Atlas-based Reconstruction of 3D Volumes of Lower Extremity from 2D Calibrated X-ray Images

Mapping Intimacies ◽

10.29007/qxff ◽

2018 ◽

Author(s):

Weimin Yu ◽

Guoyan Zheng

Keyword(s):

Knee Joint ◽

Lower Extremity ◽

3D Reconstruction ◽

Present Approach ◽

Smoothness Property ◽

B Spline ◽

X Ray ◽

B Splines ◽

Ct Data

A new atlas-based 2D-3D reconstruction of 3D volumes of lower extremity from a pair of calibrated X-ray images was presented. The approach combines non-rigid 2D- 2D registration based 3D landmark reconstruction with the B-spline parametrization of TPS transformation, incorporating the smoothness property of B-splines for regularization. Efficacy of the present approach was evaluated on the calibrated X-ray images and CT data. Also, we take the knee joint articulation into consideration. Articulated B-spline parameterization leads to the almost same accuracy as individual B-spline parameterization and has the superiority over the latter when it comes to the prevention from the knee joint penetration.

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Maximum Vanishing Moment of Compactly Supported B-spline Wavelets

Asian Journal of Probability and Statistics ◽

10.9734/ajpas/2019/v3i330095 ◽

2019 ◽

pp. 1-8

Author(s):

Kanchan Lata Gupta ◽

B. Kunwar ◽

V. K. Singh

Keyword(s):

Scaling Function ◽

Simple Procedure ◽

Smoothness Property ◽

Vanishing Moments ◽

B Spline ◽

B Splines ◽

Compactly Supported ◽

Spline Wavelets ◽

Vanishing Moment ◽

Rule Order

Spline function is of very great interest in field of wavelets due to its compactness and smoothness property. As splines have specific formulae in both time and frequency domain, it greatly facilitates their manipulation. We have given a simple procedure to generate compactly supported orthogonal scaling function for higher order B-splines in our previous work. Here we determine the maximum vanishing moments of the formed spline wavelet as established by the new refinable function using sum rule order method.

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Analyzing Specular Reflectivities with Parametric B-Splines

MRS Proceedings ◽

10.1557/proc-376-187 ◽

1994 ◽

Vol 376 ◽

Author(s):

N. F. Berk ◽

C. F. Majkrzak

Keyword(s):

Scattering Length ◽

Density Profiles ◽

B Spline ◽

X Ray ◽

B Splines ◽

Fitting Procedure ◽

Spline Curves ◽

Reflectivity Spectra ◽

Specular Reflectivity ◽

Low Dimensional

ABSTRACTA method of using parametric B-spline curves to interpret neutron and x-ray specular reflectivity spectra is described. The introduction of parametric curves for scattering length density profiles greatly expands the function space accessible to low-dimensional representations but also requires means to restrict the space to physically acceptable functions. A practical fitting procedure is outlined, and two examples are shown.

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Preoperative assessment of treatment planning on minimization of micro-movement during healing period of immediate-loaded implants using X-ray CT data-based simulation

Journal of Oral Implantology ◽

10.1563/aaid-joi-d-09-00122.1 ◽

2010 ◽

pp. 110220121911010

Author(s):

KATSUHIKO KIMURA ◽

Yasumasa Fukase ◽

Michiko Makino ◽

Chihiro Masaki ◽

Tetsuji Nakamoto ◽

...

Keyword(s):

Treatment Planning ◽

Preoperative Assessment ◽

X Ray ◽

Healing Period ◽

Ct Data

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Design and analysis of a lower extremity exoskeleton with the humanoid knee joint

Journal of Physics Conference Series ◽

10.1088/1742-6596/1633/1/012052 ◽

2020 ◽

Vol 1633 ◽

pp. 012052

Author(s):

Tingting Li ◽

Jian Li ◽

Zhonghua Han ◽

Jiechao Yang ◽

Qiang Li

Keyword(s):

Knee Joint ◽

Lower Extremity

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Complete Ring Artifacts Reduction Procedure for Lab-Based X-ray Nano CT Systems

Sensors ◽

10.3390/s21010238 ◽

2021 ◽

Vol 21 (1) ◽

pp. 238

Author(s):

Jakub Šalplachta ◽

Tomáš Zikmund ◽

Marek Zemek ◽

Adam Břínek ◽

Yoshihiro Takeda ◽

...

Keyword(s):

High Efficiency ◽

Image Inpainting ◽

Simulated Data ◽

Complementary Metal Oxide Semiconductor ◽

Oxide Semiconductor ◽

Detection Accuracy ◽

Reduction Procedure ◽

X Ray ◽

Artifacts Reduction ◽

Ct Data

In this article, we introduce a new ring artifacts reduction procedure that combines several ideas from existing methods into one complex and robust approach with a goal to overcome their individual weaknesses and limitations. The procedure differentiates two types of ring artifacts according to their cause and character in computed tomography (CT) data. Each type is then addressed separately in the sinogram domain. The novel iterative schemes based on relative total variations (RTV) were integrated to detect the artifacts. The correction process uses the image inpainting, and the intensity deviations smoothing method. The procedure was implemented in scope of lab-based X-ray nano CT with detection systems based on charge-coupled device (CCD) and scientific complementary metal–oxide–semiconductor (sCMOS) technologies. The procedure was then further tested and optimized on the simulated data and the real CT data of selected samples with different compositions. The performance of the procedure was quantitatively evaluated in terms of the artifacts’ detection accuracy, the comparison with existing methods, and the ability to preserve spatial resolution. The results show a high efficiency of ring removal and the preservation of the original sample’s structure.

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Morphological consistency of bilateral hip joints in adults based on the X-ray and CT data

Surgical and Radiologic Anatomy ◽

10.1007/s00276-020-02676-4 ◽

2021 ◽

Author(s):

Ran Zhao ◽

Hong Cai ◽

Hua Tian ◽

Ke Zhang

Keyword(s):

Hip Joint ◽

Morphological Difference ◽

Medullary Cavity ◽

Size Difference ◽

Single Plane ◽

X Ray ◽

Stem Size ◽

The Difference ◽

Ct Data ◽

Anatomical Parameters

Abstract Purpose The application of the anatomical parameters of the contralateral hip joint to guide the preoperative template of the affected side relies on the bilateral hip symmetry. We investigated the bilateral hip symmetry and range of anatomical variations by measurement and comparison of bilateral hip anatomical parameters. Methods This study included 224 patients (448 hips) who were diagnosed with osteoarthritis (OA) and avascular necrosis (AVN) of the femur head, and underwent bilateral primary total hip arthroplasty (THA) in our hospital from January 2012 to August 2020. Imaging data included 224 patients X-ray and 30 CT data at the end of the cohort. Anatomical parameters, including the acetabular abduction angle and trochanteric height, were measured using the Noble method. Postoperative measurements included stem size, difference of leg length and offset. Results Except for the isthmus width, there were no significant differences in the anatomical morphology of the hip joint. Among the demographic factors, there was a correlation between body weight and NSA. Among various anatomical parameters, a correlation was present between medullary cavity widths of T + 20, T, and T − 20. The difference in the use of stem size is not due to the morphological difference of bilateral medullary cavity, but due to the different of 1- or 2-stage surgery. Conclusion Bilateral symmetry was present among the patients with normal morphology of the hip medullary cavity, theoretically confirming the feasibility of structural reconstruction of the hip joint using the hip joint on the uninjured side. Additionally, the difference in the morphology of the hip medullary cavity is not present in a single plane but is synergistically affected by multiple adjacent planes.

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Towards B-Spline Atomic Structure Calculations

Atoms ◽

10.3390/atoms9030050 ◽

2021 ◽

Vol 9 (3) ◽

pp. 50

Author(s):

Charlotte Froese Fischer

Keyword(s):

Atomic Structure ◽

Bound States ◽

Virial Theorem ◽

B Spline ◽

B Splines ◽

Self Consistent ◽

History Of ◽

Consistent Method ◽

Atomic Structure Calculations ◽

Structure Calculations

The paper reviews the history of B-spline methods for atomic structure calculations for bound states. It highlights various aspects of the variational method, particularly with regard to the orthogonality requirements, the iterative self-consistent method, the eigenvalue problem, and the related sphf, dbsr-hf, and spmchf programs. B-splines facilitate the mapping of solutions from one grid to another. The following paper describes a two-stage approach where the goal of the first stage is to determine parameters of the problem, such as the range and approximate values of the orbitals, after which the level of accuracy is raised. Once convergence has been achieved the Virial Theorem, which is evaluated as a check for accuracy. For exact solutions, the V/T ratio for a non-relativistic calculation is −2.

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3D-Reconstruction and characterization of the pore microstructure within the asphalt FAM using the X-ray micro-computed tomography

Construction and Building Materials ◽

10.1016/j.conbuildmat.2020.121764 ◽

2021 ◽

Vol 272 ◽

pp. 121764

Author(s):

Zili Zhao ◽

Jiwang Jiang ◽

Fujian Ni ◽

Xiang Ma

Keyword(s):

Computed Tomography ◽

3D Reconstruction ◽

Micro Computed Tomography ◽

X Ray ◽

Pore Microstructure

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Limitations of body mass index for counseling individuals with unilateral lower extremity amputation

Prosthetics and Orthotics International ◽

10.1177/0309364616650079 ◽

2016 ◽

Vol 41 (2) ◽

pp. 186-193 ◽

Cited By ~ 3

Author(s):

Alexandra P Frost ◽

Tracy Norman Giest ◽

Allison A Ruta ◽

Teresa K Snow ◽

Mindy Millard-Stafford

Keyword(s):

Body Mass Index ◽

Lower Extremity ◽

Health Risk ◽

Body Mass ◽

Body Fat ◽

Lower Limb ◽

Dual Energy ◽

Limb Loss ◽

Percent Body Fat ◽

X Ray

Background: Body composition is important for health screening, but appropriate methods for unilateral lower extremity amputees have not been validated. Objectives: To compare body mass index adjusted using Amputee Coalition equations (body mass index–Amputee Coalition) to dual-energy X-ray absorptiometry in unilateral lower limb amputees. Study design: Cross-sectional, experimental. Methods: Thirty-eight men and women with lower limb amputations (transfemoral, transtibial, hip disarticulation, Symes) participated. Body mass index (mass/height2) was compared to body mass index corrected for limb loss (body mass index–Amputee Coalition). Accuracy of classification and extrapolation of percent body fat with body mass index was compared to dual-energy X-ray absorptiometry. Results: Body mass index–Amputee Coalition increased body mass index (by ~ 1.1 kg/m2) but underestimated and mis-classified 60% of obese and overestimated 100% of lean individuals according to dual-energy X-ray absorptiometry. Estimated mean percent body fat (95% confidence interval) from body mass index–Amputee Coalition (28.3% (24.9%, 31.7%)) was similar to dual-energy X-ray absorptiometry percent body fat (29.5% (25.2%, 33.7%)) but both were significantly higher ( p < 0.05) than percent body fat estimated from uncorrected body mass index (23.6% (20.4%, 26.8%)). However, total errors for body mass index and body mass index–Amputee Coalition converted to percent body fat were unacceptably large (standard error of the estimate = 6.8%, 6.2% body fat) and the discrepancy between both methods and dual-energy X-ray absorptiometry was inversely related ( r = −0.59 and r = −0.66, p < 0.05) to the individual’s level of body fatness. Conclusions: Body mass index (despite correction) underestimates health risk for obese patients and overestimates lean, muscular individuals with lower limb amputation. Clinical relevance Clinical recommendations for an ideal body mass based on body mass index–Amputee Coalition should not be relied upon in lower extremity amputees. This is of particular concern for obese lower extremity amputees whose health risk might be significantly underestimated based on body mass index despite a “correction” formula for limb loss.

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