5 results on '"Morphological database"'
Search Results
2. Semi-automated stereoradiographic upper limb 3D reconstructions using a combined parametric and statistical model: a preliminary study.
- Author
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Lebailly, F., Lima, L., Clairemidi, A., Aubert, B., Guerard, S., Chaibi, Y., de Guise, J., Fontaine, C., and Skalli, W.
- Subjects
- *
ELBOW surgery , *EPIPHYSIS , *X-rays , *STATISTICAL models , *TOMOGRAPHY - Abstract
Purpose: Quantitative assessment of 3D clinical indices may be crucial for elbow surgery planning. 3D parametric modeling from bi-planar radiographs was successfully proposed for spine and lower limb clinical investigation as an alternative for CT-scan. The aim of this study was to adapt this method to the upper limb with a preliminary validation. Methods: CT-scan 3D models of humerus, radius and ulna were obtained from 20 cadaveric upper limbs and yielded parametric models made of geometric primitives. Primitives were defined by descriptor parameters (diameters, angles...) and correlations between these descriptors were found. Using these correlations, a semi-automated reconstruction method of humerus using bi-planar radiographs was achieved: a 3D personalized parametric model was built, from which clinical parameters were computed [orientation and projections on bone surface of trochlea sulcus to capitulum (CTS) axis, trochlea sulcus anterior offset and width of distal humeral epiphysis]. This method was evaluated by accuracy compared to CT-scan and reproducibility. Results: Points-to-surface mean distance was 0.9 mm (2 RMS = 2.5 mm). For clinical parameters, mean differences were 0.4-1.9 mm and from 1.7° to 2.3°. All parameters except from angle formed by CTS axis and bi-epicondylar axis in transverse plane were reproducible. Reconstruction time was about 5 min. Conclusions: The presented method provides access to morphological upper limb parameters with very low level of radiation. Preliminary in vitro validation for humerus showed that it is fast and accurate enough to be used in clinical daily practice as an alternative to CT-scan for total elbow arthroplasty pre operative evaluation. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
3. Fast accurate stereoradiographic 3D-reconstruction of the spine using a combined geometric and statistic model
- Author
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Pomero, Vincent, Mitton, David, Laporte, Sébastien, de Guise, Jacques A., and Skalli, Wafa
- Subjects
- *
SCOLIOSIS , *RADIOGRAPHY , *SPINE , *REGRESSION analysis - Abstract
Objective. To describe and evaluate a fast accurate stereoradiographic 3D-reconstruction method of the spine.Background. Stereoradiographic methods based on anatomical landmarks identification are the only ones providing information on 3D-deformities of the spine in a standing position, but require 2–4 h for the whole spine, making the method inadequate for clinical routine.Methods. The proposed semi-automated method is based on (1) vertebral body volume reconstruction, (2) definition of a local referential associated to this volume, (3) reliable a priori knowledge of the vertebral shape using eight morphologic descriptors of the vertebral body to estimate, from a multiple linear regression, 21 3D-point coordinates per vertebra, (4) kriging of a 2000 points model with regard to the 21 points. The method was evaluated for vertebral orientation and shape accuracy.Results. 3D models of the whole spine are obtained within 15 min. Manual vs. semi-automated reconstruction comparison yield similar accuracy regarding the CT-scan references. For vertebrae orientation, results were slightly different from the manual reconstruction method (however an absolute reference is lacking).Conclusion. The stereoradiographic 3D-reconstruction method allows for a significant reduction of the whole reconstruction time, with regard to previously described methods. Moreover, the accuracy was evaluated and was found to be comparable to the accuracy of previous methods. The results of this study show that stereoradiography could now be employed in routine clinical environment.Relevance3D spine reconstruction from biplanar radiographs in standing position can be obtained using a fast and accurate method. [Copyright &y& Elsevier]
- Published
- 2004
- Full Text
- View/download PDF
4. Tagging a Morphologically Complex Language Using an Averaged Perceptron Tagger : The Case of Icelandic
- Author
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Loftsson, Hrafn and Östling, Robert
- Subjects
Morphological Database ,Linguistic Features ,Part-of-Speech Tagging ,Word Embeddings ,Averaged Perceptron ,Språkteknologi (språkvetenskaplig databehandling) ,Language Technology (Computational Linguistics) - Abstract
In this paper; we experiment with using Stagger; an open-source implementation of an Averaged Perceptron tagger; to tag Icelandic; a morphologically complex language. By adding languagespecific linguistic features and using IceMorphy; an unknown word guesser; we obtain state-of- the-art tagging accuracy of 92.82%. Furthermore; by adding data from a morphological database; and word embeddings induced from an unannotated corpus; the accuracy increases to 93.84%. This is equivalent to an error reduction of 5.5%; compared to the previously best tagger for Icelandic; consisting of linguistic rules and a Hidden Markov Model.
- Published
- 2013
5. Semi-automated stereoradiographic upper limb 3D reconstructions using a combined parametric and statistical model: a preliminary study
- Author
-
Wafa Skalli, J. A. de Guise, F. Lebailly, Yasmina Chaibi, C. Fontaine, B. Aubert, Luciano Vieira Lima, Sandra Guérard, A. Clairemidi, Laboratoire de biomécanique (LBM), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Université Sorbonne Paris Cité (USPC)-Université Paris 13 (UP13), Laboratoire de Recherche en Imagerie : Méthodes d'imagerie des Échanges transcapillaires (LRI - EA4062), Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Bioingénierie et Bioimagerie Ostéo-articulaires, Biomécanique et Biomatériaux Ostéo-Articulaires (B2OA (UMR_7052)), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-École nationale vétérinaire d'Alfort (ENVA), Université Paris 13 (UP13)-Université Sorbonne Paris Cité (USPC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), École nationale vétérinaire - Alfort (ENVA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), École nationale vétérinaire d'Alfort (ENVA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris Descartes - Paris 5 (UPD5), Université Paris 13 (UP13) - Université Sorbonne Paris Cité (USPC) - Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12) - Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM) - Université Paris Descartes - Paris 5 (UPD5), Biomécanique et Biomatériaux Ostéo-Articulaires (B2OA), and Université Paris Diderot - Paris 7 (UPD7) - Ecole Nationale Vétérinaire d'Alfort - Centre National de la Recherche Scientifique (CNRS)
- Subjects
Male ,0302 clinical medicine ,[SPI.MECA.BIOM] Engineering Sciences [physics]/Mechanics [physics.med-ph]/Biomechanics [physics.med-ph] ,Clinical investigation ,Image Processing, Computer-Assisted ,Quantitative assessment ,Medicine ,Elbow surgery ,Morphological database ,Parametric statistics ,Aged, 80 and over ,Orthodontics ,030222 orthopedics ,[SPI.MECA.BIOM]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Biomechanics [physics.med-ph] ,Middle Aged ,medicine.anatomical_structure ,Parametric model ,Upper limb ,Female ,[SDV.IB]Life Sciences [q-bio]/Bioengineering ,Radiology ,Anatomy ,medicine.medical_specialty ,Models, Biological ,Pathology and Forensic Medicine ,Upper Extremity ,03 medical and health sciences ,Imaging, Three-Dimensional ,Cadaver ,Humans ,Radiology, Nuclear Medicine and imaging ,Humerus ,[PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph] ,Mécanique: Biomécanique [Sciences de l'ingénieur] ,Aged ,[SDV.IB] Life Sciences [q-bio]/Bioengineering ,Models, Statistical ,business.industry ,[PHYS.MECA.BIOM] Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph] ,ingénierie bio-médicale [Sciences du vivant] ,Reproducibility of Results ,Statistical model ,030229 sport sciences ,CT-scan ,Elbow arthroplasty planning ,body regions ,Surgery ,Tomography, X-Ray Computed ,business - Abstract
PURPOSE: Quantitative assessment of 3D clinical indices may be crucial for elbow surgery planning. 3D parametric modeling from bi-planar radiographs was successfully proposed for spine and lower limb clinical investigation as an alternative for CT-scan. The aim of this study was to adapt this method to the upper limb with a preliminary validation. METHODS: CT-scan 3D models of humerus, radius and ulna were obtained from 20 cadaveric upper limbs and yielded parametric models made of geometric primitives. Primitives were defined by descriptor parameters (diameters, angles...) and correlations between these descriptors were found. Using these correlations, a semi-automated reconstruction method of humerus using bi-planar radiographs was achieved: a 3D personalized parametric model was built, from which clinical parameters were computed [orientation and projections on bone surface of trochlea sulcus to capitulum (CTS) axis, trochlea sulcus anterior offset and width of distal humeral epiphysis]. This method was evaluated by accuracy compared to CT-scan and reproducibility. RESULTS: Points-to-surface mean distance was 0.9 mm (2 RMS = 2.5 mm). For clinical parameters, mean differences were 0.4-1.9 mm and from 1.7° to 2.3°. All parameters except from angle formed by CTS axis and bi-epicondylar axis in transverse plane were reproducible. Reconstruction time was about 5 min. CONCLUSIONS: The presented method provides access to morphological upper limb parameters with very low level of radiation. Preliminary in vitro validation for humerus showed that it is fast and accurate enough to be used in clinical daily practice as an alternative to CT-scan for total elbow arthroplasty pre operative evaluation.
- Published
- 2012
- Full Text
- View/download PDF
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