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1
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Duraes M, Briot N, Connesson N, Chagnon G, Payan Y, Duflos C, Rathat G, Captier G, Subsol G, Herlin C. Evaluation of breast skin and tissue stiffness using a non-invasive aspiration device and impact of clinical predictors. Clin Anat 2024; 37:329-336. [PMID: 38174585 DOI: 10.1002/ca.24134] [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: 09/17/2023] [Revised: 12/01/2023] [Accepted: 12/21/2023] [Indexed: 01/05/2024]
Abstract
A personalized 3D breast model could present a real benefit for preoperative discussion with patients, surgical planning, and guidance. Breast tissue biomechanical properties have been poorly studied in vivo, although they are important for breast deformation simulation. The main objective of our study was to determine breast skin thickness and breast skin and adipose/fibroglandular tissue stiffness. The secondary objective was to assess clinical predictors of elasticity and thickness: age, smoking status, body mass index, contraception, pregnancies, breastfeeding, menopausal status, history of radiotherapy or breast surgery. Participants were included at the Montpellier University Breast Surgery Department from March to May 2022. Breast skin thickness was measured by ultrasonography, breast skin and adipose/fibroglandular tissue stiffnesses were determined with a VLASTIC non-invasive aspiration device at three different sites (breast segments I-III). Multivariable linear models were used to assess clinical predictors of elasticity and thickness. In this cohort of 196 women, the mean breast skin and adipose/fibroglandular tissue stiffness values were 39 and 3 kPa, respectively. The mean breast skin thickness was 1.83 mm. Only menopausal status was significantly correlated with breast skin thickness and adipose/fibroglandular tissue stiffness. The next step will be to implement these stiffness and thickness values in a biomechanical breast model and to evaluate its capacity to predict breast tissue deformations.
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Affiliation(s)
- Martha Duraes
- Department of Breast Surgery, Montpellier University Hospital, Montpellier, France
- Faculty of Medicine Montpellier-Nîmes, Laboratory of Anatomy of Montpellier, Montpellier University, Montpellier, France
- Research-Team ICAR, LIRMM, University of Montpellier, Montpellier, France
| | - Noemie Briot
- Univ. Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, Grenoble, France
| | - Nathanael Connesson
- Univ. Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, Grenoble, France
| | - Gregory Chagnon
- Univ. Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, Grenoble, France
| | - Yohan Payan
- Univ. Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, Grenoble, France
| | - Claire Duflos
- Department of Clinical Unit Epidemiology, Montpellier University Hospital, Montpellier, France
| | - Gauthier Rathat
- Department of Breast Surgery, Montpellier University Hospital, Montpellier, France
| | - Guillaume Captier
- Faculty of Medicine Montpellier-Nîmes, Laboratory of Anatomy of Montpellier, Montpellier University, Montpellier, France
- Research-Team ICAR, LIRMM, University of Montpellier, Montpellier, France
| | - Gerard Subsol
- Research-Team ICAR, LIRMM, University of Montpellier, Montpellier, France
| | - Christian Herlin
- Research-Team ICAR, LIRMM, University of Montpellier, Montpellier, France
- Department of Plastic Surgery, Montpellier University Hospital, Montpellier, France
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2
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Teixeira AM, Martins P. A review of bioengineering techniques applied to breast tissue: Mechanical properties, tissue engineering and finite element analysis. Front Bioeng Biotechnol 2023; 11:1161815. [PMID: 37077233 PMCID: PMC10106631 DOI: 10.3389/fbioe.2023.1161815] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 03/14/2023] [Indexed: 04/05/2023] Open
Abstract
Female breast cancer was the most prevalent cancer worldwide in 2020, according to the Global Cancer Observatory. As a prophylactic measure or as a treatment, mastectomy and lumpectomy are often performed at women. Following these surgeries, women normally do a breast reconstruction to minimize the impact on their physical appearance and, hence, on their mental health, associated with self-image issues. Nowadays, breast reconstruction is based on autologous tissues or implants, which both have disadvantages, such as volume loss over time or capsular contracture, respectively. Tissue engineering and regenerative medicine can bring better solutions and overcome these current limitations. Even though more knowledge needs to be acquired, the combination of biomaterial scaffolds and autologous cells appears to be a promising approach for breast reconstruction. With the growth and improvement of additive manufacturing, three dimensional (3D) printing has been demonstrating a lot of potential to produce complex scaffolds with high resolution. Natural and synthetic materials have been studied in this context and seeded mainly with adipose derived stem cells (ADSCs) since they have a high capability of differentiation. The scaffold must mimic the environment of the extracellular matrix (ECM) of the native tissue, being a structural support for cells to adhere, proliferate and migrate. Hydrogels (e.g., gelatin, alginate, collagen, and fibrin) have been a biomaterial widely studied for this purpose since their matrix resembles the natural ECM of the native tissues. A powerful tool that can be used in parallel with experimental techniques is finite element (FE) modeling, which can aid the measurement of mechanical properties of either breast tissues or scaffolds. FE models may help in the simulation of the whole breast or scaffold under different conditions, predicting what might happen in real life. Therefore, this review gives an overall summary concerning the human breast, specifically its mechanical properties using experimental and FE analysis, and the tissue engineering approaches to regenerate this particular tissue, along with FE models.
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Affiliation(s)
| | - Pedro Martins
- UBS, INEGI, LAETA, Porto, Portugal
- I3A, Universidad de Zaragoza, Zaragoza, Spain
- *Correspondence: Pedro Martins,
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3
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Briot N, Chagnon G, Connesson N, Payan Y. In vivo measurement of breast tissues stiffness using a light aspiration device. Clin Biomech (Bristol, Avon) 2022; 99:105743. [PMID: 36099706 DOI: 10.1016/j.clinbiomech.2022.105743] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 08/12/2022] [Indexed: 02/07/2023]
Abstract
BACKGROUND This paper addresses the question of the in vivo measurement of breast tissue stiffness, which has been poorly adressed until now, except for elastography imaging which has shown promising results but which is still difficult for clinicians to use on a day-to-day basis. Estimating subject-specific tissue stiffness is indeed a critical area of research due to the development of a large number of Finite Element (FE) breast models for various medical applications. METHODS This paper proposes to use an original aspiration device, put into contact with breast surface, and to estimate tissue stiffness using an inverse analysis of the aspiration experiment. The method assumes that breast tissue is composed of a bilayered structure made of fatty and fribroglandular tissues (lower layer) superimposed with the skin (upper layer). Young moduli of both layers are therefore estimated based on repeating low intensity suction tests (<40 mbar) of breast tissues using cups of 7 different diameters. FINDINGS Seven volunteers were involved in this pilot study with average Young moduli of 56.3 kPa ± 16.4 and 3.04 kPa ± 1.17 respectively for the skin and the fatty and fibroglandular tissue. The measurements were carried out in a reasonable time scale (<60 min in total) without any discomfort perceived by the participants. These encouraging results should be confirmed in a clinical study that will include a much larger number of volunteers and patients.
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Affiliation(s)
- N Briot
- Univ. Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, 38000 Grenoble, France.
| | - G Chagnon
- Univ. Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, 38000 Grenoble, France
| | - N Connesson
- Univ. Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, 38000 Grenoble, France
| | - Y Payan
- Univ. Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, 38000 Grenoble, France
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4
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Singh G, Chanda A. Mechanical properties of whole-body soft human tissues: a review. Biomed Mater 2021; 16. [PMID: 34587593 DOI: 10.1088/1748-605x/ac2b7a] [Citation(s) in RCA: 128] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 09/29/2021] [Indexed: 11/11/2022]
Abstract
The mechanical properties of soft tissues play a key role in studying human injuries and their mitigation strategies. While such properties are indispensable for computational modelling of biological systems, they serve as important references in loading and failure experiments, and also for the development of tissue simulants. To date, experimental studies have measured the mechanical properties of peripheral tissues (e.g. skin)in-vivoand limited internal tissuesex-vivoin cadavers (e.g. brain and the heart). The lack of knowledge on a majority of human tissues inhibit their study for applications ranging from surgical planning, ballistic testing, implantable medical device development, and the assessment of traumatic injuries. The purpose of this work is to overcome such challenges through an extensive review of the literature reporting the mechanical properties of whole-body soft tissues from head to toe. Specifically, the available linear mechanical properties of all human tissues were compiled. Non-linear biomechanical models were also introduced, and the soft human tissues characterized using such models were summarized. The literature gaps identified from this work will help future biomechanical studies on soft human tissue characterization and the development of accurate medical models for the study and mitigation of injuries.
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Affiliation(s)
- Gurpreet Singh
- Centre for Biomedical Engineering, Indian Institute of Technology (IIT), Delhi, India
| | - Arnab Chanda
- Centre for Biomedical Engineering, Indian Institute of Technology (IIT), Delhi, India.,Department of Biomedical Engineering, All India Institute of Medical Sciences (AIIMS), Delhi, India
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5
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Pasyar P, Arabalibeik H, Mohammadi M, Rezazadeh H, Sadeghi V, Askari M, Mirbagheri A. Ultrasound elastography using shear wave interference patterns: a finite element study of affecting factors. Phys Eng Sci Med 2021; 44:253-263. [PMID: 33591540 DOI: 10.1007/s13246-021-00975-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 01/18/2021] [Indexed: 11/29/2022]
Abstract
Elastography as one of the non-invasive medical imaging techniques which can help determine the stiffness of organs and other structures is currently attracting more attention. An interesting imaging rate-independent technique which has been discussed in literature uses shear wave interference patterns (SWIP). In this method, two external continuous harmonic vibration sources were used to induced SWIP and the resulting tissue displacements are mapped using ultrasonic imaging called sonoelastography. In this paper, a finite element model (FEM) of viscoelastic soft tissue with circular stiffer lesion inside, is simulated for testing the effect of stimulation characteristics on the propagation of SWIPs and shear speed map reconstruction. Also, we proposed an elastography probe, including miniature vibration sources and ultrasound transducer, which can be appropriate for experimental tests. The elastographic average speed ratio (ASR) and some scores like Dice coefficient, related to the binary image of shear speed map, are calculated for quantitatively measuring the effect of different contributing harmonic vibration parameters. Results show that the potential of providing useful diagnostic information can be improved if the preferable parameters are considered for implementation. According to these results the ASR, Dice and Jaccard scores would diverge from the ground truth of FEA if the parameter level is not selected correctly. Particularly, the Dice and Jaccard coefficients are obtained about 0.9 and 0.8, respectively, for the best vibration parameters level choice.
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Affiliation(s)
- Pezhman Pasyar
- Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran.,Research Center of Biomedical Technology and Robotics (RCBTR), Tehran University of Medical Sciences, Tehran, Iran
| | - Hossein Arabalibeik
- Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran. .,Research Center of Biomedical Technology and Robotics (RCBTR), Tehran University of Medical Sciences, Tehran, Iran.
| | - Mohammad Mohammadi
- Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran.,Research Center of Biomedical Technology and Robotics (RCBTR), Tehran University of Medical Sciences, Tehran, Iran
| | - Hassan Rezazadeh
- Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran.,Research Center of Biomedical Technology and Robotics (RCBTR), Tehran University of Medical Sciences, Tehran, Iran
| | - Vahid Sadeghi
- Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran.,Research Center of Biomedical Technology and Robotics (RCBTR), Tehran University of Medical Sciences, Tehran, Iran
| | - Milad Askari
- Department of Mechanical Engineering, Tehran University, Tehran, Iran
| | - Alireza Mirbagheri
- Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran.,Research Center of Biomedical Technology and Robotics (RCBTR), Tehran University of Medical Sciences, Tehran, Iran
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6
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Al abdi RM, Deng B, Hijazi HH, Wu M, Carp SA. Mechanical and hemodynamic responses of breast tissue under mammographic-like compression during functional dynamic optical imaging. BIOMEDICAL OPTICS EXPRESS 2020; 11:5425-5441. [PMID: 33149960 PMCID: PMC7587258 DOI: 10.1364/boe.398110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 08/24/2020] [Accepted: 08/24/2020] [Indexed: 06/11/2023]
Abstract
Studying tissue hemodynamics following breast compression has the potential to reveal new contrast mechanisms for evaluating breast cancer. However, how compression will be distributed and, consequently, how hemodynamics will be altered inside the compressed breast remain unclear. To explore the effect of compression, 12 healthy volunteers were studied by applying a step compression increase (4.5-53.4 N) using an optical imaging system capable of concurrently measuring pressure distribution and hemodynamic responses. Finite element analysis was used to predict the distribution of internal fluid pressure (IFP) in breast models. Comparisons between the measured pressure distribution and the reconstructed hemodynamic images for the healthy volunteers indicated significant (p < 0.05) negative correlations. The findings from a breast cancer patient showed that IFP distribution during compression strongly correlates with the observed differential hemodynamic images. We concluded that dynamic breast compression results in non-uniform internal pressure distribution throughout the breast that could potentially drive directed blood flow. The encouraging results obtained highlight the promise of developing dynamic optical imaging biomarkers for breast cancer by interpreting differential hemodynamic images of breast tissue during compression in the context of measured pressure distribution and predicted IFP.
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Affiliation(s)
- Rabah M. Al abdi
- Biomedical Engineering Department, Jordan University of Science and Technology, Irbid 22110, Jordan
| | - Bin Deng
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Heba H. Hijazi
- Department of Health Management and Policy, Jordan University of Science and Technology, Irbid 22110, Jordan
| | - Melissa Wu
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Stefan A. Carp
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
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7
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Patel BK, Samreen N, Zhou Y, Chen J, Brandt K, Ehman R, Pepin K. MR Elastography of the Breast: Evolution of Technique, Case Examples, and Future Directions. Clin Breast Cancer 2020; 21:e102-e111. [PMID: 32900617 DOI: 10.1016/j.clbc.2020.08.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 07/20/2020] [Accepted: 08/10/2020] [Indexed: 02/07/2023]
Abstract
Recognizing that breast cancers present as firm, stiff lesions, the foundation of breast magnetic resonance elastography (MRE) is to combine tissue stiffness parameters with sensitive breast MR contrast-enhanced imaging. Breast MRE is a non-ionizing, cross-sectional MR imaging technique that provides for quantitative viscoelastic properties, including tissue stiffness, elasticity, and viscosity, of breast tissues. Currently, the technique continues to evolve as research surrounding the use of MRE in breast tissue is still developing. In the setting of a newly diagnosed cancer, associated desmoplasia, stiffening of the surrounding stroma, and necrosis are known to be prognostic factors that can add diagnostic information to patient treatment algorithms. In fact, mechanical properties of the tissue might also influence breast cancer risk. For these reasons, exploration of breast MRE has great clinical value. In this review, we will: (1) address the evolution of the various MRE techniques; (2) provide a brief overview of the current clinical studies in breast MRE with interspersed case examples; and (3) suggest directions for future research.
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Affiliation(s)
| | | | - Yuxiang Zhou
- Department of Radiology, Mayo Clinic, Phoenix, AZ
| | - Jun Chen
- Department of Radiology, Mayo Clinic, Rochester, MN
| | - Kathy Brandt
- Department of Radiology, Mayo Clinic, Rochester, MN
| | | | - Kay Pepin
- Department of Radiology, Mayo Clinic, Rochester, MN
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8
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In Vivo Quantification of Water Diffusion, Stiffness, and Tissue Fluidity in Benign Prostatic Hyperplasia and Prostate Cancer. Invest Radiol 2020; 55:524-530. [DOI: 10.1097/rli.0000000000000685] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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9
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Mîra A, Carton AK, Muller S, Payan Y. A biomechanical breast model evaluated with respect to MRI data collected in three different positions. Clin Biomech (Bristol, Avon) 2018; 60:191-199. [PMID: 30408760 DOI: 10.1016/j.clinbiomech.2018.10.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 06/28/2018] [Accepted: 10/14/2018] [Indexed: 02/07/2023]
Abstract
BACKGROUND Mammography is a specific type of breast imaging that uses low-dose X-rays to detect cancer in early stage. During the exam, the women breast is compressed between two plates in order to even out the breast thickness and to spread out the soft tissues. This technique improves exam quality but can be uncomfortable for the patient. The perceived discomfort can be assessed by the means of a breast biomechanical model. Alternative breast compression techniques may be computationally investigated trough finite elements simulations. METHODS The aim of this work is to develop and evaluate a new biomechanical Finite Element (FE) breast model. The complex breast anatomy is considered including adipose and glandular tissues, muscle, skin, suspensory ligaments and pectoral fascias. Material hyper-elasticity is modeled using the Neo-Hookean material models. The stress-free breast geometry and subject-specific constitutive models are derived using tissues deformations measurements from MR images. FINDINGS The breast geometry in three breast configurations were computed using the breast stress-free geometry together with the estimated set of equivalent Young's modulus (Ebreastr = 0.3 kPa, Ebreastl = 0.2 kPa, Eskin = 4 kPa, Efascia = 120 kPa). The Hausdorff distance between estimated and measured breast geometries for prone, supine and supine tilted configurations is equal to 2.17 mm, 1.72 mm and 5.90 mm respectively. INTERPRETATION A subject-specific breast model allows a better characterization of breast mechanics. However, the model presents some limitations when estimating the supine tilted breast configuration. The results show clearly the difficulties to characterize soft tissues mechanics at large strain ranges with Neo-Hookean material models.
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Affiliation(s)
- Anna Mîra
- Univ. Grenoble Alpes, CNRS, Grenoble INP, VetAgro Sup, TIMC-IMAG, 38000 Grenoble, France; GE Healthcare, 78530 Buc, France.
| | | | | | - Yohan Payan
- Univ. Grenoble Alpes, CNRS, Grenoble INP, VetAgro Sup, TIMC-IMAG, 38000 Grenoble, France
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10
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Bohte AE, Nelissen JL, Runge JH, Holub O, Lambert SA, de Graaf L, Kolkman S, van der Meij S, Stoker J, Strijkers GJ, Nederveen AJ, Sinkus R. Breast magnetic resonance elastography: a review of clinical work and future perspectives. NMR IN BIOMEDICINE 2018; 31:e3932. [PMID: 29846986 DOI: 10.1002/nbm.3932] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 03/07/2018] [Accepted: 03/18/2018] [Indexed: 06/08/2023]
Abstract
This review on magnetic resonance elastography (MRE) of the breast provides an overview of available literature and describes current developments in the field of breast MRE, including new transducer technology for data acquisition and multi-frequency-derived power-law behaviour of tissue. Moreover, we discuss the future potential of breast MRE, which goes beyond its original application as an additional tool in differentiating benign from malignant breast lesions. These areas of ongoing and future research include MRE for pre-operative tumour delineation, staging, monitoring and predicting response to treatment, as well as prediction of the metastatic potential of primary tumours.
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Affiliation(s)
- A E Bohte
- Department of Radiology and Nuclear Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - J L Nelissen
- Biomedical NMR, Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
- Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, The Netherlands
| | - J H Runge
- Department of Radiology and Nuclear Medicine, Academic Medical Center, Amsterdam, The Netherlands
- Image Sciences and Biomedical Engineering, King's College London, London, UK
| | - O Holub
- Image Sciences and Biomedical Engineering, King's College London, London, UK
| | - S A Lambert
- Image Sciences and Biomedical Engineering, King's College London, London, UK
- Université Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, INSERM UMR 5220, U1206, Lyon, France
| | - L de Graaf
- Biomedical NMR, Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - S Kolkman
- Department of Radiology and Nuclear Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - S van der Meij
- Department of Surgery, Academic Medical Center, Amsterdam, The Netherlands
- Department of Surgery, Flevoziekenhuis, Almere, The Netherlands
| | - J Stoker
- Department of Radiology and Nuclear Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - G J Strijkers
- Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, The Netherlands
| | - A J Nederveen
- Department of Radiology and Nuclear Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - R Sinkus
- Image Sciences and Biomedical Engineering, King's College London, London, UK
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11
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Govrin-Yehudain O, Matanis Y, Govrin-Yehudain J. Reduced Pain and Accelerated Recovery Following Primary Breast Augmentation With Lightweight Breast Implants. Aesthet Surg J 2018; 38:1092-1096. [PMID: 29579148 PMCID: PMC6137425 DOI: 10.1093/asj/sjy071] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The posttreatment pain associated with breast augmentation is a top concern of most patients and can affect the decision concerning surgery. OBJECTIVES This study aimed to compare the posttreatment pain and recovery times of patients undergoing primary breast augmentation with lightweight vs full-mass implants of similar volumes. The authors hypothesized that the reduced mechanical strain applied by lightweight implants elicits less pain. METHODS In this retrospective, observational study, 100 women who had undergone primary breast augmentation with either a lightweight breast implant or a traditional full-mass silicone implant (n = 50), were contacted by phone and asked about their posttreatment experiences and overall satisfaction with the outcome. All women were treated by the same surgical team, and the two groups were matched by date of surgery. RESULTS Most patients in the two cohorts had a self-reported preoperative B cup size and relatively high tolerance to pain. On average, LWBI patients were 6 years older than those undergoing full-mass implantation (32.4 ± 8.7 vs 26.2 ± 8.0; P = .0004) and more had experienced at least one pregnancy (61.2% vs 24%, P = .0002). LWBI patients opted for implants 39 ± 28.4 cc larger than patients in the control group. Subglandular placement was selected in most cases (LWBI: 83.7% and full-mass: 90.0%). Mean posttreatment pain was lower in the LWBI cohort (5.5 ± 2.4 vs 6.5 ± 2.4) and required a shorter duration of analgesics (3.87 ± 1.77 days vs 5.26 ± 2.94 days; P = .009). Age- and parity-adjusted measures demonstrated a respective 2-day and 5-day shorter recovery period and return to normal activities interval in the LWBI versus full-mass implant cohorts (P = .04 and P = .002, respectively). CONCLUSIONS As compared to traditional silicone filled full-mass implants, breast augmentations with B-Lite lightweight breast implants (G&G Biotechnology Ltd., Haifa, Israel) elicit less posttreatment pain and require less down-time, ultimately, meeting patients' quest for desired breast shape at minimal discomfort. LEVEL OF EVIDENCE 3
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Affiliation(s)
| | - Yossef Matanis
- Department of Anesthesiology, Italian Hospital, Haifa, Israel
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12
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Richey WL, Luo M, Goodale SE, Clements LW, Meszoely IM, Miga MI. A system for automatic monitoring of surgical instruments and dynamic, non-rigid surface deformations in breast cancer surgery. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2018; 10576:105761H. [PMID: 31130766 PMCID: PMC6530568 DOI: 10.1117/12.2295221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
When negative tumor margins are achieved at the time of resection, breast conserving therapy (lumpectomy followed with radiation therapy) offers patients improved cosmetic outcomes and quality of life with equivalent survival outcomes to mastectomy. However, high reoperation rates ranging 10-59% continue to challenge adoption and suggest that improved intraoperative tumor localization is a pressing need. We propose to couple an optical tracker and stereo camera system for automated monitoring of surgical instruments and non-rigid breast surface deformations. A bracket was designed to rigidly pair an optical tracker with a stereo camera, optimizing overlap volume. Utilizing both devices allowed for precise instrument tracking of multiple objects with reliable, workflow friendly tracking of dynamic breast movements. Computer vision techniques were employed to automatically track fiducials, requiring one-time initialization with bounding boxes in stereo camera images. Point based rigid registration was performed between fiducial locations triangulated from stereo camera images and fiducial locations recorded with an optically tracked stylus. We measured fiducial registration error (FRE) and target registration error (TRE) with two different stereo camera devices using a phantom breast with five fiducials. Average FREs of 2.7 ± 0.4 mm and 2.4 ± 0.6 mm with each stereo-camera device demonstrate considerable promise for this approach in monitoring the surgical field. Automated tracking was shown to reduce error when compared to manually selected fiducial locations in stereo camera image-based localization. The proposed instrumentation framework demonstrated potential for the continuous measurement of surgical instruments in relation to the dynamic deformations of a breast during lumpectomy.
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Affiliation(s)
- Winona L Richey
- Vanderbilt University, Department of Biomedical Engineering, Nashville, TN USA
| | - Ma Luo
- Vanderbilt University, Department of Biomedical Engineering, Nashville, TN USA
| | - Sarah E Goodale
- Vanderbilt University, Department of Biomedical Engineering, Nashville, TN USA
| | - Logan W Clements
- Vanderbilt University, Department of Biomedical Engineering, Nashville, TN USA
| | - Ingrid M Meszoely
- Vanderbilt University Medical Center, Division of Surgical Oncology, Nashville, TN USA
| | - Michael I Miga
- Vanderbilt University, Department of Biomedical Engineering, Nashville, TN USA
- Vanderbilt University Department of Radiology and Radiological Sciences, Nashville, TN USA
- Vanderbilt Institute for Surgery and Engineering, Nashville, TN USA
- Vanderbilt University Medical Center, Department of Neurological Surgery, Nashville, TN USA
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13
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Lapuebla-Ferri A, Cegoñino-Banzo J, Jiménez-Mocholí AJ, Del Palomar AP. Towards an in-plane methodology to track breast lesions using mammograms and patient-specific finite-element simulations. Phys Med Biol 2017; 62:8720-8738. [PMID: 29091591 DOI: 10.1088/1361-6560/aa8d62] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In breast cancer screening or diagnosis, it is usual to combine different images in order to locate a lesion as accurately as possible. These images are generated using a single or several imaging techniques. As x-ray-based mammography is widely used, a breast lesion is located in the same plane of the image (mammogram), but tracking it across mammograms corresponding to different views is a challenging task for medical physicians. Accordingly, simulation tools and methodologies that use patient-specific numerical models can facilitate the task of fusing information from different images. Additionally, these tools need to be as straightforward as possible to facilitate their translation to the clinical area. This paper presents a patient-specific, finite-element-based and semi-automated simulation methodology to track breast lesions across mammograms. A realistic three-dimensional computer model of a patient's breast was generated from magnetic resonance imaging to simulate mammographic compressions in cranio-caudal (CC, head-to-toe) and medio-lateral oblique (MLO, shoulder-to-opposite hip) directions. For each compression being simulated, a virtual mammogram was obtained and posteriorly superimposed to the corresponding real mammogram, by sharing the nipple as a common feature. Two-dimensional rigid-body transformations were applied, and the error distance measured between the centroids of the tumors previously located on each image was 3.84 mm and 2.41 mm for CC and MLO compression, respectively. Considering that the scope of this work is to conceive a methodology translatable to clinical practice, the results indicate that it could be helpful in supporting the tracking of breast lesions.
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Affiliation(s)
- Andrés Lapuebla-Ferri
- Department of Continuum Mechanics and Theory of Structures, School of Industrial Engineering, Universitat Politècnica de València, Camino de Vera s/n. E-46022 Valencia, Spain
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Griesenauer RH, Weis JA, Arlinghaus LR, Meszoely IM, Miga MI. Breast tissue stiffness estimation for surgical guidance using gravity-induced excitation. Phys Med Biol 2017; 62:4756-4776. [PMID: 28520556 DOI: 10.1088/1361-6560/aa700a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Tissue stiffness interrogation is fundamental in breast cancer diagnosis and treatment. Furthermore, biomechanical models for predicting breast deformations have been created for several breast cancer applications. Within these applications, constitutive mechanical properties must be defined and the accuracy of this estimation directly impacts the overall performance of the model. In this study, we present an image-derived computational framework to obtain quantitative, patient specific stiffness properties for application in image-guided breast cancer surgery and interventions. The method uses two MR acquisitions of the breast in different supine gravity-loaded configurations to fit mechanical properties to a biomechanical breast model. A reproducibility assessment of the method was performed in a test-retest study using healthy volunteers and was further characterized in simulation. In five human data sets, the within subject coefficient of variation ranged from 10.7% to 27% and the intraclass correlation coefficient ranged from 0.91-0.944 for assessment of fibroglandular and adipose tissue stiffness. In simulation, fibroglandular content and deformation magnitude were shown to have significant effects on the shape and convexity of the objective function defined by image similarity. These observations provide an important step forward in characterizing the use of nonrigid image registration methodologies in conjunction with biomechanical models to estimate tissue stiffness. In addition, the results suggest that stiffness estimation methods using gravity-induced excitation can reliably and feasibly be implemented in breast cancer surgery/intervention workflows.
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Affiliation(s)
- Rebekah H Griesenauer
- Department of Biomedical Engineering, Vanderbilt University, 5824 Stevenson Center, Nashville, TN 37235, United States of America. Vanderbilt Institute in Surgery and Engineering (VISE), Nashville, TN, United States of America
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15
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Blank MAB, Antaki JF. Breast Lesion Elastography Region of Interest Selection and Quantitative Heterogeneity: A Systematic Review and Meta-Analysis. ULTRASOUND IN MEDICINE & BIOLOGY 2017; 43:387-397. [PMID: 27746010 DOI: 10.1016/j.ultrasmedbio.2016.09.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 07/22/2016] [Accepted: 09/06/2016] [Indexed: 05/20/2023]
Abstract
In this systematic review and meta-analysis, we report measured elasticities of benign and malignant breast pathologies from shear wave elastography (SWE), quantitatively confirm the effect of the selected region of interest (ROI) on these measures and test the hypothesis that a metric of heterogeneity based on the mean and maximum elasticity can improve specificity of diagnosis. The elasticities of benign, malignant and specific pathologic states are reported from 22 publications encompassing 2989 patients, identified from a structured search of the literature from May to September 2015. Twelve articles were included in a meta-analysis that grouped results by the method of ROI selection to discriminate between different pathologies. We observe a significant correlation between the method of selection of ROI for malignant mean (p < 0.001) and maximum (p = 0.027) elasticities, but no correlation with benign measures. We define a quantitative heterogeneity parameter, the "stiffness gradient," computed from the mean and maximum measured elasticities. The stiffness gradient out-performed the current standard maximum elasticity metric in stratifying malignancy risk by a margin of 15% for the partial ROI, and 42% for the maximized ROI. An anecdotal example of improved differentiation using the stiffness gradient on pathology-specific lesions is also provided. These results quantitatively indicate that the method of ROI selection in SWE not only has a significant impact on the resulting mean reported elasticity of a lesion, but may provide some insight into lesion heterogeneity. Our results suggest that further exploration of quantitative heterogeneity is warranted to improve the specificity of diagnosis.
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Affiliation(s)
- Molly A B Blank
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA.
| | - James F Antaki
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
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16
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Low G, Kruse SA, Lomas DJ. General review of magnetic resonance elastography. World J Radiol 2016; 8:59-72. [PMID: 26834944 PMCID: PMC4731349 DOI: 10.4329/wjr.v8.i1.59] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 11/14/2015] [Accepted: 12/04/2015] [Indexed: 02/06/2023] Open
Abstract
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.
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Hipwell JH, Vavourakis V, Han L, Mertzanidou T, Eiben B, Hawkes DJ. A review of biomechanically informed breast image registration. Phys Med Biol 2016; 61:R1-31. [PMID: 26733349 DOI: 10.1088/0031-9155/61/2/r1] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Breast radiology encompasses the full range of imaging modalities from routine imaging via x-ray mammography, magnetic resonance imaging and ultrasound (both two- and three-dimensional), to more recent technologies such as digital breast tomosynthesis, and dedicated breast imaging systems for positron emission mammography and ultrasound tomography. In addition new and experimental modalities, such as Photoacoustics, Near Infrared Spectroscopy and Electrical Impedance Tomography etc, are emerging. The breast is a highly deformable structure however, and this greatly complicates visual comparison of imaging modalities for the purposes of breast screening, cancer diagnosis (including image guided biopsy), tumour staging, treatment monitoring, surgical planning and simulation of the effects of surgery and wound healing etc. Due primarily to the challenges posed by these gross, non-rigid deformations, development of automated methods which enable registration, and hence fusion, of information within and across breast imaging modalities, and between the images and the physical space of the breast during interventions, remains an active research field which has yet to translate suitable methods into clinical practice. This review describes current research in the field of breast biomechanical modelling and identifies relevant publications where the resulting models have been incorporated into breast image registration and simulation algorithms. Despite these developments there remain a number of issues that limit clinical application of biomechanical modelling. These include the accuracy of constitutive modelling, implementation of representative boundary conditions, failure to meet clinically acceptable levels of computational cost, challenges associated with automating patient-specific model generation (i.e. robust image segmentation and mesh generation) and the complexity of applying biomechanical modelling methods in routine clinical practice.
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Affiliation(s)
- John H Hipwell
- Centre for Medical Image Computing, Malet Place Engineering Building, University College London, Gower Street, London WC1E 6BT, UK
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Pepin KM, Ehman RL, McGee KP. Magnetic resonance elastography (MRE) in cancer: Technique, analysis, and applications. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2015; 90-91:32-48. [PMID: 26592944 PMCID: PMC4660259 DOI: 10.1016/j.pnmrs.2015.06.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 06/15/2015] [Accepted: 06/16/2015] [Indexed: 05/07/2023]
Abstract
Tissue mechanical properties are significantly altered with the development of cancer. Magnetic resonance elastography (MRE) is a noninvasive technique capable of quantifying tissue mechanical properties in vivo. This review describes the basic principles of MRE and introduces some of the many promising MRE methods that have been developed for the detection and characterization of cancer, evaluation of response to therapy, and investigation of the underlying mechanical mechanisms associated with malignancy.
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Govrin-Yehudain J, Dvir H, Preise D, Govrin-Yehudain O, Govreen-Segal D. Lightweight breast implants: a novel solution for breast augmentation and reconstruction mammaplasty. Aesthet Surg J 2015; 35:965-71. [PMID: 26333989 PMCID: PMC4622048 DOI: 10.1093/asj/sjv080] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/17/2015] [Indexed: 12/04/2022] Open
Abstract
Breast augmentation and reconstruction mammaplasty have been in practice for decades and are highly prevalent surgeries performed worldwide. While overall patient satisfaction is high, common long-term effects include breast tissue atrophy, accelerated ptosis and inframammary fold breakdown. Increasing evidence attributes these events to the durative loading and compressive forces introduced by the breast implants. Mechanical challenges exceeding the elastic capacity of the breast tissue components, eventually lead to irreversible tissue stretching, directly proportional to the introduced mass. Thus, it is suggested that, contrary to long-standing dogmas, implant weight, rather than its volume, stands at the basis of future tissue compromise and deformation. A novel lightweight implant has been developed to address the drawbacks of traditional breast implants, which demonstrate equivalence between their size and weight. The B-Lite® breast implant (G&G Biotechnology Ltd., Haifa, Israel) design allows for a reduction in implant weight of up to 30%, while maintaining the size, form, and function of traditional breast implants. The CE-marked device can be effectively implanted using standard of care procedures and has been established safe for human use. Implantation of the B-Lite® breast implant is projected to significantly reduce the inherent strains imposed by standard implants, thereby conserving tissue stability and integrity over time. In summary, this novel, lightweight breast implant promises to reduce breast tissue compromise and deformation and subsequent reoperation, further improving patient safety and satisfaction.
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Affiliation(s)
- Jacky Govrin-Yehudain
- Dr Govrin-Yehudain is President, Dr Haim is Chief Technology Officer, and Mr Govreen-Segal is Chief Executive Officer, G&G Biotechnology Ltd., Haifa, Israel. Dr Govrin-Yehudain is also Founding Plastic Surgeon, Beit Harofim Medical Center, Haifa, Israel. Dr Preise is a Senior Intern in the Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel. Mr Govrin-Yehudain is a Medical Student, Bar Ilan University, Ramat Gan, Israel
| | - Haim Dvir
- Dr Govrin-Yehudain is President, Dr Haim is Chief Technology Officer, and Mr Govreen-Segal is Chief Executive Officer, G&G Biotechnology Ltd., Haifa, Israel. Dr Govrin-Yehudain is also Founding Plastic Surgeon, Beit Harofim Medical Center, Haifa, Israel. Dr Preise is a Senior Intern in the Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel. Mr Govrin-Yehudain is a Medical Student, Bar Ilan University, Ramat Gan, Israel
| | - Dina Preise
- Dr Govrin-Yehudain is President, Dr Haim is Chief Technology Officer, and Mr Govreen-Segal is Chief Executive Officer, G&G Biotechnology Ltd., Haifa, Israel. Dr Govrin-Yehudain is also Founding Plastic Surgeon, Beit Harofim Medical Center, Haifa, Israel. Dr Preise is a Senior Intern in the Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel. Mr Govrin-Yehudain is a Medical Student, Bar Ilan University, Ramat Gan, Israel
| | - Orel Govrin-Yehudain
- Dr Govrin-Yehudain is President, Dr Haim is Chief Technology Officer, and Mr Govreen-Segal is Chief Executive Officer, G&G Biotechnology Ltd., Haifa, Israel. Dr Govrin-Yehudain is also Founding Plastic Surgeon, Beit Harofim Medical Center, Haifa, Israel. Dr Preise is a Senior Intern in the Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel. Mr Govrin-Yehudain is a Medical Student, Bar Ilan University, Ramat Gan, Israel
| | - Dael Govreen-Segal
- Dr Govrin-Yehudain is President, Dr Haim is Chief Technology Officer, and Mr Govreen-Segal is Chief Executive Officer, G&G Biotechnology Ltd., Haifa, Israel. Dr Govrin-Yehudain is also Founding Plastic Surgeon, Beit Harofim Medical Center, Haifa, Israel. Dr Preise is a Senior Intern in the Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel. Mr Govrin-Yehudain is a Medical Student, Bar Ilan University, Ramat Gan, Israel
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Changes in the elasticity of fibroadenoma during the menstrual cycle determined by real-time sonoelastography. Eur J Radiol 2015; 84:1044-8. [DOI: 10.1016/j.ejrad.2015.03.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 02/02/2015] [Accepted: 03/03/2015] [Indexed: 11/19/2022]
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Busch DR, Choe R, Durduran T, Friedman DH, Baker WB, Maidment AD, Rosen MA, Schnall MD, Yodh AG. Blood flow reduction in breast tissue due to mammographic compression. Acad Radiol 2014; 21:151-61. [PMID: 24439328 DOI: 10.1016/j.acra.2013.10.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2013] [Revised: 10/08/2013] [Accepted: 10/14/2013] [Indexed: 10/25/2022]
Abstract
RATIONALE AND OBJECTIVES This study measures hemodynamic properties such as blood flow and hemoglobin concentration and oxygenation in the healthy human breast under a wide range of compressive loads. Because many breast-imaging technologies derive contrast from the deformed breast, these load-dependent vascular responses affect contrast agent-enhanced and hemoglobin-based breast imaging. METHODS Diffuse optical and diffuse correlation spectroscopies were used to measure the concentrations of oxygenated and deoxygenated hemoglobin, lipid, water, and microvascular blood flow during axial breast compression in the parallel-plate transmission geometry. RESULTS Significant reductions (P < .01) in total hemoglobin concentration (∼30%), blood oxygenation (∼20%), and blood flow (∼87%) were observed under applied pressures (forces) of up to 30 kPa (120 N) in 15 subjects. Lipid and water concentrations changed <10%. CONCLUSIONS Imaging protocols based on injected contrast agents should account for variation in tissue blood flow due to mammographic compression. Similarly, imaging techniques that depend on endogenous blood contrasts will be affected by breast compression during imaging.
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The Effect of Material Modeling on Finite Element Analysis of Human Breast Biomechanics. J Appl Biomater Funct Mater 2014; 12:27-34. [DOI: 10.5301/jabfm.2012.9337] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/28/2012] [Indexed: 11/20/2022] Open
Abstract
Purpose Finite element analysis has been used extensively in the study of biomechanical modeling of the breast. However, issues regarding the complexity of material models and the influences of geometric boundary conditions on the accuracy of a breast Finite Element (FE) model are still under debate. This work demonstrates the importance of material modeling in FE models of the breast. Methods A simple hemispherical geometry is used to model the shape of a human breast. Different material models are being investigated to accurately model changes in terms of displacement, stress, and reaction forces distribution. Results The results obtained using nonlinear material models are compared with those obtained employing their linear approximation. Results have shown that differences, in terms of displacement, ranging between 20% and more than 80%, may occur and that large differences are present in terms of maximum principal stresses when the displacement is correctly approximated. Conclusions This study clearly shows that, in a FE model, simulating large deformations material modeling strongly influences the accuracy of the solution.
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Sarvazyan AP, Urban MW, Greenleaf JF. Acoustic waves in medical imaging and diagnostics. ULTRASOUND IN MEDICINE & BIOLOGY 2013; 39:1133-46. [PMID: 23643056 PMCID: PMC3682421 DOI: 10.1016/j.ultrasmedbio.2013.02.006] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 12/13/2012] [Accepted: 02/12/2013] [Indexed: 05/03/2023]
Abstract
Up until about two decades ago acoustic imaging and ultrasound imaging were synonymous. The term ultrasonography, or its abbreviated version sonography, meant an imaging modality based on the use of ultrasonic compressional bulk waves. Beginning in the 1990s, there started to emerge numerous acoustic imaging modalities based on the use of a different mode of acoustic wave: shear waves. Imaging with these waves was shown to provide very useful and very different information about the biological tissue being examined. We discuss the physical basis for the differences between these two basic modes of acoustic waves used in medical imaging and analyze the advantages associated with shear acoustic imaging. A comprehensive analysis of the range of acoustic wavelengths, velocities and frequencies that have been used in different imaging applications is presented. We discuss the potential for future shear wave imaging applications.
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Wojcinski S, Cassel M, Farrokh A, Soliman AA, Hille U, Schmidt W, Degenhardt F, Hillemanns P. Variations in the Elasticity of Breast Tissue During the Menstrual Cycle Determined by Real-time Sonoelastography. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2012; 31:63-72. [PMID: 22215771 DOI: 10.7863/jum.2012.31.1.63] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
OBJECTIVES The purpose of this study was to determine the dependence of breast tissue elasticity on the menstrual cycle of healthy volunteers by means of real-time sonoelastography. METHODS Twenty-two healthy volunteers (aged 18-33 years) were examined once weekly during two consecutive menstrual cycles using sonoelastography. Group 1 (n= 10) was not taking hormonal medication; group 2 (n = 12) was taking oral contraceptives. RESULTS The breast parenchyma appeared softer than the dermis and harder than the adipose tissue, and elasticity varied over the menstrual cycle and between groups. Group 1 (no hormone intake) showed continuously increasing elasticity with relatively soft breast parenchyma in the menstrual and follicular phases and harder parenchyma in the luteal phase (P = .012). Group 2 (oral contraceptives) showed no statistically significant changes in breast parenchymal elasticity according to sonoelastography. The parenchyma was generally softer in group 1 compared with group 2 throughout the menstrual cycle (P = .033). The dermis, the subcutaneous adipose tissue, and the pectoralis major muscle showed no changes in elasticity. Comparison of measurements made during the first and the second menstrual cycles showed similar patterns of elasticity in both groups. CONCLUSIONS Sonoelastography is a reproducible method that can be used to determine the dependence of breast parenchyma elasticity on the menstrual cycle and on the intake of hormonal contraceptives.
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Affiliation(s)
- Sebastian Wojcinski
- Department of Obstetrics and Gynecology, Franziskus Hospital, Bielefeld, Germany.
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Matrix compliance and RhoA direct the differentiation of mammary progenitor cells. Biomech Model Mechanobiol 2011; 11:1241-9. [PMID: 22161021 DOI: 10.1007/s10237-011-0362-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2011] [Accepted: 11/24/2011] [Indexed: 02/04/2023]
Abstract
The regenerative capacity of the mammary gland following post-lactational involution depends on the presence of multipotent stem or progenitor cells. Mammary progenitor cells exist as a quiescent and self-renewing population capable of differentiating into luminal epithelial and myoepithelial cells and generating ductal and alveolar structures. The fate choices of these cells are regulated by several soluble signals as well as their surrounding extracellular matrix. Whereas matrix stiffness has been implicated in organ-specific differentiation of embryonic and mesenchymal stem cells, the effects of substratum compliance on the more limited fate switches typical of tissue-specific progenitor cells are unknown. Here, we examined how the mechanical properties of the microenvironment affect the differentiation of mammary progenitor cells. Immortalized human mammary progenitor cells were cultured on synthetic hydrogels of varying stiffness, and their self-renewal and fate decisions were quantified. We found that cells cultured on soft substrata differentiated preferentially into luminal epithelial cells, whereas those cultured on stiff substrata differentiated preferentially into myoepithelial cells. Furthermore, pharmacological manipulations of cytoskeletal tension in conjunction with analysis of gene expression revealed that mechanical properties of the microenvironment signal through the small GTPase RhoA and cytoskeletal contractility to modulate the differentiation of mammary progenitor cells. These data suggest that subtle variations in the mechanical compliance of a tissue can direct the fate decisions of its resident progenitor cells.
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Rzymski P, Kubasik M, Opala T. Use of shear wave sonoelastography in capsular contracture before and after secondary surgery: Report of two cases. J Plast Reconstr Aesthet Surg 2011; 64:e309-12. [DOI: 10.1016/j.bjps.2011.06.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 05/29/2011] [Accepted: 06/02/2011] [Indexed: 11/16/2022]
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Chan S, Su MYL, Lei FJ, Wu JP, Lin M, Nalcioglu O, Feig SA, Chen JH. Menstrual cycle-related fluctuations in breast density measured by using three-dimensional MR imaging. Radiology 2011; 261:744-51. [PMID: 21878616 DOI: 10.1148/radiol.11110506] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To investigate the fluctuation of fibroglandular tissue volume (FV) and percentage of breast density (PD) during the menstrual cycle and compare with postmenopausal women by using three-dimensional magnetic resonance (MR)-based segmentation methods. MATERIALS AND METHODS This study was approved by the Institutional Review Board and was HIPAA compliant. Written informed consent was obtained. Thirty healthy female subjects, 24 premenopausal and six postmenopausal, were recruited. All subjects underwent MR imaging examination each week for 4 consecutive weeks. The breast volume (BV), FV, and PD were measured by two operators to evaluate interoperator variation. The fluctuation of each parameter measured over the course of the four examinations was evaluated on the basis of the coefficient of variation (CV). RESULTS The results from two operators showed a high Pearson correlation for BV (R(2) = 0.99), FV (R(2) = 0.98), and PD (R(2) = 0.96). The interoperator variation was 3% for BV and around 5%-6% for FV and PD. In the respective premenopausal and postmenopausal groups, the mean CV was 5.0% and 5.6% for BV, 7.6% and 4.2% for FV, and 7.1% and 6.0% for PD. The difference between premenopausal and postmenopausal groups was not significant (all P values > .05). CONCLUSION The fluctuation of breast density measured at MR imaging during a menstrual cycle was around 7%. The results may help the design and interpretation of future studies by using the change of breast density as a surrogate marker to evaluate the efficacy of hormone-modifying drugs for cancer treatment or cancer prevention.
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Affiliation(s)
- Siwa Chan
- Department of Radiology, Taichung Veterans General Hospital, Taichung, Taiwan
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Rzymski P, Skórzewska A, Skibińska-Zielińska M, Opala T. Factors influencing breast elasticity measured by the ultrasound Shear Wave elastography - preliminary results. Arch Med Sci 2011; 7:127-33. [PMID: 22291745 PMCID: PMC3258684 DOI: 10.5114/aoms.2011.20617] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2010] [Revised: 07/05/2010] [Accepted: 07/31/2010] [Indexed: 12/21/2022] Open
Abstract
INTRODUCTION Many physiological changes of breast elasticity depend on the age, hormonal status, menstrual cycle and many others. The aim of this study was to evaluate viscoelastic properties of normal breast tissues in a large group of women and to search for factors which play a role in its mechanical properties. MATERIAL AND METHODS 101 women aged 18-74 years who underwent B-mode sonography and additionally sonoelastography. We measured viscoelasticity in 8 quadrants by a share wave ultrasonic device estimating Young modules in regions of interest. RESULTS Mean elasticity measured in all 8 scans in glandular and fatty tissue were 11.28 ±5.79 kPa (0.1-46.26 kPa) and 9.24 ±4.48 kPa (0.1-29.78 kPa), respectively. The correlation between age and mean elasticity of glandular tissue was Rs = 0.27 (p = 0.007). The correlation between glandular tissue elasticity heterogeneity and breast mastalgia measured by VAS was Rs = -0.23 (p = 0.241). Fat tissue elasticity correlated with duration of lactation was Rs = 0.21 (p = 0.01). CONCLUSIONS There are several parameters influencing breast viscoelasticity measured by share wave sonoelastography. Glandular tissue elasticity correlates positively with age, fatty tissue elasticity correlates positively with duration of lactation and heterogeneity of the elasticity map of glandular tissue correlates with breast pain and fat tissue with BMI.
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Affiliation(s)
- Paweł Rzymski
- Department of Mother’s and Child’s Health, University of Medical Sciences, Gynecologic and Obstetrical University Hospital, Poznan, Poland
| | - Agnieszka Skórzewska
- Department of Radiology, University of Medical Sciences, Gynecologic and Obstetrical University Hospital, Poznan, Poland
| | - Myriam Skibińska-Zielińska
- Department of Radiology, University of Medical Sciences, Gynecologic and Obstetrical University Hospital, Poznan, Poland
| | - Tomasz Opala
- Department of Mother’s and Child’s Health, University of Medical Sciences, Gynecologic and Obstetrical University Hospital, Poznan, Poland
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Cheng S, Gandevia S, Green M, Sinkus R, Bilston L. Viscoelastic properties of the tongue and soft palate using MR elastography. J Biomech 2011; 44:450-4. [DOI: 10.1016/j.jbiomech.2010.09.027] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Revised: 09/20/2010] [Accepted: 09/27/2010] [Indexed: 01/22/2023]
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Rajagopal V, Nielsen PMF, Nash MP. Modeling breast biomechanics for multi‐modal image analysis—successes and challenges. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2010; 2:293-304. [PMID: 20836030 DOI: 10.1002/wsbm.58] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Vijay Rajagopal
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Poul M. F. Nielsen
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Martyn P. Nash
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
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Siegmann KC, Xydeas T, Sinkus R, Kraemer B, Vogel U, Claussen CD. Diagnostic value of MR elastography in addition to contrast-enhanced MR imaging of the breast-initial clinical results. Eur Radiol 2009; 20:318-25. [PMID: 19727753 DOI: 10.1007/s00330-009-1566-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Revised: 06/14/2009] [Accepted: 07/25/2009] [Indexed: 12/21/2022]
Abstract
OBJECTIVE The purpose of the study was to assess the additional value of magnetic resonance (MR) elastography (MRE) to contrast-enhanced (ce) MR imaging (MRI) for breast lesion characterisation. METHODS Fifty-seven suspected breast lesions in 57 patients (mean age 52.4 years) were examined by ce MRI and MRE. All lesions were classified into BI-RADS categories. Viscoelastic parameters, e.g. alpha0 as an indicator of tissue stiffness, were calculated. Histology of the lesions was correlated with BI-RADS and viscoelastic properties. The positive predictive value (PPV) for malignancy, and the sensitivity and specificity of ce MRI were calculated. Receiver-operating characteristics (ROC) curves were separately calculated for both ce MRI and viscoelastic properties and conjoined to analyse the accuracy of diagnostic performance. RESULTS The lesions (mean size 27.6 mm) were malignant in 64.9% (n = 37) of cases. The PPV for malignancy was significantly (p < 0.0001) dependent on BI-RADS classification. The sensitivity of ce MRI for breast cancer detection was 97.3% (36/37), whereas specificity was 55% (11/20). If ce MRI was combined with alpha0, the diagnostic accuracy could be significantly increased (p < 0.05; AUC(ce MRI) = 0.93, AUC(combined) = 0.96). CONCLUSIONS In this study, the combination of MRE and ce MRI could increase the diagnostic performance of breast MRI. Further investigations of larger cohorts and smaller lesions (in particular those only visible on MRI) are necessary to validate these results.
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Affiliation(s)
- Katja C Siegmann
- Department of Diagnostic and Interventional Radiology, University Hospital Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen, Germany.
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Deffieux T, Montaldo G, Tanter M, Fink M. Shear wave spectroscopy for in vivo quantification of human soft tissues visco-elasticity. IEEE TRANSACTIONS ON MEDICAL IMAGING 2009; 28:313-22. [PMID: 19244004 DOI: 10.1109/tmi.2008.925077] [Citation(s) in RCA: 271] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
In vivo assessment of dispersion affecting the propagation of visco-elastic waves in soft tissues is key to understand the rheology of human tissues. In this paper, the ability of the supersonic shear imaging (SSI) technique to generate planar shear waves propagating in tissues is fully exploited. First, by strongly limiting shear wave diffraction in the imaging plane, this imaging technique enables to discriminate between the usually concomitant influences of both medium rheological properties and diffraction affecting the shear wave dispersion. Second, transient propagation of these plane shear waves in soft tissues can be measured using echographic images acquired at very high frame. In vitro and in vivo experiments demonstrate that dispersion curves, which characterize the rheological behavior of tissues by measuring the frequency dependence of shear wave speed and attenuation, can be recovered in the 75-600 Hz frequency range. Based on a phase difference algorithm, the dispersion curves are computed in 1 cm2 regions of interest from the acquired propagation movie. In vivo measurements in Biceps Brachii muscle and liver of three healthy volunteers show important differences in the rheological behavior of these different tissues. Liver tissue appears to be much more dispersive with a phase velocity ranging from approximately 1.5 m/s at 75 Hz to approximately 3 m/s at 500 Hz whereas muscle tissue shows an important anisotropy, shear waves propagating longitudinally to the muscular fibers are almost nondispersive while those propagating transversally are very dispersive with a shear wave speed ranging from 0.5 to 2 m/s between 75 and 500 Hz. The estimation of dispersion curves is local and can be performed separately in different regions of the organ. This signal processing approach based on the SSI modality introduces the new concept of in vivo shear wave spectroscopy (SWS) that could become an additional tool for tissue characterization. This paper demonstrates the in vivo ability of this SWS to quantify both local shear elasticity and dispersion in real time.
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Affiliation(s)
- Thomas Deffieux
- Laboratoire Ondes et Acoustique, ESPCI, CNRS UMR 7587, INSERM, Université Paris VII, 75005 Paris, France
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Abstract
Breast MRI is an area of intense research and is fast becoming an important tool for the diagnosis of breast cancer. This review covers recent advances in breast MRI, MRS, and image post-processing and analysis. Several studies have explored a multi-parametric approach to breast imaging that combines analysis of traditional contrast enhancement patterns and lesion architecture with novel methods such as diffusion, perfusion, and spectroscopy to increase the specificity of breast MRI studies. Diffusion-weighted MRI shows some potential for increasing the specificity of breast lesion diagnosis and is even more promise for monitoring early response to therapy. MRS also has great potential for increasing specificity and for therapeutic monitoring. A limited number of studies have evaluated perfusion imaging based on first-pass contrast bolus tracking, and these clearly identify that vascular indices have great potential to increase specificity. The review also covers the relatively new acquisition technique of MR elastography for breast lesion characterization. A brief survey of image processing algorithms tailored for breast MR, including registration of serial dynamic images, segmentation and extraction of morphological features of breast lesions, and contrast uptake modeling, is also included. Recent advances in MRI, MRS, and automated image analysis have increased the utility of breast MR in diagnosis, screening, management, and therapy monitoring of breast cancer.
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Affiliation(s)
- S Sinha
- Department of Radiology, University of California-San Diego, San Diego, CA 92121-0852, USA.
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Potente G, Messineo D, Maggi C, Savelli S. Practical application of contrast-enhanced magnetic resonance mammography [CE-MRM] by an algorithm combining morphological and enhancement patterns. Comput Med Imaging Graph 2008; 33:83-90. [PMID: 19095407 DOI: 10.1016/j.compmedimag.2008.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2005] [Revised: 03/22/2008] [Accepted: 10/10/2008] [Indexed: 10/21/2022]
Abstract
The purpose of this article is to report our practical utilization of dynamic contrast-enhanced magnetic resonance mammography [DCE-MRM] in the diagnosis of breast lesions. In many European centers, was preferred a high-temporal acquisition of both breasts simultaneously in a large FOV. We preferred to scan single breasts, with the aim to combine the analysis of the contrast intake and washout with the morphological evaluation of breast lesions. We followed an interpretation model, based upon a diagnostic algorithm, which combined contrast enhancement with morphological evaluation, in order to increase our confidence in diagnosis. DCE-MRM with our diagnostic algorithm has identified 179 malignant and 41 benign lesions; final outcome has identified 178 malignant and 42 benign lesions, 3 false positives and 2 false negatives. Sensitivity of CE-MRM was 98.3%; specificity, 95.1%; positive predictive value, 98.9%; negative predictive value, 92.8% and accuracy, 97.7%.
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Affiliation(s)
- Giuseppe Potente
- Department of Radiological Sciences, University of Rome "La Sapienza", Viale Regina Elena 324, 00161 Rome, Italy.
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Pathmanathan P, Gavaghan DJ, Whiteley JP, Chapman SJ, Brady JM. Predicting tumor location by modeling the deformation of the breast. IEEE Trans Biomed Eng 2008; 55:2471-80. [PMID: 18838373 DOI: 10.1109/tbme.2008.925714] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Breast cancer is one of the biggest killers in the western world, and early diagnosis is essential for improved prognosis. The shape of the breast varies hugely between the scenarios of magnetic resonance (MR) imaging (patient lies prone, breast hanging down under gravity), X-ray mammography (breast strongly compressed) and ultrasound or biopsy/surgery (patient lies supine), rendering image fusion an extremely difficult task. This paper is concerned with the use of the finite-element method and nonlinear elasticity to build a 3-D, patient-specific, anatomically accurate model of the breast. The model is constructed from MR images and can be deformed to simulate breast shape and predict tumor location during mammography or biopsy/surgery. Two extensions of the standard elasticity problem need to be solved: an inverse elasticity problem (arising from the fact that only a deformed, stressed, state is known initially), and the contact problem of modeling compression. The model is used for craniocaudal mediolateral oblique mammographic image matching, and a number of numerical experiments are performed.
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Affiliation(s)
- Pras Pathmanathan
- Oxford University Computing Laboratory, Department of Engineering Science, Oxford, UK.
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Abstract
In vivo measurements of the viscoelastic properties of breast tissue are described. Ultrasonic echo frames were recorded from volunteers at 5 fps while applying a uniaxial compressive force (1-20 N) within a 1 s ramp time and holding the force constant for up to 200 s. A time series of strain images was formed from the echo data, spatially averaged viscous creep curves were computed, and viscoelastic strain parameters were estimated by fitting creep curves to a second-order Voigt model. The useful strain bandwidth from this quasi-static ramp stimulus was 10(-2) < or = omega < or = 10(0) rad/s (0.0016-0.16 Hz). The stress-strain curves for normal glandular tissues are linear when the surface force applied is between 2 and 5 N. In this range, the creep response was characteristic of biphasic viscoelastic polymers, settling to a constant strain (arrheodictic) after 100 s. The average model-based retardance time constants for the viscoelastic response were 3.2 +/- 0.8 and 42.0 +/- 28 s. Also, the viscoelastic strain amplitude was approximately equal to that of the elastic strain. Above 5 N of applied force, however, the response of glandular tissue became increasingly nonlinear and rheodictic, i.e., tissue creep never reached a plateau. Contrasting in vivo breast measurements with those in gelatin hydrogels, preliminary ideas regarding the mechanisms for viscoelastic contrast are emerging.
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Affiliation(s)
- Mallika Sridhar
- Department of Biomedical Engineering, University of California, Davis, California 95616, USA
| | - Michael F. Insana
- Department of Biomedical Engineering, University of California, Davis, California 95616, USA and Department of Bioengineering and the Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61810
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Abstract
Techniques are being developed to image viscoelastic features of soft tissues from time-varying strain. A compress-hold-release stress stimulus commonly used in creep-recovery measurements is applied to samples to form images of elastic strain and strain retardance times. While the intended application is diagnostic breast imaging, results in gelatin hydrogels are presented to demonstrate the techniques. The spatiotemporal behaviour of gelatin is described by linear viscoelastic theory formulated for polymeric solids. Measured creep responses of polymers are frequently modelled as sums of exponentials whose time constants describe the delay or retardation of the full strain response. We found the spectrum of retardation times tau to be continuous and bimodal, where the amplitude at each tau represents the relative number of molecular bonds with a given strength and conformation. Such spectra indicate that the molecular weight of the polymer fibres between bonding points is large. Imaging parameters are found by summarizing these complex spectral distributions at each location in the medium with a second-order Voigt rheological model. This simplification reduces the dimensionality of the data for selecting imaging parameters while preserving essential information on how the creeping deformation describes fluid flow and collagen matrix restructuring in the medium. The focus of this paper is on imaging parameter estimation from ultrasonic echo data, and how jitter from hand-held force applicators used for clinical applications propagate through the imaging chain to generate image noise.
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Affiliation(s)
- M Sridhar
- Department of Biomedical Engineering, University of California, Davis, CA 95616, USA
| | - J Liu
- Department of Bioengineering, University of Illinois, Urbana-Champaign, IL 61801, USA, E-mail:
| | - M F Insana
- Department of Biomedical Engineering, University of California, Davis, CA 95616, USA
- Department of Bioengineering, University of Illinois, Urbana-Champaign, IL 61801, USA, E-mail:
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Abstract
Viscoelastic properties of soft tissues and hydropolymers depend on the strength of molecular bonding forces connecting the polymer matrix and surrounding fluids. The basis for diagnostic imaging is that disease processes alter molecular-scale bonding in ways that vary the measurable stiffness and viscosity of the tissues. This paper reviews linear viscoelastic theory as applied to gelatin hydrogels for the purpose of formulating approaches to molecular-scale interpretation of elasticity imaging in soft biological tissues. Comparing measurements acquired under different geometries, we investigate the limitations of viscoelastic parameters acquired under various imaging conditions. Quasi-static (step-and-hold and low-frequency harmonic) stimuli applied to gels during creep and stress relaxation experiments in confined and unconfined geometries reveal continuous, bimodal distributions of respondance times. Within the linear range of responses, gelatin will behave more like a solid or fluid depending on the stimulus magnitude. Gelatin can be described statistically from a few parameters of low-order rheological models that form the basis of viscoelastic imaging. Unbiased estimates of imaging parameters are obtained only if creep data are acquired for greater than twice the highest retardance time constant and any steady-state viscous response has been eliminated. Elastic strain and retardance time images are found to provide the best combination of contrast and signal strength in gelatin. Retardance times indicate average behavior of fast (1-10 s) fluid flows and slow (50-400 s) matrix restructuring in response to the mechanical stimulus. Insofar as gelatin mimics other polymers, such as soft biological tissues, elasticity imaging can provide unique insights into complex structural and biochemical features of connectives tissues affected by disease.
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Affiliation(s)
| | - Jie Liu
- University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - Michael F. Insana
- University of California, Davis, CA, and University of Illinois at Urbana-Champaign, 405 North Mathews, Room 4247, Urbana, IL 61801, e-mail:
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Abstract
In assessing the severity of chronic liver disease, one measures either the fibrotic structure of the liver or liver function. This article reviews the methods for evaluating the severity of liver disease noninvasively by estimating function or structure.
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Affiliation(s)
- John Carl Hoefs
- Department of Medicine, University of California-Irvine University of California Medical Center, 101 City Drive, South Orange, CA 92668, USA.
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Sandrin L, Fourquet B, Hasquenoph JM, Yon S, Fournier C, Mal F, Christidis C, Ziol M, Poulet B, Kazemi F, Beaugrand M, Palau R. Transient elastography: a new noninvasive method for assessment of hepatic fibrosis. ULTRASOUND IN MEDICINE & BIOLOGY 2003; 29:1705-13. [PMID: 14698338 DOI: 10.1016/j.ultrasmedbio.2003.07.001] [Citation(s) in RCA: 1924] [Impact Index Per Article: 87.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Chronic hepatitis is accompanied by progressive deposit of hepatic fibrosis, which may lead to cirrhosis. Evaluation of liver fibrosis is, thus, of great clinical interest and, up to now, has been assessed with liver biopsy. This work aims to evaluate a new noninvasive device to quantify liver fibrosis: the shear elasticity probe or fibroscan. This device is based on one-dimensional (1-D) transient elastography, a technique that uses both ultrasound (US) (5 MHz) and low-frequency (50 Hz) elastic waves, whose propagation velocity is directly related to elasticity. The intra- and interoperator reproducibility of the technique, as well as its ability to quantify liver fibrosis, were evaluated in 106 patients with chronic hepatitis C. Liver elasticity measurements were reproducible (standardized coefficient of variation: 3%), operator-independent and well correlated (partial correlation coefficient = 0.71, p < < 0.0001) to fibrosis grade (METAVIR). The areas under the receiver operating characteristic (ROC) curves were 0.88 and 0.99 for the diagnosis of patients with significant fibrosis (>/= F2) and with cirrhosis ( = F4), respectively. The Fibroscan is a noninvasive, painless, rapid and objective method to quantify liver fibrosis.
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