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Du H, Yousefian O, Horn T, Muller M. Evaluation of Structural Anisotropy in a Porous Titanium Medium Mimicking Trabecular Bone Structure Using Mode-Converted Ultrasonic Scattering. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2020; 67:1017-1024. [PMID: 31940527 PMCID: PMC7301879 DOI: 10.1109/tuffc.2019.2963162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The mode-converted (longitudinal to transverse, L-T) ultrasonic scattering method was utilized to characterize the structural anisotropy of a phantom mimicking the structural properties of trabecular bone. The sample was fabricated using metal additive manufacturing from high-resolution computed tomography (CT) images of a sample of trabecular horse bone with strong anisotropy. Two focused transducers were used to perform the L-T ultrasonic measurements. A normal incidence transducer was used to transmit longitudinal ultrasonic waves into the sample, while the scattered transverse signals were received by an oblique incidence transducer. At multiple locations on the sample, four L-T measurements were performed by collecting ultrasonic scattering from four directions. The amplitude of the root mean square (rms) of the collected ultrasonic scattering signals was calculated for each L-T measurement. The ratios of rms amplitudes for L-T measurements in different directions were calculated to characterize the anisotropy of sample. The results show that the amplitude of L-T converted scattering is highly dependent on the direction of microstructural anisotropy. A strong anisotropy of the microstructure was observed, which coincides with simulation results previously published on the same structure as well as with the anisotropy estimated from the CT images. These results suggest the potential of mode-converted ultrasonic scattering methods to assess the anisotropy of materials with porous, complex structures, including trabecular bone.
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Affiliation(s)
- Hualong Du
- Applied Research Associates, Inc. Littleton, CO, USA
| | - Omid Yousefian
- Center for Additive Manufacturing and Logistics, North Carolina State University, Raleigh, NC, USA
| | - Timothy Horn
- Industrial Engineering, North Carolina State University, Raleigh, NC, USA
- Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC, USA
| | - Marie Muller
- Center for Additive Manufacturing and Logistics, North Carolina State University, Raleigh, NC, USA
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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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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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Du H, Mohanty K, Muller M. Microstructural characterization of trabecular bone using ultrasonic backscattering and diffusion parameters. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2017; 141:EL445. [PMID: 28599551 PMCID: PMC6909975 DOI: 10.1121/1.4982824] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 04/13/2017] [Accepted: 04/14/2017] [Indexed: 05/28/2023]
Abstract
Finite differences time domain methods were utilized to simulate ultrasound propagation and scattering in anisotropic trabecular bone structures obtained from high resolution Computed Tomography (CT). The backscattered signals were collected and the incoherent contribution was extracted. The diffusion constant was calculated for propagations along and across the main direction of anisotropy, and was used to characterize the anisotropy of the trabecular microstructures. In anisotropic structures, the diffusion constant was significantly different in both directions, and the anisotropy of the diffusion constant was strongly correlated to the structural anisotropy measured on the CT images. These results indicate that metrics based on diffusion can be used to quantify the anisotropy of complex structures such as trabecular bone.
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Affiliation(s)
- Hualong Du
- Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA , ,
| | - Kaustav Mohanty
- Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA , ,
| | - Marie Muller
- Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA , ,
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Casciaro S, Peccarisi M, Pisani P, Franchini R, Greco A, De Marco T, Grimaldi A, Quarta L, Quarta E, Muratore M, Conversano F. An Advanced Quantitative Echosound Methodology for Femoral Neck Densitometry. ULTRASOUND IN MEDICINE & BIOLOGY 2016; 42:1337-1356. [PMID: 27033331 DOI: 10.1016/j.ultrasmedbio.2016.01.024] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 01/26/2016] [Accepted: 01/27/2016] [Indexed: 06/05/2023]
Abstract
The aim of this paper was to investigate the clinical feasibility and the accuracy in femoral neck densitometry of the Osteoporosis Score (O.S.), an ultrasound (US) parameter for osteoporosis diagnosis that has been recently introduced for lumbar spine applications. A total of 377 female patients (aged 61-70 y) underwent both a femoral dual X-ray absorptiometry (DXA) and an echographic scan of the proximal femur. Recruited patients were sub-divided into a reference database used for ultrasound spectral model construction and a study population for repeatability assessments and accuracy evaluations. Echographic images and radiofrequency signals were analyzed through a fully automatic algorithm that performed a series of combined spectral and statistical analyses, providing as a final output the O.S. value of the femoral neck. Assuming DXA as a gold standard reference, the accuracy of O.S.-based diagnoses resulted 94.7%, with k = 0.898 (p < 0.0001). Significant correlations were also found between O.S.-estimated bone mineral density and corresponding DXA values, with r(2) up to 0.79 and root mean square error = 5.9-7.4%. The reported accuracy levels, combined with the proven ease of use and very good measurement repeatability, provide the adopted method with a potential for clinical routine application in osteoporosis diagnosis.
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Affiliation(s)
- Sergio Casciaro
- National Research Council, Institute of Clinical Physiology, Lecce, Italy.
| | | | - Paola Pisani
- National Research Council, Institute of Clinical Physiology, Lecce, Italy
| | - Roberto Franchini
- National Research Council, Institute of Clinical Physiology, Lecce, Italy
| | | | | | - Antonella Grimaldi
- Operative Unit of Rheumatology, Galateo Hospital, San Cesario di Lecce, Lecce, Italy
| | - Laura Quarta
- Operative Unit of Rheumatology, Galateo Hospital, San Cesario di Lecce, Lecce, Italy
| | - Eugenio Quarta
- Operative Unit of Rheumatology, Galateo Hospital, San Cesario di Lecce, Lecce, Italy
| | - Maruizio Muratore
- Operative Unit of Rheumatology, Galateo Hospital, San Cesario di Lecce, Lecce, Italy
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Fast and easy preoperative estimation of cancellous bone mineral density in patients with proximal femur fractures. Arch Orthop Trauma Surg 2015; 135:1683-9. [PMID: 26476721 DOI: 10.1007/s00402-015-2340-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Indexed: 02/09/2023]
Abstract
INTRODUCTION Postoperative complications after hip fractures in osteoporotic bone such as implant cutout can be reduced by the use of specially designed implants or additional cement augmentation. It is not yet clear at which degree of osteoporosis, patients will profit from implant augmentation or specially designed implants for geriatric patients. As the surgeon ideally should obtain information on local bone quality at the site of implant anchorage already preoperatively, the aim of the study was to develop an easily applicable radiographic method to estimate bone quality in those patients. MATERIALS AND METHODS 75 patients with unilateral hip fracture were included. Preoperatively, a CT scan with a calibration device was conducted. Postoperatively, DXA scans were performed. The proposed method measures local cancellous bone mineral density in the contralateral and uninjured femoral head. As a control, 15 young and healthy non-osteoporotic subjects were included. Inter- and intraobserver reliability was investigated for a subgroup of 20 patients. RESULTS Study group patients had a mean BMD measured by CT scans of 194.2 mg/cm(3) (SD 40.4). There was a statistically significant correlation with data from DXA scans (r = 0.706, p < 0.001). The control group was significantly younger and showed a significantly higher BMD when compared to the study group (p < 0.001). Reliability evaluation showed no statistically significant difference in inter- and intraobserver measurements. Interclass correlation proved to be very high. CONCLUSION The proposed method is an easily applicable, reliable and useful tool to estimate bone quality preoperatively using the contralateral hip as a reference. Obtained data may facilitate the decision-making towards the use of further therapeutic measures to improve implant anchorage in osteoporotic bone such as bone cement augmentation. Thus, our method allows for a more individualized surgical treatment of hip fracture patients adapted to the estimated cancellous bone quality of the patient.
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Guipieri S, Nagatani Y, Bosc R, Nguyen VH, Chappard C, Geiger D, Haïat G. Ultrasound Speed of Sound Measurements in Trabecular Bone Using the Echographic Response of a Metallic Pin. ULTRASOUND IN MEDICINE & BIOLOGY 2015; 41:2966-2976. [PMID: 26320667 DOI: 10.1016/j.ultrasmedbio.2015.07.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 06/16/2015] [Accepted: 07/06/2015] [Indexed: 06/04/2023]
Abstract
Bone quality is an important parameter in spine surgery, but its clinical assessment remains difficult. The aim of the work described here was to demonstrate in vitro the feasibility of employing quantitative ultrasound to retrieve bone mechanical properties using an echographic technique taking advantage of the presence of a metallic pin inserted in bone tissue. A metallic pin was inserted in bone tissue perpendicular to the transducer axis. The echographic response of the bone sample was determined, and the echo of the pin inserted in bone tissue and water were compared to determine speed of sound, which was compared with bone volume fraction. A 2-D finite-element model was developed to assess the effect of positioning errors. There was a significant correlation between speed of sound and bone volume fraction (R(2) = 0.6). The numerical results indicate the relative robustness of the measurement method, which could be useful to estimate bone quality intra-operatively.
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Affiliation(s)
- Séraphin Guipieri
- CNRS, Laboratoire Modélisation et Simulation MultiEchelle, MSME UMR CNRS 8208, Créteil, France
| | - Yoshiki Nagatani
- CNRS, Laboratoire Modélisation et Simulation MultiEchelle, MSME UMR CNRS 8208, Créteil, France; Kobe City College of Technology, Nishiku, Kobe, Japan
| | - Romain Bosc
- Service de Chirurgie Plastique et Reconstructive, Hôpital Henri Mondor AP-HP, F-94000, Créteil, France
| | - Vu-Hieu Nguyen
- CNRS, Laboratoire Modélisation et Simulation MultiEchelle, MSME UMR CNRS 8208, Créteil, France
| | | | - Didier Geiger
- CNRS, Laboratoire Modélisation et Simulation MultiEchelle, MSME UMR CNRS 8208, Créteil, France
| | - Guillaume Haïat
- CNRS, Laboratoire Modélisation et Simulation MultiEchelle, MSME UMR CNRS 8208, Créteil, France.
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Casciaro S, Conversano F, Pisani P, Muratore M. New perspectives in echographic diagnosis of osteoporosis on hip and spine. ACTA ACUST UNITED AC 2015; 12:142-50. [PMID: 26604940 DOI: 10.11138/ccmbm/2015.12.2.142] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Currently, the accepted "gold standard" method for bone mineral density (BMD) measurement and osteoporosis diagnosis is dual-energy X-ray absorptiometry (DXA). However, actual DXA effectiveness is limited by several factors, including intrinsic accuracy uncertainties and possible errors in patient positioning and/or post-acquisition data analysis. DXA employment is also restricted by the typical issues related to ionizing radiation employment (high costs, need of dedicated structures and certified operators, unsuitability for population screenings). The only commercially-available alternative to DXA is represented by "quantitative ultrasound" (QUS) approaches, which are radiation-free, cheaper and portable, but they cannot be applied on the reference anatomical sites (lumbar spine and proximal femur). Therefore, their documented clinical usefulness is restricted to calcaneal applications on elderly patients (aged over 65 y), in combination with clinical risk factors and only for the identification of healthy subjects at low fracture risk. Literature-reported studies performed some QUS measurements on proximal femur, but their clinical translation is mostly hindered by intrinsic factors (e.g., device bulkiness). An innovative ultrasound methodology has been recently introduced, which performs a combined analysis of B-mode images and corresponding "raw" radiofrequency signals acquired during an echographic scan of the target reference anatomical site, providing two novel parameters: Osteoporosis Score and Fragility Score, indicative of BMD level and bone strength, respectively. This article will provide a brief review of the available systems for osteoporosis diagnosis in clinical routine contexts, followed by a synthesis of the most promising research results on the latest ultrasound developments for early osteoporosis diagnosis and fracture prevention.
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Affiliation(s)
- Sergio Casciaro
- National Research Council, Institute of Clinical Physiology, Lecce, Italy
| | | | - Paola Pisani
- National Research Council, Institute of Clinical Physiology, Lecce, Italy
| | - Maurizio Muratore
- OU of Rheumatology, "Galateo" Hospital, San Cesario di Lecce, ASL-LE, Lecce, Italy
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Conversano F, Franchini R, Greco A, Soloperto G, Chiriacò F, Casciaro E, Aventaggiato M, Renna MD, Pisani P, Di Paola M, Grimaldi A, Quarta L, Quarta E, Muratore M, Laugier P, Casciaro S. A novel ultrasound methodology for estimating spine mineral density. ULTRASOUND IN MEDICINE & BIOLOGY 2015; 41:281-300. [PMID: 25438845 DOI: 10.1016/j.ultrasmedbio.2014.08.017] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 08/14/2014] [Accepted: 08/20/2014] [Indexed: 05/10/2023]
Abstract
We investigated the possible clinical feasibility and accuracy of an innovative ultrasound (US) method for diagnosis of osteoporosis of the spine. A total of 342 female patients (aged 51-60 y) underwent spinal dual X-ray absorptiometry and abdominal echographic scanning of the lumbar spine. Recruited patients were subdivided into a reference database used for US spectral model construction and a study population for repeatability and accuracy evaluation. US images and radiofrequency signals were analyzed via a new fully automatic algorithm that performed a series of spectral and statistical analyses, providing a novel diagnostic parameter called the osteoporosis score (O.S.). If dual X-ray absorptiometry is assumed to be the gold standard reference, the accuracy of O.S.-based diagnoses was 91.1%, with k = 0.859 (p < 0.0001). Significant correlations were also found between O.S.-estimated bone mineral densities and corresponding dual X-ray absorptiometry values, with r(2) values up to 0.73 and a root mean square error of 6.3%-9.3%. The results obtained suggest that the proposed method has the potential for future routine application in US-based diagnosis of osteoporosis.
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Affiliation(s)
| | - Roberto Franchini
- National Research Council, Institute of Clinical Physiology, Lecce, Italy
| | | | - Giulia Soloperto
- National Research Council, Institute of Clinical Physiology, Lecce, Italy
| | - Fernanda Chiriacò
- National Research Council, Institute of Clinical Physiology, Lecce, Italy
| | - Ernesto Casciaro
- National Research Council, Institute of Clinical Physiology, Lecce, Italy
| | | | | | - Paola Pisani
- National Research Council, Institute of Clinical Physiology, Lecce, Italy
| | - Marco Di Paola
- National Research Council, Institute of Clinical Physiology, Lecce, Italy
| | - Antonella Grimaldi
- O.U. of Rheumatology, "Galateo" Hospital, San Cesario di Lecce, ASL-LE, Lecce, Italy
| | - Laura Quarta
- O.U. of Rheumatology, "Galateo" Hospital, San Cesario di Lecce, ASL-LE, Lecce, Italy
| | - Eugenio Quarta
- O.U. of Rheumatology, "Galateo" Hospital, San Cesario di Lecce, ASL-LE, Lecce, Italy
| | - Maurizio Muratore
- O.U. of Rheumatology, "Galateo" Hospital, San Cesario di Lecce, ASL-LE, Lecce, Italy
| | - Pascal Laugier
- Laboratoire d'Imagerie Biomédicale, Sorbonne Universités, UPMC 06, INSERM, CNRS, Paris, France
| | - Sergio Casciaro
- National Research Council, Institute of Clinical Physiology, Lecce, Italy.
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Karjalainen JP, Riekkinen O, Töyräs J, Hakulinen M, Kröger H, Rikkonen T, Salovaara K, Jurvelin JS. Multi-site bone ultrasound measurements in elderly women with and without previous hip fractures. Osteoporos Int 2012; 23:1287-95. [PMID: 21656263 DOI: 10.1007/s00198-011-1682-2] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Accepted: 05/19/2011] [Indexed: 10/18/2022]
Abstract
UNLABELLED About 75% of patients suffering from osteoporosis are not diagnosed. This study describes a multi-site bone ultrasound method for osteoporosis diagnostics. In comparison with axial dual energy X-ray absorptiometry (DXA), the ultrasound method showed good diagnostic performance and could discriminate fracture subjects among elderly females. INTRODUCTION Axial DXA, the gold standard diagnostic method for osteoporosis, predicts fractures only moderately. At present, no reliable diagnostic methods are available at the primary health care level. Here, a multi-site ultrasound method is proposed for osteoporosis diagnostics. METHODS Thirty elderly women were examined using the ultrasound backscatter measurements in proximal femur, proximal radius, proximal and distal tibia in vivo. First, we predicted the areal bone mineral density (BMD) at femoral neck by ultrasound measurements in tibia combined with specific subject characteristics (density index, DI) and, second, we tested the ability of ultrasound backscatter measurements at proximal femur to discriminate between individuals with previously fractured hips from those without fractures. Areal BMD was determined by axial DXA. RESULTS Combined ultrasound parameters, cortical thickness at distal and proximal tibia, with age and weight of the subject, provided a significant estimate of BMD(neck) (r = 0.86, p < 0.001, n = 30). When inserted into FRAX (World Health Organization fracture risk assessment tool), the DI indicated the same treatment proposal as the BMD(neck) with 86% sensitivity and 100% specificity. The receiver operating characteristic analyses, with a combination of ultrasound parameters and patient characteristics, discriminated fracture subjects from the controls similarly as the model combining BMD(neck) and patient characteristics. CONCLUSIONS For the first time, ultrasound backscatter measurements of proximal femur were conducted in vivo. The results indicate that ultrasound parameters, combined with patient characteristics, may provide a means for osteoporosis diagnostics.
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Affiliation(s)
- J P Karjalainen
- Department of Applied Physics, University of Eastern Finland, POB 1627, 70211 Kuopio, Finland.
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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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12
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Haïat G, Berti R, Galaz B, Taulier N, Amman JJ, Urbach W. Two-dimensional simulation of linear wave propagation in a suspension of polymeric microcapsules used as ultrasound contrast agents. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2011; 129:1642-1652. [PMID: 21428527 DOI: 10.1121/1.3543966] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A generation of tissue-specific stable ultrasound contrast agent (UCA) composed of a polymeric capsule with a perfluorocarbone liquid core has become available. Despite promising uses in clinical practice, the acoustical behavior of such UCA suspensions remains unclear. A simulation code (2-D finite-difference time domain, FDTD) already validated for homogeneous particles [Galaz Haiat, Berti, Taulier, Amman and Urbach, (2010). J. Acoust. Soc. Am. 127, 148-154] is used to model the ultrasound propagation in such UCA suspensions at 50 MHz to investigate the sensitivity of the ultrasonic parameters to physical parameters of UCA. The FDTD simulation code is validated by comparison with results obtained using a shell scatterer model. The attenuation coefficient (respectively, the sound velocity) increases (respectively, decreases) from 4.1 to 58.4 dB/cm (respectively, 1495 to 1428 m/s) when the concentration varies between 1.37 and 79.4 mg/ml, while the backscattered intensity increases non-linearly, showing that a concentration of around 30 mg/ml is sufficient to obtain optimal backscattering intensity. The acoustical parameters vary significantly as a function of the membrane thickness, longitudinal and transverse velocity, indicating that mode conversions in the membrane play an important role in the ultrasonic propagation. The results may be used to help manufacturers to conceive optimal liquid-filled UCA suspensions.
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Affiliation(s)
- Guillaume Haïat
- CNRS (Centre Nationale de la Recherche Scientifique), Université Paris-Est, Laboratoire Modélisation et Simulation Multi-Échelle, UMR (Unité mixte de recherche) 8208 CNRS, 94010 Créteil Cédex, France.
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Haïat G, Naili S. Independent scattering model and velocity dispersion in trabecular bone: comparison with a multiple scattering model. Biomech Model Mechanobiol 2010; 10:95-108. [PMID: 20490887 DOI: 10.1007/s10237-010-0220-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2009] [Accepted: 04/26/2010] [Indexed: 10/19/2022]
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Grondin J, Grimal Q, Engelke K, Laugier P. Potential of first arriving signal to assess cortical bone geometry at the Hip with QUS: a model based study. ULTRASOUND IN MEDICINE & BIOLOGY 2010; 36:656-666. [PMID: 20350690 DOI: 10.1016/j.ultrasmedbio.2010.01.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2009] [Revised: 12/21/2009] [Accepted: 01/22/2010] [Indexed: 05/29/2023]
Abstract
There is evidence that quantitative ultrasound (QUS) at the proximal femur involves waves propagating circumferentially in the cortical shell. These waves, in theory, convey information on bone geometrical and material characteristics and thus have the potential to improve fracture risk prediction. In this work, the time-of-flight (TOF) of the first arriving signal (FAS) that corresponds to waves propagating circumferentially is considered. The relationships between the TOF of the FAS and geometrical features of the femoral neck are investigated. Five neck cross-sections from 11 human femurs from females (>65y) were extracted from 3-D X-ray quantitative computed tomography (XR-QCT) datasets. Geometrical parameters including cross-sectional area (CSA), minimum moment of inertia (I(min)) and section modulus (Z) were computed from femoral neck cross-section images. Two-dimensional numerical simulation of US propagation through femoral neck was performed and TOF of the FAS was estimated. TOF was best correlated with I(min): R(2)=0.82 (p=10(-4); RMSE=1390mm(4) [13%]) in the region between proximal and mid-femoral neck and with Z: R(2)=0.55 (p<10(-2); RMSE=480mm(3) [17%]) and CSA: R(2)=0.62 (p<5.10(-3); RMSE=22mm(2) [7%]) in the mid-femoral neck. The results suggest that QUS has the potential to assess proximal femur strength based on estimates of geometrical properties of the cortical shell.
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Affiliation(s)
- Julien Grondin
- UPMC Univ Paris 06, UMR 7623, LIP, F-75005, Paris, France.
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15
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Naili S, Vu MB, Grimal Q, Talmant M, Desceliers C, Soize C, Haïat G. Influence of viscoelastic and viscous absorption on ultrasonic wave propagation in cortical bone: Application to axial transmission. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2010; 127:2622-2634. [PMID: 20370043 DOI: 10.1121/1.3353091] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Cortical bone and the surrounding soft tissues are attenuating and heterogeneous media, which might affect the signals measured with axial transmission devices. This work aims at evaluating the effect of the heterogeneous acoustic absorption in bone and in soft tissues on the bone ultrasonic response. Therefore, a two-dimensional finite element time-domain method is derived to model transient wave propagation in a three-layer medium composed of an inhomogeneous transverse isotropic viscoelastic solid layer, sandwiched between two viscous fluid layers. The model couples viscous acoustic propagation in both fluid media with the anisotropic viscoelastic response of the solid. A constant spatial gradient of material properties is considered for two values of bone thicknesses (0.6 and 4 mm). In the studied configuration, absorption in the surrounding fluid tissues does not affect the results, whereas bone viscoelastic properties have a significant effect on the first arriving signal (FAS) velocity. For a thin bone, the FAS velocity is governed by the spatially averaged bone properties. For a thick bone, the FAS velocity may be predicted using a one-dimensional model.
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Affiliation(s)
- Salah Naili
- Laboratoire Modelisation et Simulation Multi-Echelle, Universite Paris-Est, UMR 8208 CNRS, 94010 Creteil Cedex, France.
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16
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Galaz B, Haïat G, Berti R, Taulier N, Amman JJ, Urbach W. Experimental validation of a time domain simulation of high frequency ultrasonic propagation in a suspension of rigid particles. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2010; 127:148-154. [PMID: 20058958 DOI: 10.1121/1.3270399] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Ultrasonic propagation in suspensions of particles is a difficult problem due to the random spatial distribution of the particles. Two-dimensional finite-difference time domain simulations of ultrasonic propagation in suspensions of polystyrene 5.3 mum diameter microdisks are performed at about 50 MHz. The numerical results are compared with the Faran model, considering an isolated microdisk, leading to a maximum difference of 15% between the scattering cross-section values obtained analytically and numerically. Experiments are performed with suspensions in through transmission and backscattering modes. The attenuation coefficient at 50 MHz (alpha), the ultrasonic velocity (V), and the relative backscattered intensity (I(B)) are measured for concentrations from 2 to 25 mg/ml, obtained by modifying the number of particles. Each experimental ultrasonic parameter is compared to numerical results obtained by averaging the results derived from 15 spatial distributions of microdisks. alpha increases with the concentration from 1 to 17 dB/cm. I(B) increases with concentration from 2 to 16 dB. The variation of V versus concentration is compared with the numerical results, as well as with an effective medium model. A good agreement is found between experimental and numerical results (the larger discrepancy is found for alpha with a difference lower than 2.1 dB/cm).
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Affiliation(s)
- Belfor Galaz
- Laboratoire d'Imagerie Parametrique, UPMC Univ Paris 6, and CNRS, LIP, UMR 7623, 15 rue de l'Ecole de Medecine, 75006 Paris, France
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17
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Haïat G, Padilla F, Svrcekova M, Chevalier Y, Pahr D, Peyrin F, Laugier P, Zysset P. Relationship between ultrasonic parameters and apparent trabecular bone elastic modulus: a numerical approach. J Biomech 2009; 42:2033-9. [PMID: 19646703 DOI: 10.1016/j.jbiomech.2009.06.008] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Revised: 06/04/2009] [Accepted: 06/05/2009] [Indexed: 11/19/2022]
Abstract
The physical principles underlying quantitative ultrasound (QUS) measurements in trabecular bone are not fully understood. The translation of QUS results into bone strength remains elusive. However, ultrasound being mechanical waves, it is likely to assess apparent bone elasticity. The aim of this study is to derive the sensitivity of QUS parameters to variations of apparent bone elasticity, a surrogate for strength. The geometry of 34 human trabecular bone samples cut in the great trochanter was reconstructed using 3-D synchrotron micro-computed tomography. Finite-difference time-domain simulations coupled to 3-D micro-structural models were performed in the three perpendicular directions for each sample and each direction. A voxel-based micro-finite element linear analysis was employed to compute the apparent Young's modulus (E) of each sample for each direction. For the antero-posterior direction, the predictive power of speed of sound and normalized broadband ultrasonic attenuation to assess E was equal to 0.9 and 0.87, respectively, which is better than what is obtained using bone density alone or coupled with micro-architectural parameters and of the same order of what can be achieved with the fabric tensor approach. When the direction of testing is parallel to the main trabecular orientation, the predictive power of QUS parameters decreases and the fabric tensor approach always gives the best results. This decrease can be explained by the presence of two longitudinal wave modes. Our results, which were obtained using two distinct simulation tools applied on the same set of samples, highlight the potential of QUS techniques to assess bone strength.
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Affiliation(s)
- G Haïat
- CNRS, Université Paris 7, Laboratoire de Recherches Orthopédiques, UMR CNRS 7052 B2OA, 75010 Paris, France.
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18
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Haiat G, Padilla F, Laugier P. Sensitivity of qus parameters to controlled variations of bone strength assessed with a cellular model. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2008; 55:1488-1496. [PMID: 18986938 DOI: 10.1109/tuffc.2008.824] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The physical principles underlying quantitative ultrasound (QUS) measurements are not fully understood yet. Therefore, the translation of QUS results into bone strength remains elusive. In the present study, we derive the sensitivity of broadband ultrasonic attenuation (BUA) and speed of sound (SOS) to variations of bone strength. For this purpose, a mechanical cellular model is combined to a multiple regression resulting from the analysis of finite-difference time domain (FDTD) simulations. Specifically, we investigate how QUS variables respond to a variation in strength of 10%, realized either by a change in material properties or a change in bone volume fraction (BV/TV). The results show that except when BV/TV is high, the variations of BUA in response to a variation in strength realized by a pure change of BV/TV exceeds the technique imprecision and thus can be detected. When the variation of strength is realized by changes of compressive or shear stiffness, the response in QUS properties is dominated by the variation in C(11), whereas changes in C(44), remaining below the precision error, cannot be detected. The interpretation of these data, however, is not straightforward due to sparse description of elastic properties at the tissue level. To overcome the limitation of the cellular model, more realistic computational models such as micro- finite element analysis have to be considered.
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Affiliation(s)
- G Haiat
- Centre Nat. de la Rech. Sci. (CNRS), Univ. Paris Diderot, Paris, France.
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Haïat G, Padilla F, Peyrin F, Laugier P. Fast wave ultrasonic propagation in trabecular bone: numerical study of the influence of porosity and structural anisotropy. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2008; 123:1694-705. [PMID: 18345857 DOI: 10.1121/1.2832611] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Our goal is to assess the potential of computational methods as an alternative to analytical models to predict the two longitudinal wave modes observed in cancellous bone and predicted by the Biot theory. A three-dimensional (3D) finite-difference time-domain method is coupled with 34 human femoral trabecular microstructures measured using microcomputed tomography. The main trabecular alignment (MTA) and the degree of anisotropy (DA) were assessed for all samples. DA values were comprised between 1.02 and 1.9. The influence of bone volume fraction (BV/TV) between 5% and 25% on the properties of the fast and slow waves was studied using a dedicated image processing algorithm to modify the initial 3D microstructures. A heuristic method was devised to determine when both wave modes are time separated. The simulations (performed in three perpendicular directions) predicted that both waves generally overlap in time for a direction of propagation perpendicular to the MTA. When these directions are parallel, both waves are separated in time for samples with high DA and BV/TV values. A relationship was found between the least bone volume fraction required for the observation of nonoverlapping waves and the degree of anisotropy: The higher the DA, the lower the least BV/TV.
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Affiliation(s)
- G Haïat
- CNRS, Université Paris 7, Laboratoire de Recherches Orthopédiques, UMR CNRS 7052 B2OA, 10, avenue de Verdun, 75010 Paris, France.
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Dencks S, Barkmann R, Padilla F, Laugier P, Schmitz G, Glüer CC. Model-based estimation of quantitative ultrasound variables at the proximal femur. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2008; 55:1304-1315. [PMID: 18599418 DOI: 10.1109/tuffc.2008.793] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
To improve the prediction of the osteoporotic fracture risk at the proximal femur we are developing a scanner for quantitative ultrasound (QUS) measurements at this site. Due to multipath transmission in this complex shaped bone, conventional signal processing techniques developed for QUS measurements at peripheral sites frequently fail. Therefore, we propose a model-based estimation of the QUS variables and analyze the performance of the new algorithm. Applying the proposed method to QUS scans of excised proximal femurs increased the fraction of evaluable signals from approx. 60% (using conventional algorithms) to 97%. The correlation of the standard QUS variables broadband ultrasound attenuation (BUA) and speed of sound (SOS) with the established variable bone mineral density (BMD) reported in previous studies is maintained (BUA/BMD: r(2) = 0.69; SOS/BMD: r(2) = 0.71; SOS+BUA/BMD: r(2) = 0.88). Additionally, different wave types could be clearly detected and characterized in the trochanteric region. The ability to separate superimposed signals with this approach opens up further diagnostic potential for evaluating waves of different sound paths and wave types through bone tissue.
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Affiliation(s)
- Stefanie Dencks
- Department of Diagnostic Radiology, University Hospital Schleswig-Holstein, Kiel, Germany.
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21
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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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Dencks S, Barkmann R, Padilla F, Haïat G, Laugier P, Glüer CC. Wavelet-based signal processing of in vitro ultrasonic measurements at the proximal femur. ULTRASOUND IN MEDICINE & BIOLOGY 2007; 33:970-80. [PMID: 17445965 DOI: 10.1016/j.ultrasmedbio.2006.12.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2006] [Revised: 11/30/2006] [Accepted: 12/12/2006] [Indexed: 05/15/2023]
Abstract
To estimate osteoporotic fracture risk, several techniques for quantitative ultrasound (QUS) measurements at peripheral sites have been developed. As these techniques are limited in the prediction of fracture risk of the central skeleton, such as the hip, we are developing a QUS device for direct measurements at the femur. In doing so, we noticed the necessity to improve the conventional signal processing because it failed in a considerable number of measurements due to multipath transmission. Two sets of excised human femurs (n = 6 + 34) were scanned in transmission mode. Instead of using the conventional methods, the radio-frequency signals were processed with the continuous wavelet transform to detect their time-of-flights for the calculation of speed-of-sound (SOS) in bone. The SOS-values were averaged over a region similar to the total hip region of dual X-ray absorptiometry (DXA) measurements and compared with bone mineral density (BMD) measured with DXA. Testing six standard wavelets, this algorithm failed for only 0% to 6% of scan in test set 1 compared with 29% when using conventional algorithms. For test set 2, it failed for 2% to 12% compared with approximately 40%. SOS and BMD correlated significantly in both test sets (test set 1: r2 = 0.87 to 0.92, p < 0.007; test set 2: r2 = 0.68 to 0.79, p < 0.0001). The correlations are comparable with correlations recently reported. However, the number of evaluable signals could be substantially increased, which improves the perspectives of the in vivo measurements.
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Affiliation(s)
- Stefanie Dencks
- Medizinische Physik, Klinik für Diagnostische Radiologie, Universitätsklinikum Schleswig Holstein, Kiel, Germany.
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Haïat G, Padilla F, Peyrin F, Laugier P. Variation of ultrasonic parameters with microstructure and material properties of trabecular bone: a 3D model simulation. J Bone Miner Res 2007; 22:665-74. [PMID: 17295606 DOI: 10.1359/jbmr.070209] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
UNLABELLED This study determined the influence of trabecular bone microstructure and material properties on QUS parameters using numerical simulations coupled with high-resolution synchrotron radiation microCT. INTRODUCTION Finite-difference time domain (FDTD) simulations coupled to 3D microstructural models of trabecular bone reconstructed from synchrotron radiation microtomography (SR-microCT) were used herein to compare and quantify the effects of bone volume fraction, microstructure, and material properties on QUS parameters. MATERIALS AND METHODS 3D SR-microCT datasets of 30 trabecular human femoral bone specimens were used to create binary digital 3D models. We studied the sensitivity of quantitative ultrasound (QUS) to bone volume fraction by examining QUS parameters at different stages of trabecular thinning or thickening using an iterative dedicated algorithm. The sensitivity to bone material properties was also assessed by analyzing different scenarios in which density and stiffness could be varied independently. The effect of microstructure was qualitatively assessed by producing virtual bone specimens of identical bone volume fraction. Simulations of ultrasonic wave propagation through the trabecular bone volumes were performed using the FDTD simulation software SimSonic developed by our group. For each structure, both broadband ultrasonic attenuation (BUA) and speed of sound (SOS) were computed. RESULTS BUA and SOS showed a strong correlation with BV/TV (r(2)=0.94, p<10(-4)) and varied quasi-linearly with BV/TV at an approximate rate of 2 dB/cm.MHz and 11 m/s per percent increase of BV/TV, respectively. Bone alterations caused by variation in BV/TV between 5% and 25% had a greater impact on QUS variables (variation of BUA: 40 dB/cm.MHz; variation of SOS: 200 m/s) than variations caused by alterations of material properties realized either by a 30% change of density or 40% change of stiffness (BUA: 1.7 dB/cm.MHz; SOS: 43 m/s) or than diversity in microarchitecture (BUA:7.8 dB/cm.MHz; SOS: 36 m/s). Moreover, the sensitivity of BUA and SOS to changes in BMD by a given amount realized by a pure change in bone mass (or BV/TV) was found to be predominant over a pure change of mineralization, except for low BV/TV values, where both effects are comparable. CONCLUSIONS Trabecular bone microstructure (i.e., trabecular thickness) and material properties were changed to quantify the impact of specific determinants on QUS variables. In this sample of unselected autopsies, specimen variability in bone volume seemed to have a somewhat larger impact on QUS variables than the variability of the other determinants assessed. Whether this is also the case for osteoporotic patients remains to be studied.
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Affiliation(s)
- Guillaume Haïat
- Université Paris 12, Laboratoire de Mécanique Physique, UMR CNRS 7052 B2OA, Créteil, France.
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Siffert RS, Kaufman JJ. Ultrasonic bone assessment: "the time has come". Bone 2007; 40:5-8. [PMID: 16949900 PMCID: PMC2380261 DOI: 10.1016/j.bone.2006.07.018] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2006] [Revised: 04/26/2006] [Accepted: 07/19/2006] [Indexed: 11/20/2022]
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Barkmann R, Laugier P, Moser U, Dencks S, Padilla F, Haiat G, Heller M, Glüer CC. A method for the estimation of femoral bone mineral density from variables of ultrasound transmission through the human femur. Bone 2007; 40:37-44. [PMID: 16949896 DOI: 10.1016/j.bone.2006.07.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2005] [Revised: 03/23/2006] [Accepted: 07/14/2006] [Indexed: 10/24/2022]
Abstract
Quantitative ultrasound (QUS) measurements at peripheral sites can be used to estimate osteoporotic fracture risk. However, measurements at these sites are less suitable to predict bone mineral density (BMD) or fracture risk at the central skeleton. We investigated whether direct QUS measurements at the femur would allow to estimate dual X-ray absorptiometry (DXA) BMD of the total proximal femur with errors comparable to established DXA accuracy errors. Two independent sets of femora were measured in Kiel (6 f, 4 m, age: 55-90) and Paris (19 f, 20 m age: 45-95) using different benchtop systems in the two laboratories. The femora were scanned in transverse transmission mode using focused US transducers of 500 kHz center frequency. The QUS values were averaged over a region similar to the total hip region of dual X-ray absorptiometry (DXA) measurements. BMD was measured using DXA. SOS and BMD correlated significantly (p<0.0001) in both data sets (R2=0.81-0.93). Correlations between BUA and BMD were also significant at p<0.001, but correlation coefficients were lower (R2=0.61-0.75). Residual errors for the estimation of BMD were 8%-10% for SOS as predictor, and 14%-16% for BUA as predictor. The residual error of 8 to 10% for the estimation of BMD from SOS is comparable to variabilities among different DXA femur subregions and accuracy errors of femoral DXA measurements caused by the impact of soft tissue. It is substantially smaller than the errors of 13% for the estimation of total femur BMD from spine BMD, 14% for the estimation of total femur BMD from calcaneus SOS or 16% for the estimation of ash weight from DXA. The results of the study show that SOS is able to predict total BMD with adequate accuracy. If femoral BMD could be obtained in vivo with comparable accuracy, femoral QUS would be suited for the assessment of bone status at one of the main osteoporotic fracture sites.
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Affiliation(s)
- R Barkmann
- Medizinische Physik, Klinik für Diagnostische Radiologie, Universitätsklinikum Schleswig Holstein Campus Kiel, Kiel, Germany.
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Abstract
Quantitative Ultrasound (QUS) methods show great potential for refined assessment of bone strength. However, for widespread clinical acceptance, three issues have to be resolved: Will patients with low QUS readings benefit from approved osteoporosis medications? How can we ensure good quality of QUS measurements in daily clinical practice? How much added value does QUS bring to risk factor based case-finding strategies? When addressing these issues, differences among QUS approaches need to be recognized and vague and misleading terminology, e.g., regarding bone quality assessment, needs to be avoided. Innovations including assessment of material or micro-structural properties and direct QUS measurements at the proximal femur are likely to spark additional interest in pursuing QUS research.
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Haïat G, Padilla F, Barkmann R, Gluer CC, Laugier P. Numerical simulation of the dependence of quantitative ultrasonic parameters on trabecular bone microarchitecture and elastic constants. ULTRASONICS 2006; 44 Suppl 1:e289-94. [PMID: 16859726 DOI: 10.1016/j.ultras.2006.06.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Finite-difference numerical simulation of ultrasound propagation in complex media such as cancellous bone represents a fertile alternative to analytical approaches because it can manage the complex 3D bone structure by coupling the numerical computation with 3D numerical models of bone microarchitecture obtained from high-resolution imaging modalities. The objective of this work was to assess in silico the sensitivity of ultrasound parameters to controlled changes of microarchitecture and variation of elastic constants. The simulation software uses a finite-difference approach based on the Virieux numerical scheme. An incident plane wave was propagated through a volume of bone of approximately 5 x 5 x 8 mm(3). The volumes were reconstructed from high-resolution micro-computed tomography data. An iterative numerical scenario of "virtual osteoporosis" was implemented using a dedicated image processing algorithm in order to modify the initial 3D microstructures. Numerical computations of wave propagation were performed at each step of the process. The sensitivity to bone material properties was also tested by changing the elastic constants of bone tissue. Our results suggest that ultrasonic variables (slope of the frequency-dependent attenuation coefficient and speed of sound) are mostly influenced by bone volume fraction. However, material properties and structure also appear to play a role. The impact of modifications of the stiffness coefficients remained lower than the variability caused by structural variations. This study emphasizes the potential of numerical computations tools coupled to realistic 3D structures to elucidate the physical mechanisms of interaction between ultrasound and bone structure and to assess the sensitivity of ultrasound variables to different bone properties.
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Affiliation(s)
- G Haïat
- Laboratoire d'Imagerie Paramétrique, CNRS UMR 7623, Université Paris 6, Paris, France
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28
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Laugier P. Quantitative ultrasound of bone: looking ahead. Joint Bone Spine 2005; 73:125-8. [PMID: 16488646 DOI: 10.1016/j.jbspin.2005.10.012] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2005] [Accepted: 04/21/2005] [Indexed: 12/14/2022]
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