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Vespasiano V, Mulder CS, Klop C, Koolstra JH, Nolte JW, Lobé NHJ, Beenen LFM, Becking AG. Mineralization and thickness of the condylar cortex in skeletal remains of children's mandibles: A preliminary study. Arch Oral Biol 2024; 157:105850. [PMID: 38007946 DOI: 10.1016/j.archoralbio.2023.105850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 11/05/2023] [Accepted: 11/14/2023] [Indexed: 11/28/2023]
Abstract
OBJECTIVE To explore the relationship between the volumetric bone mineral density (vBMD), the thickness of the condylar cortex (Tcortex) and the hemimandibular volumes (Vhemimandible) of symmetrical and asymmetrical mandibles of children. DESIGN The data collection consisted of 92 archeological skeletal remains of children's mandibles between 1 and 12 years old. The mandibles were digitalized with a computed tomography (CT) scan, and three dimensional models were obtained. Vhemimandible was calculated using the optimal symmetry plane. The volumes were used to calculate the asymmetry index (AI). Mandibles with an AI of ≥ 3% (N = 9) and a sample of the most symmetrical mandibles (N = 9) were selected for this research. Three groups were created: a symmetrical, an asymmetrical and a pooled group. Micro-CT was used to measure the vBMD and Tcortex in four volumes of interest. The AI was calculated for these parameters as well. RESULTS Significant correlations were found between the vBMD and the Tcortex in the pooled group (P < .01) and between the AI of the vBMD and the AI of the Tcortex in the pooled (P < .01) and symmetrical group (P < .05). No significant correlations were found between the vBMD and the Vhemimandible and between the respective AIs. Between the Tcortex and the Vhemimandible a significant correlation was found in the pooled and asymmetrical group. CONCLUSION There is a relationship between the vBMD and the Tcortex. The correlations between the Tcortex and the Vhemimandible are insufficient to draw firm conclusions. A relationship between the vBMD and Vhemimandible was not confirmed in this study.
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Affiliation(s)
- V Vespasiano
- Department of Oral and Maxillofacial Surgery, Amsterdam University Medical Centers (location AMC) and Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam, Amsterdam Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands.
| | - C S Mulder
- Department of Oral and Maxillofacial Surgery, Amsterdam University Medical Centers (location AMC) and Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam, Amsterdam Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands
| | - C Klop
- Department of Oral and Maxillofacial Surgery, Amsterdam University Medical Centers (location AMC) and Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam, Amsterdam Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands
| | - J H Koolstra
- Department of Oral Cell Biology and Functional Anatomy, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Gustav Mahlerlaan 3004, 1081 LA Amsterdam, the Netherlands
| | - J W Nolte
- Department of Oral and Maxillofacial Surgery, Amsterdam University Medical Centers (location AMC) and Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam, Amsterdam Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands
| | - N H J Lobé
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centers (location AMC), University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands
| | - L F M Beenen
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centers (location AMC), University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands
| | - A G Becking
- Department of Oral and Maxillofacial Surgery, Amsterdam University Medical Centers (location AMC) and Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam, Amsterdam Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands
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Sánchez-Bonaste A, Merchante LFS, Gónzalez-Bravo C, Carnicero A. Systematic measuring cortical thickness in tibiae for bio-mechanical analysis. Comput Biol Med 2023; 163:107123. [PMID: 37343467 DOI: 10.1016/j.compbiomed.2023.107123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 05/08/2023] [Accepted: 05/30/2023] [Indexed: 06/23/2023]
Abstract
BACKGROUND AND OBJECTIVE Measuring the thickness of cortical bone tissue helps diagnose bone diseases or monitor the progress of different treatments. This type of measurement can be performed visually from CAT images by a radiologist or by semi-automatic algorithms from Hounsfield values. This article proposes a mechanism capable of measuring thickness over the entire bone surface, aligning and orienting all the images in the same direction to have comparable references and reduce human intervention to a minimum. The objective is to batch process large numbers of patients' CAT images obtaining thicknesses profiles of their cortical tissue to be used in many applications. METHODS Classical morphological and Deep Learning segmentation is used to extract the area of interest, filtering and interpolation to clean the bones and contour detection and Signed Distance Functions to measure the cortical Thickness. The alignment of the set of bones is achieved by detecting their longitudinal direction, and the orientation is performed by computing their principal component of the center of mass slice. RESULTS The method processed in an unattended manner 67% of the patients in the first run and 100% in the second run. The difference in the thickness values between the values provided by the algorithm and the measures done by a radiologist was, on average, 0.25 millimetres with a standard deviation of 0.2. CONCLUSION Measuring the cortical thickness of a bone would allow us to prepare accurate traumatological surgeries or study their structural properties. Obtaining thickness profiles of an extensive set of patients opens the way for numerous studies to be carried out to find patterns between bone thickness and the patients' medical, social or demographic variables.
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Affiliation(s)
- Alberto Sánchez-Bonaste
- ICAI School of Engineering, Comillas Pontifical University, Alberto Aguilera 25, 28015, Madrid, Spain
| | - Luis F S Merchante
- MOBIOS Lab, Institute for Research in Technology, Comillas Pontifical University, Sta Cruz de Marcenado 26, 28015, Madrid, Spain
| | - Carlos Gónzalez-Bravo
- ICAI School of Engineering, Comillas Pontifical University, Alberto Aguilera 25, 28015, Madrid, Spain
| | - Alberto Carnicero
- MOBIOS Lab, Institute for Research in Technology, Comillas Pontifical University, Sta Cruz de Marcenado 26, 28015, Madrid, Spain.
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Thomas PK, Caffrey J, Afetse KE, Habet NA, Ondar K, Weaver CM, Kleinberger M, Brown P, Gayzik FS. Micro-CT Imaging and Mechanical Properties of Ovine Ribs. Ann Biomed Eng 2023:10.1007/s10439-023-03156-7. [PMID: 36841890 DOI: 10.1007/s10439-023-03156-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 01/29/2023] [Indexed: 02/27/2023]
Abstract
The use of ovine animal models in the study of injury biomechanics and modeling is increasing, due to their favorable size and other physiological characteristics. Along with this increase, there has also been increased interest in the development of in silico ovine models for computational studies to compliment physical experiments. However, there remains a gap in the literature characterizing the morphological and mechanical characteristics of ovine ribs. The objective of this study therefore is to report anatomical and mechanical properties of the ovine ribs using microtomography (micro-CT) and two types of mechanical testing (quasi-static bending and dynamic tension). Using microtomography, young ovine rib samples obtained from a local abattoir were cut into approximately fourteen 38 mm sections and scanned. From these scans, the cortical bone thickness and cross-sectional area were measured, and the moment of inertia was calculated to enhance the mechanical testing data. Based on a standard least squares statistical model, the cortical bone thickness varied depending on the region of the cross-section and the position along the length of the rib (p < 0.05), whereas the cross-sectional area remained consistent (p > 0.05). Quasi-static three-point bend testing was completed on ovine rib samples, and the resulting force-displacement data was analyzed to obtain the stiffness (44.67 ± 17.65 N/mm), maximum load (170.54 ± 48.28 N) and displacement at maximum load (7.19 ± 2.75 mm), yield load (167.81 ± 48.12 N) and displacement at yield (6.10 ± 2.25 mm), and the failure load (110.90 ± 39.30 N) and displacement at failure (18.43 ± 2.10 mm). The resulting properties were not significantly affected by the rib (p > 0.05), but by the animal they originated from (p < 0.05). For the dynamic testing, samples were cut into coupons and tested in tension with an average strain rate of 18.9 strain/sec. The resulting dynamic testing properties of elastic modulus (5.16 ± 2.03 GPa), failure stress (63.29 ± 14.02 MPa), and failure strain (0.0201 ± 0.0052) did not vary based on loading rate (p > 0.05).
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Affiliation(s)
- Patricia K Thomas
- Department of Biomedical Engineering, Wake Forest School of Medicine, Winston-Salem, USA
| | - Juliette Caffrey
- Department of Biomedical Engineering, Wake Forest School of Medicine, Winston-Salem, USA
| | - K Eddie Afetse
- Musculoskeletal Research Institute, Atrium Health, Charlotte, USA
| | - Nahir A Habet
- Musculoskeletal Research Institute, Atrium Health, Charlotte, USA
| | - Kyle Ondar
- Department of Biomedical Engineering, Wake Forest School of Medicine, Winston-Salem, USA
| | - Caitlin M Weaver
- Army Research Directorate, DEVCOM Army Research Laboratory, Adelphi, USA
| | | | - Philip Brown
- Department of Biomedical Engineering, Wake Forest School of Medicine, Winston-Salem, USA
| | - F Scott Gayzik
- Department of Biomedical Engineering, Wake Forest School of Medicine, Winston-Salem, USA.
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Osteoporosis Screening: Applied Methods and Technological Trends. Med Eng Phys 2022; 108:103887. [DOI: 10.1016/j.medengphy.2022.103887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 08/30/2022] [Accepted: 09/01/2022] [Indexed: 11/15/2022]
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Statsenko Y, Habuza T, Talako T, Pazniak M, Likhorad E, Pazniak A, Beliakouski P, Gelovani JG, Gorkom KNV, Almansoori TM, Al Zahmi F, Qandil DS, Zaki N, Elyassami S, Ponomareva A, Loney T, Naidoo N, Mannaerts GHH, Al Koteesh J, Ljubisavljevic MR, Das KM. Deep Learning-Based Automatic Assessment of Lung Impairment in COVID-19 Pneumonia: Predicting Markers of Hypoxia With Computer Vision. Front Med (Lausanne) 2022; 9:882190. [PMID: 35957860 PMCID: PMC9360571 DOI: 10.3389/fmed.2022.882190] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 06/14/2022] [Indexed: 01/19/2023] Open
Abstract
Background Hypoxia is a potentially life-threatening condition that can be seen in pneumonia patients. Objective We aimed to develop and test an automatic assessment of lung impairment in COVID-19 associated pneumonia with machine learning regression models that predict markers of respiratory and cardiovascular functioning from radiograms and lung CT. Materials and Methods We enrolled a total of 605 COVID-19 cases admitted to Al Ain Hospital from 24 February to 1 July 2020 into the study. The inclusion criteria were as follows: age ≥ 18 years; inpatient admission; PCR positive for SARS-CoV-2; lung CT available at PACS. We designed a CNN-based regression model to predict systemic oxygenation markers from lung CT and 2D diagnostic images of the chest. The 2D images generated by averaging CT scans were analogous to the frontal and lateral view radiograms. The functional (heart and breath rate, blood pressure) and biochemical findings (SpO2, HCO3-, K+, Na+, anion gap, C-reactive protein) served as ground truth. Results Radiologic findings in the lungs of COVID-19 patients provide reliable assessments of functional status with clinical utility. If fed to ML models, the sagittal view radiograms reflect dyspnea more accurately than the coronal view radiograms due to the smaller size and the lower model complexity. Mean absolute error of the models trained on single-projection radiograms was approximately 11÷12% and it dropped by 0.5÷1% if both projections were used (11.97 ± 9.23 vs. 11.43 ± 7.51%; p = 0.70). Thus, the ML regression models based on 2D images acquired in multiple planes had slightly better performance. The data blending approach was as efficient as the voting regression technique: 10.90 ± 6.72 vs. 11.96 ± 8.30%, p = 0.94. The models trained on 3D images were more accurate than those on 2D: 8.27 ± 4.13 and 11.75 ± 8.26%, p = 0.14 before lung extraction; 10.66 ± 5.83 and 7.94 ± 4.13%, p = 0.18 after the extraction. The lung extraction boosts 3D model performance unsubstantially (from 8.27 ± 4.13 to 7.94 ± 4.13%; p = 0.82). However, none of the differences between 3D and 2D were statistically significant. Conclusion The constructed ML algorithms can serve as models of structure-function association and pathophysiologic changes in COVID-19. The algorithms can improve risk evaluation and disease management especially after oxygen therapy that changes functional findings. Thus, the structural assessment of acute lung injury speaks of disease severity.
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Affiliation(s)
- Yauhen Statsenko
- Department of Radiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
- Abu Dhabi Precision Medicine Virtual Research Institute (AD PM VRI), United Arab Emirates University, Al Ain, United Arab Emirates
- *Correspondence: Yauhen Statsenko
| | - Tetiana Habuza
- Department of Computer Science and Software Engineering, College of Information Technology, United Arab Emirates University, Al Ain, United Arab Emirates
- Big Data Analytics Center, United Arab Emirates University, Al Ain, United Arab Emirates
- Tetiana Habuza
| | - Tatsiana Talako
- Department of Radiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | | | - Elena Likhorad
- Department of Radiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
- Eye Microsurgery Center “Voka”, Minsk, Belarus
- Elena Likhorad
| | | | | | - Juri G. Gelovani
- Biomedical Engineering Department, College of Engineering, Wayne State University, Detroit, MI, United States
- Siriraj Hospital, Mahidol University, Nakhon Pathom, Thailand
| | - Klaus Neidl-Van Gorkom
- Department of Radiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Taleb M. Almansoori
- Department of Radiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Fatmah Al Zahmi
- Department of Neurology, Mediclinic Parkview Hospital, Dubai, United Arab Emirates
- Department of Clinical Science, College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates
| | - Dana Sharif Qandil
- College of Medical Sciences, Ras Al Khaimah Medical Health and Sciences University, Ras Al Khaimah, United Arab Emirates
| | - Nazar Zaki
- Abu Dhabi Precision Medicine Virtual Research Institute (AD PM VRI), United Arab Emirates University, Al Ain, United Arab Emirates
- Department of Computer Science and Software Engineering, College of Information Technology, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Sanaa Elyassami
- Department of Computer Science, Abu Dhabi Polytechnic, Abu Dhabi, United Arab Emirates
| | - Anna Ponomareva
- Scientific-Research Institute of Medicine and Dentistry, Moscow State University of Medicine and Dentistry, Moscow, Russia
| | - Tom Loney
- Department of Public Health and Epidemiology, College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates
| | - Nerissa Naidoo
- Department of Anatomy, College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates
| | - Guido Hein Huib Mannaerts
- Department of Surgery, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
- Department of Surgery, Tawam Hospital, Abu Dhabi, United Arab Emirates
| | - Jamal Al Koteesh
- Department of Radiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
- Department of Radiology, Tawam Hospital, Abu Dhabi, United Arab Emirates
- Jamal Al Koteesh
| | - Milos R. Ljubisavljevic
- Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Karuna M. Das
- Department of Radiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
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Chang MS, Choi JH, Yang IH, An JS, Heo MS, Ahn SJ. Association between Condylar Bone Density and Disk Displacement in the Temporomandibular Joint. J Clin Densitom 2022; 25:215-222. [PMID: 34391639 DOI: 10.1016/j.jocd.2021.07.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 07/05/2021] [Accepted: 07/06/2021] [Indexed: 11/22/2022]
Abstract
Measuring bone density (BD) is a common method of determining bone quality; however, the relationship between condylar BD and the occurrence of temporomandibular joint (TMJ) disorders has not been investigated. To address this knowledge gap, we aimed to investigate condylar BD in terms of TMJ disk displacement (TMJ DD) using computed tomography (CT) and magnetic resonance imaging (MRI). We classified TMJ MRI results according to the position of the disk: normal disk position (Normal), anterior disk displacement with reduction (ADDR), and anterior disk displacement without reduction (ADDNR). After retrospectively evaluating 86 female condyles, we determined the total, cortical, and trabecular BD in the upper-joint portion of the condyle and the whole condyle using CT data. To standardize condylar BD, we calculated the BD ratios by dividing the condylar BD by the cervical axis BD. The Kruskal-Wallis test analyzed the differences in BD measurements in the TMJ DD patient groups and showed significant between-group differences in condylar BD. The total and trabecular BD was significantly higher in ADDNR condyles than in Normal or ADDR condyles (Normal = ADDR < ADDNR). However, there was no significant difference in the cortical BD among the three TMJ DD groups. The BD ratios showed a similar tendency with condylar BD. These results suggest that increased condylar BD - specifically total and trabecular BD - may be significantly associated with ADDNR condyles. Our findings will help clinicians determine the course of treatment for patients with disk-related TMJ disorders.
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Affiliation(s)
- Min-Seok Chang
- Department of Orthodontics and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea
| | - Jeong-Ho Choi
- Department of Orthodontics, Seoul National University Dental Hospital, Seoul, Korea
| | - Il-Hyung Yang
- Department of Orthodontics and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea
| | - Jung-Sub An
- Department of Orthodontics, Seoul National University Dental Hospital, Seoul, Korea
| | - Min-Suk Heo
- Department of Oral and Maxillofacial Radiology and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea
| | - Sug-Joon Ahn
- Department of Orthodontics and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea.
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Dahan G, Safran O, Yosibash Z. Can neck fractures in proximal humeri be predicted by CT-based FEA? J Biomech 2022; 136:111039. [PMID: 35381504 DOI: 10.1016/j.jbiomech.2022.111039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 03/07/2022] [Accepted: 03/08/2022] [Indexed: 10/18/2022]
Abstract
BACKGROUND Proximal humeri fractures at anatomical and surgical neck (∼5% and ∼50% incidence respectively) are frequent in elderly population. Yet, neither in-vitro experiments nor CT-based finite element analyses (CTFEA) have investigated these in depth. Herein we enhance (Dahan et al., 2019) (addressing anatomical neck fractures) by more experiments and specimens, accounting for surgical neck fractures and explore CTFEA's prediction of humeri mechanical response and yield force. METHODS Four fresh frozen human humeri were tested in a new experimental configuration inducing surgical neck fractures. Digital image correlation (DIC) provided strains and displacements on humeri surfaces and used to validate CTFEA predictions. CTFEA were enhanced herein to improve the accuracy at the proximal neck: A cortical bone mapping (CBM) algorithm was implemented to overcome insufficient scanning resolution, and a new trabecular material mapping was investigated. RESULTS The new experimental setting induced impacted surgical neck fractures in all humeri. Excellent DIC to CTFEA correlation in strains was obtained at the shaft (slope 0.984, R2=0.99) and a fair agreement (slope 0.807, R2=0.73) at the neck. CBM algorithm had worsened the correlation, whereas the new material mapping had a negligible influence. Yield loads predictions improved considerably when trabecular yielding (maximum principal strain criterion) was considered instead of surface cortical yielding. DISCUSSION CTFEA well predicts strains on the shaft and reasonably well on the neck. This enhances former conclusions by past studies conducted using SGs, now also evident by DIC. Yield load prediction for surgical neck fractures (involving crushing of trabecular bone) is predicted better by trabecular failure laws rather than cortex ones. Further FEA studies using trabecular orthotropic constitutive models and failure laws are warrant.
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Li C, Ma C, Zhuo X, Li L, Li B, Li S, Lu WW. Focal osteoporosis defect is associated with vertebral compression fracture prevalence in a bone mineral density-independent manner. JOR Spine 2022; 5:e1195. [PMID: 35386753 PMCID: PMC8966878 DOI: 10.1002/jsp2.1195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 12/19/2021] [Accepted: 02/07/2022] [Indexed: 11/13/2022] Open
Abstract
Introduction Focal osteoporosis defect has shown a high association with the bone fragility and osteoporotic fracture prevalence. However, no routine computed tomography (CT)‐based vertebral focal osteoporosis defect measurement and its association with vertebral compression fracture (VCF) were discussed yet. This study aimed to develop a routine CT‐based measurement method for focal osteoporosis defect quantification, and to assess its association with the VCF prevalence. Materials and Methods A total of 205 cases who underwent routine CT scanning, were retrospectively reviewed and enrolled into either the VCF or the control group. The focal bone mineral content loss (focal BMC loss), measured as the cumulated demineralization within bone void space, was proposed for focal osteoporosis defect quantification. Its scan‐rescan reproducibility and its correlation with trabecular bone mineral density (BMD) and apparent microarchitecture parameters were evaluated. The association between focal BMC loss and the prevalence of VCF was studied by logistic regression. Results The measurement of focal BMC loss showed high reproducibility (RMSSD = 0.011 mm, LSC = 0.030 mm, ICC = 0.97), and good correlation with focal bone volume fraction (r = 0.79, P < 0.001), trabecular bone separation (r = 0.76, P < 0.001), but poor correlation with trabecular BMD (r = 0.37, P < 0.001). The focal BMC loss was significantly higher in the fracture group than the control (1.03 ± 0.13 vs. 0.93 ± 0.11 mm; P < 0.001), and was associated with prevalent VCF (1.87, 95% CI = 1.31–2.65, P < 0.001) independent of trabecular BMD level. Discussion As a surrogate measure of focal osteoporosis defect, focal BMC Loss independently associated with the VCF prevalence. It suggests that focal osteoporosis defect is a common manifestation that positively contributed to compression fracture risk and can be quantified with routine CT using focal BMC Loss.
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Affiliation(s)
- Chentian Li
- Department of Orthopedics and Taumatology Zhujiang Hospital, Southern Medical University Guangzhou Guangdong China.,Department of Orthopaedics & Traumatology, Li Ka Shing Faculty of Medicine The University of Hong Kong Hong Kong SAR China
| | - Chi Ma
- Department of Orthopaedics & Traumatology, Li Ka Shing Faculty of Medicine The University of Hong Kong Hong Kong SAR China
| | - Xianglong Zhuo
- Department of Orthopaedics Liuzhou Worker's Hospital, Guangxi Medical University Liuzhou Guangxi China
| | - Li Li
- Department of Orthopaedics & Traumatology, Li Ka Shing Faculty of Medicine The University of Hong Kong Hong Kong SAR China.,Department of Orthopaedics Liuzhou Worker's Hospital, Guangxi Medical University Liuzhou Guangxi China
| | - Bing Li
- Department of Orthopaedics Liuzhou Worker's Hospital, Guangxi Medical University Liuzhou Guangxi China
| | - Songjian Li
- Department of Orthopedics and Taumatology Zhujiang Hospital, Southern Medical University Guangzhou Guangdong China
| | - William W Lu
- Department of Orthopaedics & Traumatology, Li Ka Shing Faculty of Medicine The University of Hong Kong Hong Kong SAR China.,SIAT & Shenzhen Institutes of Advanced Technology Chinese Academy of Science Shenzhen Guangdong China
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Ling M, Li X, Xu Y, Fan Y. Spatial distribution of hip cortical thickness in postmenopausal women with different osteoporotic fractures. Arch Osteoporos 2021; 16:172. [PMID: 34779934 DOI: 10.1007/s11657-021-01039-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Accepted: 11/08/2021] [Indexed: 02/03/2023]
Abstract
UNLABELLED Few studies h ave discussed the association between cortical bone outside the fracture site and the fracture itself. Focusing on hip cortical thickness, this study revealed distinct distributions of the parameters for hip (trochanteric or femoral neck), vertebral, and peripheral osteoporotic fractures and suggested that the spatial distribution of hip cortical thickness was fracture-specific. PURPOSE Cortical bone is critical for bone strength. Hip cortical thickness is reported to be closely associated with the incidence of hip fractures, but its relationship with nonhip fractures is rarely studied. As the hip is a major site for fracture risk assessment, it would be of great benefit to investigate the association between hip cortical thickness and different osteoporotic fractures. METHODS One hundred age-matched postmenopausal women were equally assigned to 4 osteoporotic fracture groups (trochanteric, femoral neck, vertebral, and peripheral fractures) and a nonfracture group. Each subject had a clinical quantitative computed tomography scan of the bilateral hips and the lumbar spine. A cortical bone mapping algorithm was adopted to calculate hip cortical thickness. Hip and lumbar trabecular density and the hip cortical thickness distribution were compared among the groups. RESULTS All the fracture groups presented lower lumbar trabecular density. Compared with nonfracture controls, patients with hip or vertebral fractures but not peripheral fractures showed decreased cortical thickness and trabecular density of the hip. Fracture-specific distributions of cortical thickness were revealed, including zonal defects on the neck-intertrochanter junction, greater trochanter, and the periphery of the lesser trochanter for trochanteric fractures, a focal defect on the anterosuperior neck for femoral neck fractures, a moderate and average distribution for vertebral fractures, and focally thicker cortices on the anterosuperior greater trochanter and the periphery of the lesser trochanter for peripheral fractures. CONCLUSION The spatial distribution of hip cortical thickness was different for each type of osteoporotic fracture, and patients with centrally located fractures demonstrated more severe cortical deterioration. This finding needs to be validated in a larger sample.
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Affiliation(s)
- Ming Ling
- Department of Orthopaedics, Huadong Hospital Affiliated to Fudan University, Shanghai, China
| | - Xianlong Li
- Department of Orthopaedics, Huadong Hospital Affiliated to Fudan University, Shanghai, China
| | - Yueyang Xu
- Department of Orthopaedics, Huadong Hospital Affiliated to Fudan University, Shanghai, China
| | - Yongqian Fan
- Department of Orthopaedics, Huadong Hospital Affiliated to Fudan University, Shanghai, China.
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Brown JP, Engelke K, Keaveny TM, Chines A, Chapurlat R, Foldes AJ, Nogues X, Civitelli R, De Villiers T, Massari F, Zerbini CAF, Wang Z, Oates MK, Recknor C, Libanati C. Romosozumab improves lumbar spine bone mass and bone strength parameters relative to alendronate in postmenopausal women: results from the Active-Controlled Fracture Study in Postmenopausal Women With Osteoporosis at High Risk (ARCH) trial. J Bone Miner Res 2021; 36:2139-2152. [PMID: 34190361 PMCID: PMC9292813 DOI: 10.1002/jbmr.4409] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 06/16/2021] [Accepted: 06/25/2021] [Indexed: 01/20/2023]
Abstract
The Active-Controlled Fracture Study in Postmenopausal Women With Osteoporosis at High Risk (ARCH) trial (NCT01631214; https://clinicaltrials.gov/ct2/show/NCT01631214) showed that romosozumab for 1 year followed by alendronate led to larger areal bone mineral density (aBMD) gains and superior fracture risk reduction versus alendronate alone. aBMD correlates with bone strength but does not capture all determinants of bone strength that might be differentially affected by various osteoporosis therapeutic agents. We therefore used quantitative computed tomography (QCT) and finite element analysis (FEA) to assess changes in lumbar spine volumetric bone mineral density (vBMD), bone volume, bone mineral content (BMC), and bone strength with romosozumab versus alendronate in a subset of ARCH patients. In ARCH, 4093 postmenopausal women with severe osteoporosis received monthly romosozumab 210 mg sc or weekly oral alendronate 70 mg for 12 months, followed by open-label weekly oral alendronate 70 mg for ≥12 months. Of these, 90 (49 romosozumab, 41 alendronate) enrolled in the QCT/FEA imaging substudy. QCT scans at baseline and at months 6, 12, and 24 were assessed to determine changes in integral (total), cortical, and trabecular lumbar spine vBMD and corresponding bone strength by FEA. Additional outcomes assessed include changes in aBMD, bone volume, and BMC. Romosozumab caused greater gains in lumbar spine integral, cortical, and trabecular vBMD and BMC than alendronate at months 6 and 12, with the greater gains maintained upon transition to alendronate through month 24. These improvements were accompanied by significantly greater increases in FEA bone strength (p < 0.001 at all time points). Most newly formed bone was accrued in the cortical compartment, with romosozumab showing larger absolute BMC gains than alendronate (p < 0.001 at all time points). In conclusion, romosozumab significantly improved bone mass and bone strength parameters at the lumbar spine compared with alendronate. These results are consistent with greater vertebral fracture risk reduction observed with romosozumab versus alendronate in ARCH and provide insights into structural determinants of this differential treatment effect. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Jacques P Brown
- Centre Hospitalier Universitaire (CHU) de Québec Research Centre, Department of Medicine, Rheumatology Division, Laval University, Quebec City, Québec, Canada
| | - Klaus Engelke
- Bioclinica, Hamburg, Germany.,Department of Medicine 3, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Germany
| | - Tony M Keaveny
- Departments of Mechanical Engineering and Bioengineering, University of California Berkeley, Berkeley, California, USA
| | | | - Roland Chapurlat
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unités Mixtes de Recherche (UMR) 1033, Université de Lyon, Hôpital E Herriot, Lyon, France
| | - A Joseph Foldes
- Osteoporosis Center, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Xavier Nogues
- Institut Hospital del Mar d'Investigacions Mèdiques (IMIM), Centro de Investigación Biomédica en Red Fragilidad y Envejecimiento Saludable (CIBERFES), Autonomous University of Barcelona, Barcelona, Spain
| | - Roberto Civitelli
- Musculoskeletal Research Center, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Tobias De Villiers
- Department of Obstetrics and Gynaecology, Stellenbosch University, Stellenbosch, South Africa
| | - Fabio Massari
- Instituto de Diagnóstico e Investigaciones Metabólicas, Buenos Aires, Argentina
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11
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Warden SJ, Wright CS, Fuchs RK. Bone Microarchitecture and Strength Adaptation to Physical Activity: A Within-Subject Controlled HRpQCT Study. Med Sci Sports Exerc 2021; 53:1179-1187. [PMID: 33394902 DOI: 10.1249/mss.0000000000002571] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE Physical activity benefits bone mass and cortical bone size. The current study assessed the impact of chronic (≥10 yr) physical activity on trabecular microarchitectural properties and microfinite element analyses of estimated bone strength. METHODS Female collegiate-level tennis players (n = 15; age = 20.3 ± 0.9 yr) were used as a within-subject controlled model of chronic unilateral upper-extremity physical activity. Racquet-to-nonracquet arm differences at the distal radius and radial diaphysis were assessed using high-resolution peripheral quantitative computed tomography. The distal tibia and the tibial diaphysis in both legs were also assessed, and cross-country runners (n = 15; age = 20.8 ± 1.2 yr) included as controls. RESULTS The distal radius of the racquet arm had 11.8% (95% confidence interval [CI] = 7.9% to 15.7%) greater trabecular bone volume/tissue volume, with trabeculae that were greater in number, thickness, connectivity, and proximity to each other than that in the nonracquet arm (all P < 0.01). Combined with enhanced cortical bone properties, the microarchitectural advantages at the distal radius contributed a 18.7% (95% CI = 13.0% to 24.4%) racquet-to-nonracquet arm difference in predicted load before failure. At the radial diaphysis, predicted load to failure was 9.6% (95% CI = 6.7% to 12.6%) greater in the racquet versus nonracquet arm. There were fewer and smaller side-to-side differences at the distal tibia; however, the tibial diaphysis in the leg opposite the racquet arm was larger with a thicker cortex and had 4.4% (95% CI = 1.7% to 7.1%) greater strength than the contralateral leg. CONCLUSION Chronically elevated physical activity enhances trabecular microarchitecture and microfinite element estimated strength, furthering observations from short-term longitudinal studies. The data also demonstrate that tennis players exhibit crossed symmetry wherein the leg opposite the racquet arm possesses enhanced tibial properties compared with in the contralateral leg.
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12
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Almendros-Abellán VM, Castro-García M, Canales-Vázquez J, Berenguel-Herraiz P, Sabater S. Alterations in femoral neck strength following pelvic irradiation. A finite element analysis of simulated eccentric forces using bone density data derived from CT. Bone 2021; 145:115865. [PMID: 33513450 DOI: 10.1016/j.bone.2021.115865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 01/19/2021] [Accepted: 01/21/2021] [Indexed: 10/22/2022]
Abstract
BACKGROUND AND PURPOSE Radiotherapy is known to produce long-term skeletal complications. We aim to evaluate the biomechanical effect on femoral neck bone from hypothetical eccentric loads on pre- and post-radiotherapy CT-images for patients treated for rectal cancer. MATERIAL AND METHODS Pre- and post-radiotherapy CT-images of rectal cancer from 10 patients were selected randomly. The cortical and trabecular bone was segmented by hand. The biomechanical simulations of 4 eccentric loads and one load aligned with the femoral neck axis were completed using finite element analysis (FEA) in both pre- and post-patient models. RESULTS A comparative statistical study was completed of pre- and post-radiotherapy patient models of stress and displacement factors. Significant differences were found in eccentric loads in both factors. Natural load has a significant difference in stress, but no differences were found for displacements. The absolute difference in eccentric load applied to the anterior area location on the same patient implies from 5.3% to 40.5% of the stress yield values reported in previous studies. CONCLUSIONS Loads applied to the anterior area of the femoral head must be considered in fracture simulations because the percentage of yield stress of pre- and post-irradiated bones shows a significant biomechanical change.
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Affiliation(s)
- Víctor M Almendros-Abellán
- D-ENERMAT, Instituto de Energías Renovables, University of Castilla-La Mancha, Paseo Investigación 1, Building 3, 02071 Albacete, Spain; CADE Engineered Technologies, Albacete, Spain
| | - Miguel Castro-García
- D-ENERMAT, Instituto de Energías Renovables, University of Castilla-La Mancha, Paseo Investigación 1, Building 3, 02071 Albacete, Spain
| | - Jesús Canales-Vázquez
- D-ENERMAT, Instituto de Energías Renovables, University of Castilla-La Mancha, Paseo Investigación 1, Building 3, 02071 Albacete, Spain
| | | | - Sebastià Sabater
- Dept. of Radiation Oncology, Complejo Hospitalario Universitario de Albacete, Spain.
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13
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QCT-FE modeling of the proximal tibia: Effect of mapping strategy on convergence time and model accuracy. Med Eng Phys 2021; 88:41-46. [PMID: 33485512 DOI: 10.1016/j.medengphy.2020.12.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 12/04/2020] [Accepted: 12/22/2020] [Indexed: 11/21/2022]
Abstract
Quantitative computed tomography (QCT) based finite element (FE) modeling, referred to as QCT-FE, has seen rapid growth and application for modeling bone mechanics. With this approach, varying bone material properties are set via experimentally-derived density-modulus equations. One challenge though associated with QCT-FE is to identify the appropriate mapping strategy for assigning elastic moduli to elements. The goal of this study was to evaluate different QCT-FE mapping strategies to identify the optimum approach with fastest convergence rate and highest accuracy. Four proximal tibial medial compartments were imaged using QCT and experimentally tested to characterize proximal tibial subchondral bone stiffness at four surface points, resulting in a total of 16 indentation measures. Three material mapping methods were analyzed: (1) constant-E where an average elastic modulus was assigned to each element; (2) node-based where the material properties were first mapped on nodes then interpolated to Gaussian integration points; and (3) element-based in which the material properties were directly assigned to Gaussian integration points. Different element sizes were assessed with edge-lengths ranging from 0.9 to 3 mm. Results indicated that all converged models showed similar coefficient-of-determination (R2) and normalized root-mean-square errors (RMSE%). Though, the constant-E and node-based methods converged with the element edge-length of 1.5 mm (prediction error of 4.8% and 2.5%, respectively) whereas the element-based method converged with a larger element having an edge-length 2.5 mm (error = 4.9%). In conclusion, the element-based method, with a larger element size, resulted in similar predictive accuracy, faster convergence and shorter run-times relative to the constant-E and node-based approaches. As such, we recommend the element-based method for future subject-specific QCT-FE modeling.
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14
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Odeh K, Rosinski A, Leasure J, Kondrashov D. Pedicle Screws Challenged: Lumbar Cortical Density and Thickness Are Greater in the Posterior Elements Than in the Pedicles. Global Spine J 2021; 11:34-43. [PMID: 32875847 PMCID: PMC7734267 DOI: 10.1177/2192568219889361] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
STUDY DESIGN Controlled laboratory study. OBJECTIVE To measure the total bone mineral density (BMD), cortical volume, and cortical thickness in seven different anatomical regions of the lumbar spine. METHODS Using computed tomography (CT) images, 3 cadaveric spines were digitally isolated by applying filters for cortical and cancellous bone. Each spine model was separated into 5 lumbar vertebrae, followed by segmentation of each vertebra into 7 anatomical regions of interest using 3-dimensional software modeling. The average Hounsfield units (HU) was determined for each region and converted to BMD with calibration phantoms of known BMD. These BMD measurements were further analyzed by the total volume, cortical volume, and cancellous volume. The cortical thickness was also measured. A similar analysis was performed by vertebral segment. St Mary's Medical Center's Institutional Review Board approved this study. No external funding was received for this work. RESULTS The lamina and inferior articular process contained the highest total BMD, thickest cortical shell, and largest percent volumes of cortical bone. The vertebral body demonstrated the lowest BMD. The BMDs of the L4 and L5 segments were lower; however, there were no statistically significant differences in BMD between the L1-L5 vertebral segments. CONCLUSION Extrapedicular regions of the lumbar vertebrae, including the lamina and inferior articular process, contain denser bone than the pedicles. Since screw pullout strength relies greatly on bone density, the lamina and inferior articular processes may offer stronger fixation of the lumbar spine.
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Affiliation(s)
- Khalid Odeh
- St Mary’s Medical Center, San Francisco Orthopaedic Residency Program, San Francisco, CA, USA
| | | | - Jeremi Leasure
- St Mary’s Medical Center, San Francisco Orthopaedic Residency Program, San Francisco, CA, USA,The Taylor Collaboration, San Francisco, CA, USA,Jeremi Leasure, MSE, San Francisco Orthopaedic Residency Program, 450 Stanyan Street, San Francisco, CA 94117, USA.
| | - Dimitriy Kondrashov
- St Mary’s Medical Center, San Francisco Orthopaedic Residency Program, San Francisco, CA, USA,San Francisco Spine Surgeons, San Francisco, CA, USA
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15
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Engelkes K. Accuracy of bone segmentation and surface generation strategies analyzed by using synthetic CT volumes. J Anat 2020; 238:1456-1471. [PMID: 33325545 DOI: 10.1111/joa.13383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 11/19/2020] [Accepted: 11/25/2020] [Indexed: 11/30/2022] Open
Abstract
Different kinds of bone measurements are commonly derived from computed-tomography (CT) volumes to answer a multitude of questions in biology and related fields. The underlying steps of bone segmentation and, optionally, polygon surface generation are crucial to keep the measurement error small. In this study, the performance of different, easily accessible segmentation techniques (global thresholding, automatic local thresholding, weighted random walk, neural network, and watershed) and surface generation approaches (different algorithms combined with varying degrees of simplification) was analyzed and recommendations for minimizing inaccuracies were derived. The different approaches were applied to synthetic CT volumes for which the correct segmentation and surface geometry were known. The most accurate segmentations of the synthetic volumes were achieved by setting a case-specific window to the gray value histogram and subsequently applying automatic local thresholding with appropriately chosen thresholding method and radius. Surfaces generated by the Amira® module Generate Lego Surface in combination with careful surface simplification were the most accurate. Surfaces with sub-voxel accuracy were obtained even for synthetic CT volumes with low contrast-to-noise ratios. Segmentation trials with real CT volumes supported the findings. Very accurate segmentations and surfaces can be derived from CT volumes by using readily accessible software packages. The presented results and derived recommendations will help to reduce the measurement error in future studies. Furthermore, the demonstrated strategies for assessing segmentation and surface qualities can be adopted to quantify the performance of new segmentation approaches in future studies.
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Affiliation(s)
- Karolin Engelkes
- Center of Natural History (CeNak), Universität Hamburg, Hamburg, Germany
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16
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Besler BA, Michalski AS, Kuczynski MT, Abid A, Forkert ND, Boyd SK. Bone and joint enhancement filtering: Application to proximal femur segmentation from uncalibrated computed tomography datasets. Med Image Anal 2020; 67:101887. [PMID: 33181434 DOI: 10.1016/j.media.2020.101887] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 09/14/2020] [Accepted: 10/22/2020] [Indexed: 01/22/2023]
Abstract
Methods for reliable femur segmentation enable the execution of quality retrospective studies and building of robust screening tools for bone and joint disease. An enhance-and-segment pipeline is proposed for proximal femur segmentation from computed tomography datasets. The filter is based on a scale-space model of cortical bone with properties including edge localization, invariance to density calibration, rotation invariance, and stability to noise. The filter is integrated with a graph cut segmentation technique guided through user provided sparse labels for rapid segmentation. Analysis is performed on 20 independent femurs. Rater proximal femur segmentation agreement was 0.21 mm (average surface distance), 0.98 (Dice similarity coefficient), and 2.34 mm (Hausdorff distance). Manual segmentation added considerable variability to measured failure load and volume (CVRMS > 5%) but not density. The proposed algorithm considerably improved inter-rater reproducibility for all three outcomes (CVRMS < 0.5%). The algorithm localized the periosteal surface accurately compared to manual segmentation but with a slight bias towards a smaller volume. Hessian-based filtering and graph cut segmentation localizes the periosteal surface of the proximal femur with comparable accuracy and improved precision compared to manual segmentation.
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Affiliation(s)
- Bryce A Besler
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, Canada; Department of Radiology, University of Calgary, Calgary, Canada
| | - Andrew S Michalski
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, Canada; Department of Radiology, University of Calgary, Calgary, Canada
| | - Michael T Kuczynski
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, Canada; Department of Radiology, University of Calgary, Calgary, Canada
| | - Aleena Abid
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, Canada; Department of Radiology, University of Calgary, Calgary, Canada
| | - Nils D Forkert
- Department of Radiology, University of Calgary, Calgary, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, Canada
| | - Steven K Boyd
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, Canada; Department of Radiology, University of Calgary, Calgary, Canada.
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Maeda K, Mochizuki T, Kobayashi K, Tanifuji O, Someya K, Hokari S, Katsumi R, Morise Y, Koga H, Sakamoto M, Koga Y, Kawashima H. Cortical thickness of the tibial diaphysis reveals age- and sex-related characteristics between non-obese healthy young and elderly subjects depending on the tibial regions. J Exp Orthop 2020; 7:78. [PMID: 33025285 PMCID: PMC7538524 DOI: 10.1186/s40634-020-00297-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 09/28/2020] [Indexed: 11/10/2022] Open
Abstract
PURPOSE This study aimed to evaluate the age- and sex-related characteristics in cortical thickness of the tibial diaphysis between non-obese healthy young and elderly subjects as reference data. METHODS The study investigated 31 young subjects (12 men and 19 women; mean age, 25 ± 8 years) and 54 elderly subjects (29 men and 25 women; mean age, 70 ± 6 years). Three-dimensional estimated cortical thickness of the tibial diaphysis was automatically calculated for 5000-9000 measurement points using the high-resolution cortical thickness measurement from clinical computed tomography data. In 12 assessment regions created by combining three heights (proximal, central, and distal diaphysis) and four areas of the axial plane at 90° (medial, anterior, lateral, and posterior areas) in the tibial coordinate system, the standardized thickness was assessed using the tibial length. RESULTS As structural characteristics, there were no differences in the medial and lateral thicknesses, while the anterior thickness was greater than the posterior thickness in all groups. The sex-related difference was not shown. As an age-related difference, elderly subjects showed greater or lesser cortical thickness than the young subjects, depending on the regions of the tibia. CONCLUSIONS Cortical thickness was different depending on sex, age, and regions in the tibia. The results of this study are of clinical relevance as reference points to clarify the causes of various pathological conditions for diseases. LEVEL OF EVIDENCE Level 3.
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Affiliation(s)
- Keisuke Maeda
- Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Science, 1-757 Asahimachi-dori Chuo-ku, Niigata City, Niigata, 951-8510, Japan
| | - Tomoharu Mochizuki
- Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Science, 1-757 Asahimachi-dori Chuo-ku, Niigata City, Niigata, 951-8510, Japan.
| | - Koichi Kobayashi
- School of Health Sciences, Faculty of Medicine, Niigata University, Niigata, Japan
| | - Osamu Tanifuji
- Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Science, 1-757 Asahimachi-dori Chuo-ku, Niigata City, Niigata, 951-8510, Japan
| | - Keiichiro Someya
- Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Science, 1-757 Asahimachi-dori Chuo-ku, Niigata City, Niigata, 951-8510, Japan
| | - Sho Hokari
- Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Science, 1-757 Asahimachi-dori Chuo-ku, Niigata City, Niigata, 951-8510, Japan
| | - Ryota Katsumi
- Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Science, 1-757 Asahimachi-dori Chuo-ku, Niigata City, Niigata, 951-8510, Japan
| | - Yusuke Morise
- Graduate School of Science and Technology, Niigata University, Niigata, Japan
| | - Hiroshi Koga
- Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Science, 1-757 Asahimachi-dori Chuo-ku, Niigata City, Niigata, 951-8510, Japan
| | - Makoto Sakamoto
- School of Health Sciences, Faculty of Medicine, Niigata University, Niigata, Japan
| | - Yoshio Koga
- Department of Orthopedic Surgery, Nioji Onsen Hospital, Niigata, Japan
| | - Hiroyuki Kawashima
- Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Science, 1-757 Asahimachi-dori Chuo-ku, Niigata City, Niigata, 951-8510, Japan
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18
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Someya K, Mochizuki T, Hokari S, Tanifuji O, Katsumi R, Koga H, Takahashi Y, Kobayashi K, Morise Y, Sakamoto M, Koga Y, Endo N. Age- and sex-related characteristics in cortical thickness of femoral diaphysis for young and elderly subjects. J Bone Miner Metab 2020; 38:533-543. [PMID: 32002681 DOI: 10.1007/s00774-019-01079-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Accepted: 12/21/2019] [Indexed: 01/03/2023]
Abstract
INTRODUCTION Cortical thickness of the femoral diaphysis is assumed to be a preferred parameter in the assessment of the structural adaptation by mechanical use and biological factors. This study aimed to investigate the age- and sex-specific characteristics in cortical thickness of the femoral diaphysis between young and elderly non-obese people. MATERIALS AND METHODS This study investigated 34 young subjects (21 men and 13 women; mean age: 27 ± 8 years) and 52 elderly subjects (29 men and 23 women; mean age: 70 ± 6 years). Three-dimensional (3D) cortical thickness of the femoral diaphysis was automatically calculated for 5000-8000 measurement points using the high-resolution cortical thickness measurement from clinical CT data. In 12 assessment regions created by combining three heights (proximal, central, and distal diaphysis) and four areas of the axial plane at 90° (medial, anterior, lateral, and posterior areas) in the femoral coordinate system, the standardized thickness was assessed using the femoral length. RESULTS As per the trends, (1) there were no differences in medial and lateral thicknesses, while the posterior thickness was greater than the anterior thickness, (2) the thickness in men was higher than that in women, and (3) the thickness in young subjects was higher than that in elderly subjects. CONCLUSIONS The results of this study are of clinical relevance as reference points to clarify the causes of various pathological conditions for diseases of the lower extremities.
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Affiliation(s)
- Keiichiro Someya
- Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Science, 1-757 Asahimachi-dori Chuo-ku, Niigata City, Niigata, 951-8510, Japan
| | - Tomoharu Mochizuki
- Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Science, 1-757 Asahimachi-dori Chuo-ku, Niigata City, Niigata, 951-8510, Japan.
| | - Sho Hokari
- Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Science, 1-757 Asahimachi-dori Chuo-ku, Niigata City, Niigata, 951-8510, Japan
| | - Osamu Tanifuji
- Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Science, 1-757 Asahimachi-dori Chuo-ku, Niigata City, Niigata, 951-8510, Japan
| | - Ryota Katsumi
- Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Science, 1-757 Asahimachi-dori Chuo-ku, Niigata City, Niigata, 951-8510, Japan
| | - Hiroshi Koga
- Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Science, 1-757 Asahimachi-dori Chuo-ku, Niigata City, Niigata, 951-8510, Japan
| | - Yuki Takahashi
- Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Science, 1-757 Asahimachi-dori Chuo-ku, Niigata City, Niigata, 951-8510, Japan
| | - Koichi Kobayashi
- School of Health Sciences, Faculty of Medicine, Niigata University, Niigata, Japan
| | - Yusuke Morise
- Graduate School of Science and Technology, Niigata University, Niigata, Japan
| | - Makoto Sakamoto
- School of Health Sciences, Faculty of Medicine, Niigata University, Niigata, Japan
| | - Yoshio Koga
- Department of Orthopedic Surgery, Nioji Onsen Hospital, Niigata, Japan
| | - Naoto Endo
- Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Science, 1-757 Asahimachi-dori Chuo-ku, Niigata City, Niigata, 951-8510, Japan
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Setzer FC, Shi KJ, Zhang Z, Yan H, Yoon H, Mupparapu M, Li J. Artificial Intelligence for the Computer-aided Detection of Periapical Lesions in Cone-beam Computed Tomographic Images. J Endod 2020; 46:987-993. [PMID: 32402466 DOI: 10.1016/j.joen.2020.03.025] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 03/19/2020] [Accepted: 03/24/2020] [Indexed: 12/21/2022]
Abstract
INTRODUCTION The aim of this study was to use a Deep Learning (DL) algorithm for the automated segmentation of cone-beam computed tomographic (CBCT) images and the detection of periapical lesions. METHODS Limited field of view CBCT volumes (n = 20) containing 61 roots with and without lesions were segmented clinician dependent versus using the DL approach based on a U-Net architecture. Segmentation labeled each voxel as 1 of 5 categories: "lesion" (periapical lesion), "tooth structure," "bone," "restorative materials," and "background." Repeated splits of all images into a training set and a validation set based on 5-fold cross validation were performed using Deep Learning segmentation (DLS), and the results were averaged. DLS versus clinical-dependent segmentation was assessed by dichotomized lesion detection accuracy evaluating sensitivity, specificity, positive predictive value, negative predictive value, and voxel-matching accuracy using the DICE index for each of the 5 labels. RESULTS DLS lesion detection accuracy was 0.93 with specificity of 0.88, positive predictive value of 0.87, and negative predictive value of 0.93. The overall cumulative DICE indexes for the individual labels were lesion = 0.52, tooth structure = 0.74, bone = 0.78, restorative materials = 0.58, and background = 0.95. The cumulative DICE index for all actual true lesions was 0.67. CONCLUSIONS This DL algorithm trained in a limited CBCT environment showed excellent results in lesion detection accuracy. Overall voxel-matching accuracy may be benefited by enhanced versions of artificial intelligence.
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Affiliation(s)
- Frank C Setzer
- Department of Endodontics, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
| | - Katherine J Shi
- Private Practice, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Zhiyang Zhang
- School of Computing, Informatics, and Decision Systems Engineering, Arizona State University, Tempe, Arizona
| | - Hao Yan
- School of Computing, Informatics, and Decision Systems Engineering, Arizona State University, Tempe, Arizona
| | - Hyunsoo Yoon
- School of Computing, Informatics, and Decision Systems Engineering, Arizona State University, Tempe, Arizona
| | - Mel Mupparapu
- Department of Oral Medicine, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jing Li
- School of Computing, Informatics, and Decision Systems Engineering, Arizona State University, Tempe, Arizona
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20
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Davis AT, Muscat S, Palmer AL, Buckle D, Earley J, Williams MG, Nisbet A. Radiation dosimetry changes in radiotherapy treatment plans for adult patients arising from the selection of the CT image reconstruction kernel. BJR Open 2019; 1:20190023. [PMID: 33178950 PMCID: PMC7592475 DOI: 10.1259/bjro.20190023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 06/04/2019] [Accepted: 06/17/2019] [Indexed: 11/05/2022] Open
Abstract
Objective: The reconstruction kernel used for a CT scan strongly influences the image quality. This work investigates the changes in Hounsfield units (HUs) which can arise when altering the image reconstruction kernel for planning CT images and the associated changes in dose in the radiotherapy treatment plan if the treatment planning system (TPS) is not re-calibrated. Methods: Head and neck, prostate and lung CT images from four centres were used. For a specific scan, the base image was acquired using the original reconstruction kernel (used when the TPS was calibrated) and the treatment plan produced. The treatment plan was applied to all images from the other reconstruction kernels. Differences in dose-volume metrics for the planning target volume (PTV) and organs at risk (OARs) were noted and HU differences between images measured for air, soft tissue and bone. Results: HU change in soft tissue had the greatest influence on dose change. When within ±20 HU for soft tissue and ±50 HU for bone and air the dose change in the PTV and OAR was within ±0.5% and ±1% respectively. Conclusions: When imaging parameters were changed, if HU change was within ±20 HU for soft tissue and ±50 HU for bone and air, the change in the PTV and OAR doses was below 1%. Advances in knowledge: The degree of dose change in the treatment plan with HU change is demonstrated for current TPS algorithms. This adds to the limited evidence base for recommendations on HU tolerances as a tool for radiotherapy CT protocol optimization.
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Affiliation(s)
- Anne T Davis
- Department of Physics, Faculty of Engineering and Physical Science, University of Surrey, Surrey, Canada
- Department of Medical Physics, Portsmouth Hospitals NHS Trust, Portsmouth, UK
| | - Sarah Muscat
- Department of Medical Physics, Portsmouth Hospitals NHS Trust, Portsmouth, UK
| | - Antony L. Palmer
- Department of Physics, Faculty of Engineering and Physical Science, University of Surrey, Surrey, Canada
- Department of Medical Physics, Portsmouth Hospitals NHS Trust, Portsmouth, UK
| | - David Buckle
- Department of Medical Physics, Royal Berkshire NHS Foundation Trust Reading, Reading, UK
| | - James Earley
- Department of Medical Physics, Royal Surrey County Hospital NHS Foundation Trust, Guildford, UK
| | | | - Andrew Nisbet
- Department of Physics, Faculty of Engineering and Physical Science, University of Surrey, Surrey, Canada
- Department of Medical Physics, Royal Surrey County Hospital NHS Foundation Trust, Guildford, UK
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21
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Zaharie DT, Phillips ATM. Pelvic Construct Prediction of Trabecular and Cortical Bone Structural Architecture. J Biomech Eng 2019; 140:2678341. [PMID: 29801165 DOI: 10.1115/1.4039894] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Indexed: 11/08/2022]
Abstract
The pelvic construct is an important part of the body as it facilitates the transfer of upper body weight to the lower limbs and protects a number of organs and vessels in the lower abdomen. In addition, the importance of the pelvis is highlighted by the high mortality rates associated with pelvic trauma. This study presents a mesoscale structural model of the pelvic construct and the joints and ligaments associated with it. Shell elements were used to model cortical bone, while truss elements were used to model trabecular bone and the ligaments and joints. The finite element (FE) model was subjected to an iterative optimization process based on a strain-driven bone adaptation algorithm. The bone model was adapted to a number of common daily living activities (walking, stair ascent, stair descent, sit-to-stand, and stand-to-sit) by applying onto it joint and muscle loads derived using a musculoskeletal modeling framework. The cortical thickness distribution and the trabecular architecture of the adapted model were compared qualitatively with computed tomography (CT) scans and models developed in previous studies, showing good agreement. The sensitivity of the model to changes in material properties of the ligaments and joint cartilage and changes in parameters related to the adaptation algorithm was assessed. Changes to the target strain had the largest effect on predicted total bone volumes. The model showed low sensitivity to changes in all other parameters. The minimum and maximum principal strains predicted by the structural model compared to a continuum CT-derived model in response to a common test loading scenario showed good agreement with correlation coefficients of 0.813 and 0.809, respectively. The developed structural model enables a number of applications such as fracture modeling, design, and additive manufacturing of frangible surrogates.
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Affiliation(s)
- Dan T Zaharie
- The Royal British Legion Centre for Blast Injury Studies, Imperial College London, London SW7 2AZ, UK.,Structural Biomechanics, Department of Civil and Environmental Engineering, Imperial College London, Skempton Building, South Kensington Campus, London SW7 2AZ, UK e-mail:
| | - Andrew T M Phillips
- The Royal British Legion Centre for Blast Injury Studies, , London SW7 2AZ, UK.,Structural Biomechanics, Department of Civil and Environmental Engineering, Imperial College London, , London SW7 2AZ, UK e-mail:
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22
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Hosseini Kalajahi SM, Nazemi SM, Johnston JD. Separate modeling of cortical and trabecular bone offers little improvement in FE predictions of local structural stiffness at the proximal tibia. Comput Methods Biomech Biomed Engin 2019; 22:1258-1268. [DOI: 10.1080/10255842.2019.1661386] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
| | - S. Majid Nazemi
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Canada
| | - James D. Johnston
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Canada
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23
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Daniels AM, Theelen LMA, Wyers CE, Janzing HMJ, van Rietbergen B, Vranken L, van der Velde RY, Geusens PPMM, Kaarsemaker S, Poeze M, van den Bergh JP. Bone Microarchitecture and Distal Radius Fracture Pattern Complexity. J Orthop Res 2019; 37:1690-1697. [PMID: 30977554 PMCID: PMC6767516 DOI: 10.1002/jor.24306] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 03/02/2019] [Accepted: 03/27/2019] [Indexed: 02/04/2023]
Abstract
Distal radius fractures (DRFs) occur in various complexity patterns among patients differing in age, gender, and bone mineral density (BMD). Our aim was to investigate the association of patient characteristics, BMD, bone microarchitecture, and bone strength with the pattern complexity of DRFs. In this study, 251 patients aged 50-90 years with a radiologically confirmed DRF who attended the Fracture Liaison Service of VieCuri Medical Centre, the Netherlands, between November 2013 and June 2016 were included. In all patients fracture risk factors and underling metabolic disorders were evaluated and BMD measurement with vertebral fractures assessment by dual-energy X-ray absorptiometry was performed. Radiographs of all DRFs were reviewed by two independent investigators to assess fracture pattern complexity according to the AO/OTA classification in extra-articular (A), partially articular (B), and complete articular (C) fractures. For this study, patients with A and C fractures were compared. Seventy-one patients were additionally assessed by high-resolution peripheral quantitative computed tomography. Compared to group A, mean age, the proportion of males, and current smokers were higher in group C, but BMD and prevalent vertebral fractures were not different. In univariate analyses, age, male gender, trabecular area, volumetric BMD (vBMD), and stiffness were associated with type C fractures. In multivariate analyses, only male gender (odds ratio (OR) 8.48 95% confidence interval (CI) 1.75-41.18, p = 0.008]) and age (OR 1.11 [95% CI 1.03-1.19, p = 0.007]) were significantly associated with DRF pattern complexity. In conclusion, our data demonstrate that age and gender, but not body mass index, BMD, bone microarchitecture, or strength were associated with pattern complexity of DRFs.© 2019 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. J Orthop Res 37:1690-1697, 2019.
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Affiliation(s)
- Anne M. Daniels
- Department of SurgeryVieCuri Medical CentreVenloThe Netherlands,NUTRIM School for Nutrition and Translational Research in MetabolismMaastricht UniversityMaastrichtThe Netherlands
| | - Luuk M. A. Theelen
- Department of Orthopaedic SurgeryVieCuri Medical CentreVenloThe Netherlands
| | - Caroline E. Wyers
- NUTRIM School for Nutrition and Translational Research in MetabolismMaastricht UniversityMaastrichtThe Netherlands,Department of Internal MedicineVieCuri Medical CentreVenloThe Netherlands,Department of Internal MedicineMaastricht UniversityMaastrichtThe Netherlands
| | | | - Bert van Rietbergen
- Department of Biomedical Engineering, Orthopaedic BiomechanicsEindhoven University of TechnologyEind hovenThe Netherlands,Department of Orthopaedic Surgery, Research School CAPHRIMaastricht University Medical CentreMaastrichtThe Netherlands
| | - Lisanne Vranken
- NUTRIM School for Nutrition and Translational Research in MetabolismMaastricht UniversityMaastrichtThe Netherlands,Department of Internal MedicineVieCuri Medical CentreVenloThe Netherlands
| | - Robert Y. van der Velde
- NUTRIM School for Nutrition and Translational Research in MetabolismMaastricht UniversityMaastrichtThe Netherlands,Department of Internal MedicineVieCuri Medical CentreVenloThe Netherlands
| | - Piet P. M. M. Geusens
- Department of Internal MedicineMaastricht UniversityMaastrichtThe Netherlands,Faculty of Medicine, Division of Internal MedicineHasselt UniversityHasseltBelgium
| | - Sjoerd Kaarsemaker
- Department of Orthopaedic SurgeryVieCuri Medical CentreVenloThe Netherlands
| | - Martijn Poeze
- NUTRIM School for Nutrition and Translational Research in MetabolismMaastricht UniversityMaastrichtThe Netherlands,Department of Surgery, Division of TraumasurgeryMaastricht University Medical CentreMaastrichtThe Netherlands
| | - Joop P. van den Bergh
- NUTRIM School for Nutrition and Translational Research in MetabolismMaastricht UniversityMaastrichtThe Netherlands,Department of Internal MedicineVieCuri Medical CentreVenloThe Netherlands,Department of Internal MedicineMaastricht UniversityMaastrichtThe Netherlands,Faculty of Medicine, Division of Internal MedicineHasselt UniversityHasseltBelgium
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24
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Su YB, Wang L, Wu XB, Yi C, Yang MH, Yan D, Cheng KB, Cheng XG. The spatial differences in bone mineral density and hip structure between low-energy femoral neck and trochanteric fractures in elderly Chinese using quantitative computed tomography. Bone 2019; 124:62-68. [PMID: 31004806 DOI: 10.1016/j.bone.2019.04.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Revised: 03/12/2019] [Accepted: 04/13/2019] [Indexed: 11/28/2022]
Abstract
The purpose of this study was to investigate the differences in bone mineral density (BMD) and hip structure between femoral neck and trochanteric fractures in elderly Chinese individuals using quantitative computed tomography (QCT). A total of 625 Chinese patients (mean age 75.8 years) who sustained low-energy hip fractures (female: 293 femoral neck, 175 trochanteric; male: 82 femoral neck, 75 trochanteric) were recruited. Each patient underwent a hip QCT scan. The areal BMD (aBMD) of the contralateral normal hip was obtained using a computed tomography X-ray absorptiometry module. Using the bone investigation toolkit (BIT) module, the femoral neck was divided into four quadrants: supero-anterior (SA), infero-anterior (IA), infero-posterior (IP), and supero-posterior (SP). Estimated cortical thickness, cortical BMD, and trabecular BMD were measured in each quadrant. Using the hip structure analysis (HSA) function, several parameters were calculated. Stratified by sex, covariance analyses were applied to compare the femoral neck fractures group with trochanteric fractures group after adjustments for age, height, and weight. In women, trochanteric fractures exhibited lower trabecular BMD and estimated cortical thickness at three quadrants of the femoral neck (IA: P = 0.02, P < 0.01; IP: P < 0.01, P = 0.01; SP: P = 0.01, P < 0.01), and lower aBMD at the trochanter area (P < 0.01); femoral neck fractures exhibited lower cortical BMD and estimated cortical thickness at the SA quadrant (P = 0.04, P = 0.01). Differences in HSA parameters were not statistically significant. Among all parameters, the most valuable ones to discrimination of hip fracture type are estimated cortical thickness of the SA quadrant of femoral neck and the aBMD of the trochanter area. In men, only lower cortical BMD at the SP quadrant and aBMD at the trochanter were found in the trochanteric fractures (P = 0.02, P < 0.01). QCT outcomes indicate that spatial differences are helpful to explore the pathogenesis of different type of hip fractures. In women, trochanteric fractures are related to severer osteoporosis, whereas cortical fragility in the SA region of the femoral neck predominates in cases of femoral neck fractures. In men, trochanteric fractures are related to more bone loss of trochanter.
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Affiliation(s)
- Yong-Bin Su
- Department of Radiology, Beijing Jishuitan Hospital, Beijing, China
| | - Ling Wang
- Department of Radiology, Beijing Jishuitan Hospital, Beijing, China
| | - Xin-Bao Wu
- Department of Orthopaedic Trauma, Beijing Jishuitan Hospital, Beijing, China
| | - Chen Yi
- Department of Orthopaedic Trauma, Beijing Jishuitan Hospital, Beijing, China
| | - Ming-Hui Yang
- Department of Orthopaedic Trauma, Beijing Jishuitan Hospital, Beijing, China
| | - Dong Yan
- Department of Radiology, Beijing Jishuitan Hospital, Beijing, China
| | - Ke-Bin Cheng
- Department of Radiology, Beijing Jishuitan Hospital, Beijing, China
| | - Xiao-Guang Cheng
- Department of Radiology, Beijing Jishuitan Hospital, Beijing, China.
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25
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Damm T, Peña JA, Campbell GM, Bastgen J, Barkmann R, Glüer CC. Improved accuracy in the assessment of vertebral cortical thickness by quantitative computed tomography using the Iterative Convolution OptimizatioN (ICON) method. Bone 2019; 120:194-203. [PMID: 30201318 DOI: 10.1016/j.bone.2018.08.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 08/29/2018] [Accepted: 08/30/2018] [Indexed: 10/28/2022]
Abstract
Vertebral whole bone strength is substantially affected by cortical bone properties. Disease and therapy may affect cancellous and cortical bone differently. Unlike Dual X-ray Absorptiometry (DXA), Quantitative Computed Tomography (QCT) permits selective assessment of cortical and cancellous bone, but image quality limits the accuracy. We present an image processing method specifically adopted to thin cortices that substantially improves accuracy. Ten human vertebrae embedded in epoxy resin were imaged using clinical QCT and High-Resolution QCT (HR-QCT) protocols, both acquired on a clinical whole body CT scanner, whereas high resolution peripheral QCT (HR-pQCT) was used as gold standard. Microstructural variables and BMD were calculated using in-house software StructuralInsight for QCT and HR-QCT and the manufacturer's μCT evaluation software for HR-pQCT. An adjusted measure, a deconvolved cortical thickness (dcCt.Th), corrected for partial volume effects, was derived applying the new Iterative Convolution OptimizatioN (ICON) method. Direct measurements of cortical thickness (Ct.Th) showed substantial overestimation with mean ± standard deviation of 1.8 ± 0.5 mm for QCT and 1.5 ± 0.3 mm for HR-QCT compared to 0.37 ± 0.07 mm using HR-pQCT. Correlations of both QCT (r2 = 0.05, p > 0.5.) and HR-QCT (r2 = 0.38, p = 0.060) with the gold standard HR-pQCT were not significant. Also QCT-based BMD and BMC as well as HR-QCT-based BMD did not show a significant correlation with the gold standard approach. Only HR-QCT-based BMC showed a modest correlation (r2 = 0.59, p = 0.01) After applying ICON corrections, dcCt.Th resulted in 0.52 ± 0.09 mm for QCT and 0.43 ± 0.07 mm for HR-QCT, both significantly correlated to HR-pQCT (r2 = 0.75, p = 0.0012 and r2 = 0.93, p < 0.0001, respectively). The average overestimation bias of Ct.Th was reduced from (402 ± 157)% to (45 ± 17)% for QCT and from (330 ± 69)% to (19 ± 8)% for HR-QCT. Due to inaccurate segmentation uncorrected QCT-based Ct.Th measures as well as BMD and BMC showed no correlation to HR-pQCT and thus such bias cortical data can be misleading. The application of ICON reduced random overestimation bias to about 50 μm and 20 μm for QCT and HR-QCT, respectively, leading to a recovery of a significant correlation with the reference data of HR-pQCT. This reveals the potential for fairly accurate assessment of cortical thickness, allowing to better characterize cortical mechanical competence. These results warrant testing of the performance in vivo.
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Affiliation(s)
- Timo Damm
- Section Biomedical Imaging, Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, MOIN CC, Am Botansichen Garten 14, 24118 Kiel, Germany.
| | - Jaime A Peña
- Section Biomedical Imaging, Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, MOIN CC, Am Botansichen Garten 14, 24118 Kiel, Germany.
| | - Graeme Michael Campbell
- Helmholtz Zentrum Geesthacht, Institute for Materials Research, Max-Planck Straße 1, 21502 Geesthacht, Germany.
| | - Jan Bastgen
- Helmholtz Zentrum Geesthacht, Institute for Materials Research, Max-Planck Straße 1, 21502 Geesthacht, Germany; Section for Trauma Surgery, Lubinus Clinicum for Orthopaedic Surgery and Trauma Surgery, Steenbeeker Weg 25, 24106 Kiel, Germany.
| | - Reinhard Barkmann
- Section Biomedical Imaging, Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, MOIN CC, Am Botansichen Garten 14, 24118 Kiel, Germany.
| | - Claus-Christian Glüer
- Section Biomedical Imaging, Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, MOIN CC, Am Botansichen Garten 14, 24118 Kiel, Germany.
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26
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Chandran V, Maquer G, Gerig T, Zysset P, Reyes M. Supervised learning for bone shape and cortical thickness estimation from CT images for finite element analysis. Med Image Anal 2019; 52:42-55. [DOI: 10.1016/j.media.2018.11.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 08/24/2018] [Accepted: 11/02/2018] [Indexed: 01/31/2023]
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27
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Giudice JS, Poulard D, Nie B, Wu T, Panzer MB. A Cortical Thickness Mapping Method for the Coxal Bone Using Morphing. Front Bioeng Biotechnol 2018; 6:149. [PMID: 30406094 PMCID: PMC6200845 DOI: 10.3389/fbioe.2018.00149] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 09/28/2018] [Indexed: 11/13/2022] Open
Abstract
As human body finite element models become more integrated with the design of safety countermeasures and regulations, novel models need to be developed that reflect the variation in the population's anthropometry. However, these new models may be missing information which will need to be translated from existing models. During the development of a 5th percentile female occupant model (F05), cortical thickness information of the coxal bone was unavailable due to resolution limits in the computed tomography (CT) scans. In this study, a method for transferring cortical thickness information from a source to a target model with entirely different geometry and architecture is presented. The source and target models were the Global Human Body Models Consortium (GHBMC) 50th percentile male (M50) and F05 coxal bones, respectively. To project the coxal bone cortical thickness from the M50 to the F05, the M50 model was first morphed using a Kriging method with 132 optimized control points to the F05 anthropometry. This technique was found to be accurate with a mean nodal discrepancy of 1.27 mm between the F05 and morphed M50 (mM50) coxal bones. Cortical thickness at each F05 node was determined by taking the average cortical thickness of every mM50 node, non-linearly weighted by its distance to the F05 nodes. The non-linear weighting coefficient, β, had a large effect on the accuracy and smoothness of the projected cortical bone thickness. The optimal projection had β = 4 and was defined when the tradeoff between projection accuracy and smoothness was equal. Finally, a quasi-static pelvis compression was simulated to examine to effect of β. As β, increased from 0 to 4, the failure force decreased by ~100 N, whereas the failure displacement increased by 0.9 mm. Results from quasi-static compression tests of the F05 pelvis were comparable to experimental results. This method could be applied to other anatomical regions where cortical thickness variation is important, such as the femur and ribs and is not limited to GHBMC-family models. Furthermore, this process will aid the development of subject-specific finite element models where accurate cortical bone thickness measurements cannot be obtained.
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28
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Cervinka T, Giangregorio L, Sievanen H, Cheung AM, Craven BC. Peripheral Quantitative Computed Tomography: Review of Evidence and Recommendations for Image Acquisition, Analysis, and Reporting, Among Individuals With Neurological Impairment. J Clin Densitom 2018; 21:563-582. [PMID: 30196052 DOI: 10.1016/j.jocd.2018.07.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 05/07/2018] [Accepted: 10/07/2018] [Indexed: 02/06/2023]
Abstract
In 2015, the International Society for Clinical Densitometry (ISCD) position statement regarding peripheral quantitative computed tomography (pQCT) did not recommend routine use of pQCT, in clinical settings until consistency in image acquisition and analysis protocols are reached, normative studies conducted, and treatment thresholds identified. To date, the lack of consensus-derived recommendations regarding pQCT implementation remains a barrier to implementation of pQCT technology. Thus, based on description of available evidence and literature synthesis, this review recommends the most appropriate pQCT acquisition and analysis protocols for clinical care and research purposes, and recommends specific measures for diagnosis of osteoporosis, assigning fracture risk, and monitoring osteoporosis treatment effectiveness, among patients with neurological impairment. A systematic literature search of MEDLINE, EMBASE©, CINAHL, and PubMed for available pQCT studies assessing bone health was carried out from inception to August 8th, 2017. The search was limited to individuals with neurological impairment (spinal cord injury, stroke, and multiple sclerosis) as these groups have rapid and severe regional declines in bone mass. Of 923 references, we identified 69 that met review inclusion criteria. The majority of studies (n = 60) used the Stratec XCT 2000/3000 pQCT scanners as reflected in our evaluation of acquisition and analysis protocols. Overall congruence with the ISCD Official Positions was poor. Only 11% (n = 6) studies met quality reporting criteria for image acquisition and 32% (n = 19) reported their data analysis in a format suitable for reproduction. Therefore, based on current literature synthesis, ISCD position statement standards and the authors' expertise, we propose acquisition and analysis protocols at the radius, tibia, and femur sites using Stratec XCT 2000/3000 pQCT scanners among patients with neurological impairment for clinical and research purposes in order to drive practice change, develop normative datasets and complete future meta-analysis to inform fracture risk and treatment efficacy evaluation.
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Affiliation(s)
- T Cervinka
- Neural Engineering and Therapeutics Team, Toronto Rehabilitation Research Institute-University Health Network, Toronto, Ontario, Canada.
| | - L Giangregorio
- Neural Engineering and Therapeutics Team, Toronto Rehabilitation Research Institute-University Health Network, Toronto, Ontario, Canada; Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - H Sievanen
- Bone Research Group, UKK Institute, Tampere, Finland
| | - A M Cheung
- Centre of Excellence in Skeletal Health Assessment, University Health Network, Toronto, Ontario, Canada; Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - B C Craven
- Neural Engineering and Therapeutics Team, Toronto Rehabilitation Research Institute-University Health Network, Toronto, Ontario, Canada; Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada; Centre of Excellence in Skeletal Health Assessment, University Health Network, Toronto, Ontario, Canada; Brain and Spinal Cord Rehabilitation Program, Toronto Rehabilitation Institute-University Health Network, Toronto, Canada; Department of Medicine, University of Toronto, Toronto, Ontario, Canada
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29
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Cho H, Yoon HJ, Jung JY. Effects of the Ground Resolution and Thresholding on Crack Width Measurements. SENSORS 2018; 18:s18082644. [PMID: 30103551 PMCID: PMC6111740 DOI: 10.3390/s18082644] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 07/29/2018] [Accepted: 08/09/2018] [Indexed: 11/16/2022]
Abstract
When diagnosing the condition of a structure, it is necessary to measure the widths of any existing cracks in the structure. To ensure safety when relying on images of cracks, the selected imaging parameters and processing technology must be well understood. In this study, the effects of the ground sample distance and threshold values on the crack width measurement error are analyzed from a theoretical perspective. Here, the main source of such errors is assumed to be due to the mixed pixel phenomena in the left and right boundary pixels. Thus, a mathematical model is proposed in which the intensity changes in these pixels are computed via an equation. In addition, the relationship between the error and error probability distribution is represented with an equation based on the threshold values and mean error. Upon analysis, it was found that the threshold value that minimizes the error is at the mid-point between the background and foreground, and the probabilistic nature of the error indicates that it is theoretically possible to predict both the error and its probability distribution. The proposed model was validated using artificial images.
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Affiliation(s)
- Hyunwoo Cho
- Robotics and Virtual Engineering, University of Science and Technology, Daejeon-si 34113, Korea.
| | - Hyuk-Jin Yoon
- Korea Railroad Research Institute, Uiwang-si 16105, Korea.
| | - Ju-Yeong Jung
- Korea Railroad Research Institute, Uiwang-si 16105, Korea.
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30
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Johannesdottir F, Allaire B, Bouxsein ML. Fracture Prediction by Computed Tomography and Finite Element Analysis: Current and Future Perspectives. Curr Osteoporos Rep 2018; 16:411-422. [PMID: 29846870 DOI: 10.1007/s11914-018-0450-z] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE OF REVIEW This review critiques the ability of CT-based methods to predict incident hip and vertebral fractures. RECENT FINDINGS CT-based techniques with concurrent calibration all show strong associations with incident hip and vertebral fracture, predicting hip and vertebral fractures as well as, and sometimes better than, dual-energy X-ray absorptiometry areal biomass density (DXA aBMD). There is growing evidence for use of routine CT scans for bone health assessment. CT-based techniques provide a robust approach for osteoporosis diagnosis and fracture prediction. It remains to be seen if further technical advances will improve fracture prediction compared to DXA aBMD. Future work should include more standardization in CT analyses, establishment of treatment intervention thresholds, and more studies to determine whether routine CT scans can be efficiently used to expand the number of individuals who undergo evaluation for fracture risk.
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Affiliation(s)
- Fjola Johannesdottir
- Center for Advanced Orthopedic Studies, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, RN 120, Boston, MA, 02215, USA.
- Department of Orthopedic Surgery, Harvard Medical School, Boston, MA, USA.
| | - Brett Allaire
- Center for Advanced Orthopedic Studies, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, RN 120, Boston, MA, 02215, USA
| | - Mary L Bouxsein
- Center for Advanced Orthopedic Studies, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, RN 120, Boston, MA, 02215, USA
- Department of Orthopedic Surgery, Harvard Medical School, Boston, MA, USA
- Endocrine Unit, Massachusetts General Hospital, Boston, MA, USA
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31
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Wagner D, Hofmann A, Kamer L, Sawaguchi T, Richards RG, Noser H, Gruszka D, Rommens PM. Fragility fractures of the sacrum occur in elderly patients with severe loss of sacral bone mass. Arch Orthop Trauma Surg 2018; 138:971-977. [PMID: 29700604 DOI: 10.1007/s00402-018-2938-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Indexed: 10/17/2022]
Abstract
INTRODUCTION Patients suffering from osteoporosis-associated fragility fractures of the sacrum (FFS; also termed sacral insufficiency fractures) are increasingly observed. They have typical fracture patterns with fracture lines located in the sacral ala. When treating these patients operatively, iliosacral screw loosening is not uncommon. We aimed to study the sacral bone mass in patients presenting with a FFS using 3D statistical models. MATERIALS AND METHODS 3D models of averaged Hounsfield units (HU) were generated based on CT scans from 13 patients with a unilateral FFS (mean age 79.6 years; 11 females, 2 males). The control group without fractures consisted of 28 males and 32 females (mean age of 68.3 years). A virtual bone probe along the trans-sacral corridors S1 and S2 was taken. RESULTS The bone mass distribution in the fractured sacra was similar to the control group, however, with overall lower HU. Large zones of negative HU were located in the sacral ala. In the fractured sacra, the HU in the sacral ala was significantly lower on the non-injured side when comparing to the fractured side (p < 0.001) as well as compared to the non-fractured group (p < 0.001). Low bone mass was observed in sacral body S1 (40 HU) and S2 (20 HU). CONCLUSIONS The extensive area of negative HU may explain the fracture location in the sacral ala. The low HU in the sacral bodies advocates the use of trans-sacral implants or augmented iliosacral screws to enhance the strength of fracture fixation. The increased HU in the fractured ala could be explained by fracture-asssociated hemorrhage and can be used as a diagnostic tool.
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Affiliation(s)
- Daniel Wagner
- Department of Orthopaedics and Traumatology, University Medical Center Mainz, Johannes Gutenberg-University, Langenbeckstr. 1, 55131, Mainz, Germany. .,AO Research Institute Davos, Davos, Switzerland.
| | - Alexander Hofmann
- Department of Orthopaedics and Traumatology, University Medical Center Mainz, Johannes Gutenberg-University, Langenbeckstr. 1, 55131, Mainz, Germany
| | - Lukas Kamer
- AO Research Institute Davos, Davos, Switzerland
| | - Takeshi Sawaguchi
- Department of Orthopedics and Joint Reconstructive Surgery, Toyama Municipal Hospital, Toyama, Japan
| | | | | | - Dominik Gruszka
- Department of Orthopaedics and Traumatology, University Medical Center Mainz, Johannes Gutenberg-University, Langenbeckstr. 1, 55131, Mainz, Germany
| | - Pol M Rommens
- Department of Orthopaedics and Traumatology, University Medical Center Mainz, Johannes Gutenberg-University, Langenbeckstr. 1, 55131, Mainz, Germany
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Museyko O, Gerner B, Engelke K. A new method to determine cortical bone thickness in CT images using a hybrid approach of parametric profile representation and local adaptive thresholds: Accuracy results. PLoS One 2017; 12:e0187097. [PMID: 29107950 PMCID: PMC5673192 DOI: 10.1371/journal.pone.0187097] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 10/15/2017] [Indexed: 11/18/2022] Open
Abstract
Motivation Cortical bone is an important contributor to bone strength and is pivotal to understand the etiology of osteoporotic fractures and the specific mechanisms of antiosteoporotic treatment regimen. 3D computed tomography (CT) can be used to measure cortical thickness, density, and mass in the proximal femur, lumbar vertebrae, and distal forearm. However, the spatial resolution of clinical whole body CT scanners is limited by radiation exposure; partial volume artefacts severely impair the accurate assessment of cortical parameters, in particular in locations where the cortex is thin such as in the lumbar vertebral bodies or in the femoral neck. Method Model-based deconvolution approaches recover the cortical thickness by numerically deconvolving the image along 1D profiles using an estimated scanner point spread function (PSF) and a hypothesized uniform cortical bone mineral density (reference density). In this work we provide a new essentially analytical unique solution to the model-based cortex recovery problem using few characteristics of the measured profile and thus eliminate the non-linear optimization step for deconvolution. Also, the proposed approach allows to get rid of the PSF in the model and reduces sensitivity to errors in the reference density. Additionally, run-time and memory effective computation of cortical thickness was achieved with the help of a lookup table. Results The method accuracy and robustness was validated and compared to that of a deconvolution approach recently proposed for cortical bone and of the 50% relative threshold technique: in a simulated environment with noise and various error levels in the reference density and using CT acquisitions of the European Forearm Phantom (EFP II), a modification of a widely used anthropomorphic standard of cortical and trabecular bone compartments that was scanned with various scan protocols. Conclusion Results of simulations and of phantom data analysis verified the following properties of the new method: 1) Robustness against errors in the reference density. 2) Excellent accuracy on ground truth data with various noise levels. 3) Very fast computation using a lookup table.
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Affiliation(s)
- Oleg Museyko
- Institute of Medical Physics, University of Erlangen-Nuremberg, Henkestr. 91, Erlangen, Germany
- * E-mail:
| | - Bastian Gerner
- Institute of Medical Physics, University of Erlangen-Nuremberg, Henkestr. 91, Erlangen, Germany
| | - Klaus Engelke
- Institute of Medical Physics, University of Erlangen-Nuremberg, Henkestr. 91, Erlangen, Germany
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Regmi P, Cox A, Robison C, Karcher D. Correlation analysis of cortical geometry of tibia and humerus of white leghorns using clinical quantitative computed tomography and microcomputed tomography scans. Poult Sci 2017; 96:2950-2955. [DOI: 10.3382/ps/pex064] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 02/28/2017] [Indexed: 11/20/2022] Open
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Abstract
This review focuses on new developments and current controversies in the field of quantitative computed tomography. Recent positions of the International Society for Clinical Densitometry acknowledged the clinical value of quantitative computed tomography of the spine and the hip using clinical whole-body computed tomography (CT) scanners. Opportunistic screening summarizes a number of new approaches describing the dual use of clinical CT scans. For example, CT scans may have been taken for tumor diagnosis but may also be used for the prediction of high or low fracture risks as an additional benefit for the patient. The assessment of the cortical parameters is another topic of current research. In CT images of the spine and the hip, a number of techniques have been developed to determine the thickness, mass, and bone density of the cortex. In higher-spatial resolution peripheral CT images of the radius and tibia obtained from special purpose scanners, 1 focus is the measurement of cortical porosity. Two different approaches, one based on the direct segmentation of the pores and one based on cortical density, will be reviewed.
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Affiliation(s)
- Klaus Engelke
- Institute of Medical Physics, University of Erlangen, Erlangen, Germany; Bioclinica, Inc, Hamburg, Germany.
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Karpetas GE, Michail CM, Fountos GP, Kalyvas NI, Valais IG, Kandarakis IS, Panayiotakis GS. Detective quantum efficiency (DQE) in PET scanners: A simulation study. Appl Radiat Isot 2017; 125:154-162. [PMID: 28437735 DOI: 10.1016/j.apradiso.2017.04.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 03/26/2017] [Accepted: 04/10/2017] [Indexed: 11/18/2022]
Abstract
The aim of the present study is to introduce the detective quantum efficiency (DQE) for the image quality assessment of positron emission tomography (PET) scanners. For this purpose, a thin layer chromatography (TLC) plane source was simulated using a previously validated, scanner and source geometry, Monte Carlo (MC) model. The model was developed with the Geant4 application for tomographic emission (GATE) MC package and reconstructed images obtained with the software for tomographic image reconstruction (STIR), with cluster computing. The GE Discovery ST PET scanner was simulated by using a previously validated code. A plane source consisting of a TLC plate, was simulated by a layer of silica gel on aluminum (Al) foil substrate, immersed in 18F-FDG bath solution (1MBq). Image quality was assessed in terms of the modulation transfer function (MTF) and the normalized noise power spectrum (NNPS) in order to obtain the detective quantum efficiency (DQE). MTF curves were estimated from transverse reconstructed images of the plane source, whereas the NNPS data were estimated from the corresponding coronal images. Images were reconstructed by the maximum likelihood estimation ordered subsets maximum a posteriori one step late (MLE)-OS-MAP-OSL algorithm, by using various subsets 1-21) and iterations 1-20). MTF values were found to increase up to the 12th iteration whereas remain almost constant thereafter. However, the range of the increase in the MTF is limited as the number of subsets increases. The noise levels were found to increase with the corresponding increase of both the number of iterations and subsets. The maximum NNPS value (0.517mm2) was observed for the 420 MLEM-equivalent iterations reconstructed image at 0cycles/mm. Finally DQE values were found to increase for spatial frequencies up to 0.038cycles/mm and to decrease thereafter with the corresponding increase in both number of iterations and subsets. The maximum DQE value (0.48 at 0.038cycles/mm) was obtained for the 8 MLEM-equivalent iterations image. The simulated PET evaluation method based on the TLC plane source can be useful in the quality control and in the further development of PET and SPECT scanners though GATE simulations.
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Affiliation(s)
- George E Karpetas
- Department of Medical Physics, Faculty of Medicine, University of Patras, 265 00 Patras, Greece
| | - Christos M Michail
- Radiation Physics, Materials Technology and Biomedical Imaging Laboratory, Department of Biomedical Engineering, Technological Educational Institute of Athens, Egaleo 122 10, Athens, Greece
| | - George P Fountos
- Radiation Physics, Materials Technology and Biomedical Imaging Laboratory, Department of Biomedical Engineering, Technological Educational Institute of Athens, Egaleo 122 10, Athens, Greece.
| | - Nektarios I Kalyvas
- Radiation Physics, Materials Technology and Biomedical Imaging Laboratory, Department of Biomedical Engineering, Technological Educational Institute of Athens, Egaleo 122 10, Athens, Greece
| | - Ioannis G Valais
- Radiation Physics, Materials Technology and Biomedical Imaging Laboratory, Department of Biomedical Engineering, Technological Educational Institute of Athens, Egaleo 122 10, Athens, Greece
| | - Ioannis S Kandarakis
- Radiation Physics, Materials Technology and Biomedical Imaging Laboratory, Department of Biomedical Engineering, Technological Educational Institute of Athens, Egaleo 122 10, Athens, Greece
| | - George S Panayiotakis
- Department of Medical Physics, Faculty of Medicine, University of Patras, 265 00 Patras, Greece
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Humbert L, Hazrati Marangalou J, Del Río Barquero LM, van Lenthe GH, van Rietbergen B. Technical Note: Cortical thickness and density estimation from clinical CT using a prior thickness-density relationship. Med Phys 2016; 43:1945. [PMID: 27036590 DOI: 10.1118/1.4944501] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
PURPOSE Cortical thickness and density are critical components in determining the strength of bony structures. Computed tomography (CT) is one possible modality for analyzing the cortex in 3D. In this paper, a model-based approach for measuring the cortical bone thickness and density from clinical CT images is proposed. METHODS Density variations across the cortex were modeled as a function of the cortical thickness and density, location of the cortex, density of surrounding tissues, and imaging blur. High resolution micro-CT data of cadaver proximal femurs were analyzed to determine a relationship between cortical thickness and density. This thickness-density relationship was used as prior information to be incorporated in the model to obtain accurate measurements of cortical thickness and density from clinical CT volumes. The method was validated using micro-CT scans of 23 cadaver proximal femurs. Simulated clinical CT images with different voxel sizes were generated from the micro-CT data. Cortical thickness and density were estimated from the simulated images using the proposed method and compared with measurements obtained using the micro-CT images to evaluate the effect of voxel size on the accuracy of the method. Then, 19 of the 23 specimens were imaged using a clinical CT scanner. Cortical thickness and density were estimated from the clinical CT images using the proposed method and compared with the micro-CT measurements. Finally, a case-control study including 20 patients with osteoporosis and 20 age-matched controls with normal bone density was performed to evaluate the proposed method in a clinical context. RESULTS Cortical thickness (density) estimation errors were 0.07 ± 0.19 mm (-18 ± 92 mg/cm(3)) using the simulated clinical CT volumes with the smallest voxel size (0.33 × 0.33 × 0.5 mm(3)), and 0.10 ± 0.24 mm (-10 ± 115 mg/cm(3)) using the volumes with the largest voxel size (1.0 × 1.0 × 3.0 mm(3)). A trend for the cortical thickness and density estimation errors to increase with voxel size was observed and was more pronounced for thin cortices. Using clinical CT data for 19 of the 23 samples, mean errors of 0.18 ± 0.24 mm for the cortical thickness and 15 ± 106 mg/cm(3) for the density were found. The case-control study showed that osteoporotic patients had a thinner cortex and a lower cortical density, with average differences of -0.8 mm and -58.6 mg/cm(3) at the proximal femur in comparison with age-matched controls (p-value < 0.001). CONCLUSIONS This method might be a promising approach for the quantification of cortical bone thickness and density using clinical routine imaging techniques. Future work will concentrate on investigating how this approach can improve the estimation of mechanical strength of bony structures, the prevention of fracture, and the management of osteoporosis.
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Affiliation(s)
| | - Javad Hazrati Marangalou
- Orthopaedic Biomechanics, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven 5600 MB, The Netherlands
| | | | - G Harry van Lenthe
- Biomechanics Section, KU Leuven-University of Leuven, Leuven 3001, Belgium
| | - Bert van Rietbergen
- Orthopaedic Biomechanics, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven 5600 MB, The Netherlands
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Nauleau P, Minonzio JG, Chekroun M, Cassereau D, Laugier P, Prada C, Grimal Q. A method for the measurement of dispersion curves of circumferential guided waves radiating from curved shells: experimental validation and application to a femoral neck mimicking phantom. Phys Med Biol 2016; 61:4746-62. [PMID: 27272197 DOI: 10.1088/0031-9155/61/13/4746] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Our long-term goal is to develop an ultrasonic method to characterize the thickness, stiffness and porosity of the cortical shell of the femoral neck, which could enhance hip fracture risk prediction. To this purpose, we proposed to adapt a technique based on the measurement of guided waves. We previously evidenced the feasibility of measuring circumferential guided waves in a bone-mimicking phantom of a circular cross-section of even thickness. The goal of this study is to investigate the impact of the complex geometry of the femoral neck on the measurement of guided waves. Two phantoms of an elliptical cross-section and one phantom of a realistic cross-section were investigated. A 128-element array was used to record the inter-element response matrix of these waveguides. This experiment was simulated using a custom-made hybrid code. The response matrices were analyzed using a technique based on the physics of wave propagation. This method yields portions of dispersion curves of the waveguides which were compared to reference dispersion curves. For the elliptical phantoms, three portions of dispersion curves were determined with a good agreement between experiment, simulation and theory. The method was thus validated. The characteristic dimensions of the shell were found to influence the identification of the circumferential wave signals. The method was then applied to the signals backscattered by the superior half of constant thickness of the realistic phantom. A cut-off frequency and some portions of modes were measured, with a good agreement with the theoretical curves of a plate waveguide. We also observed that the method cannot be applied directly to the signals backscattered by the lower half of varying thicknesses of the phantom. The proposed approach could then be considered to evaluate the properties of the superior part of the femoral neck, which is known to be a clinically relevant site.
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Affiliation(s)
- Pierre Nauleau
- Sorbonne Universités, UPMC Univ Paris 06, CNRS UMR 7371, INSERM UMR_S 1146, Laboratoire d'imagerie biomédicale, 15 rue de l'école de médecine, F-75006, Paris, France
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Perez-Orribo L, Snyder LA, Kalb S, Elhadi AM, Hsu F, Newcomb AGUS, Malhotra D, Crawford NR, Theodore N. Comparison of CT versus MRI measurements of transverse atlantal ligament integrity in craniovertebral junction injuries. Part 1: A clinical study. J Neurosurg Spine 2016; 24:897-902. [DOI: 10.3171/2015.9.spine13808] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE
Craniovertebral junction (CVJ) injuries complicated by transverse atlantal ligament (TAL) disruption often require surgical stabilization. Measurements based on the atlantodental interval (ADI), atlas lateral diameter (ALD1), and axis lateral diameter (ALD2) may help clinicians identify TAL disruption. This study used CT scanning to evaluate the reliability of these measurements and other variants in the clinical setting.
METHODS
Patients with CVJ injuries treated at the authors' institution between 2004 and 2011 were evaluated retrospectively for demographics, mechanism and location of CVJ injury, classification of injury, treatment, and modified Japanese Orthopaedic Association score at the time of injury and follow-up. The integrity of the TAL was evaluated using MRI. The ADI, ALD1, and ALD2 were measured on CT to identify TAL disruption indirectly.
RESULTS
Among the 125 patients identified, 40 (32%) had atlas fractures, 59 (47.2%) odontoid fractures, 31 (24.8%) axis fractures, and 4 (3.2%) occipital condyle fractures. TAL disruption was documented on MRI in 11 cases (8.8%). The average ADI for TAL injury was 1.8 mm (range 0.9–3.9 mm). Nine (81.8%) of the 11 patients with TAL injury had an ADI of less than 3 mm. In 10 patients (90.9%) with TAL injury, overhang of the C-1 lateral masses on C-2 was less than 7 mm. ADI, ALD1, ALD2, ALD1 – ALD2, and ALD1/ALD2 did not correlate with the integrity of the TAL.
CONCLUSIONS
No current measurement method using CT, including the ADI, ALD1, and ALD2 or their differences or ratios, consistently indicates the integrity of the TAL. A more reliable CT-based criterion is needed to diagnose TAL disruption when MRI is unavailable.
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Affiliation(s)
| | - Laura A. Snyder
- 2Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona
| | - Samuel Kalb
- 2Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona
| | - Ali M. Elhadi
- 2Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona
| | - Forrest Hsu
- 2Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona
| | | | | | | | - Nicholas Theodore
- 2Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona
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Restoration of Thickness, Density, and Volume for Highly Blurred Thin Cortical Bones in Clinical CT Images. Ann Biomed Eng 2016; 44:3359-3371. [DOI: 10.1007/s10439-016-1654-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 05/14/2016] [Indexed: 11/26/2022]
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Wagner D, Kamer L, Sawaguchi T, Richards RG, Noser H, Rommens PM. Sacral Bone Mass Distribution Assessed by Averaged Three-Dimensional CT Models: Implications for Pathogenesis and Treatment of Fragility Fractures of the Sacrum. J Bone Joint Surg Am 2016; 98:584-90. [PMID: 27053587 DOI: 10.2106/jbjs.15.00726] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Fragility fractures of the sacrum are increasing in prevalence due to osteoporosis and epidemiological changes and are challenging in their treatment. They exhibit specific fracture patterns with unilateral or bilateral fractures lateral to the sacral foramina, and sometimes an additional transverse fracture leads to spinopelvic dissociation. The goal of this study was to assess sacral bone mass distribution and corresponding changes with decreased general bone mass. METHODS Clinical computed tomography (CT) scans of intact pelves in ninety-one individuals (mean age and standard deviation, 61.5 ± 11.3 years) were used to generate three-dimensional (3D) models of the sacrum averaging bone mass in Hounsfield units (HU). Individuals with decreased general bone mass were identified by measuring bone mass in L5 (group 1 with <100 HU; in contrast to group 2 with ≥100 HU). RESULTS In group 1, a large zone of negative Hounsfield units was located in the paraforaminal lateral region from S1 to S3. Along the trans-sacral corridors, a Hounsfield unit peak was observed laterally, corresponding to cortical bone of the auricular surface. The lowest Hounsfield unit values were found in the paraforaminal lateral region in the sacral ala. An intermediate level of bone mass was observed in the area of the vertebral bodies, which also demonstrated the largest difference between groups 1 and 2. Overall, the Hounsfield units were lower at S2 than S1. CONCLUSIONS The models of averaged bone mass in the sacrum revealed a distinct 3D distribution pattern. CLINICAL RELEVANCE The negative values in the paraforaminal lateral region may explain the specific fracture patterns in fragility fractures of the sacrum involving the lateral areas of the sacrum. Transverse fractures located between S1 and S2 leading to spinopelvic dissociation may occur because of decreased bone mass in S2. The largest difference between the studied groups was found in the vertebral bodies and might support the use of transsacral or cement-augmented implants.
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Affiliation(s)
- Daniel Wagner
- AO Research Institute Davos, Davos, Switzerland Department of Orthopaedics and Traumatology, University Medical Center Mainz, Mainz, Germany
| | - Lukas Kamer
- AO Research Institute Davos, Davos, Switzerland
| | - Takeshi Sawaguchi
- Department of Orthopedics and Joint Reconstructive Surgery, Toyama Municipal Hospital, Toyama, Japan
| | | | | | - Pol M Rommens
- Department of Orthopaedics and Traumatology, University Medical Center Mainz, Mainz, Germany
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Museyko O, Bousson V, Adams J, Laredo JD, Engelke K. QCT of the proximal femur--which parameters should be measured to discriminate hip fracture? Osteoporos Int 2016; 27:1137-1147. [PMID: 26415934 DOI: 10.1007/s00198-015-3324-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 09/11/2015] [Indexed: 02/04/2023]
Abstract
SUMMARY For quantitative computed tomography (QCT), most relevant variables to discriminate hip fractures were determined. A multivariate analysis showed that trabecular bone mineral density (BMD) of the trochanter with "cortical" thickness of the neck provided better fracture discrimination than total hip integral BMD. A slice-by-slice analysis of the neck or the inclusion of strength-based parameters did not improve fracture discrimination. INTRODUCTION For QCT of the proximal femur, a large variety of analysis parameters describing bone mineral density, geometry, or strength has been considered. However, in each given study, generally just a small subset was used. The aim of this study was to start with a comprehensive set and then select a best subset of QCT parameters for discrimination of subjects with and without acute osteoporotic hip fractures. METHODS The analysis was performed using the population of the European Femur Fracture (EFFECT) study (Bousson et al. J Bone Min Res: Off J Am Soc Bone Min Res 26:881-893, 2011). Fifty-six female control subjects (age 73.2 ± 9.3 years) were compared with 46 female patients (age 80.9 ± 11.1 years) with acute hip fractures. The QCT analysis software MIAF-Femur was used to virtually dissect the proximal femur and analyze more than 1000 parameters, predominantly in the femoral neck. A multivariate best-subset analysis was used to extract the parameters best discriminating hip fractures. All results were adjusted for age, height, and weight differences between the two groups. RESULTS For the discrimination of all proximal hip fractures as well as for cervical fractures alone, the measurement of neck parameters suffices (area under the curve (AUC) = 0.84). Parameters characterizing bone strength are discriminators of hip fractures; however, in multivariate models, only "cortical" cross-sectional area in the neck center remained as a significant contributor. The combination of one BMD parameter, trabecular BMD of the trochanter, and one geometry parameter, "cortical" thickness of the neck discriminated hip fracture with an AUC value of 0.83 which was significantly better than 0.77 for total femur BMD alone. A comprehensive slice-based analysis of the neck along its axis did not significantly improve hip fracture discrimination. CONCLUSIONS If QCT of the hip is performed, the analysis should include neck and trochanter. In particular, for fractures of any type, a comprehensive slice-based analysis of the neck along its axis did not significantly improve hip fracture discrimination nor did the inclusion of strength-related parameters other than "cortical" area or thickness. One BMD and one geometry parameter, in this study, the combination of trabecular BMD of the trochanter and of "cortical" thickness of the neck resulted in significant hip fracture discrimination.
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Affiliation(s)
- O Museyko
- Institute of Medical Physics (IMP), University of Erlangen, Henkestr. 91, 91052, Erlangen, Germany.
| | - V Bousson
- Service de Radiologie OstéoArticulaire, Hôpital Lariboisière, Paris, France
| | - J Adams
- Clinical Radiology, The Royal Infirmary, University of Manchester, Manchester, UK
| | - J -D Laredo
- Service de Radiologie OstéoArticulaire, Hôpital Lariboisière, Paris, France
| | - K Engelke
- Institute of Medical Physics (IMP), University of Erlangen, Henkestr. 91, 91052, Erlangen, Germany
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Vaughan PE, Orth MW, Haut RC, Karcher DM. A method of determining bending properties of poultry long bones using beam analysis and micro-CT data. Poult Sci 2016; 95:207-12. [PMID: 26794840 DOI: 10.3382/ps/pev345] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
While conventional mechanical testing has been regarded as a gold standard for the evaluation of bone heath in numerous studies, with recent advances in medical imaging, virtual methods of biomechanics are rapidly evolving in the human literature. The objective of the current study was to evaluate the feasibility of determining the elastic and failure properties of poultry long bones using established methods of analysis from the human literature. In order to incorporate a large range of bone sizes and densities, a small number of specimens were utilized from an ongoing study of Regmi et al. (2016) that involved humeri and tibiae from 3 groups of animals (10 from each) including aviary, enriched, and conventional housing systems. Half the animals from each group were used for 'training' that involved the development of a regression equation relating bone density and geometry to bending properties from conventional mechanical tests. The remaining specimens from each group were used for 'testing' in which the mechanical properties from conventional tests were compared to those predicted by the regression equations. Based on the regression equations, the coefficients of determination for the 'test' set of data were 0.798 for bending bone stiffness and 0.901 for the yield (or failure) moment of the bones. All regression slopes and intercepts values for the tests versus predicted plots were not significantly different from 1 and 0, respectively. The study showed the feasibility of developing future methods of virtual biomechanics for the evaluation of poultry long bones. With further development, virtual biomechanics may have utility in future in vivo studies to assess laying hen bone health over time without the need to sacrifice large groups of animals at each time point.
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Affiliation(s)
- Patrick E Vaughan
- Orthopaedic Biomechanics Laboratories, College of Osteopathic Medicine, Michigan State University, East Lansing, MI
| | - Michael W Orth
- Department of Animal and Food Sciences, Texas Tech University, Lubbock, TX
| | - Roger C Haut
- Orthopaedic Biomechanics Laboratories, College of Osteopathic Medicine, Michigan State University, East Lansing, MI
| | - Darrin M Karcher
- Department of Animal Science Michigan State University, East Lansing, MI, Scientific Section: "Physiology and Reproduction"
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Davis ML, Vavalle NA, Stitzel JD, Gayzik FS. A technique for developing CAD geometry of long bones using clinical CT data. Med Eng Phys 2015; 37:1116-23. [DOI: 10.1016/j.medengphy.2015.08.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 06/23/2015] [Accepted: 08/19/2015] [Indexed: 11/26/2022]
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Poole KE, Treece GM, Gee AH, Brown JP, McClung MR, Wang A, Libanati C. Response to: Comment on: "Denosumab Rapidly Increases Cortical Bone in Key Locations of the Femur: A 3D Bone Mapping Study in Women With Osteoporosis". J Bone Miner Res 2015; 30:1939-40. [PMID: 26174164 DOI: 10.1002/jbmr.2569] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 06/03/2015] [Indexed: 01/22/2023]
Affiliation(s)
| | - Graham M Treece
- Department of Engineering, University of Cambridge, Cambridge, UK
| | - Andrew H Gee
- Department of Engineering, University of Cambridge, Cambridge, UK
| | - Jacques P Brown
- CHU de Québec Research Centre (CRCHU), Laval University, Quebec City, Québec, Canada
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Imai K. Analysis of vertebral bone strength, fracture pattern, and fracture location: a validation study using a computed tomography-based nonlinear finite element analysis. Aging Dis 2015; 6:180-7. [PMID: 26029476 DOI: 10.14336/ad.2014.0621] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 06/21/2014] [Indexed: 11/01/2022] Open
Abstract
Finite element analysis (FEA) is an advanced computer technique of structural stress analysis developed in engineering mechanics. Because the compressive behavior of vertebral bone shows nonlinear behavior, a nonlinear FEA should be utilized to analyze the clinical vertebral fracture. In this article, a computed tomography-based nonlinear FEA (CT/FEA) to analyze the vertebral bone strength, fracture pattern, and fracture location is introduced. The accuracy of the CT/FEA was validated by performing experimental mechanical testing with human cadaveric specimens. Vertebral bone strength and the minimum principal strain at the vertebral surface were accurately analyzed using the CT/FEA. The experimental fracture pattern and fracture location were also accurately simulated. Optimization of the element size was performed by assessing the accuracy of the CT/FEA, and the optimum element size was assumed to be 2 mm. It is expected that the CT/FEA will be valuable in analyzing vertebral fracture risk and assessing therapeutic effects on osteoporosis.
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Affiliation(s)
- Kazuhiro Imai
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
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Abstract
Bone is a dynamic organ of the endoskeleton, playing an important role in structural integrity, mineral reservoirs, blood production, coagulation, and immunity. Metabolic bone disease encompasses a broad spectrum of inherited and acquired disorders that disrupt the normal homeostasis of bone formation and resorption. For patients affected by these processes, radiologic imaging plays a central role in diagnosis, monitoring treatment, and risk stratification. Radiologists should be familiar with the diseases, intimately aware of the imaging findings, and possessive of multimodality expertise to wisely guide the best practice of medicine. The purpose of this paper is to review the imaging features and characteristics of the most common types of metabolic bone disease with highlights of clinically relevant information so that readers can better generate appropriate differential diagnoses and recommendations. For this review, a thorough literature search for the most up-to-date information was performed on several key types of metabolic bone disease: osteoporosis, osteomalacia, rickets, scurvy, renal osteodystrophy, hyperparathyroidism, Paget’s disease, osteogenesis imperfecta, acromegaly, and osteopetrosis. Although they all affect the bone, these diseases have both shared characteristic features that can be discerned through imaging.
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Zebaze R, Seeman E. Cortical bone: a challenging geography. J Bone Miner Res 2015; 30:24-9. [PMID: 25431247 DOI: 10.1002/jbmr.2419] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 11/18/2014] [Accepted: 11/22/2014] [Indexed: 12/25/2022]
Affiliation(s)
- Roger Zebaze
- Departments of Endocrinology and Medicine, Austin Health, University of Melbourne, Melbourne, Australia
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Treece GM, Gee AH. Independent measurement of femoral cortical thickness and cortical bone density using clinical CT. Med Image Anal 2014; 20:249-64. [PMID: 25541355 DOI: 10.1016/j.media.2014.11.012] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 07/31/2014] [Accepted: 11/28/2014] [Indexed: 11/25/2022]
Abstract
The local structure of the proximal femoral cortex is of interest since both fracture risk, and the effects of various interventions aimed at reducing that risk, are associated with cortical properties focused in particular regions rather than dispersed over the whole bone. Much of the femoral cortex is less than 3mm thick, appearing so blurred in clinical CT that its actual density is not apparent in the data, and neither thresholding nor full-width half-maximum techniques are capable of determining its width. Our previous work on cortical bone mapping showed how to produce more accurate estimates of cortical thickness by assuming a fixed value of the cortical density for each hip. However, although cortical density varies much less over the proximal femur than thickness, what little variation there is leads to errors in thickness measurement. In this paper, we develop the cortical bone mapping technique by exploiting local estimates of imaging blur to correct the global density estimate, thus providing a local density estimate as well as more accurate estimates of thickness. We also consider measurement of cortical mass surface density and the density of trabecular bone immediately adjacent to the cortex. Performance is assessed with ex vivo clinical QCT scans of proximal femurs, with true values derived from high resolution HRpQCT scans of the same bones. We demonstrate superior estimation of thickness than is possible with alternative techniques (accuracy 0.12 ± 0.39 mm for cortices in the range 1-3mm), and that local cortical density estimation is feasible for densities >800 mg/cm(3).
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Affiliation(s)
- G M Treece
- University of Cambridge, Department of Engineering, Trumpington Street, Cambridge CB2 1PZ, UK.
| | - A H Gee
- University of Cambridge, Department of Engineering, Trumpington Street, Cambridge CB2 1PZ, UK.
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Lillie EM, Urban JE, Weaver AA, Powers AK, Stitzel JD. Estimation of skull table thickness with clinical CT and validation with microCT. J Anat 2014; 226:73-80. [PMID: 25441171 DOI: 10.1111/joa.12259] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/14/2014] [Indexed: 11/29/2022] Open
Abstract
Brain injuries resulting from motor vehicle crashes (MVC) are extremely common yet the details of the mechanism of injury remain to be well characterized. Skull deformation is believed to be a contributing factor to some types of traumatic brain injury (TBI). Understanding biomechanical contributors to skull deformation would provide further insight into the mechanism of head injury resulting from blunt trauma. In particular, skull thickness is thought be a very important factor governing deformation of the skull and its propensity for fracture. Current computed tomography (CT) technology is limited in its ability to accurately measure cortical thickness using standard techniques. A method to evaluate cortical thickness using cortical density measured from CT data has been developed previously. This effort validates this technique for measurement of skull table thickness in clinical head CT scans using two postmortem human specimens. Bone samples were harvested from the skulls of two cadavers and scanned with microCT to evaluate the accuracy of the estimated cortical thickness measured from clinical CT. Clinical scans were collected at 0.488 and 0.625 mm in plane resolution with 0.625 mm thickness. The overall cortical thickness error was determined to be 0.078 ± 0.58 mm for cortical samples thinner than 4 mm. It was determined that 91.3% of these differences fell within the scanner resolution. Color maps of clinical CT thickness estimations are comparable to color maps of microCT thickness measurements, indicating good quantitative agreement. These data confirm that the cortical density algorithm successfully estimates skull table thickness from clinical CT scans. The application of this technique to clinical CT scans enables evaluation of cortical thickness in population-based studies.
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Affiliation(s)
- Elizabeth M Lillie
- Virginia Tech-Wake Forest University Center for Injury Biomechanics, Winston-Salem, NC, USA; Wake Forest University School of Medicine, Winston-Salem, NC, USA
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Abstract
OBJECTIVE The aim of this study was to propose a novel method for image quality assessment in PET scanners through estimation of the modulation transfer function (MTF) of a plane source. The simulation was implemented using the previously validated Monte-Carlo model. A comparison of the proposed method with the more traditional technique, based on a line source, was also performed. MATERIALS AND METHODS The Geant4 application for tomographic emission (GATE) Monte-Carlo package was used for model development, and reconstructed images were obtained using software for tomographic image reconstruction (STIR) with cluster computing. A novel plane source consisting of a radioactive ((18)F-fluorodeoxyglucose) thin-layer chromatography plate was simulated (total source activity: 44.4 MBq) to assess image quality through the MTF. All images were reconstructed with the three-dimensional filtered back projection (FBP3DRP) and ordered-subsets expectation maximization (OSEM) reprojection algorithms. RESULTS The MTFs obtained using ordered-subsets expectation maximization show, in all cases, that higher frequencies are preserved compared with those obtained using the FBP3DRP. In addition, the plane source method is less prone to noise than the conventional line source method (SD=0.0031 and 0.0203, respectively). CONCLUSION The thin-layer chromatography-based plane source presented requires materials commonly found in a clinical environment and could be used to assess image quality in nuclear medicine departments and to further develop PET and single-photon emission computed tomography scanners through Monte-Carlo simulations.
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