A new threshold selection method for X-ray computed tomography for dimensional metrology

Kowaluk, Tomasz; Woźniak, A.

doi:10.1016/j.precisioneng.2017.06.020

Cited by 21 publications

(10 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Another method uses the histogram of individual cross-sectional slices with a separate determination of the threshold value for each stack, although its use is only recommended in CT images of parts made of a single material [ 8 ]. The surface extraction procedure presented in [ 9 ] is a method that requires the calibration of a reference workpiece to determine a certain correction for air-material threshold values on the gray scale of the CT volume. An alternative method is based on the local or dynamic threshold, in which a threshold value can be defined for each of the elements or zones of the tomographic volume [ 10 ].…”

Section: Introductionmentioning

confidence: 99%

Analysis of Surface Extraction Methods Based on Gradient Operators for Computed Tomography in Metrology Applications

et al. 2018

View full text Add to dashboard Cite

Among the multiple factors influencing the accuracy of Computed Tomography measurements, the surface extraction process is a significant contributor. The location of the surface for metrological applications is generally based on the definition of a gray value as a characteristic of similarity to define the regions of interest. A different approach is to perform the detection or location of the surface based on the discontinuity or gradient. In this paper, an adapted 3D Deriche algorithm based on gradient information is presented and compared with a previously developed adapted Canny algorithm for different surface types. Both algorithms have been applied to nine calibrated workpieces with different geometries and materials. Both the systematic error and measurement uncertainty have been determined. The results show a significant reduction of the deviations obtained with the Deriche-based algorithm in the dimensions defined by flat surfaces.

show abstract

Section: Introductionmentioning

confidence: 99%

Analysis of Surface Extraction Methods Based on Gradient Operators for Computed Tomography in Metrology Applications

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Verification of the model consists in comparing the results obtained from the simulated images with those obtained for CT scans (comparing the percentage value of the deviation of the cross-sectional area in terms of the default value -PS deviation). The deviation values of PS from both methods are determined according to [11]. Example image of a 50 mm sphere, obtained by MCM simulation and actual measurement, is shown in Fig.2.…”

Section: Resultsmentioning

confidence: 99%

“…Offset of the reference workpiece from the axis of rotation will change the value of the cross-section area of the sphere depending on the angular setting. For this reason, each measurement was made from 1500 projections, recorded every 50 X-ray images, and for each image the PS value was determined according to [11]. The obtained values of the deviations were determined as the average value of PS for comparison with the results from the simulation.…”

Section: Measurementsmentioning

confidence: 99%

“…Several threshold correction methods can be found in the literature [9]- [10]. A new method for such applications has been recently developed in our Department [11]. The method involves executing additional calibration measurement and determining certain corrections PS for airmaterial threshold values on the greyscale of the volumetric tomographic files.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Proposed Use of Monte Carlo Simulated Images to Evaluate the Accuracy of Measurements on X-Ray Computed Tomography

Kowaluk

Maciak

Woźniak

et al. 2018

Measurement Science Review

Self Cite

View full text Add to dashboard Cite

X-ray computed tomography (CT) is increasingly recognized as a promising measuring technique for dimensional metrology. Various methods are being developed to improve measurement accuracy. Tests of new methods for such applications include accuracy evaluation with the use of calibrated workpieces; however, the internal algorithms of image acquisition and data processing might influence the experimental error, and then also the comparison of methods at different CTs. The accuracy of the results of tomographic measurements is influenced by many factors, one of which is the setting of the threshold value. The article presents the results of an attempt to use Monte Carlo simulated images to estimate deviations to determine threshold values to improve measurement accuracy and additionally, to estimate the impact of data processing. The differences of the results obtained from the simulated images were up to 4 % larger than those from tomographic images. It was caused by degradation of the image contrast by scattered radiation.

show abstract

“…The bone tissue is isolated from air, soft tissue (bone marrow), and metallic implant by the different specific threshold values. The ISO 50% method based on the grayscale histogram is commonly used to determine the bone threshold [ 18 , 27 ]. However, the low-mineralized bone has a similar threshold value with bone marrow or soft tissue, and their threshold ranges unavoidably overlap with each other.…”

Section: Discussionmentioning

confidence: 99%

Correlation between two-dimensional micro-CT and histomorphometry for assessment of the implant osseointegration in rabbit tibia model

Lyu

Lee

2021

Biomater Res

View full text Add to dashboard Cite

Background Histology is considered as a gold standard for analyzing bone architecture. However, histomorphometry is a destructive method and only offers the bone information of a limited location. Micro-computed tomography (μCT) is a non-destructive technology and provides a slice at any site. The aim of this study was to compare the correlation of the Bone-to-Implant Contact ratio (BIC) between 2D micro-CT (μCT) and histomorphometry and to investigate a method for assessing the osseointegration of the implant by 2D μCT. Methods A total of 18 implants were divided into three groups (6 implants per group), and inserted into the rabbit tibia defects as follow: implant only (Implant group), implant with β-TCP/hydrogel (TCP group), implant with rhBMP-2 loaded β-TCP/hydrogel composite (BMP-2 group). After 4 weeks of implantation, the specimens were collected to take the micro-CT scan with an aluminum filter and performed H&E staining on the undecalcified sections. The 2D μCT slices were chosen at an angle of 0°, 45°, 90° and 135° with the representative histological section to measure BIC. And the correlations between BICs of 2D μCT and BICs of histology were evaluated. Results In each group, BICs at the same sites measured by histomorphometry and corresponding 2D μCT presented the same trend and shown no significant difference between the two methods (P > 0.05). BICs of histological sections and BICs of corresponding 2D μCT slices presented a strong correlation in the implant group (γ = 0.74, P = 0.09), a moderate correlation in the TCP group (γ = 0.46, P = 0.35), a weak correlation in the BMP-2 group (γ = 0.30, P = 0.56). In the implant group, the relationship between BIC-Mean-μCTs and BICs-Histology has presented a significant linear correlation (γ = 0.84, P = 0.04). Conclusions Integrating bone information of several 2D μCT slices in different sites to measure BIC is a feasible method for assessing the implant osseointegration.

show abstract

A new threshold selection method for X-ray computed tomography for dimensional metrology

Cited by 21 publications

References 12 publications

Analysis of Surface Extraction Methods Based on Gradient Operators for Computed Tomography in Metrology Applications

Analysis of Surface Extraction Methods Based on Gradient Operators for Computed Tomography in Metrology Applications

Proposed Use of Monte Carlo Simulated Images to Evaluate the Accuracy of Measurements on X-Ray Computed Tomography

Correlation between two-dimensional micro-CT and histomorphometry for assessment of the implant osseointegration in rabbit tibia model

Contact Info

Product

Resources

About