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Athanasios T, Konstantinos A, Despoina D. Three-dimensional-printed replica models of bone for experimentally decoupling trabecular bone properties contribution to ultrasound propagation parameters. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2021; 149:296. [PMID: 33514143 DOI: 10.1121/10.0003048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 12/11/2020] [Indexed: 06/12/2023]
Abstract
A detailed investigation of the relationship between ultrasonic (US) properties and trabecular bone microstructure is difficult because of the great variability in the bone loss process. The aim of this work was twofold. First, to verify by compressive tests that the three-dimensional (3D)-printer is able to produce precisely and repeatedly "bone replica models" of different size and density. Following, replicas of the original specimens with two different polymers and thinned trabeculae models were used to investigate US properties (speed of sound, SOS, and backscatter coefficient), aiming to deconvolute the influence of material properties on ultrasound characteristics. The results revealed that matrix material properties influence only the magnitude of the backscatter coefficient, whereas the characteristic undulated patterns are related to the trabecular structure. Simulation of perforation and thinning of cancellous bone, associated with bone loss, showed that SOS and mechanical properties were reduced perfectly linearly with apparent density when structure deteriorated. The 3D-printed bone replicas have the potential to enable systematic investigations of the influence of structure on both acoustical and mechanical properties and evaluate changes caused by bone loss. The development of replicas from materials with properties close to those of bone will permit quantitative conclusions for trabecular bone.
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Affiliation(s)
- Tsirigotis Athanasios
- Laboratory of Biomechanics and Biomedical Engineering, Department of Mechanical Engineering & Aeronautics, University of Patras, Rio, Greece
| | - Apostolopoulos Konstantinos
- Laboratory of Biomechanics and Biomedical Engineering, Department of Mechanical Engineering & Aeronautics, University of Patras, Rio, Greece
| | - Deligianni Despoina
- Laboratory of Biomechanics and Biomedical Engineering, Department of Mechanical Engineering & Aeronautics, University of Patras, Rio, Greece
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2
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Wear KA. Mechanisms of Interaction of Ultrasound With Cancellous Bone: A Review. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2020; 67:454-482. [PMID: 31634127 PMCID: PMC7050438 DOI: 10.1109/tuffc.2019.2947755] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Ultrasound is now a clinically accepted modality in the management of osteoporosis. The most common commercial clinical devices assess fracture risk from measurements of attenuation and sound speed in cancellous bone. This review discusses fundamental mechanisms underlying the interaction between ultrasound and cancellous bone. Because of its two-phase structure (mineralized trabecular network embedded in soft tissue-marrow), its anisotropy, and its inhomogeneity, cancellous bone is more difficult to characterize than most soft tissues. Experimental data for the dependencies of attenuation, sound speed, dispersion, and scattering on ultrasound frequency, bone mineral density, composition, microstructure, and mechanical properties are presented. The relative roles of absorption, scattering, and phase cancellation in determining attenuation measurements in vitro and in vivo are delineated. Common speed of sound metrics, which entail measurements of transit times of pulse leading edges (to avoid multipath interference), are greatly influenced by attenuation, dispersion, and system properties, including center frequency and bandwidth. However, a theoretical model has been shown to be effective for correction for these confounding factors in vitro and in vivo. Theoretical and phantom models are presented to elucidate why cancellous bone exhibits negative dispersion, unlike soft tissue, which exhibits positive dispersion. Signal processing methods are presented for separating "fast" and "slow" waves (predicted by poroelasticity theory and supported in cancellous bone) even when the two waves overlap in time and frequency domains. Models to explain dependencies of scattering on frequency and mean trabecular thickness are presented and compared with measurements. Anisotropy, the effect of the fluid filler medium (marrow in vivo or water in vitro), phantoms, computational modeling of ultrasound propagation, acoustic microscopy, and nonlinear properties in cancellous bone are also discussed.
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Liu C, Li B, Li Y, Mao W, Chen C, Zhang R, Ta D. Ultrasonic Backscatter Difference Measurement of Bone Health in Preterm and Term Newborns. ULTRASOUND IN MEDICINE & BIOLOGY 2020; 46:305-314. [PMID: 31791554 DOI: 10.1016/j.ultrasmedbio.2019.10.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 10/24/2019] [Accepted: 10/26/2019] [Indexed: 06/10/2023]
Abstract
Metabolic bone disease of prematurity remains a significant problem for preterm infants. Quantitative ultrasound (QUS) has potential as a non-invasive tool for assessing bone health of newborns. The aim of this study was to assess bone health in preterm and term newborns using ultrasonic backscatter difference measurement. This study analyzed a total of 493 neonates, including 239 full-term infants (gestational age [GA] >37 wk), 201 preterm I infants (GA: 32-37 wk) and 53 extreme preterm II infants (GA <32 wk). Ultrasonic backscatter measurements were performed on the calcaneus of infants at birth, and the normalized mean of the backscatter difference spectrum (nMBD) was calculated as an ultrasonic index of neonatal bone status. Simple and multiple linear regressions were performed to determine the association of ultrasonic nMBD with GA, anthropometric characteristics and biochemical markers. Statistically significant differences in GA, anthropometric characteristics (birth weight, birth length [BL], birth head circumference and body mass index [BMI]) and biochemical markers (alkaline phosphatase, serum calcium and serum phosphate) were observed among preterm and term infants. The nMBD for term infants (median = 3.72 dB/μs, interquartile range [IR] = 1.95 dB/μs) was significantly higher than that for preterm I infants (median = 1.95 dB/μs, IR = 3.12 dB/μs), which was, in turn, significantly higher than that for preterm II infants (median = 0.19 dB/μs, IR = 3.50 dB/μs). The nMBD yielded moderate correlations (ρ = 0.57-0.62, p < 0.001) with GA and anthropometric characteristics and weak correlations (|ρ| = 0.08-0.21, p < 0.001 or not significant) with biochemical markers. Multivariate regressions revealed that only BL (p = 0.002) and BMI (p = 0.032) yielded significantly independent contributions to the nMBD measurement, and combinations of BL and BMI could explain up to 42% of the variation of nMBD in newborn infants. This study found that ultrasonic backscatter difference measurement might be helpful in bone health evaluation in preterm and term newborns. The utility of ultrasonic backscatter measurement in diagnosis of metabolic bone disease in infants should be investigated further.
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Affiliation(s)
- Chengcheng Liu
- Institute of Acoustics, School of Physics Science and Engineering, Tongji University, Shanghai, China
| | - Boyi Li
- Department of Electronic Engineering, Fudan University, Shanghai, China
| | - Ying Li
- Department of Electronic Engineering, Fudan University, Shanghai, China
| | - Weiying Mao
- Department of Neonatology, Children's Hospital of Fudan University, Shanghai, China
| | - Chao Chen
- Department of Neonatology, Children's Hospital of Fudan University, Shanghai, China
| | - Rong Zhang
- Department of Neonatology, Children's Hospital of Fudan University, Shanghai, China.
| | - Dean Ta
- Department of Electronic Engineering, Fudan University, Shanghai, China; Academy for Engineering & Technology, Fudan University, Shanghai, China
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Li Y, Li B, Li Y, Liu C, Xu F, Zhang R, Ta D, Wang W. The Ability of Ultrasonic Backscatter Parametric Imaging to Characterize Bovine Trabecular Bone. ULTRASONIC IMAGING 2019; 41:271-289. [PMID: 31307317 DOI: 10.1177/0161734619862190] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The ultrasonic backscatter technique holds the promise of characterizing bone density and microstructure. This paper conducts ultrasonic backscatter parametric imaging based on measurements of apparent integrated backscatter (AIB), spectral centroid shift (SCS), frequency slope of apparent backscatter (FSAB), and frequency intercept of apparent backscatter (FIAB) for representing trabecular bone mass and microstructure. We scanned 33 bovine trabecular bone samples using a 7.5 MHz focused transducer in a 20 mm × 20 mm region of interest (ROI) with a step interval of 0.05 mm. Images based on the ultrasonic backscatter parameters (i.e., AIB, SCS, FSAB, and FIAB) were constructed to compare with photographic images of the specimens as well as two-dimensional (2D) μ-CT images from approximately the same depth and location of the specimen. Similar structures and trabecular alignments can be observed among these images. Statistical analyses demonstrated that the means and standard deviations of the ultrasonic backscatter parameters exhibited significant correlations with bone density (|R| = 0.45-0.78, p < 0.01) and bone microstructure (|R| = 0.44-0.87, p < 0.001). Some bovine trabecular bone microstructure parameters were independently associated with the ultrasonic backscatter parameters (ΔR2 = 4.18%-44.45%, p < 0.05) after adjustment for bone apparent density (BAD). The results show that ultrasonic backscatter parametric imaging can provide a direct view of the trabecular microstructure and can reflect information about the density and microstructure of trabecular bone.
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Affiliation(s)
- Ying Li
- 1 Department of Electronic Engineering, Fudan University, Shanghai, China
| | - Boyi Li
- 1 Department of Electronic Engineering, Fudan University, Shanghai, China
| | - Yifang Li
- 1 Department of Electronic Engineering, Fudan University, Shanghai, China
| | - Chengcheng Liu
- 2 Institute of Acoustics, Tongji University, Shanghai, China
| | - Feng Xu
- 1 Department of Electronic Engineering, Fudan University, Shanghai, China
| | - Rong Zhang
- 3 Department of Neonatology, Children's Hospital of Fudan University, Shanghai, China
| | - Dean Ta
- 1 Department of Electronic Engineering, Fudan University, Shanghai, China
- 4 Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention (MICCAI) of Shanghai, Shanghai, China
- 5 Human Phenome Institute, Fudan University, Shanghai, China
| | - Weiqi Wang
- 1 Department of Electronic Engineering, Fudan University, Shanghai, China
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Lee KI. Correlations of the frequency dependence of the ultrasonic backscatter coefficient with the bone volume fraction and the trabecular thickness in bovine trabecular bone: Application of the binary mixture model. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 145:EL393. [PMID: 31153347 DOI: 10.1121/1.5107435] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 04/24/2019] [Indexed: 06/09/2023]
Abstract
The ultrasonic backscatter coefficient and the exponent n (frequency dependence of the backscatter coefficient) were measured in 24 bovine femoral trabecular bone samples. The binary mixture model for ultrasonic scattering from trabecular bone was applied to predict the variations of the ultrasound parameters with the bone volume fraction (BV/TV) and the trabecular thickness (Tb.Th) in trabecular bone. The backscatter coefficient exhibited significant, positive correlations with the BV/TV (R = 0.82) and the Tb.Th (R = 0.79). In contrast, the exponent n was found to be significantly, negatively correlated with the BV/TV (R = -0.77) and the Tb.Th, (R = -0.71).
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Affiliation(s)
- Kang Il Lee
- Department of Physics, Kangwon National University, Chuncheon 24341, Republic of
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6
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Liu C, Li B, Diwu Q, Li Y, Zhang R, Ta D, Wang W. Relationships of Ultrasonic Backscatter With Bone Densities and Microstructure in Bovine Cancellous Bone. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2018; 65:2311-2321. [PMID: 30575524 DOI: 10.1109/tuffc.2018.2872084] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
This study was designed to investigate the associations among ultrasonic backscatter, bone densities, and microstructure in bovine cancellous bone. Ultrasonic backscatter measurements were performed on 33 bovine cancellous bone specimens with a 2.25-MHz transducer. Ultrasonic apparent backscatter parameters ("apparent" means not compensating for ultrasonic attenuation and diffraction) were calculated with optimal signals of interest. The results showed that ultrasonic backscatter was significantly related to bone densities and microstructure ( R2 = 0.17 -0.88 and ). After adjusting the correlations by bone mineral density (BMD), the bone apparent density (BAD) and some trabecular structural features still contributed significantly to the adjusted correlations, with moderate additional variance explained ( ∆R2 = 9.7 % at best). Multiple linear regressions revealed that both BAD and trabecular structure contributed significantly and independently to the prediction of ultrasound backscatter (adjusted R2 = 0.75 -0.89 and ), explaining an additional 14% of the variance at most, compared with that of BMD measurements alone. The results proved that ultrasonic backscatter was primarily determined by BAD, not BMD, but the combination of bone structure and densities could achieve encouragingly better performances (89% of the variance explained at best) in predicting backscatter properties. This study demonstrated that ultrasonic apparent backscatter might provide additional density and structural features unrelated to current BMD measurement. Therefore, we suggest that ultrasonic backscatter measurement could play a more important role in cancellous bone evaluation.
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7
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Hoffmeister BK, Viano AM, Huang J, Fairbanks LC, Ebron SC, Moore JT, Ankersen JP, Huber MT, Diaz AA. Ultrasonic backscatter difference measurements of cancellous bone from the human femur: Relation to bone mineral density and microstructure. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2018; 143:3642. [PMID: 29960442 PMCID: PMC6014850 DOI: 10.1121/1.5043385] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 05/21/2018] [Accepted: 06/02/2018] [Indexed: 05/26/2023]
Abstract
Ultrasonic backscatter techniques are being developed to detect changes in cancellous bone caused by osteoporosis. One technique, called the backscatter difference technique, measures the power difference between two portions of a backscatter signal. The goal of the present study is to investigate how bone mineral density (BMD) and the microstructure of human cancellous bone influence four backscatter difference parameters: the normalized mean of the backscatter difference (nMBD) spectrum, the normalized slope of the backscatter difference spectrum, the normalized intercept of the backscatter difference spectrum, and the normalized backscatter amplitude ratio (nBAR). Ultrasonic measurements were performed with a 3.5 MHz broadband transducer on 54 specimens of human cancellous bone from the proximal femur. Volumetric BMD and the microstructural characteristics of the specimens were measured using x-ray micro-computed tomography. Of the four ultrasonic parameters studied, nMBD and nBAR demonstrated the strongest univariate correlations with density and microstructure. Multivariate analyses indicated that nMBD and nBAR depended on trabecular separation and possibly other microstructural characteristics of the specimens independently of BMD. These findings suggest that nMBD and nBAR may be sensitive to changes in the density and microstructure of bone caused by osteoporosis.
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Affiliation(s)
| | - Ann M Viano
- Department of Physics, Rhodes College, Memphis, Tennessee 38112, USA
| | - Jinsong Huang
- College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
| | - Luke C Fairbanks
- Department of Physics, Rhodes College, Memphis, Tennessee 38112, USA
| | - Sheldon C Ebron
- Department of Physics, Rhodes College, Memphis, Tennessee 38112, USA
| | - Joshua T Moore
- Department of Physics, Rhodes College, Memphis, Tennessee 38112, USA
| | - Jordan P Ankersen
- Department of Physics, Rhodes College, Memphis, Tennessee 38112, USA
| | - Matthew T Huber
- Department of Physics, Rhodes College, Memphis, Tennessee 38112, USA
| | - Abel A Diaz
- Department of Physics, Rhodes College, Memphis, Tennessee 38112, USA
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8
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Wear KA, Nagaraja S, Dreher ML, Sadoughi S, Zhu S, Keaveny TM. Relationships among ultrasonic and mechanical properties of cancellous bone in human calcaneus in vitro. Bone 2017; 103:93-101. [PMID: 28666970 PMCID: PMC6941483 DOI: 10.1016/j.bone.2017.06.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 06/01/2017] [Accepted: 06/26/2017] [Indexed: 11/15/2022]
Abstract
Clinical bone sonometers applied at the calcaneus measure broadband ultrasound attenuation and speed of sound. However, the relation of ultrasound measurements to bone strength is not well-characterized. Addressing this issue, we assessed the extent to which ultrasonic measurements convey in vitro mechanical properties in 25 human calcaneal cancellous bone specimens (approximately 2×4×2cm). Normalized broadband ultrasound attenuation, speed of sound, and broadband ultrasound backscatter were measured with 500kHz transducers. To assess mechanical properties, non-linear finite element analysis, based on micro-computed tomography images (34-micron cubic voxel), was used to estimate apparent elastic modulus, overall specimen stiffness, and apparent yield stress, with models typically having approximately 25-30 million elements. We found that ultrasound parameters were correlated with mechanical properties with R=0.70-0.82 (p<0.001). Multiple regression analysis indicated that ultrasound measurements provide additional information regarding mechanical properties beyond that provided by bone quantity alone (p≤0.05). Adding ultrasound variables to linear regression models based on bone quantity improved adjusted squared correlation coefficients from 0.65 to 0.77 (stiffness), 0.76 to 0.81 (apparent modulus), and 0.67 to 0.73 (yield stress). These results indicate that ultrasound can provide complementary (to bone quantity) information regarding mechanical behavior of cancellous bone.
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Affiliation(s)
- Keith A Wear
- U.S. Food and Drug Administration, Center for Devices and Radiological Health, 10903 New Hampshire Blvd., Silver Spring, MD 20993, USA.
| | - Srinidhi Nagaraja
- U.S. Food and Drug Administration, Center for Devices and Radiological Health, 10903 New Hampshire Blvd., Silver Spring, MD 20993, USA.
| | - Maureen L Dreher
- U.S. Food and Drug Administration, Center for Devices and Radiological Health, 10903 New Hampshire Blvd., Silver Spring, MD 20993, USA.
| | - Saghi Sadoughi
- Orthopaedic Biomechanics Laboratory, Department of Mechanical Engineering, 5124 Etcheverry Hall, Mailstop 1740, University of California at Berkeley, Berkeley, CA 94720-1740, USA.
| | - Shan Zhu
- Orthopaedic Biomechanics Laboratory, Department of Mechanical Engineering, 5124 Etcheverry Hall, Mailstop 1740, University of California at Berkeley, Berkeley, CA 94720-1740, USA.
| | - Tony M Keaveny
- Orthopaedic Biomechanics Laboratory, Department of Mechanical Engineering, 5124 Etcheverry Hall, Mailstop 1740, University of California at Berkeley, Berkeley, CA 94720-1740, USA; Department of Bioengineering, University of California, Berkeley, CA, USA.
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9
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Nagatani Y, Guipieri S, Nguyen VH, Chappard C, Geiger D, Naili S, Haїat G. Three-dimensional Simulation of Quantitative Ultrasound in Cancellous Bone Using the Echographic Response of a Metallic Pin. ULTRASONIC IMAGING 2017; 39:295-312. [PMID: 28492108 DOI: 10.1177/0161734617698648] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Degenerative discopathy is a common pathology that may require spine surgery. A metallic cylindrical pin is inserted into the vertebral body to maintain soft tissues and may be used as a reflector of ultrasonic wave to estimate bone density. The first aim of this paper is to validate a three-dimensional (3-D) model to simulate the ultrasonic propagation in a trabecular bone sample in which a metallic pin has been inserted. We also aim at determining the effect of changes of bone volume fraction (BV/TV) and of positioning errors on the quantitative ultrasound (QUS) parameters in this specific configuration. The approach consists in coupling finite-difference time-domain simulation with X-ray microcomputed tomography. The correlation coefficient between experimental and simulated speed of sound (SOS)-respectively, broadband ultrasonic attenuation (BUA)-was equal to 0.90 (respectively, 0.55). The results show a significant correlation of SOS with BV/TV ( R = 0.82), while BUA values exhibit a nonlinear behavior versus BV/TV. The orientation of the pin should be controlled with an accuracy of around 1° to obtain accurate results. The results indicate that using the ultrasonic wave reflected by a pin has a potential to estimate the bone density. SOS is more reliable than BUA due to its lower sensitivity to the tilt angle.
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Affiliation(s)
- Yoshiki Nagatani
- 1 Department of Electronics, Kobe City College of Technology, Kobe, Japan
- 2 Laboratoire de Modélisation et Simulation Multi Echelle, UMR CNRS 8208, Université Paris-Est, Créteil, France
| | - Séraphin Guipieri
- 2 Laboratoire de Modélisation et Simulation Multi Echelle, UMR CNRS 8208, Université Paris-Est, Créteil, France
| | - Vu-Hieu Nguyen
- 2 Laboratoire de Modélisation et Simulation Multi Echelle, UMR CNRS 8208, Université Paris-Est, Créteil, France
| | | | - Didier Geiger
- 2 Laboratoire de Modélisation et Simulation Multi Echelle, UMR CNRS 8208, Université Paris-Est, Créteil, France
| | - Salah Naili
- 2 Laboratoire de Modélisation et Simulation Multi Echelle, UMR CNRS 8208, Université Paris-Est, Créteil, France
| | - Guillaume Haїat
- 4 CNRS, Laboratoire de Modélisation et Simulation Multi Echelle, UMR CNRS 8208, Créteil, France
- 5 École de technologie supérieure, Montreal, QC, Canada
- 6 Research Center, Hôpital du Sacré-Cœur de Montréal, Montreal, QC, Canada
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10
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Potsika VT, Protopappas VC, Grivas KN, Gortsas TV, Raum K, Polyzos DK, Fotiadis DI. Numerical evaluation of the backward propagating acoustic field in healing long bones. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2017; 142:962. [PMID: 28863592 DOI: 10.1121/1.4998722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The propagation of ultrasound in healing long bones induces complex scattering phenomena due to the interaction of an ultrasonic wave with the composite nature of callus and osseous tissues. This work presents numerical simulations of ultrasonic propagation in healing long bones using the boundary element method aiming to provide insight into the complex scattering mechanisms and better comprehend the state of bone regeneration. Numerical models of healing long bones are established based on scanning acoustic microscopy images from successive postoperative weeks considering the effect of the nonhomogeneous callus structure. More specifically, the scattering amplitude and the acoustic pressure variation are calculated in the backward direction to investigate their potential to serve as quantitative and qualitative indicators for the monitoring of the bone healing process. The role of the excitation frequency is also examined considering frequencies in the range 0.2-1 MHz. The results indicate that the scattering amplitude decreases at later stages of healing compared to earlier stages of healing. Also, the acoustic pressure could provide supplementary qualitative information on the interaction of the scattered energy with bone and callus.
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Affiliation(s)
- Vassiliki T Potsika
- Unit of Medical Technology and Intelligent Information Systems, Department of Materials Science and Engineering, University of Ioannina, GR 45110 Ioannina, Greece
| | - Vasilios C Protopappas
- Unit of Medical Technology and Intelligent Information Systems, Department of Materials Science and Engineering, University of Ioannina, GR 45110 Ioannina, Greece
| | - Konstantinos N Grivas
- Department of Mechanical Engineering and Aeronautics, University of Patras, GR 26500 Patras, Greece
| | - Theodoros V Gortsas
- Department of Mechanical Engineering and Aeronautics, University of Patras, GR 26500 Patras, Greece
| | - Kay Raum
- Berlin-Brandenburg School for Regenerative Therapies, Charité-Universitätsmedizin Berlin, AugustenburgerPlatz 1, 13353 Berlin, Germany
| | - Demosthenes K Polyzos
- Department of Mechanical Engineering and Aeronautics, University of Patras, GR 26500 Patras, Greece
| | - Dimitrios I Fotiadis
- Unit of Medical Technology and Intelligent Information Systems, Department of Materials Science and Engineering, University of Ioannina, GR 45110 Ioannina, Greece
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11
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Hoffmeister BK, Mcpherson JA, Smathers MR, Spinolo PL, Sellers ME. Ultrasonic backscatter from cancellous bone: the apparent backscatter transfer function. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2015; 62:2115-25. [PMID: 26683412 DOI: 10.1109/tuffc.2015.007299] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Ultrasonic backscatter techniques are being developed to detect changes in cancellous bone caused by osteoporosis. Many techniques are based on measurements of the apparent backscatter transfer function (ABTF), which represents the backscattered power from bone corrected for the frequency response of the measurement system. The ABTF is determined from a portion of the backscatter signal selected by an analysis gate of width τw delayed by an amount τd from the start of the signal. The goal of this study was to characterize the ABTF for a wide range of gate delays (1 μs ≤ τd ≤ 6 μs) and gate widths (1 μs ≤ τw ≤ 6 μs). Measurements were performed on 29 specimens of human cancellous bone in the frequency range 1.5 to 6.0 MHz using a broadband 5-MHz transducer. The ABTF was found to be an approximately linear function of frequency for most choices of τd and τw. Changes in τd and τw caused the frequency-averaged ABTF [quantified by apparent integrated backscatter (AIB)] and the frequency dependence of the ABTF [quantified by frequency slope of apparent backscatter (FSAB)] to change by as much as 24.6 dB and 6.7 dB/MHz, respectively. τd strongly influenced the measured values of AIB and FSAB and the correlation of AIB with bone density (-0.95 ≤ R ≤ +0.68). The correlation of FSAB with bone density was influenced less strongly by τd (-0.97 ≤ R ≤ -0.87). τw had a weaker influence than τd on the measured values of AIB and FSAB and the correlation of these parameters with bone density.
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12
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Hoffmeister BK, Spinolo PL, Sellers ME, Marshall PL, Viano AM, Lee SR. Effect of intervening tissues on ultrasonic backscatter measurements of bone: An in vitro study. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2015; 138:2449-57. [PMID: 26520327 PMCID: PMC4627934 DOI: 10.1121/1.4931906] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 09/07/2015] [Accepted: 09/12/2015] [Indexed: 05/28/2023]
Abstract
Ultrasonic backscatter techniques are being developed to diagnose osteoporosis. Tissues that lie between the transducer and the ultrasonically interrogated region of bone may produce errors in backscatter measurements. The goal of this study is to investigate the effects of intervening tissues on ultrasonic backscatter measurements of bone. Measurements were performed on 24 cube shaped specimens of human cancellous bone using a 5 MHz transducer. Measurements were repeated after adding a 1 mm thick plate of cortical bone to simulate the bone cortex and a 3 cm thick phantom to simulate soft tissue at the hip. Signals were analyzed to determine three apparent backscatter parameters (apparent integrated backscatter, frequency slope of apparent backscatter, and frequency intercept of apparent backscatter) and three backscatter difference parameters [normalized mean backscatter difference (nMBD), normalized slope of the backscatter difference, and normalized intercept of the backscatter difference]. The apparent backscatter parameters were impacted significantly by the presence of intervening tissues. In contrast, the backscatter difference parameters were not affected by intervening tissues. However, only one backscatter difference parameter, nMBD, demonstrated a strong correlation with bone mineral density. Thus, among the six parameters tested, nMBD may be the best choice for in vivo backscatter measurements of bone when intervening tissues are present.
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Affiliation(s)
| | - P Luke Spinolo
- Department of Physics, Rhodes College, Memphis, Tennessee 38112, USA
| | - Mark E Sellers
- Department of Physics, Rhodes College, Memphis, Tennessee 38112, USA
| | - Peyton L Marshall
- Department of Physics, Rhodes College, Memphis, Tennessee 38112, USA
| | - Ann M Viano
- Department of Physics, Rhodes College, Memphis, Tennessee 38112, USA
| | - Sang-Rok Lee
- Department of Kinesiology and Dance, New Mexico State University, Las Cruces, New Mexico 88003, USA
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Abstract
Bone quality is determined by a variety of compositional, micro- and ultrastructural properties of the mineralized tissue matrix. In contrast to X-ray-based methods, the interaction of acoustic waves with bone tissue carries information about elastic and structural properties of the tissue. Quantitative ultrasound (QUS) methods represent powerful alternatives to ionizing x-ray based assessment of fracture risk. New in vivo applicable methods permit measurements of fracture-relevant properties, [eg, cortical thickness and stiffness at fragile anatomic regions (eg, the distal radius and the proximal femur)]. Experimentally, resonance ultrasound spectroscopy and acoustic microscopy can be used to assess the mesoscale stiffness tensor and elastic maps of the tissue matrix at microscale resolution, respectively. QUS methods, thus, currently represent the most promising approach for noninvasive assessment of components of fragility beyond bone mass and bone microstructure providing prospects for improved assessment of fracture risk.
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Affiliation(s)
- Kay Raum
- Julius Wolff Institute & Berlin-Brandenburg School for Regenerative Therapies, Augustenburger Platz 1, 13353, Berlin, Germany,
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Lee KI. Dependences of quantitative ultrasound parameters on frequency and porosity in water-saturated nickel foams. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2014; 135:EL61-7. [PMID: 25234916 DOI: 10.1121/1.4862878] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The frequency-dependent phase velocity, attenuation coefficient, and backscatter coefficient were measured from 0.8 to 1.2 MHz in 24 water-saturated nickel foams as trabecular-bone-mimicking phantoms. The power law fits to the measurements showed that the phase velocity, the attenuation coefficient, and the backscatter coefficient were proportional to the frequency with exponents n of 0.95, 1.29, and 3.18, respectively. A significant linear correlation was found between the phase velocity at 1.0 MHz and the porosity. In contrast, the best regressions for the normalized broadband ultrasound attenuation and the backscatter coefficient at 1.0 MHz were obtained with the polynomial fits of second order.
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Affiliation(s)
- Kang Il Lee
- Department of Physics, Kangwon National University, Chuncheon 200-701, Republic of Korea
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Wear KA, Nagaraja S, Dreher ML, Gibson SL. Relationships of quantitative ultrasound parameters with cancellous bone microstructure in human calcaneus in vitro. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2012; 131:1605-12. [PMID: 22352530 PMCID: PMC6931152 DOI: 10.1121/1.3672701] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Ultrasound parameters (attenuation, phase velocity, and backscatter), bone mineral density (BMD), and microarchitectural features were measured on 29 human cancellous calcaneus samples in vitro. Regression analysis was performed to predict ultrasound parameters from BMD and microarchitectural features. The best univariate predictors of the ultrasound parameters were the indexes of bone quantity: BMD and bone volume fraction (BV/TV). The most predictive univariate models for attenuation, phase velocity, and backscatter coefficient yielded adjusted squared correlation coefficients of 0.69-0.73. Multiple regression models yielded adjusted correlation coefficients of 0.74-0.83. Therefore attenuation, phase velocity, and backscatter are primarily determined by bone quantity, but multiple regression models based on bone quantity plus microarchitectural features achieve slightly better predictive performance than models based on bone quantity alone.
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Affiliation(s)
- Keith A Wear
- U.S. Food and Drug Administration, Center for Devices and Radiological Health, 10903 New Hampshire Boulevard, Silver Spring, Maryland 20993, USA.
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Il Lee K, Joo Choi M. Frequency-dependent attenuation and backscatter coefficients in bovine trabecular bone from 0.2 to 1.2 MHz. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2012; 131:EL67-73. [PMID: 22280732 DOI: 10.1121/1.3671064] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The frequency-dependent attenuation and backscatter coefficients were measured in 25 bovine femoral trabecular bone samples from 0.2 to 1.2 MHz. When the average attenuation coefficient was fitted to a nonlinear power law α(f)=α(0)+α(1)f(n), the exponent n was found to be 1.65. In contrast, the average backscatter coefficient was fitted to a power law η(f)=η(1)f(n) and the exponent n was measured as 3.25. The apparent bone density was significantly correlated with the parameter α(1) (0.2-0.7 MHz: r = 0.852, 0.6-1.2 MHz: r = 0.832) as well as the backscatter coefficient (0.5 MHz: r = 0.751, 1.0 MHz: r = 0.808).
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Affiliation(s)
- Kang Il Lee
- Department of Physics, Kangwon National University, Chuncheon 200-701, Republic of Korea
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Hoffmeister BK. Frequency dependence of apparent ultrasonic backscatter from human cancellous bone. Phys Med Biol 2011; 56:667-83. [DOI: 10.1088/0031-9155/56/3/009] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Kantelhardt SR, Larsen J, Bockermann V, Schillinger W, Giese A, Rohde V. Intraosseous ultrasonography to determine the accuracy of drill hole positioning prior to the placement of pedicle screws: an experimental study. J Neurosurg Spine 2009; 11:673-80. [DOI: 10.3171/2009.6.spine08640] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
Dorsal fixation with rods and pedicle screws (PSs) is the most frequently used surgery to correct traumatic and degenerative instabilities of the human spine. Prior to screw placement, screw holes are drilled along the vertebral pedicles. Despite the use of a variety of techniques, misplacement of screw holes, and consequently of the PSs, is a common problem. The authors investigated the usefulness of an intraspinal, intraosseous ultrasonography technique to determine the accuracy of drill hole positioning.
Methods
An endovascular ultrasound transducer was used for the intraluminal scanning of bore holes in trabecular bovine bone, 12 pedicle drill holes in cadaveric human spine, and 4 pedicle drill holes in a patient undergoing thoracic spondylodesis. Seven of the experimental bore holes in the cadaveric spine were placed optimally (that is, inside the pedicle) and 5 were placed suboptimally (breaching the medial or lateral cortical surface of the pedicle). Computed tomography scans were obtained in the patient and cadaveric specimen after the procedure.
Results
The image quality achieved in examinations of native bovine bone tissue, the formalin-fixed human spine specimen, and human vertebrae in vivo was equal. The authors endosonographically identified correct intrapedicular and intravertebral positions as well as poor (cortex breached) placement of drill holes.
Conclusions
Intraosseous ultrasonography is a promising technique for the investigation of PS holes prior to screw implantation, and may add to the safety of PS placement.
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Wear KA. Mechanisms for attenuation in cancellous-bone-mimicking phantoms. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2008; 55:2418-25. [PMID: 19049921 PMCID: PMC6935503 DOI: 10.1109/tuffc.949] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Broadband ultrasound attenuation (BUA) in cancellous bone is useful for prediction of osteoporotic fracture risk, but its causes are not well understood. To investigate attenuation mechanisms, 9 cancellous-bone-mimicking phantoms containing nylon filaments (simulating bone trabeculae) embedded within soft-tissue-mimicking fluid (simulating marrow) were interrogated. The measurements of frequency-dependent attenuation coefficient had 3 separable components: 1) a linear (with frequency) component attributable to absorption in the soft-tissue-mimicking fluid, 2) a quasilinear (with frequency) component, which may include absorption in and longitudinal-shear mode conversion by the nylon filaments, and 3) a nonlinear (with frequency) component, which may be attributable to longitudinal-longitudinal scattering by the nylon filaments. The slope of total linear (with frequency) attenuation coefficient (sum of components #1 and #2) versus frequency was found to increase linearly with volume fraction, consistent with reported measurements on cancellous bone. Backscatter coefficient measurements in the 9 phantoms supported the claim that the nonlinear (with frequency) component of attenuation coefficient (component #3) was closely associated with longitudinal-longitudinal scattering. This work represents the first experimental separation of these 3 components of attenuation in cancellous bone-mimicking phantoms.
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Affiliation(s)
- Keith A Wear
- U.S. Food and Drug Administration, Center for Devices and Radiological Health, Silver Spring, MD, USA.
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Wear KA, Padilla F, Laugier P. Comparison of the Faran Cylinder Model and the Weak Scattering Model for predicting the frequency dependence of backscatter from human cancellous femur in vitro. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2008; 124:1408-10. [PMID: 19045632 PMCID: PMC9341363 DOI: 10.1121/1.2956480] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
This letter presents the first side-by-side comparison of the Faran Cylinder Model and the Weak Scattering Model for predicting backscatter from human femur. Both models are applied to the same dataset of frequency-dependent backscatter coefficients from 26 human femur cancellous bone samples in vitro. The Faran Cylinder Model predicts a slightly slower rate of increase of backscatter with frequency than the Weak Scattering Model, but both models are in reasonable agreement with the data and with each other, given the uncertainty in the measurements.
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Affiliation(s)
- Keith A Wear
- Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland 20993, USA
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Wear KA. Ultrasonic scattering from cancellous bone: a review. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2008; 55:1432-41. [PMID: 18986932 PMCID: PMC6935504 DOI: 10.1109/tuffc.2008.818] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
This paper reviews theory, measurements, and computer simulations of scattering from cancellous bone reported by many laboratories. Three theoretical models (binary mixture, Faran cylinder, and weak scattering) for scattering from cancellous bone have demonstrated some consistency with measurements of backscatter. Backscatter is moderately correlated with bone mineral density in human calcaneus in vitro (r(2) = 0.66 - 0.68). Backscatter varies approximately as frequency cubed and trabecular thickness cubed in human calcaneus and femur in vitro. Backscatter from human calcaneus and bovine tibia exhibits substantial anisotropy. So far, backscatter has demonstrated only modest clinical utility. Computer simulation models have helped to elucidate mechanisms underlying scattering from cancellous bones.
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Affiliation(s)
- K A Wear
- Center for Devices & Radiol. Health, U.S. Food & Drug Adm., Silver Spring, MD, USA.
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Hoffmeister BK, Johnson DP, Janeski JA, Keedy DA, Steinert BW, Viano AM, Kaste SC. Ultrasonic characterization of human cancellous bone in vitro using three different apparent backscatter parameters in the frequency range 0.6-15.0 mhz. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2008; 55:1442-52. [PMID: 18986933 DOI: 10.1109/tuffc.2008.819] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Ultrasonic techniques based on measurements of apparent backscatter may provide a useful means for diagnosing bone diseases such as osteoporosis. The term "apparent" means that the backscattered signals are not compensated for the frequency-dependent effects of attenuation and diffraction. We performed in vitro apparent backscatter measurements on 23 specimens of human cancellous bone prepared from the left and right femoral heads of seven donors. A mechanical scanning system was used to obtain backscattered signals from each specimen at several sites. Scans were performed using five different ultrasonic transducers with center frequencies of 1, 2.25, 5, 7.5, and 10 MHz. The -6 dB bandwidths of these transducers covered a frequency range of 0.6-15.0 MHz. The backscattered signals were analyzed to determine three ultrasonic parameters: apparent integrated backscatter (AIB), frequency slope of apparent backscatter (FSAB), and time slope of apparent backscatter (TSAB). Linear regression analysis was used to examine the correlation of these ultrasonic parameters with five measured physical characteristics of the specimens: mass density, X-ray bone mineral density, Young's modulus, yield strength, and ultimate strength. A total of 75 such correlations were examined (3 ultrasonic parameters x 5 specimen characteristics x 5 transducers). Good correlations were observed for AIB using the 5 MHz (r = 0.70 - 0.89) and 7.5 MHz (r = 0.75-0.93) transducers; for FSAB using the 2.25 MHz (r = 0.70 - 0.88), 5 MHz (r = 0.79 - 0.94), and 7.5 MHz (r = 0.80 - 0.92) transducers; and for TSAB using the 5 MHz (r = 0.68 - 0.89), 7.5 MHz (r = 0.75 - 0.89), and 10 MHz (r = 0.75 - 0.92) transducers.
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Padilla F, Jenson F, Bousson V, Peyrin F, Laugier P. Relationships of trabecular bone structure with quantitative ultrasound parameters: in vitro study on human proximal femur using transmission and backscatter measurements. Bone 2008; 42:1193-202. [PMID: 18396124 DOI: 10.1016/j.bone.2007.10.024] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Revised: 09/28/2007] [Accepted: 10/23/2007] [Indexed: 10/22/2022]
Abstract
The present study was designed to assess the relationships between QUS parameters and bone density or microarchitecture on samples of human femoral trabecular bone. The normalized slope of the frequency-dependent attenuation (nBUA), the speed of sound (SOS) and the broadband ultrasound backscatter coefficient (BUB) were measured on 37 specimens of pure trabecular bones removed from upper parts of fresh human femurs. Bone mineral density (BMD) was assessed using a clinical scanner. Finally, 8 mm diameter cylindrical cores were extracted from the specimens and their microarchitecture was reconstructed after synchrotron radiation microtomography experiments (isotropic resolution of 10 microm). A large number of microarchitectural parameters were computed, describing morphology, connectivity and geometry of the specimens. BMD correlated with all the microarchitectural parameters and the number of significant correlations was found among the architectural parameters themselves. All QUS parameters were significantly correlated to BMD (R=0.83 for nBUA, R=0.81 for SOS and R=0.69 for BUB) and to microarchitectural parameters (R=-0.79 between nBUA and Tb.Sp, R=-0.81 between SOS and Tb.Sp, R=-0.65 between BUB and BS/BV). Using multivariate model, it was found that microstructural parameters adds 10%, 19%, and 4% to the respective BMD alone contribution for the three variables BUA, SOS and BUB. Moreover, the RMSE was reduced by up to 50% for SOS, by up to 21% for nBUA and up to 11% when adding structural variables to BMD in explaining QUS results. Given the sample, which is not osteoporosis-enriched, the added contribution is quite substantial. The variability of SOS was indeed completely explained by a multivariate model including BMD and independent structural parameters (R(2)=0.94). The inverse problem on the data presented here has been addressed using simple and multiple linear regressions. It was shown that the predictions (in terms of R(2) or RMSE) of microarchitectural parameters was not enhanced when combining 2 or 3 QUS in multiple linear regressions compared to the prediction obtained with one QUS parameter alone. The best model was found for the prediction of Tb.Th() from BUA (R(2)=0.58, RMSE=17 microm). Given the high values of RMSE, these linear models appear of limited clinical value, suggesting that appropriate models have to be derived in order to solve the inverse problem. In this regard, a very interesting multivariate model was found for nBUA and BUB with Tb.Th and Tb.N, in agreement with single scattering theories by random medium. However, the source of residual variability of nBUA and BUB (15% and 45% respectively) remained unexplained.
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Affiliation(s)
- F Padilla
- CNRS, UMR7623 LIP, Paris, F-75006 France.
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Wear KA. The effect of phase cancellation on estimates of broadband ultrasound attenuation and backscatter coefficient in human calcaneus in vitro. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2008; 55:384-90. [PMID: 18334344 PMCID: PMC6931155 DOI: 10.1109/tuffc.2008.656] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Broadband ultrasound attenuation (BUA) is a clinically proven indicator of osteoporotic fracture risk. BUA measurements are typically performed in throughtransmission with single-element phase sensitive (PS) receivers and therefore can be compromised by phase cancellation artifact. Phase-insensitive (PI) receivers suppress phase cancellation artifact. To study the effect of phase cancellation on BUA measurements, through-transmission measurements were performed on 16 human calcaneus samples in vitro using a two-dimensional receiver array that enabled PS and PI BUA estimation. The means plus or minus standard deviations for BUA measurements were 22.1 +/- 15.8 dB/MHz (PS) and 17.6 +/- 7.2 dB/MHz (PI), suggesting that, on the average, approximately 20% of PS BUA values in vitro can be attributed to phase cancellation artifact. Therefore, although cortical plates are often regarded as the primary source of phase cancellation artifact, the heterogeneity of cancellous bone in the calcaneal interior may also be a significant source. Backscatter coefficient estimates in human calcaneus that are based on PS attenuation compensation overestimate 1) average magnitude of backscatter coefficient at 500 kHz by a factor of about 1.6 +/- 0.3 and 2) average exponent (n) of frequency dependence by about 0.34 +/- 0.12 (where backscatter coefficient is fit to a power law form proportional to frequency to the nth power).
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Affiliation(s)
- Keith A Wear
- US Food and Drug Administration, Silver Spring, MD 20993-0002, USA.
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25
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Apostolopoulos KN, Deligianni DD. Influence of microarchitecture alterations on ultrasonic backscattering in an experimental simulation of bovine cancellous bone aging. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2008; 123:1179-87. [PMID: 18247917 DOI: 10.1121/1.2822291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
An experimental model which can simulate physical changes that occur during aging was developed in order to evaluate the effects of change of mineral content and microstructure on ultrasonic properties of bovine cancellous bone. Timed immersion in hydrochloric acid was used to selectively alter the mineral content. Scanning electron microscopy and histological staining of the acid-treated trabeculae demonstrated a heterogeneous structure consisting of a mineralized core and a demineralized layer. The presence of organic matrix contributed very little to normalized broadband ultrasound attenuation (nBUA) and speed of sound. All three ultrasonic parameters, speed of sound, nBUA and backscatter coefficient, were sensitive to changes in apparent density of bovine cancellous bone. A two-component model utilizing a combination of two autocorrelation functions (a densely populated model and a spherical distribution) was used to approximate the backscatter coefficient. The predicted attenuation due to scattering constituted a significant part of the measured total attenuation (due to both scattering and absorption mechanisms) for bovine cancellous bone. Linear regression, performed between trabecular thickness values and estimated from the model correlation lengths, showed significant linear correlation, with R(2)=0.81 before and R(2)=0.80 after demineralization. The accuracy of estimation was found to increase with trabecular thickness.
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Affiliation(s)
- K N Apostolopoulos
- Biomedical Engineering Laboratory, Department of Mechanical Engineering & Aeronautics, University of Patras, Rion 26500, Greece
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Laugier P. Instrumentation for in vivo ultrasonic characterization of bone strength. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2008; 55:1179-96. [PMID: 18599407 DOI: 10.1109/tuffc.2008.782] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Although it has been more than 20 years since the first recorded use of a quantitative ultrasound (QUS) technology to predict bone fragility, the field has not yet reached its maturity. QUS has the potential to predict fracture risk in several clinical circumstances and has the advantages of being nonionizing, inexpensive, portable, highly acceptable to patients, and repeatable. However, the wide dissemination of QUS in clinical practice is still limited and suffering from the absence of clinical consensus on how to integrate QUS technologies in bone densitometry armamentarium. Several critical issues need to be addressed to develop the role of QUS within rheumatology. These include issues of technologies adapted to measure the central skeleton, data acquisition, and signal processing procedures to reveal bone properties beyond bone mineral quantity and elucidation of the complex interaction between ultrasound and bone structure. This article reviews the state-of-the art in technological developments applied to assess bone strength in vivo. We describe generic measurement and signal processing methods implemented in clinical ultrasound devices, the devices and their practical use, and performance measures. The article also points out the present limitations, especially those related to the absence of standardization, and the lack of comprehensive theoretical models. We conclude with suggestions of future lines and trends in technology challenges and research areas such as new acquisition modes, advanced signal processing techniques, and modelization.
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Affiliation(s)
- Pascal Laugier
- Université Pierre et Marie Curie-Paris 5, Laboratoire d'Imagerie Paramétrique, Paris, France.
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