoorva; Leo, Jayanth; A., Rekha

    2015-01-01

    Introduction Endoscopic thyroidectomy, initially an experimental procedure, is now being performed in increasing frequency. It aims to provide patients undergoing thyroidectomy with a ‘scar-free’ surgery. Transoral endoscopic thyroidectomy is one such novel procedure that is based on the principles of natural orifice translumenal surgery (NOTES) and allows for a truly scar-free surgery with minimal dissection. Presentation of case A 21-year-old female presented with a swelling over the left side of her neck. Ultrasound revealed a solitary nodule and FNAC showed features suggestive of a follicular adenoma. Discussion The patient underwent transoral endoscopic hemi-thyroidectomy. The procedure lasted for 2 h and is one of the few documented cases of transoral endoscopic thyroidectomy performed on live patients. Conclusion Transoral endoscopic thyroidectomy is proving to be a feasible technique with little or no complications as compared to other endoscopic thyroid surgeries. It provides surgeons with easy access to the thyroid gland and patients with aesthetically pleasing results. PMID:26048629

  3. Whole breast tissue characterization with ultrasound tomography

    NASA Astrophysics Data System (ADS)

    Duric, Neb; Littrup, Peter; Li, Cuiping; Roy, Olivier; Schmidt, Steve; Seamans, John; Wallen, Andrea; Bey-Knight, Lisa

    2015-03-01

    A number of clinical trials have shown that screening ultrasound, supplemental to mammography, detects additional cancers in women with dense breasts. However, labor intensity, operator dependence and high recall rates have limited adoption. This paper describes the use of ultrasound tomography for whole-breast tissue stiffness measurements as a first step toward addressing the issue of high recall rates. The validation of the technique using an anthropomorphic phantom is described. In-vivo applications are demonstrated on 13 breast masses, indicating that lesion stiffness correlates with lesion type as expected. Comparison of lesion stiffness measurements with standard elastography was available for 11 masses and showed a strong correlation between the 2 measures. It is concluded that ultrasound tomography can map out the 3 dimensional distribution of tissue stiffness over the whole breast. Such a capability is well suited for screening where additional characterization may improve the specificity of screening ultrasound, thereby lowering barriers to acceptance.

  4. Recent technological advancements in breast ultrasound.

    PubMed

    Eisenbrey, John R; Dave, Jaydev K; Forsberg, Flemming

    2016-08-01

    Ultrasound is becoming increasingly common as an imaging tool for the detection and characterization of breast tumors. This paper provides an overview of recent technological advancements, especially those that may have an impact in clinical applications in the field of breast ultrasound in the near future. These advancements include close to 100% fractional bandwidth high frequency (5-18MHz) 2D and 3D arrays, automated breast imaging systems to minimize the operator dependence and advanced processing techniques, such as those used for detection of microcalcifications. In addition, elastography and contrast-enhanced ultrasound examinations that are expected to further enhance the clinical importance of ultrasound based breast tumor screening are briefly reviewed. These techniques have shown initial promise in clinical trials and may translate to more comprehensive clinical adoption in the future. PMID:27179143

  5. Shear wave elastography using amplitude-modulated acoustic radiation force and phase-sensitive optical coherence tomography

    PubMed Central

    Nguyen, Thu-Mai; Arnal, Bastien; Song, Shaozhen; Huang, Zhihong; Wang, Ruikang K.; O’Donnell, Matthew

    2015-01-01

    Abstract. Investigating the elasticity of ocular tissue (cornea and intraocular lens) could help the understanding and management of pathologies related to biomechanical deficiency. In previous studies, we introduced a setup based on optical coherence tomography for shear wave elastography (SWE) with high resolution and high sensitivity. SWE determines tissue stiffness from the propagation speed of shear waves launched within tissue. We proposed acoustic radiation force to remotely induce shear waves by focusing an ultrasound (US) beam in tissue, similar to several elastography techniques. Minimizing the maximum US pressure is essential in ophthalmology for safety reasons. For this purpose, we propose a pulse compression approach. It utilizes coded US emissions to generate shear waves where the energy is spread over a long emission, and then numerically compressed into a short, localized, and high-energy pulse. We used a 7.5-MHz single-element focused transducer driven by coded excitations where the amplitude is modulated by a linear frequency-swept square wave (1 to 7 kHz). An inverse filter approach was used for compression. We demonstrate the feasibility of performing shear wave elastography measurements in tissue-mimicking phantoms at low US pressures (mechanical index <0.6). PMID:25554970

  6. Endoscopic Ultrasonograpy for Choledocholithiasis and Biliary Malignancy.

    PubMed

    Moparty, Bhavani; Bhutani, Manoop S

    2005-04-01

    Endoscopic ultrasound (EUS) is a valuable tool in gastrointestinal endoscopy, with various applications such as diagnosis, staging, and evaluation of the pancreaticobiliary system. EUS has comparable sensitivity to magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography (ERCP) for detection of choledocholithiasis. EUS may be considered for evaluation for choledocholithiasis as prelude to ERCP when there is a low to intermediate suspicion for common bile duct stones or when there is an increased risk for complications from ERCP. Endosonography may also be useful in the evaluation of cholangiocarcinoma. Intraductal ultrasound within the bile duct may help differentiate malignant from benign strictures. EUS-guided fine needle aspiration can be helpful in the diagnosis of cholangiocarcinoma, especially in the region of the hilum. PMID:15769435

  7. Quantitative Ultrasound for Nondestructive Characterization of Engineered Tissues and Biomaterials.

    PubMed

    Dalecki, Diane; Mercado, Karla P; Hocking, Denise C

    2016-03-01

    Non-invasive, non-destructive technologies for imaging and quantitatively monitoring the development of artificial tissues are critical for the advancement of tissue engineering. Current standard techniques for evaluating engineered tissues, including histology, biochemical assays and mechanical testing, are destructive approaches. Ultrasound is emerging as a valuable tool for imaging and quantitatively monitoring the properties of engineered tissues and biomaterials longitudinally during fabrication and post-implantation. Ultrasound techniques are rapid, non-invasive, non-destructive and can be easily integrated into sterile environments necessary for tissue engineering. Furthermore, high-frequency quantitative ultrasound techniques can enable volumetric characterization of the structural, biological, and mechanical properties of engineered tissues during fabrication and post-implantation. This review provides an overview of ultrasound imaging, quantitative ultrasound techniques, and elastography, with representative examples of applications of these ultrasound-based techniques to the field of tissue engineering. PMID:26581347

  8. Photoacoustic endoscopic imaging of the rabbit mediastinum

    NASA Astrophysics Data System (ADS)

    Yang, Joon-Mo; Favazza, Christopher; Chen, Ruimin; Yao, Junjie; Cai, Xin; Li, Chiye; Maslov, Konstantin; Zhou, Qifa; Shung, K. Kirk; Wang, Lihong V.

    2013-03-01

    Like ultrasound endoscopy, photoacoustic endoscopy (PAE) could become a valuable addition to clinical practice due to its deep imaging capability. Results from our recent in vivo transesophageal endoscopic imaging study on rabbits demonstrate the technique's capability to image major organs in the mediastinal region, such as the lung, trachea, and cardiovascular systems. Here, we present various features from photoacoustic images from the mediastinal region of several rabbits and discuss possible clinical contributions of this technique and directions of future technology development.

  9. Intravascular ultrasound

    MedlinePlus

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

  10. Duplex ultrasound

    MedlinePlus

    ... ultrasound with Doppler ultrasound . Traditional ultrasound uses sound waves that bounce off blood vessels to create pictures. Doppler ultrasound records sound waves reflecting off moving objects, such as blood, to ...

  11. Elastography to assess the effect of varicoceles on testes: a prospective controlled study.

    PubMed

    Dede, O; Teke, M; Daggulli, M; Utangaç, M; Baş, O; Penbegül, N

    2016-04-01

    Varicoceles are the most common and treatable cause of male infertility. The pathophysiology of varicoceles primarily includes elevated temperature, adrenal hormone reflux, gonadotoxic metabolite reflux, altered testicular blood flow, antisperm antibody formation and oxidative stress. The diagnosis of a varicocele is mainly clinical. However, a Doppler ultrasound is used to obtain clinical data and to more accurately measure testicular size. Acoustic radiation force impulse (ARFI) is an additional technique to simultaneously show different areas with different densities in a colour-coded image and a B-mode or greyscale image. This can be used for structural analysis of testicular tissue and has become an additional method for detecting pathologic tissue alterations. We enrolled 30 patients who had clinically diagnosed with left varicoceles and male infertility (Group 1). All patients were evaluated by history taking, physical examination, a spermiogram and an endocrine profile. Thirty control patients (Group 2) were randomly chosen from patients who had applied to an andrology clinic for infertility; their physical examinations and laboratory results showed normal findings. Mean elastography results were significantly different between the groups, and significantly lower in patients who had varicoceles. The relationship between hormonal profiles and elastography parameters was calculated as statistically significant negative correlations between FSH and elasticity. Additionally, a negative correlation was determined between varicocele grade and elasticity of testes. In conclusion, our prospective study showed that ARFI imaging may be more useful than palpation for determining early damage of testicular structure by varicoceles. PMID:26011193

  12. Patient-specific Deformation Modelling via Elastography: Application to Image-guided Prostate Interventions.

    PubMed

    Wang, Yi; Ni, Dong; Qin, Jing; Xu, Ming; Xie, Xiaoyan; Heng, Pheng-Ann

    2016-01-01

    Image-guided prostate interventions often require the registration of preoperative magnetic resonance (MR) images to real-time transrectal ultrasound (TRUS) images to provide high-quality guidance. One of the main challenges for registering MR images to TRUS images is how to estimate the TRUS-probe-induced prostate deformation that occurs during TRUS imaging. The combined statistical and biomechanical modeling approach shows promise for the adequate estimation of prostate deformation. However, the right setting of the biomechanical parameters is very crucial for realistic deformation modeling. We propose a patient-specific deformation model equipped with personalized biomechanical parameters obtained from shear wave elastography to reliably predict the prostate deformation during image-guided interventions. Using data acquired from a prostate phantom and twelve patients with suspected prostate cancer, we compared the prostate deformation model with and without patient-specific biomechanical parameters in terms of deformation estimation accuracy. The results show that the patient-specific deformation model possesses favorable model ability, and outperforms the model without patient-specific biomechanical parameters. The employment of the patient-specific biomechanical parameters obtained from elastography for deformation modeling shows promise for providing more precise deformation estimation in applications that use computer-assisted image-guided intervention systems. PMID:27272239

  13. Patient-specific Deformation Modelling via Elastography: Application to Image-guided Prostate Interventions

    PubMed Central

    Wang, Yi; Ni, Dong; Qin, Jing; Xu, Ming; Xie, Xiaoyan; Heng, Pheng-Ann

    2016-01-01

    Image-guided prostate interventions often require the registration of preoperative magnetic resonance (MR) images to real-time transrectal ultrasound (TRUS) images to provide high-quality guidance. One of the main challenges for registering MR images to TRUS images is how to estimate the TRUS-probe-induced prostate deformation that occurs during TRUS imaging. The combined statistical and biomechanical modeling approach shows promise for the adequate estimation of prostate deformation. However, the right setting of the biomechanical parameters is very crucial for realistic deformation modeling. We propose a patient-specific deformation model equipped with personalized biomechanical parameters obtained from shear wave elastography to reliably predict the prostate deformation during image-guided interventions. Using data acquired from a prostate phantom and twelve patients with suspected prostate cancer, we compared the prostate deformation model with and without patient-specific biomechanical parameters in terms of deformation estimation accuracy. The results show that the patient-specific deformation model possesses favorable model ability, and outperforms the model without patient-specific biomechanical parameters. The employment of the patient-specific biomechanical parameters obtained from elastography for deformation modeling shows promise for providing more precise deformation estimation in applications that use computer-assisted image-guided intervention systems. PMID:27272239

  14. Wide-range dynamic magnetic resonance elastography.

    PubMed

    Riek, Kerstin; Klatt, Dieter; Nuzha, Hassan; Mueller, Susanne; Neumann, Ulf; Sack, Ingolf; Braun, Jürgen

    2011-04-29

    Tissue mechanical parameters have been shown to be highly sensitive to disease by elastography. Magnetic resonance elastography (MRE) in the human body relies on the low-dynamic range of tissue mechanics <100 Hz. In contrast, MRE suited for investigations of mice or small tissue samples requires vibration frequencies 10-20 times higher than those used in human MRE. The dispersion of the complex shear modulus (G(⁎)) prevents direct comparison of elastography data at different frequency bands and, consequently, frequency-independent viscoelastic models that fit to G(*) over a wide dynamic range have to be employed. This study presents data of G(*) of samples of agarose gel, liver, brain, and muscle measured by high-resolution MRE in a 7T-animal scanner at 200-800 Hz vibration frequency. Material constants μ and α according to the springpot model and related to shear elasticity and slope of the G(*)-dispersion were determined. Both μ and α of calf brain and bovine liver were found to be similar, while a sample of fibrotic human liver (METAVIR score of 3) displayed about fifteen times higher shear elasticity, similar to μ of bovine muscle measured in muscle fiber direction. α was the highest in fibrotic liver, followed by normal brain and liver, while muscle had the lowest α-values of all biological samples investigated in this study. As expected, the least G(*)-dispersion was seen in soft gel. The proposed technique of wide-range dynamic MRE can provide baseline data for both human MRE and high-dynamic MRE for better understanding tissue mechanics of different tissue structures. PMID:21295305

  15. Passive in vivo elastography from skeletal muscle noise

    SciTech Connect

    Sabra, Karim G.; Conti, Stephane; Roux, Philippe; Kuperman, W. A.

    2007-05-07

    Measuring the in vivo elastic properties of muscles (e.g., stiffness) provides a means for diagnosing and monitoring muscular activity. The authors demonstrated a passive in vivo elastography technique without an active external radiation source. This technique instead uses cross correlations of contracting skeletal muscle noise recorded with skin-mounted sensors. Each passive sensor becomes a virtual in vivo shear wave source. The results point to a low-cost, noninvasive technique for monitoring biomechanical in vivo muscle properties. The efficacy of the passive elastography technique originates from the high density of cross paths between all sensor pairs, potentially achieving the same sensitivity obtained from active elastography methods.

  16. Quantitative shear wave optical coherence elastography (SW-OCE) with acoustic radiation force impulses (ARFI) induced by phase array transducer

    NASA Astrophysics Data System (ADS)

    Song, Shaozhen; Le, Nhan Minh; Wang, Ruikang K.; Huang, Zhihong

    2015-03-01

    Shear Wave Optical Coherence Elastography (SW-OCE) uses the speed of propagating shear waves to provide a quantitative measurement of localized shear modulus, making it a valuable technique for the elasticity characterization of tissues such as skin and ocular tissue. One of the main challenges in shear wave elastography is to induce a reliable source of shear wave; most of nowadays techniques use external vibrators which have several drawbacks such as limited wave propagation range and/or difficulties in non-invasive scans requiring precisions, accuracy. Thus, we propose linear phase array ultrasound transducer as a remote wave source, combined with the high-speed, 47,000-frame-per-second Shear-wave visualization provided by phase-sensitive OCT. In this study, we observed for the first time shear waves induced by a 128 element linear array ultrasound imaging transducer, while the ultrasound and OCT images (within the OCE detection range) were triggered simultaneously. Acoustic radiation force impulses are induced by emitting 10 MHz tone-bursts of sub-millisecond durations (between 50 μm - 100 μm). Ultrasound beam steering is achieved by programming appropriate phase delay, covering a lateral range of 10 mm and full OCT axial (depth) range in the imaging sample. Tissue-mimicking phantoms with agarose concentration of 0.5% and 1% was used in the SW-OCE measurements as the only imaging samples. The results show extensive improvements over the range of SW-OCE elasticity map; such improvements can also be seen over shear wave velocities in softer and stiffer phantoms, as well as determining the boundary of multiple inclusions with different stiffness. This approach opens up the feasibility to combine medical ultrasound imaging and SW-OCE for high-resolution localized quantitative measurement of tissue biomechanical property.

  17. Endoscopic surgery of the parathyroid glands: methods and principles.

    PubMed

    Prades, J-M; Gavid, M; Timoshenko, A T; Richard, C; Martin, C

    2013-06-01

    Targeted endoscopic parathyroidectomy without gas insufflation is a relatively non-invasive means of discovering and resecting parathyroid adenomas in sporadic primary hyperparathyroidism. This standardized technique depends on the quality of the preoperative imaging: cervical ultrasound and sestamibi scintigraphy, and can be optimized by preoperative insertion of an ultrasound-guided "harpoon" and rapid peroperative parathyroid hormone analysis. Failure rates range between 1.7% and 4%. PMID:23562229

  18. In-vitro quantification of rat liver viscoelasticity with shear wave dispersion ultrasound vibrometry.

    PubMed

    Guo, Yan-rong; Chen, Xin; Lin, Haoming; Zhang, Xinyu

    2013-01-01

    As a new imaging method for tissue mechanical properties, ultrasound elastography has always been the research focus in the field of medical ultrasound imaging ever since it has been proposed. This paper developed an ultrasound viscoelasticity measurement system based on shear wave dispersion ultrasound vibrometry (SDUV). This system applied acoustic radiation force to excite harmonic vibration in soft tissue. The propagation of the shear wave induced by the vibration was detected and the tissue viscoelasticity properties were calculated. Based on this system, rat livers were measured in vitro. The results shows that the system can measure the viscoelasticity reliably, offering a potential alternative to diagnosis of liver fibrosis. PMID:24110087

  19. Endoscopic frontiers in the field of hepatology.

    PubMed

    Clarke, J O; Thuluvath, P J

    2007-03-01

    Hepatology is considered a cognitive specialty, but it will not be surprising if a subgroup of future hepatologists (''invasive hepatologists'') performed a variety of advanced endoscopic, laparoscopic, vascular or ablative procedures just like interventional gastroenterologists, interventional radiologists or minimally invasive surgeons. The increase in the prevalence of liver diseases including hepatocellular carcinoma, and effective treatment of end-stage liver disease with liver transplantation has expanded the subspecialty of hepatology into a major specialty. Therefore, it is only natural that some of the trainees in hepatology, familiar with invasive procedures just like their counterparts in gastroenterology, may become subspecialized in invasive aspects of this specialty, traditionally performed by interventional endoscopists, radiologists and surgeons. Moreover, there will be major developments in the management of the complications of liver disease. Endoscopic screening with esophageal capsule endoscopy and, to a lesser extent, ultrathin upper gastrointestinal endoscopy may replace conventional endoscopy. In addition to standard treatments for esophageal varices, removable esophageal stents with expansile pressure may be utilized in refractory variceal hemorrhage. Transjugular intrahepatic portosystemic shunts may be performed by hepatologists. Advances in argon plasma coagulation, cryotherapy and photodynamic therapy may result in novel treatment options for portal hypertensive gastropathy. Single-fiber cholangioscopy will allow for directed endoscopic screening for cholangiocarcinoma and primary sclerosing cholangitis in high-risk individuals. Minilaparoscopy will allow a macroscopic assessment of the liver surface as well as the ability to target specific regions for histopathology, and treatment including radiofrequency ablation of liver cancer. Endoscopic ultrasound (EUS) may provide the potential to directly measure portal vein pressure and this

  20. Lorentz force megahertz optical coherence elastography

    NASA Astrophysics Data System (ADS)

    Wu, Chen; Singh, Manmohan; Han, Zhaolong; Raghunathan, Raksha; Liu, Chih-Hao; Li, Jiasong; Schill, Alexander; Larin, Kirill V.

    2016-03-01

    Optical Coherence Elastography (OCE) is a rapidly developing technique for assessing tissue biomechanical properties. This study demonstrates the first use of the Lorentz force to induce elastic waves within tissue to quantify the elasticity of tissue in combination with a phase-sensitive OCE system at ~1.5 million A-scans per second. The feasibility of this technique was tested on tissue-mimicking agar phantoms of various concentrations. The results as assessed by OCE were in good agreement with standard mechanical testing of the samples. After the preliminary experiments, the stiffness of porcine liver was examined. The results demonstrate that Lorentz force MHz OCE can be applied to study the elasticity of biological tissue effectively and has the potential for clinical applications due to rapid excitation and imaging.

  1. Endoscopic therapy in chronic pancreatitis: current perspectives.

    PubMed

    Seicean, Andrada; Vultur, Simona

    2015-01-01

    Endoscopic therapy in chronic pancreatitis (CP) aims to provide pain relief and to treat local complications, by using the decompression of the pancreatic duct and the drainage of pseudocysts and biliary strictures, respectively. This is the reason for using it as first-line therapy for painful uncomplicated CP. The clinical response has to be evaluated at 6-8 weeks, when surgery may be chosen. This article reviews the main possibilities of endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound (EUS) therapies. Endotherapy for pancreatic ductal stones uses ultrasound wave lithotripsy and sometimes additional stone extractions. The treatment of pancreatic duct strictures consists of a single large stenting for 1 year. If the stricture persists, simultaneous multiple stents are applied. In case of unsuccessful ERCP, the EUS-guided drainage of the main pancreatic duct (MPD) or a rendezvous technique can solve the ductal strictures. EUS-guided celiac plexus block has limited efficiency in CP. The drainage of symptomatic or complicated pancreatic pseudocysts can be performed transpapillarily or transgastrically/transduodenally, preferably by EUS guidance. When the biliary stricture is symptomatic or progressive, multiple plastic stents are indicated. In conclusion, as in many fields of symptomatic treatment, endoscopy remains the first choice, either by using ERCP or EUS-guided procedures, after consideration of a multidisciplinary team with endoscopists, surgeons, and radiologists. However, what is crucial is establishing the right timing for surgery. PMID:25565876

  2. Prostate Ultrasound

    MedlinePlus

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

  3. Hip Ultrasound

    MedlinePlus

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

  4. Ultrasound -- Vascular

    MedlinePlus

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

  5. Musculoskeletal Ultrasound

    MedlinePlus

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

  6. Ultrasound - Scrotum

    MedlinePlus

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

  7. Endoscopic Evaluation of Swallowing (Endoscopy)

    MedlinePlus

    ... the Public / Speech, Language and Swallowing / Swallowing Endoscopic Evaluation of Swallowing (Endoscopy) Do you have problems swallowing? ... Some names you might hear are: Endoscopy Endoscopic Evaluation of swallowing FEES (Fiberoptic Endoscopic Evaluation of Swallowing) ...

  8. Overhauser-enhanced magnetic resonance elastography.

    PubMed

    Salameh, Najat; Sarracanie, Mathieu; Armstrong, Brandon D; Rosen, Matthew S; Comment, Arnaud

    2016-05-01

    Magnetic resonance elastography (MRE) is a powerful technique to assess the mechanical properties of living tissue. However, it suffers from reduced sensitivity in regions with short T2 and T2 * such as in tissue with high concentrations of paramagnetic iron, or in regions surrounding implanted devices. In this work, we exploit the longer T2 * attainable at ultra-low magnetic fields in combination with Overhauser dynamic nuclear polarization (DNP) to enable rapid MRE at 0.0065 T. A 3D balanced steady-state free precession based MRE sequence with undersampling and fractional encoding was implemented on a 0.0065 T MRI scanner. A custom-built RF coil for DNP and a programmable vibration system for elastography were developed. Displacement fields and stiffness maps were reconstructed from data recorded in a polyvinyl alcohol gel phantom loaded with stable nitroxide radicals. A DNP enhancement of 25 was achieved during the MRE sequence, allowing the acquisition of 3D Overhauser-enhanced MRE (OMRE) images with (1.5 × 2.7 × 9) mm(3) resolution over eight temporal steps and 11 slices in 6 minutes. In conclusion, OMRE at ultra-low magnetic field can be used to detect mechanical waves over short acquisition times. This new modality shows promise to broaden the scope of conventional MRE applications, and may extend the utility of low-cost, portable MRI systems to detect elasticity changes in patients with implanted devices or iron overload. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26915977

  9. Enhanced endoscopic detection of early colon cancer

    NASA Astrophysics Data System (ADS)

    Balachandar, Gowra; Trowers, Eugene A.

    1999-06-01

    Enhanced endoscopic detection of small flat adenomas is becoming increasingly important as they have a reported 14 percent incidence of dysplasia when compared with 5% incidence in polypod adenomas of the same size. These lesions even when invasive do not show up against the translucent surrounding mucosa making endoscopic detection difficult. Dye spraying with indigo carmine makes their morphology clear, with well-circumscribed borders. Dye spraying and magnifying endoscopes can be used to observe pit patterns on the surface of the bowel. Combining dye spraying and high-resolution video endoscopy demonstrates well the colorectal epithelial surface. Scanning immersion video endoscopy visualizes the epithelial surface of the colorectal mucosa by high-resolution endoscopy after filling the lumen with water. Endoscopic ultrasound can be used to see if the lesion is intramucosal or not and assess the depth of invasion if malignancy is presented. Laser induced fluorescence spectroscopy has the potential to detect colonic dysplasia in vivo. Combining such technologies with conventional colonoscopy can help in the surveillance of large areas of colonic mucosa for the presence of dysplasia. Guided biopsy can replace random biopsy based on information provided at the time of colonoscopic examination.

  10. Critical comparison of elastography methods to assess chronic liver disease.

    PubMed

    Friedrich-Rust, Mireen; Poynard, Thierry; Castera, Laurent

    2016-07-01

    Staging of liver fibrosis and diagnosis, or exclusion, of early compensated liver cirrhosis are important in the treatment decisions and surveillance of patients with chronic liver disease. Good diagnostic accuracy, increased availability and the possibility to perform follow-up examinations led to the implementation of noninvasive methods into clinical practice. Noninvasive tests are increasingly included in national and international guidelines, leaving liver biopsy reserved for patients with unexplained discordance or suspected additional aetiologies of liver disease. In addition to staging of liver fibrosis, data on the prognostic value of these methods have increased in the past few years and are of great importance for patient care. This Review focuses on elastography methods for noninvasive assessment of liver fibrosis, disease severity and prognosis. Although liver elastography started with transient elastography, at present all large ultrasonography companies offer an elastography technique integrated in their machines. The goal of this Review is to summarize the methodological problems of noninvasive tests in general, in addition to providing an overview on currently available techniques and latest developments in liver elastography. PMID:27273167

  11. Ultrasound 2D Strain Estimator Based on Image Registration for Ultrasound Elastography

    PubMed Central

    Yang, Xiaofeng; Torres, Mylin; Kirkpatrick, Stephanie; Curran, Walter J.; Liu, Tian

    2015-01-01

    In this paper, we present a new approach to calculate 2D strain through the registration of the pre- and post-compression (deformation) B-mode image sequences based on an intensity-based non-rigid registration algorithm (INRA). Compared with the most commonly used cross-correlation (CC) method, our approach is not constrained to any particular set of directions, and can overcome displacement estimation errors introduced by incoherent motion and variations in the signal under high compression. This INRA method was tested using phantom and in vivo data. The robustness of our approach was demonstrated in the axial direction as well as the lateral direction where the standard CC method frequently fails. In addition, our approach copes well under large compression (over 6%). In the phantom study, we computed the strain image under various compressions and calculated the signal-to-noise (SNR) and contrast-to-noise (CNS) ratios. The SNR and CNS values of the INRA method were much higher than those calculated from the CC-based method. Furthermore, the clinical feasibility of our approach was demonstrated with the in vivo data from patients with arm lymphedema. PMID:25914492

  12. Ultrasound 2D strain estimator based on image registration for ultrasound elastography

    NASA Astrophysics Data System (ADS)

    Yang, Xiaofeng; Torres, Mylin; Kirkpatrick, Stephanie; Curran, Walter J.; Liu, Tian

    2014-03-01

    In this paper, we present a new approach to calculate 2D strain through the registration of the pre- and post-compression (deformation) B-mode image sequences based on an intensity-based non-rigid registration algorithm (INRA). Compared with the most commonly used cross-correlation (CC) method, our approach is not constrained to any particular set of directions, and can overcome displacement estimation errors introduced by incoherent motion and variations in the signal under high compression. This INRA method was tested using phantom and in vivo data. The robustness of our approach was demonstrated in the axial direction as well as the lateral direction where the standard CC method frequently fails. In addition, our approach copes well under large compression (over 6%). In the phantom study, we computed the strain image under various compressions and calculated the signal-to-noise (SNR) and contrast-to-noise (CNS) ratios. The SNR and CNS values of the INRA method were much higher than those calculated from the CC-based method. Furthermore, the clinical feasibility of our approach was demonstrated with the in vivo data from patients with arm lymphedema.

  13. Nakagami imaging for detecting thermal lesions induced by high-intensity focused ultrasound in tissue.

    PubMed

    Rangraz, Parisa; Behnam, Hamid; Tavakkoli, Jahan

    2014-01-01

    High-intensity focused ultrasound induces focalized tissue coagulation by increasing the tissue temperature in a tight focal region. Several methods have been proposed to monitor high-intensity focused ultrasound-induced thermal lesions. Currently, ultrasound imaging techniques that are clinically used for monitoring high-intensity focused ultrasound treatment are standard pulse-echo B-mode ultrasound imaging, ultrasound temperature estimation, and elastography-based methods. On the contrary, the efficacy of two-dimensional Nakagami parametric imaging based on the distribution of the ultrasound backscattered signals to quantify properties of soft tissue has recently been evaluated. In this study, ultrasound radio frequency echo signals from ex vivo tissue samples were acquired before and after high-intensity focused ultrasound exposures and then their Nakagami parameter and scaling parameter of Nakagami distribution were estimated. These parameters were used to detect high-intensity focused ultrasound-induced thermal lesions. Also, the effects of changing the acoustic power of the high-intensity focused ultrasound transducer on the Nakagami parameters were studied. The results obtained suggest that the Nakagami distribution's scaling and Nakagami parameters can effectively be used to detect high-intensity focused ultrasound-induced thermal lesions in tissue ex vivo. These parameters can also be used to understand the degree of change in tissue caused by high-intensity focused ultrasound exposures, which could be interpreted as a measure of degree of variability in scatterer concentration in various parts of the high-intensity focused ultrasound lesion. PMID:24264647

  14. Fine Needle Elastography (FNE) device for biomechanically determining local variations of tissue mechanical properties.

    PubMed

    Wickramaratne, Dayan; Wilkinson, Paul; Rao, JianYu; Ragavendra, Nagesh; Sharma, Shivani; Gimzewski, James K

    2015-01-01

    Diseased tissues exhibit changes in mechanical properties and thus possess clinical diagnostic significance. We report the design and development of a Fine Needle Elastography (FNE) prototype device integrated with Fine Needle Aspiration Cytology (FNAC) needle that allows for quantitative and sensitive assessment of tissues and materials based on local variations in elastic, friction, and cutting forces on needle insertion. A piezoelectric force-sensor at the base of FNA needle measures the forces opposing needle penetration with micrometer scale resolution. Measurement precision (±5 μm) and axial resolution (~20 μm) of FNE device was tested using control mm size gelatin matrices and unripe pear in assessing needle penetration resistance, force heterogeneity and optimization of needle penetration velocity. Further, we demonstrated the usefulness of FNE in quantitative, biomechanical differentiation of simulated thyroid tumor nodules in an ultrasound neck phantom. Fluid or solid nodules were probed in the phantom study coupled with ultrasound guidance. Our data shows significantly higher force variations (1-D force heterogeneity; HF,a=6.5 mN, HF,q=8.25 mN and stiffness heterogeneity; HS,a=0.0274 kN/m, HS,q=0.0395 kN/m) in solid nodules compared either to fluid nodules or to regions corresponding to healthy thyroid tissue within the ultrasound phantom. The results suggest future applications of in vivo FNE biopsies based on force heterogeneity to diagnose thyroid tumors in areas where ultrasound instrumentation or access to a qualified pathologist for FNAC are unavailable, as well as an ancillary diagnostic tool in thyroid cancer management. PMID:25468668

  15. New endoscopic ultrasonography techniques for pancreaticobiliary diseases.

    PubMed

    Kamata, Ken; Kitano, Masayuki; Omoto, Shunsuke; Kadosaka, Kumpei; Miyata, Takeshi; Minaga, Kosuke; Yamao, Kentaro; Imai, Hajime; Kudo, Masatoshi

    2016-07-01

    Endoscopic ultrasonography (EUS) is widely used to evaluate pancreaticobiliary diseases, especially pancreatic masses. EUS has a good ability to detect pancreatic masses, but it is not sufficient for the differential diagnosis of various types of lesions. In order to address the limitations of EUS, new techniques have been developed to improve the characterization of the lesions detected by EUS. EUS-guided fine needle aspiration (EUS-FNA) has been used for diagnosing pancreatic tumors. In order to improve the histological diagnostic yield, a EUS-FNA needle with a core trap has recently been developed. Contrast-enhanced harmonic EUS is a new imaging modality that uses an ultrasonographic contrast agent to visualize blood flow in fine vessels. This technique is useful in the diagnosis of pancreatic solid lesions and in confirming the presence of vascularity in mural nodules for cystic lesions. EUS elastography analyzes several different variables to measure tissue elasticity, color patterns, and strain ratio, using analytical techniques such as hue-histogram analysis, and artificial neural networks, which are useful for the diagnosis of chronic pancreatitis and pancreatic cancer. PMID:27214660

  16. New endoscopic ultrasonography techniques for pancreaticobiliary diseases

    PubMed Central

    2016-01-01

    Endoscopic ultrasonography (EUS) is widely used to evaluate pancreaticobiliary diseases, especially pancreatic masses. EUS has a good ability to detect pancreatic masses, but it is not sufficient for the differential diagnosis of various types of lesions. In order to address the limitations of EUS, new techniques have been developed to improve the characterization of the lesions detected by EUS. EUS-guided fine needle aspiration (EUS-FNA) has been used for diagnosing pancreatic tumors. In order to improve the histological diagnostic yield, a EUS-FNA needle with a core trap has recently been developed. Contrast-enhanced harmonic EUS is a new imaging modality that uses an ultrasonographic contrast agent to visualize blood flow in fine vessels. This technique is useful in the diagnosis of pancreatic solid lesions and in confirming the presence of vascularity in mural nodules for cystic lesions. EUS elastography analyzes several different variables to measure tissue elasticity, color patterns, and strain ratio, using analytical techniques such as hue-histogram analysis, and artificial neural networks, which are useful for the diagnosis of chronic pancreatitis and pancreatic cancer. PMID:27214660

  17. In vivo study of myocardial elastography under graded ischemia conditions

    NASA Astrophysics Data System (ADS)

    Lee, Wei-Ning; Provost, Jean; Fujikura, Kana; Wang, Jie; Konofagou, Elisa E.

    2011-02-01

    The capability of currently available echocardiography-based strain estimation techniques to fully map myocardial abnormality at early stages of myocardial ischemia is yet to be investigated. In this study, myocardial elastography (ME), a radio-frequency (RF)-based strain imaging technique that maps the full 2D transmural angle-independent strain tensor in standard echocardiographic views at both high spatial and temporal resolution is presented. The objectives were to (1) evaluate the performance of ME on mapping the onset, extent and progression of myocardial ischemia at graded coronary constriction levels (from partial to complete coronary flow reduction), and (2) validate the accuracy of the strain estimates against sonomicrometry (SM) measurements. A non-survival canine ischemic model (n = 5) was performed by gradually constricting the left anterior descending (LAD) coronary blood flow from 0% (baseline blood flow) to 100% (zero blood flow) at 20% increments. An open-architecture ultrasound system was used to acquire RF echocardiograms in a standard full short-axis view at the frame rate of 211 fps, at least twice higher than what is typically used in conventional echocardiographic systems, using a previously developed, fully automated composite technique. Myocardial deformation was estimated by ME and validated against sonomicrometry. ME estimates and maps transmural (1) 2D displacements using RF cross-correlation and recorrelation; and (2) 2D polar (radial and circumferential) strains, derived from 2D (i.e. both lateral and axial) displacement components, at high accuracy. Full-view strain images were shown and found to reliably depict decreased myocardial function in the region at risk at increased levels of coronary flow reduction. The ME radial strain was deemed to be a more sensitive, quantitative, regional measure of myocardial ischemia as a result of coronary flow reduction when compared to the conventional wall motion score index and ejection fraction

  18. Shear Wave Elastography in the Living, Perfused, Post-Delivery Placenta.

    PubMed

    McAleavey, Stephen A; Parker, Kevin J; Ormachea, Juvenal; Wood, Ronald W; Stodgell, Christopher J; Katzman, Philip J; Pressman, Eva K; Miller, Richard K

    2016-06-01

    The placenta is the critical interface between the mother and the developing fetus and is essential for survival and growth. Despite the widespread use of ultrasound imaging and Doppler in obstetrics and gynecology and the recent growth of elastographic technologies, little is known about the biomechanical (elastic shear wave) properties of the placenta and the range of normal and pathologic parameters that are present. This study uses a well-developed protocol for perfusing whole placentas, post-delivery, to maintain tissue integrity and function for hours. In this model, the placenta is living, whole and maintained within normal physiologic parameters such as flow, arterial pressure and oxygen, throughout examination by ultrasound, Doppler and shear wave elastography. The preliminary results indicate that normal placental tissue on the fetal side has shear wave speeds on the order of 2 m/s, in a range similar to those of animal livers. Some abnormalities are found outside this range, and thus, elastographic measures of the placenta may provide useful assessments related to the state of the tissue. PMID:27006269

  19. Papillary thyroid microcarcinoma co-exists with Hashimoto's thyroiditis: Is strain elastography still useful?

    PubMed

    Li, Yi; Wang, Yan; Wu, Qiong; Hu, Bing

    2016-05-01

    To study the performance of strain elastography in differentiating papillary thyroid microcarcinoma (PTMC) combined with Hashimoto's thyroiditis (HT), conventional ultrasound scan (US) and strain elastography (SE) were performed on 558 nodules smaller than 10mm by one examiner before surgeries. Serum concentrations of thyroid peroxidase antibody (TPO-Ab) (normal range: 0-60U/ml) were measured. Continuous variables were analyzed by independent t test. Receiver operating characteristics (ROC) curve analysis was applied to calculate the cut-off values of strain ratio (SR) and elastography score (ES). The comparison of AUCs is performed by Z test. 482 nodules were diagnosed as PTMC and there were 181 nodules co-existed with HT. SR measurements were lower in PTMC co-existed with HT when comparing to those without HT. (7.292±6.581 vs 11.319±13.155, p<0.000). Taking the data from all of the 558 nodules, the best cut-off of diagnosing PTMC was SR>2.58. When taking the data from 181 PTMC with HT, the best cut-off was SR>2.10. The diagnostic value of SR>2.1 were higher than ES>3, conventional US and combining US and SE (z=3.595, 4.876, 4.420, p<0.001), but cut-off of SR>2.1 did not show significant enhancement of diagnostic value compared to SR>2.58 (z=0.439, p=0.8903>0.001) in PTMC with HT. There is a negative relation between SR and titer of TPO-Ab (r=-0.650, p<0.0001). PTMC with high TPO-Ab (>1000) titer presented lower SR (5.972±4.118 vs 8.379±9.172, p=0.009). Although SR measurements were lower in nodules co-existed with HT when comparing those without HT, using a regular ES and cut-off of SR measurement would not influence the diagnosing performance. SE is still very useful for diagnosing PTMC with HT. PTMC with high TPO-Ab titer might require a lower cut-off of SR. PMID:26945905

  20. Endoscopic Skull Base Surgery

    PubMed Central

    Senior, Brent A

    2008-01-01

    Endoscopic skull base surgery has undergone rapid advancement in the past decade moving from pituitary surgery to suprasellar lesions and now to a myriad of lesions extending from the cribriform plate to C2 and laterally out to the infratemporal fossa and petrous apex. Evolution of several technological advances as well as advances in understanding of endoscopic anatomy and the development of surgical techniques both in resection and reconstruction have fostered this capability. Management of benign disease via endoscopic methods is largely accepted now but more data is needed before the controversy on the role of endoscopic management of malignant disease is decided. Continued advances in surgical technique, navigation systems, endoscopic imaging technology, and robotics assure continued brisk evolution in this expanding field. PMID:19434274

  1. Endoscopic Devices for Obesity.

    PubMed

    Sampath, Kartik; Dinani, Amreen M; Rothstein, Richard I

    2016-06-01

    The obesity epidemic, recognized by the World Health Organization in 1997, refers to the rising incidence of obesity worldwide. Lifestyle modification and pharmacotherapy are often ineffective long-term solutions; bariatric surgery remains the gold standard for long-term obesity weight loss. Despite the reported benefits, it has been estimated that only 1% of obese patients will undergo surgery. Endoscopic treatment for obesity represents a potential cost-effective, accessible, minimally invasive procedure that can function as a bridge or alternative intervention to bariatric surgery. We review the current endoscopic bariatric devices including space occupying devices, endoscopic gastroplasty, aspiration technology, post-bariatric surgery endoscopic revision, and obesity-related NOTES procedures. Given the diverse devices already FDA approved and in development, we discuss the future directions of endoscopic therapies for obesity. PMID:27115879

  2. Magnetic hyperthermia dosimetry by biomechanical properties revealed in magnetomotive optical coherence elastography (MM-OCE) (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Huang, Pin-Chieh; Marjanovic, Marina; Spillman, Darold R.; Odintsov, Boris M.; Boppart, Stephen A.

    2016-03-01

    Magnetic nanoparticles (MNPs) have been utilized in magnetic hyperthermia to treat solid tumors. Under an appropriate AC magnetic field, energy can be transferred to the MNPs to heat up the intended tissue target while sparing non-targeted healthy tissue. However, a sensitive monitoring technique for the dose of MNP thermal therapy is desirable in order to prevent over-treatment and collateral injury. Typical hyperthermia dosimetry often relies on changes in imaging properties or temperature measurements based on the thermal distribution. Alternative dosimetric indicators can include the biomechanical properties of the tissue, reflecting the changes due to protein denaturation, coagulation, and tissue dehydration during hyperthermia treatments. Tissue stiffness can be probed by elastography modalities including MRI, ultrasound imaging, and optical coherence elastography (OCE), with OCE showing the highest displacement sensitivity (tens of nanometers). Magnetomotive optical coherence elastography (MM-OCE) is one type of OCE that utilizes MNPs as internal force transducers to probe the tissue stiffness. Therefore, we examined the feasibility of evaluating the hyperthermia dose based on the elasticity changes revealed by MM-OCE. Superparamagnetic MNPs were applied to ex vivo tissue specimens for both magnetic hyperthermia and MM-OCE experiments, where temperature and elastic modulus were obtained. A correlation between temperature rise and measured stiffness was observed. In addition, we found that with repetitive sequential treatments, tissue stiffness increased, while temperature rise remained relatively constant. These results potentially suggest that MM-OCE could indicate the irreversible changes the tissue undergoes during thermal therapy, which supports the idea for MM-OCE-based hyperthermia dosage control in future applications.

  3. Shear Wave Elastography of Passive Skeletal Muscle Stiffness: Influences of Sex and Age throughout Adulthood

    PubMed Central

    Eby, Sarah F.; Cloud, Beth A.; Brandenburg, Joline E.; Giambini, Hugo; Song, Pengfei; Chen, Shigao; LeBrasseur, Nathan K.; An, Kai-Nan

    2014-01-01

    Background Numerous structural and compositional changes – related not only to age, but also activity level and sex – may affect skeletal muscle stiffness across the adult age-span. Measurement techniques available thus far have largely limited passive stiffness evaluations to those of entire joints and muscle-tendon units. Shear wave elastography is an increasingly popular ultrasound technique for evaluating the mechanical properties of skeletal muscle tissue. The purpose of this study was to quantify the passive stiffness, or shear modulus, of the biceps brachii throughout adulthood in flexed and extended elbow positions. We hypothesized that shear modulus would be higher in males relative to females, and with advanced age in both sexes. Methods Shear wave elastography quantified biceps brachii stiffness at 90° elbow flexion and full extension in a large sample of adults between 21–94 years old (n=133; 47 males). Findings Regression analysis found sex and age were significant parameters for older adults (>60 years) in full extension. As expected, shear modulus values increased with advancing age; however, shear modulus values for females tended to be higher than those for males. Interpretation This study begins to establish normative trends for skeletal muscle shear modulus throughout adulthood. Specifically, this work establishes for the first time that the higher passive joint torque often found in males relative to females likely relates to parameters other than muscle shear modulus. Indeed, perhaps increases in skeletal muscle passive stiffness, though potentially altering the length-tension curve, serve a protective role – maintaining the tendon-muscle-tendon length-tension curve within a functional range. PMID:25483294

  4. Multifrequency time-harmonic elastography for the measurement of liver viscoelasticity in large tissue windows.

    PubMed

    Tzschätzsch, Heiko; Ipek-Ugay, Selcan; Trong, Manh Nguyen; Guo, Jing; Eggers, Jonathan; Gentz, Enno; Fischer, Thomas; Schultz, Michael; Braun, Jürgen; Sack, Ingolf

    2015-03-01

    Elastography of the liver for the non-invasive diagnosis of hepatic fibrosis is an established method. However, investigations of obese patients or patients with ascites are often limited by small and superficial elastographic windows. Therefore, multifrequency time-harmonic elastography (THE) based on time-resolved A-line ultrasound has recently been developed for measuring liver viscoelasticity in wide soft tissue windows and at greater depths. In this study, THE was integrated into a clinical B-mode scanner connected to a dedicated actuator bed driven by superimposed vibrations of 30- to 60-Hz frequencies. The resulting shear waves in the liver were captured along multiple profiles 7 to 14 cm in width and automatically processed for reconstruction of mean efficient shear wave speed and shear wave dispersion slope. This new modality was tested in healthy volunteers and 22 patients with clinically proven cirrhosis. Patients could be separated from controls by higher shear wave speeds (3.11 ± 0.64 m/s, 2.14-4.81 m/s, vs. 1.74 ± 0.10 m/s, 1.60-1.91 m/s) without significant degradation of data by high body mass index or ascites. Furthermore, the wave speed dispersion slope was significantly (p = 0.0025) lower in controls (5.2 ± 1.8 m/s/kHz) than in patients (39.1 ± 32.2 m/s/kHz). In conclusion, THE is useful for the diagnosis of cirrhosis in large tissue windows. PMID:25638319

  5. Assessment of mechanical properties of porcine aortas under physiological loading conditions using vascular elastography.

    PubMed

    Mascarenhas, Edgar J S; Peters, Mathijs F J; Nijs, Jan; Rutten, Marcel C M; van de Vosse, Frans N; Lopata, Richard G P

    2016-06-01

    Non-invasive assessment of the elastic properties of the arterial wall is often performed with ultrasound (US) imaging. The purpose of this study is to estimate mechanical properties of the vascular wall using in vitro inflation testing on biological tissue and two-dimensional (2-D) US elastography, and investigate the performance of the proposed methodology for physiological conditions. An inflation experiment was performed on 12 porcine aortas for (a) a large pressure range (0-140mmHg); and (b) physiological pressures (70-130mmHg) to mimic in vivo hemodynamic conditions. Two-dimensional radiofrequency (RF) data were acquired for one longitudinal and two transverse cross-sections for both experiments, and were analyzed to obtain the geometry and diameter-time behavior. The shear modulus (G) was estimated from these data for each pressure range applied. In addition, an incremental study based on the static data was performed to (1) investigate the changes in G for increasing mean arterial pressure (MAP) for a certain pressure difference (30, 40, 50 and 60mmHg); (2) compare the results with those from the dynamic experiment, for the same pressure range. The resulting stress-strain curves and shear moduli G (94±16kPa) for the static experimentare in agreement with literature and previous work. A linear dependency on MAP was found for G, yet the effect of the pulse pressure difference was negligible. The dynamic data revealed a G of 250±20kPa, whereas the incremental shear modulus (Ginc) was 240±39kPa. For all experiments, no significant differences in the values of G were found between different image planes. This study shows that 2-D US elastography of aortas during inflation testing is feasible and reproducible under controlled and physiological circumstances. In future studies, the in vivo, dynamic experiment should be repeated for a range of MAPs, and pathological vessels should be examined. PMID:26766329

  6. Acoustic Radiation Force Impulse Elastography for Focal Hepatic Tumors: Usefulness for Differentiating Hemangiomas from Malignant Tumors

    PubMed Central

    Kim, Ji Eun; Bae, Kyung Soo; Han, Joon Koo; Choi, Byung Ihn

    2013-01-01

    Objective The purpose of this study is to investigate whether acoustic radiation force impulse (ARFI) elastography with ARFI quantification and ARFI 2-dimensional (2D) imaging is useful for differentiating hepatic hemangiomas from malignant hepatic tumors. Materials and Methods One-hundred-and-one tumors in 74 patients were included in this study: 28 hemangiomas, 26 hepatocellular carcinomas (HCCs), three cholangiocarcinomas (CCCs), 20 colon cancer metastases and 24 other metastases. B-mode ultrasound, ARFI 2D imaging, and ARFI quantification were performed in all tumors. Shear wave velocities (SWVs) of the tumors and the adjacent liver and their SWV differences were compared among the tumor groups. The ARFI 2D images were compared with B-mode images regarding the stiffness, conspicuity and size of the tumors. Results The mean SWV of the hemangiomas was significantly lower than the malignant hepatic tumor groups: hemangiomas, 1.80 ± 0.57 m/sec; HCCs, 2.66 ± 0.94 m/sec; CCCs, 3.27 ± 0.64 m/sec; colon cancer metastases, 3.70 ± 0.61 m/sec; and other metastases, 2.82 ± 0.96 m/sec (p < 0.05). The area under the receiver operating characteristics curve of SWV for differentiating hemangiomas from malignant tumors was 0.86, with a sensitivity of 96.4% and a specificity of 65.8% at a cut-off value of 2.73 m/sec (p < 0.05). In the ARFI 2D images, the malignant tumors except HCCs were stiffer and more conspicuous as compared with the hemangiomas (p < 0.05). Conclusion ARFI elastography with ARFI quantification and ARFI 2D imaging may be useful for differentiating hepatic hemangiomas from malignant hepatic tumors. PMID:24043967

  7. A two-step optical flow method for strain estimation in elastography: Simulation and phantom study.

    PubMed

    Pan, Xiaochang; Gao, Jing; Tao, Shengzhen; Liu, Ke; Bai, Jing; Luo, Jianwen

    2014-04-01

    Optical flow (OF) method has been used in ultrasound elastography to estimate the strain distribution in tissues. However the bias of strain estimation by OF has previously been shown to be close to 20%. The objective in this paper is to improve the performance of OF-based strain estimation, a two-step OF method with a local warping technique is proposed in this paper. The local warping technique effectively decreases the decorrelation of the signals, and hence improves the performance of strain estimation. Simulations on both homogeneous and heterogeneous models with different strains are performed. Experiments on a heterogeneous tissue-mimicking phantom are also carried out. Simulation results of the homogeneous model show that the two-step OF method reduces the bias of strain estimation from 23.77% to 1.65%, and reduces the standard deviation of strain estimation from 2.9×10(-3) to 0.47×10(-3). Simulation results of the heterogeneous model shows that the signals-to-noise ratio (SNRe) of strain estimation is improved by 2.1 and 5.3dB in the inclusion and background, respectively, and the contrast-to-noise ratio (CNRe) is improved by 6.8dB. Finally, results of phantom experiments show that, by using the proposed method, the SNRe is increased by 4.0dB and 8.9dB in the inclusion and background, respectively, while the CNRe is increased by 13.1dB. The proposed two-step OF method is thus demonstrated capable of improving the performance of strain estimation in OF-based elastography. PMID:24393537

  8. Quantitative micro-elastography: imaging of tissue elasticity using compression optical coherence elastography

    NASA Astrophysics Data System (ADS)

    Kennedy, Kelsey M.; Chin, Lixin; McLaughlin, Robert A.; Latham, Bruce; Saunders, Christobel M.; Sampson, David D.; Kennedy, Brendan F.

    2015-10-01

    Probing the mechanical properties of tissue on the microscale could aid in the identification of diseased tissues that are inadequately detected using palpation or current clinical imaging modalities, with potential to guide medical procedures such as the excision of breast tumours. Compression optical coherence elastography (OCE) maps tissue strain with microscale spatial resolution and can delineate microstructural features within breast tissues. However, without a measure of the locally applied stress, strain provides only a qualitative indication of mechanical properties. To overcome this limitation, we present quantitative micro-elastography, which combines compression OCE with a compliant stress sensor to image tissue elasticity. The sensor consists of a layer of translucent silicone with well-characterized stress-strain behaviour. The measured strain in the sensor is used to estimate the two-dimensional stress distribution applied to the sample surface. Elasticity is determined by dividing the stress by the strain in the sample. We show that quantification of elasticity can improve the ability of compression OCE to distinguish between tissues, thereby extending the potential for inter-sample comparison and longitudinal studies of tissue elasticity. We validate the technique using tissue-mimicking phantoms and demonstrate the ability to map elasticity of freshly excised malignant and benign human breast tissues.

  9. Quantitative micro-elastography: imaging of tissue elasticity using compression optical coherence elastography

    PubMed Central

    Kennedy, Kelsey M.; Chin, Lixin; McLaughlin, Robert A.; Latham, Bruce; Saunders, Christobel M.; Sampson, David D.; Kennedy, Brendan F.

    2015-01-01

    Probing the mechanical properties of tissue on the microscale could aid in the identification of diseased tissues that are inadequately detected using palpation or current clinical imaging modalities, with potential to guide medical procedures such as the excision of breast tumours. Compression optical coherence elastography (OCE) maps tissue strain with microscale spatial resolution and can delineate microstructural features within breast tissues. However, without a measure of the locally applied stress, strain provides only a qualitative indication of mechanical properties. To overcome this limitation, we present quantitative micro-elastography, which combines compression OCE with a compliant stress sensor to image tissue elasticity. The sensor consists of a layer of translucent silicone with well-characterized stress-strain behaviour. The measured strain in the sensor is used to estimate the two-dimensional stress distribution applied to the sample surface. Elasticity is determined by dividing the stress by the strain in the sample. We show that quantification of elasticity can improve the ability of compression OCE to distinguish between tissues, thereby extending the potential for inter-sample comparison and longitudinal studies of tissue elasticity. We validate the technique using tissue-mimicking phantoms and demonstrate the ability to map elasticity of freshly excised malignant and benign human breast tissues. PMID:26503225

  10. Current applications of endoscopic suturing

    PubMed Central

    Stavropoulos, Stavros N; Modayil, Rani; Friedel, David

    2015-01-01

    Endoscopic suturing had previously been considered an experimental procedure only performed in a few centers and often by surgeons. Now, however, endoscopic suturing has evolved sufficiently to be easily implemented during procedures and is more commonly used by gastroenterologists. We have employed the Apollo OverStitch suturing device in a variety of ways including closure of perforations, closure of full thickness defects in the gastrointestinal wall created during endoscopic full thickness resection, closure of mucosotomies during peroral endoscopic myotomy, stent fixation, fistula closure, post endoscopic submucosal dissection, endoscopic mucosal resection and Natural Orifice Transluminal Endoscopic Surgery defect closures, post-bariatric surgery gastrojejunal anastomosis revision and primary sleeve gastroplasty. PMID:26191342

  11. Tomographic elastography of contracting skeletal muscles from their natural vibrations

    NASA Astrophysics Data System (ADS)

    Sabra, Karim G.; Archer, Akibi

    2009-11-01

    Conventional elastography techniques require an external mechanical or radiation excitation to measure noninvasively the viscoelastic properties of skeletal muscles and thus monitor human motor functions. We developed instead a passive elastography technique using only an array of skin-mounted accelerometers to record the low-frequency vibrations of the biceps brachii muscle naturally generated during voluntary contractions and to determine their two-dimensional directionality. Cross-correlating these recordings provided travel-times measurements of these muscle vibrations between multiple sensor pairs. Travel-time tomographic inversions yielded spatial variations of their propagation velocity during isometric elbow flexions which indicated a nonuniform longitudinal stiffening of the biceps.

  12. [Ultrasound of the Thyroid].

    PubMed

    Dietrich, C F; Bojunga, J

    2016-02-01

    Thyroid nodules and thyroid abnormalities are common findings in the general population. Ultrasonography is the most important imaging tool for diagnosing thyroid disease. In the majority of cases a correct diagnosis can already be made in synopsis of the sonographic together with clinical findings and basal thyroid hormone parameters and an appropriate therapy can be initiated thereafter. A differentiation of hormonally active vs. inactive nodes, and in particular benign vs. malignant nodules is sonographically, however, not reliably possible. In this context, radioscanning has its clinical significance predominantly in diagnosing hormonal activity of thyroid nodules. Efforts of the past years aimed to improve sonographic risk stratification to predict malignancy of thyroid nodules through standardized diagnostic assessment of evaluated risk factors in order to select patients, who need further diagnostic work up. According to the "Breast Imaging Reporting and Data System" (BI-RADS), "Thyroid Imaging Reporting and Data Systems" (TI-RADS) giving standardized categories with rates of malignancy were evaluated as a basis for further clinical management. Recent technological developments, such as elastography, also showpromising data and could gain entrance into clinical practice. The ultrasound-guided fineneedle aspiration is the key element in the diagnosis of sonographically suspicious thyroid nodules and significantly contributes to the diagnosis of malignancy versus benignity. PMID:26859730

  13. General review of magnetic resonance elastography

    PubMed Central

    Low, Gavin; Kruse, Scott A; Lomas, David J

    2016-01-01

    Magnetic resonance elastography (MRE) is an innovative imaging technique for the non-invasive quantification of the biomechanical properties of soft tissues via the direct visualization of propagating shear waves in vivo using a modified phase-contrast magnetic resonance imaging (MRI) sequence. Fundamentally, MRE employs the same physical property that physicians utilize when performing manual palpation - that healthy and diseased tissues can be differentiated on the basis of widely differing mechanical stiffness. By performing “virtual palpation”, MRE is able to provide information that is beyond the capabilities of conventional morphologic imaging modalities. In an era of increasing adoption of multi-parametric imaging approaches for solving complex problems, MRE can be seamlessly incorporated into a standard MRI examination to provide a rapid, reliable and comprehensive imaging evaluation at a single patient appointment. Originally described by the Mayo Clinic in 1995, the technique represents the most accurate non-invasive method for the detection and staging of liver fibrosis and is currently performed in more than 100 centers worldwide. In this general review, the mechanical properties of soft tissues, principles of MRE, clinical applications of MRE in the liver and beyond, and limitations and future directions of this discipline -are discussed. Selected diagrams and images are provided for illustration. PMID:26834944

  14. Vibration safety limits for magnetic resonance elastography

    NASA Astrophysics Data System (ADS)

    Ehman, E. C.; Rossman, P. J.; Kruse, S. A.; Sahakian, A. V.; Glaser, K. J.

    2008-02-01

    Magnetic resonance elastography (MRE) has been demonstrated to have potential as a clinical tool for assessing the stiffness of tissue in vivo. An essential step in MRE is the generation of acoustic mechanical waves within a tissue via a coupled mechanical driver. Motivated by an increasing volume of human imaging trials using MRE, the objectives of this study were to audit the vibration amplitude of exposure for our IRB-approved human MRE studies, to compare these values to a conservative regulatory standard for vibrational exposure and to evaluate the applicability and implications of this standard for MRE. MRE displacement data were examined from 29 MRE exams, including the liver, brain, kidney, breast and skeletal muscle. Vibrational acceleration limits from a European Union directive limiting occupational exposure to whole-body and extremity vibrations (EU 2002/44/EC) were adjusted for time and frequency of exposure, converted to maximum displacement values and compared to the measured in vivo displacements. The results indicate that the vibrational amplitudes used in MRE studies are below the EU whole-body vibration limit, and the EU guidelines represent a useful standard that could be readily accepted by Institutional Review Boards to define standards for vibrational exposures for MRE studies in humans.

  15. General review of magnetic resonance elastography.

    PubMed

    Low, Gavin; Kruse, Scott A; Lomas, David J

    2016-01-28

    Magnetic resonance elastography (MRE) is an innovative imaging technique for the non-invasive quantification of the biomechanical properties of soft tissues via the direct visualization of propagating shear waves in vivo using a modified phase-contrast magnetic resonance imaging (MRI) sequence. Fundamentally, MRE employs the same physical property that physicians utilize when performing manual palpation - that healthy and diseased tissues can be differentiated on the basis of widely differing mechanical stiffness. By performing "virtual palpation", MRE is able to provide information that is beyond the capabilities of conventional morphologic imaging modalities. In an era of increasing adoption of multi-parametric imaging approaches for solving complex problems, MRE can be seamlessly incorporated into a standard MRI examination to provide a rapid, reliable and comprehensive imaging evaluation at a single patient appointment. Originally described by the Mayo Clinic in 1995, the technique represents the most accurate non-invasive method for the detection and staging of liver fibrosis and is currently performed in more than 100 centers worldwide. In this general review, the mechanical properties of soft tissues, principles of MRE, clinical applications of MRE in the liver and beyond, and limitations and future directions of this discipline -are discussed. Selected diagrams and images are provided for illustration. PMID:26834944

  16. Magnetic resonance elastography hardware design: a survey.

    PubMed

    Tse, Z T H; Janssen, H; Hamed, A; Ristic, M; Young, I; Lamperth, M

    2009-05-01

    Magnetic resonance elastography (MRE) is an emerging technique capable of measuring the shear modulus of tissue. A suspected tumour can be identified by comparing its properties with those of tissues surrounding it; this can be achieved even in deep-lying areas as long as mechanical excitation is possible. This would allow non-invasive methods for cancer-related diagnosis in areas not accessible with conventional palpation. An actuating mechanism is required to generate the necessary tissue displacements directly on the patient in the scanner and three different approaches, in terms of actuator action and position, exist to derive stiffness measurements. However, the magnetic resonance (MR) environment places considerable constraints on the design of such devices, such as the possibility of mutual interference between electrical components, the scanner field, and radio frequency pulses, and the physical space restrictions of the scanner bore. This paper presents a review of the current solutions that have been developed for MRE devices giving particular consideration to the design criteria including the required vibration frequency and amplitude in different applications, the issue of MR compatibility, actuation principles, design complexity, and scanner synchronization issues. The future challenges in this field are also described. PMID:19499839

  17. Compression-sensitive magnetic resonance elastography

    NASA Astrophysics Data System (ADS)

    Hirsch, Sebastian; Beyer, Frauke; Guo, Jing; Papazoglou, Sebastian; Tzschaetzsch, Heiko; Braun, Juergen; Sack, Ingolf

    2013-08-01

    Magnetic resonance elastography (MRE) quantifies the shear modulus of biological tissue to detect disease. Complementary to the shear elastic properties of tissue, the compression modulus may be a clinically useful biomarker because it is sensitive to tissue pressure and poromechanical interactions. In this work, we analyze the capability of MRE to measure volumetric strain and the dynamic bulk modulus (P-wave modulus) at a harmonic drive frequency commonly used in shear-wave-based MRE. Gel phantoms with various densities were created by introducing CO2-filled cavities to establish a compressible effective medium. The dependence of the effective medium's bulk modulus on phantom density was investigated via static compression tests, which confirmed theoretical predictions. The P-wave modulus of three compressible phantoms was calculated from volumetric strain measured by 3D wave-field MRE at 50 Hz drive frequency. The results demonstrate the MRE-derived volumetric strain and P-wave modulus to be sensitive to the compression properties of effective media. Since the reconstruction of the P-wave modulus requires third-order derivatives, noise remains critical, and P-wave moduli are systematically underestimated. Focusing on relative changes in the effective bulk modulus of tissue, compression-sensitive MRE may be useful for the noninvasive detection of diseases involving pathological pressure alterations such as hepatic hypertension or hydrocephalus.

  18. Wideband MR elastography for viscoelasticity model identification.

    PubMed

    Yasar, Temel K; Royston, Thomas J; Magin, Richard L

    2013-08-01

    The growing clinical use of MR elastography requires the development of new quantitative standards for measuring tissue stiffness. Here, we examine a soft tissue mimicking phantom material (Ecoflex) over a wide frequency range (200 Hz to 7.75 kHz). The recorded data are fit to a cohort of viscoelastic models of varying complexity (integer and fractional order). This was accomplished using multiple sample sizes by employing geometric focusing of the shear wave front to compensate for the changes in wavelength and attenuation over this broad range of frequencies. The simple axisymmetric geometry and shear wave front of this experiment allows us to calculate the frequency-dependent complex-valued shear modulus of the material. The data were fit to several common models of linear viscoelasticity, including those with fractional derivative operators, and we identified the best possible matches over both a limited frequency band (often used in clinical studies) and over the entire frequency span considered. In addition to demonstrating the superior capability of the fractional order viscoelastic models, this study highlights the advantages of measuring the complex-valued shear modulus over as wide a range of frequencies as possible. PMID:23001852

  19. Compression-sensitive magnetic resonance elastography.

    PubMed

    Hirsch, Sebastian; Beyer, Frauke; Guo, Jing; Papazoglou, Sebastian; Tzschaetzsch, Heiko; Braun, Juergen; Sack, Ingolf

    2013-08-01

    Magnetic resonance elastography (MRE) quantifies the shear modulus of biological tissue to detect disease. Complementary to the shear elastic properties of tissue, the compression modulus may be a clinically useful biomarker because it is sensitive to tissue pressure and poromechanical interactions. In this work, we analyze the capability of MRE to measure volumetric strain and the dynamic bulk modulus (P-wave modulus) at a harmonic drive frequency commonly used in shear-wave-based MRE. Gel phantoms with various densities were created by introducing CO2-filled cavities to establish a compressible effective medium. The dependence of the effective medium's bulk modulus on phantom density was investigated via static compression tests, which confirmed theoretical predictions. The P-wave modulus of three compressible phantoms was calculated from volumetric strain measured by 3D wave-field MRE at 50 Hz drive frequency. The results demonstrate the MRE-derived volumetric strain and P-wave modulus to be sensitive to the compression properties of effective media. Since the reconstruction of the P-wave modulus requires third-order derivatives, noise remains critical, and P-wave moduli are systematically underestimated. Focusing on relative changes in the effective bulk modulus of tissue, compression-sensitive MRE may be useful for the noninvasive detection of diseases involving pathological pressure alterations such as hepatic hypertension or hydrocephalus. PMID:23852144

  20. Scatter-based magnetic resonance elastography

    NASA Astrophysics Data System (ADS)

    Papazoglou, Sebastian; Xu, Chao; Hamhaber, Uwe; Siebert, Eberhard; Bohner, Georg; Klingebiel, Randolf; Braun, Jürgen; Sack, Ingolf

    2009-04-01

    Elasticity is a sensitive measure of the microstructural constitution of soft biological tissues and increasingly used in diagnostic imaging. Magnetic resonance elastography (MRE) uniquely allows in vivo measurement of the shear elasticity of brain tissue. However, the spatial resolution of MRE is inherently limited as the transformation of shear wave patterns into elasticity maps requires the solution of inverse problems. Therefore, an MRE method is introduced that avoids inversion and instead exploits shear wave scattering at elastic interfaces between anatomical regions of different shear compliance. This compliance-weighted imaging (CWI) method can be used to evaluate the mechanical consistency of cerebral lesions or to measure relative stiffness differences between anatomical subregions of the brain. It is demonstrated that CWI-MRE is sensitive enough to reveal significant elasticity variations within inner brain parenchyma: the caudate nucleus (head) was stiffer than the lentiform nucleus and the thalamus by factors of 1.3 ± 0.1 and 1.7 ± 0.2, respectively (P < 0.001). CWI-MRE provides a unique method for characterizing brain tissue by identifying local stiffness variations.

  1. Magnetic Resonance Elastography: Inversions in Bounded Media

    PubMed Central

    Kolipaka, Arunark; McGee, Kiaran P.; Manduca, Armando; Romano, Anthony J.; Glaser, Kevin J.; Araoz, Philip A.; Ehman, Richard L.

    2009-01-01

    Magnetic resonance elastography (MRE) is a noninvasive imaging technique capable of quantifying and spatially resolving the shear stiffness of soft tissues by visualization of synchronized mechanical wave displacement fields. However, MRE inversions generally assume that the measured tissue motion consists primarily of shear waves propagating in a uniform, infinite medium. This assumption is not valid in organs such as the heart, eye, bladder, skin, fascia, bone and spinal cord in which the shear wavelength approaches the geometric dimensions of the object. The aim of this study was to develop and test mathematical inversion algorithms capable of resolving shear stiffness from displacement maps of flexural waves propagating in bounded media such as beams, plates and spherical shells using geometry-specific equations of motion. MRE and finite element modeling (FEM) of beam, plate, and spherical shell phantoms of various geometries were performed. Mechanical testing of the phantoms agreed with the stiffness values obtained from FEM and MRE data and a linear correlation of r2 ≥ 0.99 was observed between the stiffness values obtained using MRE and FEM data. In conclusion, we have demonstrated new inversion methods for calculating shear stiffness that may be more appropriate for waves propagating in bounded media. PMID:19780146

  2. DYNAMIC OPTICAL COHERENCE ELASTOGRAPHY: A REVIEW

    PubMed Central

    LIANG, XING; CRECEA, VASILICA; BOPPART, STEPHEN A.

    2012-01-01

    With the development of optical coherence tomography, the application optical coherence elastography (OCE) has gained more and more attention in biomechanics for its unique features including micron-scale resolution, real-time processing, and non-invasive imaging. In this review, one group of OCE techniques, namely dynamic OCE, are introduced and discussed including external dynamic OCE mapping and imaging of ex vivo breast tumor, external dynamic OCE measurement of in vivo human skin, and internal dynamic OCE including acoustomotive OCE and magnetomotive OCE. These techniques overcame some of the major drawbacks of traditional static OCE, and broadened the OCE application fields. Driven by scientific needs to engineer new quantitative methods that utilize the high micron-scale resolution achievable with optics, results of biomechanical properties were obtained from biological tissues. The results suggest potential diagnostic and therapeutic clinical applications. Results from these studies also help our understanding of the relationship between biomechanical variations and functional tissue changes in biological systems. PMID:22448192

  3. Wideband MR elastography for viscoelasticity model identification

    PubMed Central

    Yasar, Temel K.; Royston, Thomas J.; Magin, Richard L.

    2012-01-01

    The growing clinical use of MR Elastography (MRE) requires the development of new quantitative standards for measuring tissue stiffness. Here, we examine a soft tissue mimicking phantom material (Ecoflex) over a wide frequency range (200 Hz to 7.75 kHz). The recorded data are fit to a cohort of viscoelastic models of varying complexity (integer and fractional order). This was accomplished using multiple sample sizes by employing geometric focusing of the shear wave front to compensate for the changes in wavelength and attenuation over this broad range of frequencies. The simple axisymmetric geometry and shear wave front of this experiment allows us to calculate the frequency-dependent complex-valued shear modulus of the material. The data were fit to several common models of linear viscoelasticity, including those with fractional derivative operators, and we identified the best possible matches over both a limited frequency band (often used in clinical studies) and over the entire frequency span considered. In addition to demonstrating the superior capability of the fractional ord