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Diffusion Tensor Imaging of Lumbar Vertebras in Female Adolescent Idiopathic Scoliosis: Initial Findings. J Comput Assist Tomogr 2017; 42:317-322. [PMID: 28937482 DOI: 10.1097/rct.0000000000000667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The purpose of this study was to characterize diffusion tensor imaging (DTI) features of lumbar vertebras in adolescent idiopathic scoliosis (AIS) patients. METHODS Fifty-two AIS patients and 20 healthy volunteers underwent 3-T magnetic resonance scanning including DTI sequence. The fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values on the convex and concave sides of lumbar vertebras were obtained and compared. RESULTS The FA and ADC values differed significantly between the convex and concave side of lumbar vertebras in AIS (P < 0.01). The ADC values in AIS differed significantly with healthy volunteers (P < 0.01). The FA values on the convex side of L1 to L2 were significantly lower than L4 to L5 in AIS. The difference of FA values between the concave and convex sides of the apex vertebra correlated significantly with Cobb angle (r = 0.436, P < 0.01). CONCLUSIONS The convex and concave sides of lumbar vertebras in AIS patients showed different DTI features.
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Gdyczynski CM, Manbachi A, Hashemi S, Lashkari B, Cobbold RSC. On estimating the directionality distribution in pedicle trabecular bone from micro-CT images. Physiol Meas 2014; 35:2415-28. [PMID: 25391037 DOI: 10.1088/0967-3334/35/12/2415] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Our interest in the trabecular alignment within bone stems from the need to better understand the manner in which it can affect ultrasound propagation, particularly in pedicles. Within long bones it is well established that trabecular structures are aligned in an organized manner associated with the direction of load distribution; however, for smaller bones there are limited alignment studies. To investigate the directionality distribution in a quantitative manner we used a micro-CT to obtain three-dimensional (3D) structural data and developed analytical methods based on the special properties of Gabor filters. Implementation of these techniques has been developed and tested on a variety of simulated images as well as on 3D structures whose geometry is well-defined. To test the use of this technique we compared the results obtained on vertebral body trabecular bone with visual directionality and previous measurements by others. The method has been applied to six human pedicle samples in two orthogonal planes with results that provide reasonable proof-of-principle evidence that the method is well suited for estimating the directionality distribution within pedicle bones.
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Affiliation(s)
- Catherine M Gdyczynski
- Institute of Biomaterials and Biomedical Engineering (IBBME), University of Toronto, M5S 3G9, Toronto, Canada. Spinesonics Medical Inc, 411-112 College St, M5G 1L6, Toronto, Ontario, Canada
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Tsouknidas A, Maliaris G, Savvakis S, Michailidis N. Anisotropic post-yield response of cancellous bone simulated by stress–strain curves of bulk equivalent structures. Comput Methods Biomech Biomed Engin 2013; 18:839-46. [DOI: 10.1080/10255842.2013.849342] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Mahato NK. Trabecular bone structure in lumbosacral transitional vertebrae: distribution and densities across sagittal vertebral body segments. Spine J 2013; 13:932-7. [PMID: 23582426 DOI: 10.1016/j.spinee.2013.02.072] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Revised: 11/20/2012] [Accepted: 02/25/2013] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Lumbosacral transitional vertebrae (LSTV) are associated with altered articular morphology at the L5-S1 junction. Studies related to lumbo-sacral trabecular architecture in LSTV are few. Altered lumbosacral load bearing at these anomalous junctions possibly results in changes in the number, density, and trajectory of the trabecular bone in transitional lumbosacral vertebral bodies. PURPOSE To investigate the pattern, distribution, and density of trabecular bone in the terminal lumbar vertebrae and the first sacral segments in LSTV-affected spines. Measurements were compared with those obtained from normal lumbosacral specimens. STUDY DESIGN Observational and descriptive human cadaveric study of vertebral trabecular architecture. METHODS Blocks of tissues were obtained from normal (n=20) and LSTV cadaveric specimens (n=16) by sectioning vertically through the fifth lumbar and the first sacral vertebra on either side of the midsagittal plane. Photographs of the cut surfaces were computationally enlarged and mapped for vertical and transverse trabecular numbers and surface areas using the software Image J. All parameters including the trabecular density were computed for anterior, middle, and posterior segments of each of the vertebral elements. RESULTS The anterior and the posterior segments showed greater number of trabeculae across all LSTV subtypes in both the terminal lumbar and first sacral vertebrae in comparison with the middle segment. L5 exhibited greater number of vertical trabeculae, whereas the first sacral segments demonstrated greater number and densities of transverse trabeculae. Transition-associated vertebrae showed overall reduced number of the lumbar trabeculae but relatively compact sacral posterior segments with greater number of horizontal trabeculae. CONCLUSIONS Findings suggest that some of these variations have overall reduced number of trabeculae across lumbo-sacral vertebrae in LSTV. Screw placements and subsequent pullouts in LSTV may be reviewed in light of different trabecular patterns as reported in this study.
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Affiliation(s)
- Niladri Kumar Mahato
- Department of Anatomy, SRM Medical College, Kattankulathur, Kanchipuram District, Tamil Nadu 603203, India.
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Parkinson IH, Forbes D, Sutton-Smith P, Fazzalari NL. Model-Independent 3D Descriptors of Vertebral Cancellous Bone Architecture. J Osteoporos 2009; 2010:641578. [PMID: 20975775 PMCID: PMC2957160 DOI: 10.4061/2010/641578] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2009] [Revised: 09/07/2009] [Accepted: 10/13/2009] [Indexed: 11/20/2022] Open
Abstract
High-resolution micro computed tomography has enabled measurement of bone architecture derived from 3D representations of cancellous bone. Twenty-eight vertebral bodies were obtained from four embalmed male cadavers. From 3D anaglyphs, trabecular rod thickness and length were measured and the trabecular rod Buckling index was calculated. From 3D voxel-based datasets, bone volume density, trabecular thickness, and trabecular separation were measured. Also, trabecular bone pattern factor, structural model index, connectivity density, and degree of anisotropy were calculated. Bone volume density alone explains 59% of the variability in trabecular rod Buckling index. The addition of connectivity density, trabecular separation, and structural model index, in a multiple regression statistical model, improves the explanatory power to 77%. The relationships between measures of cancellous bone architecture and a derived measure of trabecular rod strength were investigated. Morphological descriptors of cancellous bone provide a composite explanatory model of trabecular rod strength.
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Affiliation(s)
- Ian H. Parkinson
- Bone and Joint Research Laboratory, SA Pathology and Hanson Institute, Discipline of Pathology, University of Adelaide, Adelaide, South Australia 5000, Australia,*Ian H. Parkinson:
| | - Danielle Forbes
- Bone and Joint Research Laboratory, SA Pathology and Hanson Institute, Discipline of Pathology, University of Adelaide, Adelaide, South Australia 5000, Australia
| | - Peter Sutton-Smith
- Bone and Joint Research Laboratory, SA Pathology and Hanson Institute, Discipline of Pathology, University of Adelaide, Adelaide, South Australia 5000, Australia
| | - Nicola L. Fazzalari
- Bone and Joint Research Laboratory, SA Pathology and Hanson Institute, Discipline of Pathology, University of Adelaide, Adelaide, South Australia 5000, Australia
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Boehm HF, Lutz J, Körner M, Mutschler W, Reiser M, Pfeifer KJ. Using Radon transform of standard radiographs of the hip to differentiate between post-menopausal women with and without fracture of the proximal femur. Osteoporos Int 2009; 20:323-33. [PMID: 18560746 DOI: 10.1007/s00198-008-0663-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2007] [Accepted: 05/09/2008] [Indexed: 11/25/2022]
Abstract
UNLABELLED Texture features based on the Radon transform were extracted from clinical radiographs of the hip in post-menopausal women. The novel algorithm allowed us to identify patients with fracture of the proximal femur and may provide an alternative to measuring bone mineral density in predicting the fracture-risk in osteoporosis, especially where densitometry is regionally unavailable. INTRODUCTION The aim of this study is to introduce an algorithm for differentiation between patients with and without fracture of the hip using parameters based on the Radon transform (RT) and applied to standard radiographs of the proximal femur and to compare the results with bone mineral density (BMD). METHODS The study comprised 50 post-menopausal women (78.6 +/- 11.5 years of age), including 25 patients with hip fracture and 25 age-matched controls. We obtained lumbar and femoral BMD and standard femoral radiographs. In the radiographs we analysed trabecular patterns of the hip in a region-of-interest of 57 x 29 mm using the RT. From the histogram-representation of the RT, we extracted several characteristic parameters. By ROC and discriminant-analysis, we assessed the statistical power of both methods. RESULTS For correct differentiation between fracture and non-fracture cases by femoral BMD, area-under-the-curve (AUC) was 0.78; AUC for the RT-based parameters ranged from 0.73 to 0.8. By combination of densitometric and textural information in a multivariate model the fracture status of 84% of subjects was predicted correctly, identification of fracture cases rose to 88%. CONCLUSION Identification of fracture patients by RT applied to femoral radiographs was feasible and seemed to have a discriminative potential comparable to that of standard densitometry. In the future, the new method may provide an alternative to DXA or in conjunction with conventional densitometry may enhance the detection of patients with elevated risk of hip fracture.
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Affiliation(s)
- H F Boehm
- Department of Radiology, University of Munich, Germany.
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Gregory JS, Stewart A, Undrill PE, Reid DM, Aspden RM. Bone shape, structure, and density as determinants of osteoporotic hip fracture: a pilot study investigating the combination of risk factors. Invest Radiol 2006; 40:591-7. [PMID: 16118552 DOI: 10.1097/01.rli.0000174475.41342.42] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES This article compares and combines methods for examining the external shape and the internal structure of the proximal femur with bone mineral density (BMD) to provide a classifier for hip fracture. MATERIALS AND METHODS Fifty standard pelvic radiographs were available from age-matched fracture and control groups of postmenopausal women. Femoral shape was measured using an active shape model, the trabecular structure by means of a Fourier transform. RESULTS Both the shape and various structure measures were independent of BMD (P=0.16 and >0.50, respectively). Calculating the area under the receiver operator characteristic (ROC) curve (Az), each of shape (Az=0.81), the best structure measure (Az=0.79-0.93), and BMD (Az=0.79), could partially classify the fracture and control groups. However, the combination achieved almost perfect separation (Az=0.99). CONCLUSIONS This pilot study shows how bone shape and structure can complement BMD measurements for investigations of fracture risk.
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Affiliation(s)
- Jennifer S Gregory
- Department of Orthopaedics, University of Aberdeen, Aberdeen, Scotland, U.K.
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Brunet-Imbault B, Lemineur G, Chappard C, Harba R, Benhamou CL. A new anisotropy index on trabecular bone radiographic images using the fast Fourier transform. BMC Med Imaging 2005; 5:4. [PMID: 15927072 PMCID: PMC1173107 DOI: 10.1186/1471-2342-5-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2004] [Accepted: 05/31/2005] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The degree of anisotropy (DA) on radiographs is related to bone structure, we present a new index to assess DA. METHODS In a region of interest from calcaneus radiographs, we applied a Fast Fourier Transform (FFT). All the FFT spectra involve the horizontal and vertical components corresponding respectively to longitudinal and transversal trabeculae. By visual inspection, we measured the spreading angles: Dispersion Longitudinal Index (DLI) and Dispersion Transverse Index (DTI) and calculated DA = 180/(DLI+DTI). To test the reliability of DA assessment, we synthesized images simulating radiological projections of periodic structures with elements more or less disoriented. RESULTS Firstly, we tested synthetic images which comprised a large variety of structures from highly anisotropic structure to the almost isotropic, DA was ranging from 1.3 to 3.8 respectively. The analysis of the FFT spectra was performed by two observers, the Coefficients of Variation were 1.5% and 3.1 % for intra-and inter-observer reproducibility, respectively. In 22 post-menopausal women with osteoporotic fracture cases and 44 age-matched controls, DA values were respectively 1.87 +/- 0.15 versus 1.72 +/- 0.18 (p = 0.001). From the ROC analysis, the Area Under Curve (AUC) were respectively 0.65, 0.62, 0.64, 0.77 for lumbar spine, femoral neck, total femoral BMD and DA. CONCLUSION The highest DA values in fracture cases suggest that the structure is more anisotropic in osteoporosis due to preferential deletion of trabeculae in some directions.
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Affiliation(s)
| | - Gerald Lemineur
- Equipe Inserm 658, Hôpital Porte Madeleine, BP 2439, 45032 Orléans Cedex 1, France
- Laboratoire d'Electronique, Signaux, Images, Université d'Orléans, BP 6744, 45067 Orléans, France
| | - Christine Chappard
- Equipe Inserm 658, Hôpital Porte Madeleine, BP 2439, 45032 Orléans Cedex 1, France
| | - Rachid Harba
- Laboratoire d'Electronique, Signaux, Images, Université d'Orléans, BP 6744, 45067 Orléans, France
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Gregory JS, Stewart A, Undrill PE, Reid DM, Aspden RM. Identification of hip fracture patients from radiographs using Fourier analysis of the trabecular structure: a cross-sectional study. BMC Med Imaging 2004; 4:4. [PMID: 15469614 PMCID: PMC524177 DOI: 10.1186/1471-2342-4-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2004] [Accepted: 10/06/2004] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND: This study presents an analysis of trabecular bone structure in standard radiographs using Fourier transforms and principal components analysis (PCA) to identify contributions to hip fracture risk. METHODS: Radiographs were obtained from 26 hip fracture patients and 24 controls. They were digitised and five regions of interest (ROI) were identified from the femoral head and neck for analysis. The power spectrum was obtained from the Fourier transform of each region and three profiles were produced; a circular profile and profiles parallel and perpendicular to the preferred orientation of the trabeculae. PCA was used to generate a score from each profile, which we hypothesised could be used to discriminate between the fracture and control groups. The fractal dimension was also calculated for comparison. The area under the receiver operating characteristic curve (Az) discriminating the hip fracture cases from controls was calculated for each analysis. RESULTS: Texture analysis of standard radiographs using the fast Fourier transform yielded variables that were significantly associated with fracture and not significantly correlated with age, body mass index or femoral neck bone mineral density. The anisotropy of the trabecular structure was important; both the perpendicular and circular profiles were significantly better than the parallel-profile (P < 0.05). No significant differences resulted from using the various ROI within the proximal femur. For the best three groupings of profile (circular, parallel or perpendicular), method (PCA or fractal) and ROI (Az = 0.84 - 0.93), there were no significant correlations with femoral neck bone mineral density, age, or body mass index. PCA analysis was found to perform better than fractal analysis (P = 0.019). CONCLUSIONS: Both PCA and fractal analysis of the FFT data could discriminate successfully between the fracture and control groups, although PCA was significantly stronger than fractal dimension. This method appears to provide a powerful tool for the assessment of bone structure in vivo with advantages over standard fractal methods.
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Affiliation(s)
- Jennifer S Gregory
- Department of Orthopaedics, University of Aberdeen, Aberdeen, United Kingdom
| | - Alison Stewart
- Department of Medicine and Therapeutics, University of Aberdeen, Aberdeen, United Kingdom
| | - Peter E Undrill
- Department of Biomedical Physics and Bioengineering, University of Aberdeen, Aberdeen, United Kingdom
| | - David M Reid
- Department of Medicine and Therapeutics, University of Aberdeen, Aberdeen, United Kingdom
| | - Richard M Aspden
- Department of Orthopaedics, University of Aberdeen, Aberdeen, United Kingdom
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