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Song A, Li T, Ding X, Wu M, Wang R. TSE-GAN: strain elastography using generative adversarial network for thyroid disease diagnosis. Front Bioeng Biotechnol 2024; 12:1330713. [PMID: 38361791 PMCID: PMC10867782 DOI: 10.3389/fbioe.2024.1330713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 01/15/2024] [Indexed: 02/17/2024] Open
Abstract
Over the past 35 years, studies conducted worldwide have revealed a threefold increase in the incidence of thyroid cancer. Strain elastography is a new imaging technique to identify benign and malignant thyroid nodules due to its sensitivity to tissue stiffness. However, there are certain limitations of this technique, particularly in terms of standardization of the compression process, evaluation of results and several assumptions used in commercial strain elastography modes for the purpose of simplifying imaging analysis. In this work, we propose a novel conditional generative adversarial network (TSE-GAN) for automatically generating thyroid strain elastograms, which adopts a global-to-local architecture to improve the ability of extracting multi-scale features and develops an adaptive deformable U-net structure in the sub-generator to apply effective deformation. Furthermore, we introduce a Lab-based loss function to induce the networks to generate realistic thyroid elastograms that conform to the probability distribution of the target domain. Qualitative and quantitative assessments are conducted on a clinical dataset provided by Shanghai Sixth People's Hospital. Experimental results demonstrate that thyroid elastograms generated by the proposed TSE-GAN outperform state-of-the-art image translation methods in meeting the needs of clinical diagnostic applications and providing practical value.
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Affiliation(s)
- Anping Song
- School of Computer Engineering and Science, Shanghai University, Shanghai, China
| | - Tianyi Li
- School of Computer Engineering and Science, Shanghai University, Shanghai, China
| | - Xuehai Ding
- School of Computer Engineering and Science, Shanghai University, Shanghai, China
| | - Mingye Wu
- Department of Medical Ultrasonics, Shanghai University of Traditional Chinese Medicine Affiliated Shuguang Hospital, Shanghai, China
| | - Ren Wang
- Department of Ultrasound Medicine, Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Sforza M, Kul Z, Saghir R, Saghir N, Okhiria R, Okhiria T, Sidhu M. Predicting the expansion of the lower pole of the breast following smooth breast implant augmentation: A novel shear wave elastography study. J Plast Reconstr Aesthet Surg 2023; 84:574-581. [PMID: 37441854 DOI: 10.1016/j.bjps.2023.06.051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 06/12/2023] [Accepted: 06/22/2023] [Indexed: 07/15/2023]
Abstract
OBJECTIVES This study aimed to educate and demonstrate how the use of shear wave elastography (SWE) can be used to determine the elasticity of patient tissues preoperatively, which can then be used to predict the level of lower pole expansion postoperatively, following breast augmentation surgery. MATERIALS AND METHODS This study evaluated 60 breasts in 30 patients that were divided in 3 equal groups (n = 20) according to their predefined elastography criteria measured via SWE (loose, moderate, and tight tissue elasticity). All measurements were taken under maximum stretch between the inferior border of the nipple alveolar complex (NAC) and inframammary fold (IMF) using a measuring tape in millimetres (mm). The follow-up appointments for routine assessments and measurements were done at 3, 6, 12, 18, and 24 months. RESULTS The study engaged 38 patients over 4 years, but only 10 patients in each group attended all the appointments. Statistical analysis showed the elastic skin types (loose, moderate, and tight) had significantly different rates of lower pole expansion, and the rate of expansion increased significantly after 6 months postoperatively, whereas prior to 6 months, the rates were comparable (p < 0.05). DISCUSSION The results showed that increasingly elastic skin types have a greater rate of lower pole expansion. This is important for the operating surgeon to be aware of as looser skin types will be more prone to lower pole expansion, and thus, a higher surgical IMF suture may be advised to manage patient expectations. CONCLUSION This study can be used as a guideline for surgeons, which will allow for a more predictable surgical planning system that will ultimately lead to fewer revisions and risks for patients worldwide.
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Affiliation(s)
- Marcos Sforza
- Department of Surgery and Interventional Sciences, University College of London, London, UK; Royal College of Surgeons of England, UK.
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Huerta-Calpe S, Salas B, Inarejos Clemente EJ, Guitart C, Balaguer M, Jordan I. Sono-Elastography: An Ultrasound Quantitative Non-Invasive Measurement to Guide Bacterial Pneumonia Diagnosis in Children. CHILDREN (BASEL, SWITZERLAND) 2023; 10:1335. [PMID: 37628334 PMCID: PMC10453076 DOI: 10.3390/children10081335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/26/2023] [Accepted: 07/31/2023] [Indexed: 08/27/2023]
Abstract
Lung ultrasound (LUS) is, at present, a standard technique for the diagnosis of acute lower respiratory tract infections (ALRTI) and other lung pathologies. Its protocolised use has replaced chest radiography and has led to a drastic reduction in radiation exposure in children. Despite its undeniable usefulness, there are situations in which certain quantitative measurements could provide additional data to differentiate the etiology of some pulmonary processes and thus adapt the treatment. Our research group hypothesises that several lung processes such pneumonia may lead to altered lung tissue stiffness, which could be quantified with new diagnostic tests such as lung sono-elastography (SE). An exhaustive review of the literature has been carried out, concluding that the role of SE for the study of pulmonary processes is currently scarce and poorly studied, particularly in pediatrics. The aim of this review is to provide an overview of the technical aspects of SE and to explore its potential usefulness as a non-invasive diagnostic technique for ALRTI in children by implementing an institutional image acquisition protocol.
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Affiliation(s)
- Sergi Huerta-Calpe
- Pediatric Intensive Care Unit, Hospital Sant Joan de Déu, 08950 Barcelona, Spain; (S.H.-C.); (C.G.); (M.B.)
- Immune and Respiratory Dysfunction Research Group, Institut de Recerca Sant Joan de Déu, 08950 Barcelona, Spain
| | - Bárbara Salas
- Radiology and Diagnostic Imaging Unit, Hospital Sant Joan de Déu, 08950 Barcelona, Spain; (B.S.); (E.J.I.C.)
| | - Emilio J. Inarejos Clemente
- Radiology and Diagnostic Imaging Unit, Hospital Sant Joan de Déu, 08950 Barcelona, Spain; (B.S.); (E.J.I.C.)
| | - Carmina Guitart
- Pediatric Intensive Care Unit, Hospital Sant Joan de Déu, 08950 Barcelona, Spain; (S.H.-C.); (C.G.); (M.B.)
- Immune and Respiratory Dysfunction Research Group, Institut de Recerca Sant Joan de Déu, 08950 Barcelona, Spain
| | - Mònica Balaguer
- Pediatric Intensive Care Unit, Hospital Sant Joan de Déu, 08950 Barcelona, Spain; (S.H.-C.); (C.G.); (M.B.)
- Immune and Respiratory Dysfunction Research Group, Institut de Recerca Sant Joan de Déu, 08950 Barcelona, Spain
| | - Iolanda Jordan
- Pediatric Intensive Care Unit, Hospital Sant Joan de Déu, 08950 Barcelona, Spain; (S.H.-C.); (C.G.); (M.B.)
- Immune and Respiratory Dysfunction Research Group, Institut de Recerca Sant Joan de Déu, 08950 Barcelona, Spain
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Wu H, Tang Y, Zhang B, Klippel P, Jing Y, Yao J, Jiang X. Miniaturized Stacked Transducer for Intravascular Sonothrombolysis With Internal-Illumination Photoacoustic Imaging Guidance and Clot Characterization. IEEE Trans Biomed Eng 2023; 70:2279-2288. [PMID: 37022249 PMCID: PMC10399617 DOI: 10.1109/tbme.2023.3240725] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Thromboembolism in blood vessels can lead to stroke or heart attack and even sudden death unless brought under control. Sonothrombolysis enhanced by ultrasound contrast agents has shown promising outcome on effective treatment of thromboembolism. Intravascular sonothrombolysis was also reported recently with a potential for effective and safe treatment of deep thrombosis. Despite the promising treatment results, the treatment efficiency for clinical application may not be optimized due to the lack of imaging guidance and clot characterization during the thrombolysis procedure. In this paper, a miniaturized transducer was designed to have an 8-layer PZT-5A stacked with an aperture size of 1.4 × 1.4 mm2 and assembled in a customized two-lumen 10-Fr catheter for intravascular sonothrombolysis. The treatment process was monitored with internal-illumination photoacoustic tomography (II-PAT), a hybrid imaging modality that combines the rich contrast of optical absorption and the deep penetration of ultrasound detection. With intravascular light delivery using a thin optical fiber integrated with the intravascular catheter, II-PAT overcomes the penetration depth limited by strong optical attenuation of tissue. In-vitro PAT-guided sonothrombolysis experiments were carried out with synthetic blood clots embedded in tissue phantom. Clot position, shape, stiffness, and oxygenation level can be estimated by II-PAT at clinically relevant depth of ten centimeters. Our findings have demonstrated the feasibility of the proposed PAT-guided intravascular sonothrombolysis with real-time feedback during the treatment process.
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Guo T, Wantono C, Tan Y, Deng F, Duan T, Liu D. Regulators, functions, and mechanotransduction pathways of matrix stiffness in hepatic disease. Front Physiol 2023; 14:1098129. [PMID: 36711017 PMCID: PMC9878334 DOI: 10.3389/fphys.2023.1098129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 01/06/2023] [Indexed: 01/15/2023] Open
Abstract
The extracellular matrix (ECM) provides physical support and imparts significant biochemical and mechanical cues to cells. Matrix stiffening is a hallmark of liver fibrosis and is associated with many hepatic diseases, especially liver cirrhosis and carcinoma. Increased matrix stiffness is not only a consequence of liver fibrosis but is also recognized as an active driver in the progression of fibrotic hepatic disease. In this article, we provide a comprehensive view of the role of matrix stiffness in the pathological progression of hepatic disease. The regulators that modulate matrix stiffness including ECM components, MMPs, and crosslinking modifications are discussed. The latest advances of the research on the matrix mechanics in regulating intercellular signaling and cell phenotype are classified, especially for hepatic stellate cells, hepatocytes, and immunocytes. The molecular mechanism that sensing and transducing mechanical signaling is highlighted. The current progress of ECM stiffness's role in hepatic cirrhosis and liver cancer is introduced and summarized. Finally, the recent trials targeting ECM stiffness for the treatment of liver disease are detailed.
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Affiliation(s)
- Ting Guo
- Department of Gastroenterology, The Second Xiangya Hospital of Central South University, Changsha, China,Research Center of Digestive Disease, Central South University, Changsha, China
| | - Cindy Wantono
- Department of Gastroenterology, The Second Xiangya Hospital of Central South University, Changsha, China,Research Center of Digestive Disease, Central South University, Changsha, China
| | - Yuyong Tan
- Department of Gastroenterology, The Second Xiangya Hospital of Central South University, Changsha, China,Research Center of Digestive Disease, Central South University, Changsha, China
| | - Feihong Deng
- Department of Gastroenterology, The Second Xiangya Hospital of Central South University, Changsha, China,Research Center of Digestive Disease, Central South University, Changsha, China
| | - Tianying Duan
- Department of Gastroenterology, The Second Xiangya Hospital of Central South University, Changsha, China,Research Center of Digestive Disease, Central South University, Changsha, China
| | - Deliang Liu
- Department of Gastroenterology, The Second Xiangya Hospital of Central South University, Changsha, China,Research Center of Digestive Disease, Central South University, Changsha, China,*Correspondence: Deliang Liu,
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Tang Y, Wu H, Klippel P, Zhang B, Huang HYS, Jing Y, Jiang X, Yao J. Deep thrombosis characterization using photoacoustic imaging with intravascular light delivery. Biomed Eng Lett 2022; 12:135-145. [PMID: 35529341 PMCID: PMC9046522 DOI: 10.1007/s13534-022-00216-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 01/18/2022] [Accepted: 01/22/2022] [Indexed: 11/28/2022] Open
Abstract
Venous thromboembolism (VTE) is a condition in which blood clots form within the deep veins of the leg or pelvis to cause deep vein thrombosis. The optimal treatment of VTE is determined by thrombus properties such as the age, size, and chemical composition of the blood clots. The thrombus properties can be readily evaluated by using photoacoustic computed tomography (PACT), a hybrid imaging modality that combines the rich contrast of optical imaging and deep penetration of ultrasound imaging. With inherent sensitivity to endogenous chromophores such as hemoglobin, multispectral PACT can provide composition information and oxygenation level in the clots. However, conventional PACT of clots relies on external light illumination, which provides limited penetration depth due to strong optical scattering of intervening tissue. In our study, this depth limitation is overcome by using intravascular light delivery with a thin optical fiber. To demonstrate in vitro blood clot characterization, clots with different acuteness and oxygenation levels were placed underneath ten-centimeter-thick chicken breast tissue and imaged using multiple wavelengths. Acoustic frequency analysis was performed on the received PA channel signals, and oxygenation level was estimated using multispectral linear spectral unmixing. The results show that, with intravascular light delivery, clot oxygenation level can be accurately measured, and the clot age can thus be estimated. In addition, we found that retracted and unretracted clots had different acoustic frequency spectrum. While unretracted clots had stronger high frequency components, retracted clots had much higher low frequency components due to densely packed red blood cells. The PACT characterization of the clots was consistent with the histology results and mechanical tests.
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Affiliation(s)
- Yuqi Tang
- Department of Biomedical Engineering, Duke University, Durham, NC USA
| | - Huaiyu Wu
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC USA
| | - Paul Klippel
- Graduate Program in Acoustics and Department of Biomedical Engineering, Pennsylvania State University, University Park, PA USA
| | - Bohua Zhang
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC USA
| | - Hsiao-Ying Shadow Huang
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC USA
| | - Yun Jing
- Graduate Program in Acoustics and Department of Biomedical Engineering, Pennsylvania State University, University Park, PA USA
| | - Xiaoning Jiang
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC USA
| | - Junjie Yao
- Department of Biomedical Engineering, Duke University, Durham, NC USA
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Lateral Abdominal Muscles Shear Modulus and Thickness Measurements under Controlled Ultrasound Probe Compression by External Force Sensor: A Comparison and Reliability Study. SENSORS 2021; 21:s21124036. [PMID: 34208168 PMCID: PMC8230760 DOI: 10.3390/s21124036] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 06/06/2021] [Accepted: 06/07/2021] [Indexed: 01/01/2023]
Abstract
The aim of this study was to perform a reliability and agreement analysis and to compare lateral abdominal muscles (LAMs) thickness and elasticity results obtained by an experienced operator, by a non-experienced operator, and in an ultrasound imaging probe compression controlled (PCC) condition with minimal force necessary to obtain a proper ultrasound image. The sample consisted of 39 adolescents. An Aixplorer ultrasound scanner was used to evaluate the LAM. The probe in PCC condition was positioned in a prepared probe holder coupled with a pressure sensor. The LAM thickness and elasticity measurements were significantly (p < 0.05) different in the ultrasound PCC condition, compared to results obtained by both examiners. The abdominal oblique external and internal muscle thickness measurements were underestimated and all LAM shear moduli were overestimated during measurements without controlling the probe compression by an external sensor. The intra-class correlation coefficient was excellent in all conditions, but the smallest detectable differences were approximately 43–60% lower during the measurements collected in PCC condition. Differences in LAM measurements between PCC and ‘on-hand’ conditions may be clinically irrelevant when the force applied by the probe is consciously controlled by the examiner. However, during ultrasound measurements of the LAM morphology, the potential under/over estimation should always be considered when measurements are performed without controlling probe compression by an external sensor.
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Tang X, Zhu B, Tian M, Guo R, Huang S, Tang Y, Qiu L. Preliminary study on the influencing factors of shear wave elastography for peripheral nerves in healthy population. Sci Rep 2021; 11:5582. [PMID: 33692411 PMCID: PMC7946935 DOI: 10.1038/s41598-021-84900-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 02/23/2021] [Indexed: 02/08/2023] Open
Abstract
This study took shear wave elastography (SWE) technology to measure the shear wave velocity (SWV) of peripheral nerve in healthy population, which represents the stiffness of the peripheral nerves, and research whether these parameters (location, age, sex, body mass index (BMI), the thickness and cross-sectional area(CSA) of the nerve) would affect the stiffness of the peripheral nerves. 105 healthy volunteers were enrolled in this study. We recorded the genders and ages of these volunteers, measured height and weight, calculated BMI, measured nerve thickness and CSA using high-frequency ultrasound (HFUS), and then, we measured and compared the SWV of the right median nerve at the middle of the forearm and at the proximal entrance of the carpal tunnel. The SWV of the median nerve of the left side was measured to explore whether there exist differences of SWV in bilateral median nerve. Additionally, we also measured the SWV of the right tibial nerve at the ankle canal to test whether there is any difference in shear wave velocity between different peripheral nerves. This study found that there existed significant differences of SWV between different sites in one nerve and between different peripheral nerves. No significant difference was found in SWV between bilateral median nerves. Additionally, the SWV of peripheral nerves was associated with gender, while not associated with age or BMI. The mean SWV of the studied male volunteers in median nerve were significantly higher than those of female (p < 0.05). Peripheral nerve SWE measurement in healthy people is affected by different sites, different nerves and genders, and not associated with age, BMI, nerve thickness or CSA.
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Affiliation(s)
- Xinyi Tang
- Department of Medical Ultrasound, West China Hospital of Sichuan University, No.37 Guoxue Alley, Chengdu, 610041, Sichuan Province, People's Republic of China
| | - Bihui Zhu
- Department of Medical Ultrasound, West China Hospital of Sichuan University, No.37 Guoxue Alley, Chengdu, 610041, Sichuan Province, People's Republic of China
| | - Mei Tian
- Department of Medical Ultrasound, West China Hospital of Sichuan University, No.37 Guoxue Alley, Chengdu, 610041, Sichuan Province, People's Republic of China
| | - Ruiqian Guo
- Department of Medical Ultrasound, West China Hospital of Sichuan University, No.37 Guoxue Alley, Chengdu, 610041, Sichuan Province, People's Republic of China
| | - Songya Huang
- Department of Medical Ultrasound, West China Hospital of Sichuan University, No.37 Guoxue Alley, Chengdu, 610041, Sichuan Province, People's Republic of China
| | - Yuanjiao Tang
- Department of Medical Ultrasound, West China Hospital of Sichuan University, No.37 Guoxue Alley, Chengdu, 610041, Sichuan Province, People's Republic of China
| | - Li Qiu
- Department of Medical Ultrasound, West China Hospital of Sichuan University, No.37 Guoxue Alley, Chengdu, 610041, Sichuan Province, People's Republic of China.
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Berry DB, Englund EK, Chen S, Frank LR, Ward SR. Medical imaging of tissue engineering and regenerative medicine constructs. Biomater Sci 2021; 9:301-314. [PMID: 32776044 PMCID: PMC8262082 DOI: 10.1039/d0bm00705f] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Advancement of tissue engineering and regenerative medicine (TERM) strategies to replicate tissue structure and function has led to the need for noninvasive assessment of key outcome measures of a construct's state, biocompatibility, and function. Histology based approaches are traditionally used in pre-clinical animal experiments, but are not always feasible or practical if a TERM construct is going to be tested for human use. In order to transition these therapies from benchtop to bedside, rigorously validated imaging techniques must be utilized that are sensitive to key outcome measures that fulfill the FDA standards for TERM construct evaluation. This review discusses key outcome measures for TERM constructs and various clinical- and research-based imaging techniques that can be used to assess them. Potential applications and limitations of these techniques are discussed, as well as resources for the processing, analysis, and interpretation of biomedical images.
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Affiliation(s)
- David B Berry
- Departments of NanoEngineering, University of California, San Diego, USA.
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Dzoic Dominkovic M, Ivanac G, Bojanic K, Kralik K, Smolic M, Divjak E, Smolic R, Brkljacic B. Exploring Association of Breast Pain, Pregnancy, and Body Mass Index with Breast Tissue Elasticity in Healthy Women: Glandular and Fat Differences. Diagnostics (Basel) 2020; 10:diagnostics10060393. [PMID: 32532143 PMCID: PMC7345881 DOI: 10.3390/diagnostics10060393] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 06/03/2020] [Accepted: 06/08/2020] [Indexed: 12/15/2022] Open
Abstract
Breast sonoelastography is a relatively novel ultrasound (US) method that enables estimation of tissue stiffness to estimate the elasticity of normal breast tissue and seek to correlate it with well-known breast cancer risk factors. Two hundred women of different age were included in the study and completed a questionnaire about personal, familiar, and reproductive history. Glandular and fatty tissue elasticity in all breast quadrants was measured by shear wave elastography (SWE). Mean elastographic values of breast tissue were calculated and compared to personal history risk factors. Elasticity of normal glandular tissue (66.4 kilopascals (kPa)) was higher than fatty tissue (26.1 kPa) in all breast quadrants and in both breasts. Lower outer quadrant (LOQ) had the lowest elasticity values of both parenchyma and fat. Higher elasticity values of breast tissue were confirmed in the left breast than in the right breast. Glandular and fat tissue elasticity negatively correlated with body mass index (BMI). Women with mastodynia had higher glandular elastographic values compared to subjects without breast pain. Nuliparity was also associated with higher elasticity of glandular breast tissue. The results of this study are promising and could, over time, contribute to a better understanding of glandular breast tissue elasticity as a potential risk factor for breast cancer.
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Affiliation(s)
- Martina Dzoic Dominkovic
- Department of Radiology, General Hospital Orasje, 3rd Street, 76270 Orasje, Bosnia and Herzegovina;
| | - Gordana Ivanac
- Department of Diagnostic and Interventional Radiology, University Hospital Dubrava, Avenue Gojka Suska 6, 10000 Zagreb, Croatia; (G.I.); (E.D.); (B.B.)
- University of Zagreb School of Medicine, Salata 3, 10000 Zagreb, Croatia
| | - Kristina Bojanic
- Department of Biophysics and Radiology, Faculty of Dental Medicine and Health Osijek, J.J. Strossmayer University of Osijek, 31000 Osijek, Croatia;
- Department of Biophysics and Radiology, Faculty of Medicine Osijek, J.J. Strossmayer University of Osijek, 31000 Osijek, Croatia
- Department of Radiology, Health Center Osijek, 31000 Osijek, Croatia
| | - Kristina Kralik
- Department of Medical Statistics and Medical Informatics, Faculty of Medicine Osijek, J.J. Strossmayer University of Osijek, 31000 Osijek, Croatia;
| | - Martina Smolic
- Department of Pharmacology and Biochemistry, Faculty of Dental Medicine and Health Osijek, J.J. Strossmayer University of Osijek, 31000 Osijek, Croatia;
- Department of Pharmacology, Faculty of Medicine Osijek, J.J. Strossmayer University of Osijek, 31000 Osijek, Croatia
| | - Eugen Divjak
- Department of Diagnostic and Interventional Radiology, University Hospital Dubrava, Avenue Gojka Suska 6, 10000 Zagreb, Croatia; (G.I.); (E.D.); (B.B.)
- University of Zagreb School of Medicine, Salata 3, 10000 Zagreb, Croatia
| | - Robert Smolic
- Department of Pathophysiology, Physiology and Immunology, Faculty of Dental Medicine and Health Osijek, J.J. Strossmayer University of Osijek, 31000 Osijek, Croatia
- Department of Pathophysiology, Faculty of Medicine Osijek, J.J. Strossmayer University of Osijek, 31000 Osijek, Croatia
- Department of Medicine, Division of Gastroenterology/Hepatology, University Hospital Osijek, 31000 Osijek, Croatia
- Correspondence: ; Tel.: +385-31-512-800; Fax: +385-31-512-833
| | - Boris Brkljacic
- Department of Diagnostic and Interventional Radiology, University Hospital Dubrava, Avenue Gojka Suska 6, 10000 Zagreb, Croatia; (G.I.); (E.D.); (B.B.)
- University of Zagreb School of Medicine, Salata 3, 10000 Zagreb, Croatia
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Rus G, Faris IH, Torres J, Callejas A, Melchor J. Why Are Viscosity and Nonlinearity Bound to Make an Impact in Clinical Elastographic Diagnosis? SENSORS (BASEL, SWITZERLAND) 2020; 20:E2379. [PMID: 32331295 PMCID: PMC7219338 DOI: 10.3390/s20082379] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/17/2020] [Accepted: 04/20/2020] [Indexed: 12/24/2022]
Abstract
The adoption of multiscale approaches by the biomechanical community has caused a major improvement in quality in the mechanical characterization of soft tissues. The recent developments in elastography techniques are enabling in vivo and non-invasive quantification of tissues' mechanical properties. Elastic changes in a tissue are associated with a broad spectrum of pathologies, which stems from the tissue microstructure, histology and biochemistry. This knowledge is combined with research evidence to provide a powerful diagnostic range of highly prevalent pathologies, from birth and labor disorders (prematurity, induction failures, etc.), to solid tumors (e.g., prostate, cervix, breast, melanoma) and liver fibrosis, just to name a few. This review aims to elucidate the potential of viscous and nonlinear elastic parameters as conceivable diagnostic mechanical biomarkers. First, by providing an insight into the classic role of soft tissue microstructure in linear elasticity; secondly, by understanding how viscosity and nonlinearity could enhance the current diagnosis in elastography; and finally, by compounding preliminary investigations of those elastography parameters within different technologies. In conclusion, evidence of the diagnostic capability of elastic parameters beyond linear stiffness is gaining momentum as a result of the technological and imaging developments in the field of biomechanics.
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Affiliation(s)
- Guillermo Rus
- Ultrasonics Group (TEP-959), Department of Structural Mechanics, University of Granada, 18071 Granada, Spain; (G.R.); (I.H.F.); (A.C.)
- Biomechanics Group (TEC-12), Instituto de Investigación Biosanitaria, ibs.GRANADA, 18012 Granada, Spain;
- Excellence Research Unit “ModelingNature” MNat UCE.PP2017.03, University of Granada, 18071 Granada, Spain
| | - Inas H. Faris
- Ultrasonics Group (TEP-959), Department of Structural Mechanics, University of Granada, 18071 Granada, Spain; (G.R.); (I.H.F.); (A.C.)
- Biomechanics Group (TEC-12), Instituto de Investigación Biosanitaria, ibs.GRANADA, 18012 Granada, Spain;
| | - Jorge Torres
- Ultrasonics Group (TEP-959), Department of Structural Mechanics, University of Granada, 18071 Granada, Spain; (G.R.); (I.H.F.); (A.C.)
- Biomechanics Group (TEC-12), Instituto de Investigación Biosanitaria, ibs.GRANADA, 18012 Granada, Spain;
| | - Antonio Callejas
- Ultrasonics Group (TEP-959), Department of Structural Mechanics, University of Granada, 18071 Granada, Spain; (G.R.); (I.H.F.); (A.C.)
- Biomechanics Group (TEC-12), Instituto de Investigación Biosanitaria, ibs.GRANADA, 18012 Granada, Spain;
| | - Juan Melchor
- Biomechanics Group (TEC-12), Instituto de Investigación Biosanitaria, ibs.GRANADA, 18012 Granada, Spain;
- Excellence Research Unit “ModelingNature” MNat UCE.PP2017.03, University of Granada, 18071 Granada, Spain
- Department of Statistics and Operations Research, University of Granada, 18071 Granada, Spain
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Jin Y, Walker E, Krokhin A, Heo H, Choi TY, Neogi A. Enhanced Instantaneous Elastography in Tissues and Hard Materials Using Bulk Modulus and Density Determined Without Externally Applied Material Deformation. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2020; 67:624-634. [PMID: 31675326 DOI: 10.1109/tuffc.2019.2950343] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Ultrasound is a continually developing technology that is broadly used for fast, non-destructive mechanical property detection of hard and soft materials in applications ranging from manufacturing to biomedical. In this study, a novel monostatic longitudinal ultrasonic pulsing elastography imaging method is introduced. The existing elastography methods require an acoustic radiational or dynamic compressive externally applied force to determine the effective bulk modulus or density. This new, passive M-mode imaging technique does not require an external stress and can be effectively used for both soft and hard materials. Strain map imaging and shear wave elastography are two current categories of M-mode imaging that show both relative and absolute elasticity information. The new technique is applied to hard materials and soft material tissue phantoms for demonstrating effective bulk modulus and effective density mapping. When compared with standard techniques, the effective parameters fall within 10% of standard characterization methods for both hard and soft materials. As neither the standard A-mode imaging technique nor the presented technique require an external applied force, the techniques are applied to composite heterostructures and the findings presented for comparison. The presented passive M-mode technique is found to have enhanced resolution over standard A-mode modalities.
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Moraes PHDM, Sigrist R, Takahashi MS, Schelini M, Chammas MC. Ultrasound elastography in the evaluation of thyroid nodules: evolution of a promising diagnostic tool for predicting the risk of malignancy. Radiol Bras 2019; 52:247-253. [PMID: 31435087 PMCID: PMC6696751 DOI: 10.1590/0100-3984.2018.0084] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The elastic properties of tissue have always been of interest in clinical practice. In the past, the identification of structures that were stiffer on physical palpation would raise the suspicion that "there was something wrong". With the development and advancement of medicine, there proved to be a true correlation in the prediction of malignancy of a lesion: malignant disease tends to stiffen the affected tissue, either by increased cell proliferation or fibrosis. Palpation is the oldest method for the detection of thyroid nodules, which is informed by the knowledge that malignant thyroid lesions tend to be much harder than benign ones. Unfortunately, palpation is a highly subjective method that is dependent on the size and location of the lesion, as well as on the skill of the physician. In cases where these nodules are very small or are located in deep regions, their detection by palpation is difficult or even impossible. In addition, although a malignant lesion differs in terms of elasticity, it may not have echogenic properties, preventing its detection by conventional ultrasound. Imaging that indicates the stiffness or deformation of tissues, through the use of ultrasound elastography techniques, adds new information related to their structural formation. In this article, we review the basic physical principles of elastography and the evolution of the method for the evaluation of thyroid nodules, as well as the limitations of and future perspectives for its use.
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Affiliation(s)
- Pedro Henrique de Marqui Moraes
- Instituto de Radiologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (InRad/HC-FMUSP), São Paulo, SP, Brazil
| | - Rosa Sigrist
- Instituto de Radiologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (InRad/HC-FMUSP), São Paulo, SP, Brazil
| | - Marcelo Straus Takahashi
- Instituto da Criança do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (ICr/HC-FMUSP), São Paulo, SP, Brazil
| | - Marcelo Schelini
- Instituto de Radiologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (InRad/HC-FMUSP), São Paulo, SP, Brazil
| | - Maria Cristina Chammas
- Instituto de Radiologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (InRad/HC-FMUSP), São Paulo, SP, Brazil
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Linek P, Wolny T, Sikora D, Klepek A. Supersonic Shear Imaging for Quantification of Lateral Abdominal Muscle Shear Modulus in Pediatric Population with Scoliosis: A Reliability and Agreement Study. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:1551-1561. [PMID: 31031032 DOI: 10.1016/j.ultrasmedbio.2019.03.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Revised: 02/16/2019] [Accepted: 03/02/2019] [Indexed: 06/09/2023]
Abstract
The aim of this study was to assess the intra- and inter-rater reliability/agreement of the lateral abdominal muscle (LAM) stiffness and thickness measurements at rest and during contraction and to determine the relationship between the superficial fat thickness and the LAM stiffness measurements. LAM stiffness and thickness were measured using supersonic shear wave elastography (SSI) in pediatric participants. The reliability of LAM stiffness and thickness measurements ranged from moderate to excellent. There was an inverse correlation between fat thickness and between-rater difference in the resting external oblique stiffness (r > -0.37) and the contracted external and internal oblique stiffness (r > -0.40). SSI is a reliable method for assessing LAM stiffness and thickness in pediatric populations. To remove potential systematic errors: (i) the first round of measurements should be performed to familiarize patients with procedures; (ii) the examiner should pay more attention while performing LAM measurements on the opposite side of the body.
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Affiliation(s)
- Pawel Linek
- Department of Kinesitherapy and Special Methods in Physiotherapy, The Jerzy Kukuczka Academy of Physical Education, Katowice, Poland; Musculoskeletal Elastography and Ultrasonography Laboratory, The Jerzy Kukuczka Academy of Physical Education, Katowice, Poland.
| | - Tomasz Wolny
- Department of Kinesitherapy and Special Methods in Physiotherapy, The Jerzy Kukuczka Academy of Physical Education, Katowice, Poland
| | - Damian Sikora
- Department of Kinesitherapy and Special Methods in Physiotherapy, The Jerzy Kukuczka Academy of Physical Education, Katowice, Poland
| | - Anna Klepek
- Rehabilitation Department, Stokrotka Health Resort, Goczałkowice-Zdrój, Poland
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Yoon H, Zhu YI, Yarmoska SK, Emelianov SY. Design and Demonstration of a Configurable Imaging Platform for Combined Laser, Ultrasound, and Elasticity Imaging. IEEE TRANSACTIONS ON MEDICAL IMAGING 2019; 38:1622-1632. [PMID: 30596572 PMCID: PMC7286075 DOI: 10.1109/tmi.2018.2889736] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
This paper introduces a configurable combined laser, ultrasound, and elasticity (CLUE) imaging platform. The CLUE platform enables imaging sequences capable of simultaneously providing quantitative acoustic, optical, and mechanical contrast for comprehensive diagnosis and monitoring of complex diseases, such as cancer. The CLUE imaging platform was developed on a Verasonics ultrasound scanner integrated with a pulsed laser, and it was designed to be modular and scalable to allow researchers to create their own specific imaging sequences efficiently. The CLUE imaging platform and sequence were demonstrated in a tissue-mimicking phantom containing a stiff inclusion labeled with optically-activated nanodroplets and in an ex vivo mouse spleen. We have shown that CLUE imaging can simultaneously capture multi-functional imaging signals providing quantitative information on tissue.
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Mumoli N, Mastroiacovo D, Giorgi-Pierfranceschi M, Pesavento R, Mochi M, Cei M, Pomero F, Mazzone A, Vitale J, Ageno W, Dentali F. Ultrasound elastography is useful to distinguish acute and chronic deep vein thrombosis. J Thromb Haemost 2018; 16:2482-2491. [PMID: 30225971 DOI: 10.1111/jth.14297] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Indexed: 12/18/2022]
Abstract
Essentials Ultrasound elastography uses tissue deformation to assess the relative quantification of its elasticity. Compression and duplex ultrasonography may be unable to correctly determine the thrombus age. Ultrasound elastography may be useful to distinguish between acute and chronic deep vein thrombosis. The exact determination of the thrombus age could have both therapeutic and prognostic implications. BACKGROUND: Background Ultrasound elastography (UE) imaging is a novel sonographic technique that is commonly employed for relative quantification of tissue elasticity. Its applicability to venous thromboembolic events has not yet been fully established; in particular, it is unclear whether this technique may be useful in determining the age of deep vein thrombosis (DVT). Thus, the aim of this study was to assess the role of UE in distinguishing acute from chronic DVT. Methods Consecutive patients with a first unprovoked acute and chronic (3 months old) DVT of the lower limbs were analyzed. Patients with recurrent DVT or with a suspected recurrence were excluded. The mean elasticity index (EI) values of acute and chronic popliteal and femoral vein thrombosis were compared. The accuracy of the EI in distinguishing acute from chronic DVT was also assessed by measuring the sensitivity, specificity, positive and negative predictive values, and likelihood ratios. Results One-hundred and forty-nine patients (mean age 63.9 years, standard deviation 13.6; 73 males) with acute and chronic DVT were included. The mean EI of acute femoral DVT was higher than that of chronic femoral DVT (5.09 versus 2.46), and the mean EI of acute popliteal DVT was higher than that of chronic popliteal DVT (4.96 versus 2.48). An EI value of > 4 resulted in a sensitivity of 98.9% (95% confidence interval [CI] 93.3-99.9), a specificity of 99.1% (95% CI 94.8-99.9), a positive predictive value of 91.1% (95% CI 77.9-97.1), a negative predictive value of 98.6% (95% CI 91.3-99.9), a positive likelihood ratio of 13.23 (95% CI 93-653) and a negative likelihood ratio of 0.001 (95% CI 0.008-0.05) for acute DVT. Conclusions UE appears to be a promising technique for distinguishing between acute and chronic DVT. Larger prospective studies are warranted to confirm our preliminary findings.
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Affiliation(s)
- N Mumoli
- Department of Internal Medicine, Livorno Hospital, Livorno, Italy
| | - D Mastroiacovo
- Department of Internal Medicine, Livorno Hospital, Livorno, Italy
| | | | - R Pesavento
- Department of Internal Medicine, Livorno Hospital, Livorno, Italy
| | - M Mochi
- General Electric Healthcare, Milano, Italy
| | - M Cei
- Department of Internal Medicine, Livorno Hospital, Livorno, Italy
| | - F Pomero
- Department of Internal Medicine, Livorno Hospital, Livorno, Italy
| | - A Mazzone
- Department of Internal Medicine, Livorno Hospital, Livorno, Italy
| | - J Vitale
- Department of Clinical and Experimental Medicine, Insubria University, Varese, Italy
| | - W Ageno
- Department of Clinical and Experimental Medicine, Insubria University, Varese, Italy
| | - F Dentali
- Department of Clinical and Experimental Medicine, Insubria University, Varese, Italy
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Vachutka J, Sedlackova Z, Furst T, Herman M, Herman J, Salzman R, Dolezal L. Evaluation of the Effect of Tissue Compression on the Results of Shear Wave Elastography Measurements. ULTRASONIC IMAGING 2018; 40:380-393. [PMID: 30101677 DOI: 10.1177/0161734618793837] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Shear wave imaging is considered to be more precise and less operator dependent when compared with strain imaging. It enables quantitative and reproducible data (Young's modulus of the imaged tissue). However, results of shear wave imaging can be affected by a variety of different factors. The aim of this study is to evaluate the effect of the pressure applied by the ultrasound probe during examination on the measured values of Young's modulus. The effect of the tissue compression on the results of the real-time shear wave elastography was evaluated via the gelatine phantom measurements, via the ex vivo experiments with pig liver, and via the in vivo measurements of the thyroid gland stiffness on healthy volunteers. The results of our measurements confirmed that the measured value of Young's modulus increases with the increasing pressure applied on the imaged object. The highest increase was observed during the ex vivo experiments (400%), and the lowest increase was detected in the case of the phantom measurements (8%). A two- to threefold increase in Young's modulus was observed between the minimum and maximum pressure in the case of the in vivo elastography measurements of thyroid gland. The Veronda-Westman theoretical model was used for the description of the tissue nonlinearity. We conclude that tissue compression by the force exerted on the probe can significantly affect the results of the real-time shear wave elastography measurements. Minimum pressure should be used when measuring the absolute value of Young's modulus of superficial organs.
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Affiliation(s)
- Jaromir Vachutka
- 1 Department of Medical Biophysics, Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University Olomouc, Olomouc, Czech Republic
| | - Zuzana Sedlackova
- 2 Department of Radiology, Faculty of Medicine and Dentistry, Palacky University Olomouc and University Hospital Olomouc, Olomouc, Czech Republic
| | - Tomas Furst
- 2 Department of Radiology, Faculty of Medicine and Dentistry, Palacky University Olomouc and University Hospital Olomouc, Olomouc, Czech Republic
| | - Miroslav Herman
- 2 Department of Radiology, Faculty of Medicine and Dentistry, Palacky University Olomouc and University Hospital Olomouc, Olomouc, Czech Republic
| | - Jan Herman
- 3 Department of Otorhinolaryngology, Faculty of Medicine and Dentistry, Palacky University Olomouc and University Hospital Olomouc, Olomouc, Czech Republic
| | - Richard Salzman
- 3 Department of Otorhinolaryngology, Faculty of Medicine and Dentistry, Palacky University Olomouc and University Hospital Olomouc, Olomouc, Czech Republic
| | - Ladislav Dolezal
- 1 Department of Medical Biophysics, Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University Olomouc, Olomouc, Czech Republic
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Ultrasonographic elastography in the evaluation of normal and pathological skin - a review. Postepy Dermatol Alergol 2018; 36:667-672. [PMID: 31997992 PMCID: PMC6986292 DOI: 10.5114/ada.2018.77069] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 06/19/2018] [Indexed: 11/17/2022] Open
Abstract
The aim of this review article is to discuss the role of ultrasonographic elastography, a technique used to quantify tissue stiffness, in the evaluation of normal and pathological skin. A growing body of evidence suggests that elastography may be used for the diagnosis and monitoring of skin pathologies, in particular tumors, and fibrotic and sclerotic processes. Our knowledge about the elastographic parameters of normal skin is sparse, which together with the lack of reference values for cutaneous stiffness constitutes a serious limitation to the use of elastography in some medical disciplines, including aesthetic medicine.
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Ultrasound elastography of the lower uterine segment in women with a previous cesarean section: Comparison of in-/ex-vivo elastography versus tensile-stress-strain-rupture analysis. Eur J Obstet Gynecol Reprod Biol 2018; 225:172-180. [PMID: 29729520 DOI: 10.1016/j.ejogrb.2018.04.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 04/10/2018] [Indexed: 01/05/2023]
Abstract
OBJECTIVES The purpose of this study was to assess, if the biomechanical properties of the lower uterine segment (LUS) in women with a previous cesarean section (CS) can be determined by ultrasound (US) elastography. The first aim was to establish an ex-vivo LUS tensile-stress-strain-rupture(break point) analysis with the possibility of simultaneously using US elastography. The second aim was to investigate the relationship between measurement results of LUS stiffness using US elastography in-/ex-vivo with results of tensile-stress-strain-rupture analysis, and to compare different US elastography LUS-stiffness-measurement methods ex-vivo. STUDY DESIGN An explorative experimental, in-/ex-vivo US study of women with previous CS was conducted. LUS elasticity was measured by point Shear Wave Elastography (pSWE) and bidimensional Shear-Wave-Elastography (2D-SWE) first in-vivo during preoperative examination within 24 h before repeat CS (including resection of the thinnest part of the LUS = uterine scar area during CS), second within 1 h after operation during the ex-vivo experiment, followed by tensile-stress-strain-rupture analysis. Pearson's correlation coefficient and scatter plots, Bland-Altman plots and paired T-tests, were used. RESULTS Thirty three women were included in the study; elastography measurements n = 1412. The feasibility of ex-vivo assessment of LUS by quantitative US elastography using pSWE and 2D-SWE to detect stiffness of LUS was demonstrated. The strongest correlation with tensile-stress-strain analysis was found in the US elastography examination carried out with 2D-SWE (0.78, p < 0.001, 95%CI [0.48, 0.92]). The laboratory experiment illustrated that, the break point - as a surrogate marker for the risk of rupture of the LUS after CS - is linearly dependent on the thickness of the LUS in the scar area (Coefficient of correlation: 0.79, p < 0.001, 95%CI [0.55, 0.91]). Two extremely stiff LUS-specimens (outlier or extreme values) rupture even at less stroke/strain than would be expected by their thickness. CONCLUSION This study confirms that US elastography can help in determining viscoelastic properties of the LUS in women with a previous CS. The data from our small series are promising. However whether individual extreme values of high stiffness and consecutive restricted biomechanical resilience can explain the phenomenon of rupture during TOLAC in cases of LUS with adequate thickness remains a question which prospective trials have to analyze before US elastography can be introduced into clinical practice.
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Hollerieth K, Gaßmann B, Wagenpfeil S, Kemmner S, Heemann U, Stock KF. Does standoff material affect acoustic radiation force impulse elastography? A preclinical study of a modified elastography phantom. Ultrasonography 2017; 37:140-148. [PMID: 29032665 PMCID: PMC5885480 DOI: 10.14366/usg.17002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Revised: 07/26/2017] [Accepted: 07/28/2017] [Indexed: 12/21/2022] Open
Abstract
PURPOSE This study was conducted to determine the influence of standoff material on acoustic radiation force impulse (ARFI) measurements in an elasticity phantom by using two different probes. METHODS Using ARFI elastography, 10 observers measured the shear wave velocity (SWV, m/sec) in different lesions of an elasticity phantom with a convex 4C1 probe and a linear 9L4 probe. The experimental setup was expanded by the use of an interposed piece of porcine muscle as standoff material. The probe pressure on the phantom was registered. RESULTS Faulty ARFI measurements occurred more often when quantifying the hardest lesion (74.0 kPa 4.97 m/sec) by the 9L4 probe with the porcine muscle as a standoff material interposed between the probe and the phantom. The success rate for ARFI measurements in these series was 52.4%, compared with 99.5% in the other series. The SWV values measured with the 9L4 probe were significantly higher (3.33±1.39 m/sec vs. 2.60±0.74 m/sec, P<0.001 in the group without muscle) and were closer to the reference value than those measured with the 4C1 probe (0.25±0.23 m/sec vs. 0.85±1.21 m/sec, P<0.001 in the same group). The SWV values measured when using the muscle as a standoff material were lower than those without the muscle (significant for 9L4, P=0.040). The deviation from the reference value and the variance increased significantly with the 9L4 probe if the muscle was in situ (B=0.27, P=0.004 and B=0.32, P<0.001). In our study, the pressure exerted by the operator had no effect on the SWV values. CONCLUSION The presence of porcine muscle acting as a standoff material influenced the occurrence of failed measurements as well as the variance and the accuracy of the measured values. The linear high-frequency probe was particularly affected.
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Affiliation(s)
- Katharina Hollerieth
- Department of Nephrology, Klinikum Rechts der Isar of the Technical University of Munich, Munich, Germany
| | | | - Stefan Wagenpfeil
- Institute for Medical Biometry, Epidemiology and Medical Informatics, Saarland University, Campus Homburg, Homburg, Saar, Germany
| | - Stephan Kemmner
- Department of Nephrology, Klinikum Rechts der Isar of the Technical University of Munich, Munich, Germany
| | - Uwe Heemann
- Department of Nephrology, Klinikum Rechts der Isar of the Technical University of Munich, Munich, Germany
| | - Konrad Friedrich Stock
- Department of Nephrology, Klinikum Rechts der Isar of the Technical University of Munich, Munich, Germany
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Nguyen MM, Ding X, Leers SA, Kim K. Multi-Focus Beamforming for Thermal Strain Imaging Using a Single Ultrasound Linear Array Transducer. ULTRASOUND IN MEDICINE & BIOLOGY 2017; 43:1263-1274. [PMID: 28318887 PMCID: PMC5429981 DOI: 10.1016/j.ultrasmedbio.2017.01.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 01/20/2017] [Accepted: 01/23/2017] [Indexed: 06/06/2023]
Abstract
Ultrasound-induced thermal strain imaging (TSI) has been used successfully to identify lipid- and water-based tissues in atherosclerotic plaques in some research settings. However, TSI faces several challenges to be realized in clinics. These challenges include motion artifacts and displacement tracking accuracy, as well as limited heating capability, which contributes to low thermal strain signal-to-noise ratio, and a limited field of view. Our goal was to address the challenge in heating tissue in TSI. Current TSI systems use separate heating and imaging transducers, which require physical alignment of the heating and imaging beams and result in a bulky setup that limits in vivo operation. We evaluated a new design for heating beams that can be implemented on a linear array imaging transducer and can provide improved heating area and efficiency as compared with previous implementations. The heating beams designed were implemented with a clinical linear array imaging transducer connected to a research ultrasound platform. In vitro experiments using tissue-mimicking phantoms with no blood flow revealed that the new design resulted in an effective heating area of approximately 0.85 cm2 and a 0.3°C temperature rise in 2 s of heating, which compared well with in silico finite-element simulations. With the new heating beams, TSI was found to be able to detect a lipid-mimicking rubber inclusion with a diameter of 1 cm from the water-based gelatin background, with a strain contrast of 2.3 (+0.14% strain in the rubber inclusion and -0.06% strain in the gelatin background). Lastly, lipid-based tissue in a 1-cm-diameter human carotid endarterectomy (CEA) sample was identified in good agreement with histology.
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Affiliation(s)
- Man M Nguyen
- Center for Ultrasound Molecular Imaging and Therapeutics, Department of Medicine, University of Pittsburgh School of Medicine and University of Pittsburgh Medical Center (UPMC), Pittsburgh, Pennsylvania, USA
| | - Xuan Ding
- Center for Ultrasound Molecular Imaging and Therapeutics, Department of Medicine, University of Pittsburgh School of Medicine and University of Pittsburgh Medical Center (UPMC), Pittsburgh, Pennsylvania, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Medical Scientist Training Program, University of Pittsburgh and Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | - Steven A Leers
- Heart and Vascular Institute, University of Pittsburgh School of Medicine and UPMC, Pittsburgh, Pennsylvania, USA
| | - Kang Kim
- Center for Ultrasound Molecular Imaging and Therapeutics, Department of Medicine, University of Pittsburgh School of Medicine and University of Pittsburgh Medical Center (UPMC), Pittsburgh, Pennsylvania, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Heart and Vascular Institute, University of Pittsburgh School of Medicine and UPMC, Pittsburgh, Pennsylvania, USA; McGowan Institute of Regenerative Medicine, University of Pittsburgh and UPMC, Pittsburgh, Pennsylvania, USA.
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Sigrist RM, Liau J, Kaffas AE, Chammas MC, Willmann JK. Ultrasound Elastography: Review of Techniques and Clinical Applications. Theranostics 2017; 7:1303-1329. [PMID: 28435467 PMCID: PMC5399595 DOI: 10.7150/thno.18650] [Citation(s) in RCA: 907] [Impact Index Per Article: 129.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 01/04/2017] [Indexed: 12/15/2022] Open
Abstract
Elastography-based imaging techniques have received substantial attention in recent years for non-invasive assessment of tissue mechanical properties. These techniques take advantage of changed soft tissue elasticity in various pathologies to yield qualitative and quantitative information that can be used for diagnostic purposes. Measurements are acquired in specialized imaging modes that can detect tissue stiffness in response to an applied mechanical force (compression or shear wave). Ultrasound-based methods are of particular interest due to its many inherent advantages, such as wide availability including at the bedside and relatively low cost. Several ultrasound elastography techniques using different excitation methods have been developed. In general, these can be classified into strain imaging methods that use internal or external compression stimuli, and shear wave imaging that use ultrasound-generated traveling shear wave stimuli. While ultrasound elastography has shown promising results for non-invasive assessment of liver fibrosis, new applications in breast, thyroid, prostate, kidney and lymph node imaging are emerging. Here, we review the basic principles, foundation physics, and limitations of ultrasound elastography and summarize its current clinical use and ongoing developments in various clinical applications.
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Affiliation(s)
- Rosa M.S. Sigrist
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, School of Medicine, Stanford, CA, USA
| | - Joy Liau
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, School of Medicine, Stanford, CA, USA
| | - Ahmed El Kaffas
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, School of Medicine, Stanford, CA, USA
| | - Maria Cristina Chammas
- Department of Ultrasound, Institute of Radiology, Hospital das Clínicas, Medical School of University of São Paulo
| | - Juergen K. Willmann
- Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, School of Medicine, Stanford, CA, USA
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Greening J, Dilley A. Posture-induced changes in peripheral nerve stiffness measured by ultrasound shear-wave elastography. Muscle Nerve 2016; 55:213-222. [DOI: 10.1002/mus.25245] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 06/24/2016] [Accepted: 07/07/2016] [Indexed: 12/11/2022]
Affiliation(s)
- Jane Greening
- Division of Clinical and Laboratory Investigation; Brighton and Sussex Medical School, Medical Research Building, University of Sussex; Falmer Brighton BN1 9PS United Kingdom
| | - Andrew Dilley
- Division of Clinical and Laboratory Investigation; Brighton and Sussex Medical School, Medical Research Building, University of Sussex; Falmer Brighton BN1 9PS United Kingdom
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Hollerieth K, Gaßmann B, Wagenpfeil S, Moog P, Vo-Cong MT, Heemann U, Stock KF. Preclinical evaluation of acoustic radiation force impulse measurements in regions of heterogeneous elasticity. Ultrasonography 2016; 35:345-52. [PMID: 27599889 PMCID: PMC5040141 DOI: 10.14366/usg.16024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Revised: 07/08/2016] [Accepted: 07/25/2016] [Indexed: 01/02/2023] Open
Abstract
Purpose The purpose of this study was to compare the reliability of ultrasound-based shear wave elastography in regions of homogeneous versus heterogeneous elasticity by using two different probes. Methods Using acoustic radiation force impulse (ARFI) elastography, we measured the shear wave velocity (SWV) in different lesions of an elastography phantom with the convex 4C1 probe and the linear 9L4 probe. The region of interest (ROI) was positioned in such a way that it was partly filled by one of the lesions (0%, 25%, 50%, 75%, and 100%) and partly by the background of the phantom (100%, 75%, 50%, 25%, and 0%, respectively). Results The success rate was 98.5%. The measured value and the reference value of SWV correlated significantly (r=0.89, P<0.001). Further, a comparison of the two probes revealed that there was no statistical difference in either the mean or the variance values. However, the deviation of SWV from the reference was higher in the case of the 9L4 probe than in the case of the 4C1 probe, both overall and in measurements in which the ROI contained structures of different elasticity (P=0.021 and P=0.002). Taking into account all data, for both probes, we found that there was a greater spread and deviation of the SWV from the reference value when the ROI was positioned in structures having different elastic properties (standard deviation, 0.02±0.01 m/sec vs. 0.04±0.04 m/sec; P=0.010; deviation from the reference value, 0.21±0.12 m/sec vs. 0.38±0.27 m/sec; P=0.050). Conclusion Quantitative ARFI elastography was achievable in structures of different elasticity; however, the validity and the reliability of the SWV measurements decreased in comparison to those of the measurements performed in structures of homogeneous elasticity. Therefore, a convex probe is preferred for examining heterogeneous structures.
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Affiliation(s)
- Katharina Hollerieth
- Nephrology Department, Klinikum Rechts der Isar of the Technical University of Munich, Munich, Germany
| | | | - Stefan Wagenpfeil
- Institute for Medical Biometry, Epidemiology and Medical Informatics, Saarland University, Campus Homburg (Saar), Homburg, Germany
| | - Philipp Moog
- Nephrology Department, Klinikum Rechts der Isar of the Technical University of Munich, Munich, Germany
| | - Minh-Truc Vo-Cong
- Nephrology Department, Klinikum Rechts der Isar of the Technical University of Munich, Munich, Germany
| | - Uwe Heemann
- Nephrology Department, Klinikum Rechts der Isar of the Technical University of Munich, Munich, Germany
| | - Konrad Friedrich Stock
- Nephrology Department, Klinikum Rechts der Isar of the Technical University of Munich, Munich, Germany
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Labuda C, Tierney CM, Dayavansha EGSK, Gladden JR. Direct visualization of shear waves in viscoelastic fluid using microspheres. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2015; 137:EL456-61. [PMID: 26093455 DOI: 10.1121/1.4921728] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Wormlike micellar fluids, being viscoelastic, support shear waves. Shear waves in 500 mM CTAB-NaSal micellar fluid were visualized by seeding the fluid with 212-250 μm diameter polyethylene microspheres. This method was compared to visualization through birefringence induced by shear stress in the fluid. Measured shear wave speeds were 733 and 722 mm/s, respectively, for each technique. Particle displacement was a sinusoidal function of time and displacement amplitude decreased quadratically with distance from the source. This supports the possibility of using particle amplitude measurements as a measure of attenuation even at low fluid concentration where birefringence visualization techniques fail.
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Affiliation(s)
- C Labuda
- Department of Physics and Astronomy, University of Mississippi, University, Mississippi 38677, USA , , ,
| | - C M Tierney
- Department of Physics and Astronomy, University of Mississippi, University, Mississippi 38677, USA , , ,
| | - E G Sunethra K Dayavansha
- Department of Physics and Astronomy, University of Mississippi, University, Mississippi 38677, USA , , ,
| | - J R Gladden
- Department of Physics and Astronomy, University of Mississippi, University, Mississippi 38677, USA , , ,
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Teber MA, Oğur T, Bozkurt A, Er B, Turan A, Gülbay M, Akdağ İ. Real-time sonoelastography of the quadriceps tendon in patients undergoing chronic hemodialysis. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2015; 34:671-677. [PMID: 25792583 DOI: 10.7863/ultra.34.4.671] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
OBJECTIVES This study aimed to compare sonoelastographic findings for the quadriceps tendon in patients with chronic renal failure who were in a dialysis program to findings in a control group. METHODS Fifty-three randomly allocated patients (mean age, 54.3 years; range, 27-86 years) with chronic renal failure who were in a dialysis program 3 days a week between January and May 2012 were included. The measurements were performed in both knees of 53 patients undergoing dialysis and 25 individuals in the control group. The tendons were classified as follows: type 1, very stiff tissue (blue); type 2, stiff tissue (blue-green); and type 3, intermediate tissue (green-yellow) according to color mapping. RESULTS The mean quadriceps tendon thicknesses in the patient group were 4.9 mm (range, 1.9-6.5 mm) for the right knee and 4.9 mm (1.4-6.5 mm) for the left knee; the values in the control group were 5.4 mm (3.6-7.0 mm) for the right knee and 5.4 mm (3.4-7.0 mm) for the left knee. The mean elasticity scores in the patient group were 3.14 (1.03-5.23) for the right knee and 3.33 (1.29-5.00) for the left knee; in the control group, the values were 3.79 (1.73-5.23) and 3.69 (1.23-5.53) for the right and left knees, respectively (right knee, P = .025; left knee, P = .018; Mann-Whitney U test). The quadriceps tendons were significantly thinner in the patient group (right knee, P = .054; left knee, P = .015; Mann-Whitney U test). CONCLUSIONS Quadriceps tendons in patients with chronic renal failure are thinner and have lower elasticity scores compared to controls.
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Affiliation(s)
- Mehmet A Teber
- Departments of Radiology (M.A.T., T.O., A.B., A.T., M.G.) and Nephrology (B.E., İ.A.), Etlik Ihtisas Training and Research Hospital, Etlik, Ankara, Turkey.
| | - Törel Oğur
- Departments of Radiology (M.A.T., T.O., A.B., A.T., M.G.) and Nephrology (B.E., İ.A.), Etlik Ihtisas Training and Research Hospital, Etlik, Ankara, Turkey
| | - Alper Bozkurt
- Departments of Radiology (M.A.T., T.O., A.B., A.T., M.G.) and Nephrology (B.E., İ.A.), Etlik Ihtisas Training and Research Hospital, Etlik, Ankara, Turkey
| | - Bülent Er
- Departments of Radiology (M.A.T., T.O., A.B., A.T., M.G.) and Nephrology (B.E., İ.A.), Etlik Ihtisas Training and Research Hospital, Etlik, Ankara, Turkey
| | - Aynur Turan
- Departments of Radiology (M.A.T., T.O., A.B., A.T., M.G.) and Nephrology (B.E., İ.A.), Etlik Ihtisas Training and Research Hospital, Etlik, Ankara, Turkey
| | - Mutlu Gülbay
- Departments of Radiology (M.A.T., T.O., A.B., A.T., M.G.) and Nephrology (B.E., İ.A.), Etlik Ihtisas Training and Research Hospital, Etlik, Ankara, Turkey
| | - İbrahim Akdağ
- Departments of Radiology (M.A.T., T.O., A.B., A.T., M.G.) and Nephrology (B.E., İ.A.), Etlik Ihtisas Training and Research Hospital, Etlik, Ankara, Turkey
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Figueira C, Thassila CFC, Maria CC. Elastography: Principles and considerations for clinical research in veterinary medicine cibele. ACTA ACUST UNITED AC 2015. [DOI: 10.5897/jvmah2014.0344] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Quantitative cervical elastography during pregnancy: influence of setting features on strain calculation. J Med Ultrason (2001) 2015; 42:387-94. [DOI: 10.1007/s10396-015-0619-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 02/12/2015] [Indexed: 10/23/2022]
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Affiliation(s)
- E I Galperin
- Department of hepatopancreatobiliary and regenerative surgery, I.M.Sechenov First Moscow State Medical University, Health Ministry of the Russian Federation, Moscow
| | - I A Semenenko
- Department of hepatopancreatobiliary and regenerative surgery, I.M.Sechenov First Moscow State Medical University, Health Ministry of the Russian Federation, Moscow
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Quantitative elastography of the uterine cervix as a predictor of preterm delivery. J Perinatol 2014; 34:774-80. [PMID: 24811225 DOI: 10.1038/jp.2014.87] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 03/19/2014] [Accepted: 03/24/2014] [Indexed: 12/21/2022]
Abstract
OBJECTIVE To evaluate the correlation between preterm delivery before 37 weeks of gestation and ultrasound elastography strain measurement of cervical stiffness. STUDY DESIGN In this prospective study, 182 pregnant women were examined vaginally by ultrasound elastography from a mid-sagittal plane. Cervical length was measured and strain was calculated in four regions of interest on the anterior cervical lip. First, the software was validated by intraobserver variability. Second, strain and strain ratios were calculated with adjusted software presets and correlated to the outcome of spontaneous preterm delivery (sPTD). RESULT A total of 8928 regions of interest (ROIs) and 6696 ratios were evaluated. The median gestational age at examination was 26 ± 6.1 weeks. A median maternal age of 33 ± 5.6 and a medial parity of 1 ± 0.9 were observed. Intra-Class-Correlation values in validation phase ranged from 0.893 to 0.967. The prevalence of sPTD was 11.9%. Strain ratio Rselective was identified as the best predictor of preterm delivery. Rselective values >0.89 were associated with preterm delivery with a sensitivity of 0.59 and a specificity of 0.86 (odds ratio=1.474 for an increase of 0.1 in Rselective; P=0.002). CONCLUSION Ultrasound elastography strain measurement of cervical stiffness is correlated with the predictability of preterm delivery.
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Silva Junior RG, Schmillevitch J, Nascimento MDFA, Miranda MLQ, Brant PEAC, Schulz PO, Vieira A, Szutan LA. Acoustic radiation force impulse elastography and serum fibrosis markers in chronic hepatitis C. Scand J Gastroenterol 2014; 49:986-92. [PMID: 24742130 DOI: 10.3109/00365521.2014.909528] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Liver biopsy (LB) remains the gold standard for the assessment of liver fibrosis, although it is invasive and can have complications. The present study compares several noninvasive methods of fibrosis assessment in chronic hepatitis C (CHC), including acoustic radiation force impulse (ARFI) elastography, aspartate aminotransferase:platelet ratio index (APRI), Forns, FIB-4, and King scores versus percutaneous LB. MATERIAL AND METHODS This prospective study enrolled 51 untreated CHC patients. Biological tests necessary for the calculation of the scores (according to the classic formulas) were performed within a week of LB. The time interval between LB and tissue stiffness, assessed according to the Metavir score, was <6 months. Cutoff values were determined using area under receiver-operating characteristic curves (AUROC). RESULTS The best test for predicting significant fibrosis (F ≥2 Metavir) was ARFI elastography with an AUROC of 0.90, followed by FIB-4 (AUROC = 0.86), King (AUROC = 0.85), Forns (AUROC = 0.84), and APRI (AUROC = 0.82). For a cutoff of 1.31 m/s, ARFI had 89.3% sensitivity (Se) and 87% specificity (Sp). The best test for predicting cirrhosis was ARFI elastography with an AUROC of 0.98, followed by FIB-4 (AUROC = 0.94), King (AUROC = 0.90), APRI (AUROC = 0.82), and Forns (AUROC = 0.81). For a cutoff of 1.95 m/s, ARFI had 100% Se and 95.2% Sp. CONCLUSION ARFI elastography had very good accuracy for the assessment of liver fibrosis. It was more effective than APRI, Forns, King, and FIB-4 scores for the prediction of significant fibrosis and cirrhosis in CHC patients.
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Affiliation(s)
- Roberto Gomes Silva Junior
- Liver and Portal Hypertension Group, Santa Casa de São Paulo School of Medical Sciences , São Paulo , Brazil
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Quantitative elastography for cervical stiffness assessment during pregnancy. BIOMED RESEARCH INTERNATIONAL 2014; 2014:826535. [PMID: 24734246 PMCID: PMC3964773 DOI: 10.1155/2014/826535] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 12/27/2013] [Accepted: 12/30/2013] [Indexed: 11/17/2022]
Abstract
AIM Feasibility and reliability of tissue Doppler imaging-(TDI-) based elastography for cervical quantitative stiffness assessment during all three trimesters of pregnancy were evaluated. MATERIALS AND METHODS Prospective case-control study including seventy-four patients collected between the 12th and 42nd weeks of gestation. The tissue strain (TS) was measured by two independent operators as natural strain. Intra- and interoperator intraclass correlation coefficient (ICC) agreements were evaluated. RESULTS TS measurement was always feasible and exhibited a high performance in terms of reliability (intraoperator ICC-agreement=0.93; interoperator ICC agreement=0.89 and 0.93 for a single measurement and for the average of two measurements, resp.). Cervical TS showed also a significant correlation with gestational age, cervical length, and parity. CONCLUSIONS TS measurement during pregnancy demonstrated high feasibility and reliability. Furthermore, TS significantly correlated with gestational age, cervical length, and parity.
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Chandler JH, Hood A, Culmer PR, Jayne D, Neville A. Technological assessment of the biogalvanic method for tissue characterization. Physiol Meas 2014; 35:297-308. [PMID: 24451318 DOI: 10.1088/0967-3334/35/2/297] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Biogalvanic cells have the potential to be used in characterizing biological tissue properties and ultimately tissue health. A biogalvanic cell is established by placing two differing metal electrodes across a target tissue allowing an electrical tissue-specific internal resistance to be determined. A novel data analysis method using least-squares fitting has been developed to more effectively determine the parameters of the biogalvanic system model proposed in the literature. The validity of the method has been examined through characterization of electrical models, ex vivo porcine tissue, and in vivo porcine tissue. Strong agreement between test results and the proposed characterization model has been shown. However, determined internal resistances are influenced by mechanical strain, current modulation direction and tissue thickness, indicating complexities at the electrode–tissue interface. These complexities undermine some assumptions upon which the biogalvanic model is based. Ultimately this technique could offer potential for use in minimally invasive surgery for discriminating tissue health but requires improved understanding and control of testing conditions.
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Fruscalzo A, Schmitz R. Reply: To PMID 22173854. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2013; 41:712-714. [PMID: 23712889 DOI: 10.1002/uog.12475] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
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