Anatomical region identification in medical X-ray computed tomography (CT) scans: development and comparison of alternative data analysis and vision-based methods

X-ray Computed Tomography (CT) is a powerful non-destructive technique that can yield interesting structural information not discernible through visual examination only. This paper presents the results of the CT scans of four objects belonging to the Romanian cultural heritage attributed to the Vinča, Cucuteni and Cruceni-Belegiš cultures. The study was performed with an X-ray tomographic device developed at the Department for Applied Nuclear Physics from Horia Hulubei National Institute for Nuclear Physics and Engineering in Măgurele, Romania. This apparatus was specially designed for archaeometric studies of low-Z artifacts: ceramic, wood, bone. The tomographic investigations revealed the internal configuration of the objects and provided information about the degree to which the previous manipulations affected the archaeological items. Based on the X-ray images resulting from the CT scans, hints about the techniques used in the manufacturing of the artifacts were obtained, as well as some indications useful for conservation/restoration purposes.

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Fiber orientation quantification utilizing X-ray micro-computed tomography

Journal of Composite Materials ◽

10.1177/0021998320962555 ◽

2020 ◽

pp. 002199832096255

Author(s):

Jennifer M Sietins ◽

Jessica C Sun ◽

Daniel B Knorr Jr

Keyword(s):

Computed Tomography ◽

Fiber Orientation ◽

Mechanical Performance ◽

Ct Scans ◽

Micro Computed Tomography ◽

Orientation Data ◽

Orientation Analysis ◽

X Ray ◽

Software Analysis ◽

X Ray Computed

It is well known that the mechanical performance of composite materials is highly dependent on the fiber orientation. Several techniques have historically been used to quantify fiber orientation experimentally. Newer methods have involved 3 D X-ray computed tomography (CT) scans due to the high resolution that is now achievable within a laboratory setting. The accuracy of the analysis, however, is a function of the resulting scan image quality and the specific parameters influencing the resulting orientation analysis. This report summarizes a methodology to quantify fiber orientation from 3 D CT scans. Optimal scanning parameters are presented taking into account both the necessary resolution, geometric unsharpness, and the scan volume size. The influence of varied software analysis parameters and their effects on the resulting orientation data is discussed. The selection of software analysis parameters was independently validated with optical microscopy on a sample with only two fibers. Lastly, the orientation analysis was applied to a 0/+45/−45/90 composite to demonstrate this technique on a larger scale.

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The influence of defects at the steel/concrete interface for pitting corrosion initiation studied through X-ray Computed Tomography and image analysis

MATEC Web of Conferences ◽

10.1051/matecconf/201928910011 ◽

2019 ◽

Vol 289 ◽

pp. 10011

Author(s):

Emanuele Rossi ◽

Timo Nijland ◽

Oğuzhan Çopuroğlu ◽

Rob Polder ◽

Branko Šavija

Keyword(s):

Computed Tomography ◽

Image Analysis ◽

Reinforced Concrete ◽

Pitting Corrosion ◽

Ct Scans ◽

Volume Loss ◽

Air Voids ◽

X Ray ◽

X Ray Computed ◽

Concrete Interface

Although corrosion of reinforcement is a well-known issue for the construction industry, there are still open questions about some fundamentals of corrosion in reinforced concrete. These points include, among others, which are the most sensitive locations of the steel/concrete interface for pitting corrosion to initiate and to propagate. In this study, X-ray computed tomography (CT-scan) is used to characterize eight 20-years-old reinforced concrete cores naturally deteriorated due to chloride-induced corrosion. The volume loss due to corrosion of the reinforcement was quantified through image analysis of CT-scans. The volume loss of the steel was found to be higher for steel rebars embedded in Portland cement specimens rather than in blended cement specimens. Furthermore, CT-scans revealed that the deepest and most frequent corrosion pits, as well as the consequent highest volume loss of steel, were present at the portion of the reinforcement closer to the outdoor environment and in proximity to air voids at the steel/concrete interface. As a consequence, the highest decrease of structural performance of the rebars would be likely localized at those locations. Therefore, the presence of interfacial air voids should be considered as relevant factor when assessing the risk of corrosion of reinforced concrete structures.

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Refinement of clinical X-ray computed tomography (CT) scans containing metal implants

Computerized Medical Imaging and Graphics ◽

10.1016/j.compmedimag.2017.01.005 ◽

2017 ◽

Vol 56 ◽

pp. 11-23 ◽

Cited By ~ 5

Author(s):

Graham Treece

Keyword(s):

Computed Tomography ◽

Ct Scans ◽

X Ray ◽

Metal Implants ◽

X Ray Computed

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Evaluation of marbling traits by X-ray computed tomography in Hungarian Simmental bulls

Advances in Animal Biosciences ◽

10.1017/s2040470017001704 ◽

2017 ◽

Vol 8 (s1) ◽

pp. s51-s54

Author(s):

G. Holló ◽

B. Húth ◽

I. Holló ◽

I. Anton

Keyword(s):

Computed Tomography ◽

Growth Rate ◽

Intramuscular Fat ◽

Fat Content ◽

Ct Scans ◽

Marbling Score ◽

Average Growth ◽

Mean Values ◽

X Ray ◽

X Ray Computed

Marbling is an economically important factor in many beef carcass grading schemes. This study aimed to evaluate marbling traits of longissimus thoracis muscle (LT) with different methods: USDA marbling score, intramuscular fat (IMF) content by image analysis of X-ray computed tomography (CT) scans and by conventional analytical method. Bulls (n=46) were slaughtered at an average weight of 536 kg and an average age of 646 days. Mean values of EUROP fat scores varied from 2− to 2+, whereas mean values of EUROP conformation grade from O0 to R0. Average growth rate of bulls was 955 g/day. Average chemical fat content of LT varied from 2.2% to 3.1% across conformation classes, and from 2.3% to 5.0% across fat classes. Intramuscular fat content in the 12th rib and in LT on CT-scans closely correlated with chemical fat content (r=0.81 and 0.85, respectively). The highest frequency of USDA marbling score was ‘small’ (55.2%), followed by ‘slight’ (25.5%), ‘modest’ (17%) and ‘moderate’ (2.1%). Computed tomography scans of LT can be used for the evaluation of marbling in Hungarian Simmental cattle. Bulls with higher growth rate had lower marbling level in LT (r=−0.4 to −0.5). EUROP conformation and fat scores have no relationship with marbling traits in this specific cattle population.

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Rising from the ashes: resurrection of the Malagasy chameleons Furcifer monoceras and F. voeltzkowi (Squamata: Chamaeleonidae), based on micro-CT scans and external morphology

Zootaxa ◽

10.11646/zootaxa.4483.3.7 ◽

2018 ◽

Vol 4483 (3) ◽

pp. 549 ◽

Cited By ~ 1

Author(s):

MARINA SENTÍS ◽

YIYIN CHANG ◽

MARK D. SCHERZ ◽

DAVID PRÖTZEL ◽

FRANK GLAW

Keyword(s):

Computed Tomography ◽

Conservation Status ◽

Taxonomic Status ◽

Morphological Characters ◽

The Other ◽

Ct Scans ◽

Micro Ct ◽

X Ray ◽

Dorsal Edge ◽

X Ray Computed

The taxonomy of the Malagasy chameleon Furcifer rhinoceratus (Gray, 1845) is poorly resolved. The aim of this study is to clarify the taxonomic status of Chamaeleon voeltzkowi Boettger, 1893 and Chamaeleon monoceras Boettger, 1913 both only known from single or very few specimens mostly collected more than 100 years ago and currently considered as synonyms of Furcifer rhinoceratus. Using osteological data from micro-X-ray computed tomography (micro-CT) combined with traditional morphological characters and morphometrics we resurrect both taxa from the synonymy of F. rhinoceratus as F. voeltzkowi and F. monoceras, respectively. Compared to F. rhinoceratus, F. monoceras is smaller, has a relatively shorter tail, a longer and thinner rostral appendage, a poorly developed gular crest and no ventral crest, whereas F. voeltzkowi has a smaller rostral appendage, higher casque and the dorsal crest is continuous with the tail crest. Compared to the broad rostral appendage formed by the anterior protuberance of the premaxillary process of the maxilla, which has serrated edges in F. rhinoceratus, F. monoceras presents a long rostral appendage with a smooth dorsal edge that progressively narrows, and the nasal aperture is extended along the elongated appendage; F. voeltzkowi presents a smaller but curved rostral appendage with a crenate edge. The prefrontal and postorbitofrontal approach one another forming a large, laterally closed supraorbital fontanelle in F. rhinoceratus while in F. monoceras they do not approach, leaving a laterally open fontanelle, and in F. voeltzkowi the fontanelle is diminutive. Furcifer voeltzkowi also differs from the similar F. labordi by a smaller size of the rostral appendage, less bulging casque and body pholidosis. The former exhibits a conspicuous white lateral band comprising heterogeneous scalation. Furcifer labordi, on the other hand, has a homogeneous scalation with a remarkable reticulate pattern. Osteologically, the shape of the prefrontal and the connection of the postorbitofrontal with the parietal also differ greatly between the two. Using micro-CT scans we detected key differences that would be otherwise impossible to determine. We also provide a brief morphological and osteological description of the species and strongly recommend efforts to rediscover these two poorly known taxa in order to enable additional studies and to assess their conservation status.

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Three-dimensional imaging and morphometric analysis of alveolar tissue from microfocal X-ray-computed tomography

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00088.2005 ◽

2006 ◽

Vol 291 (3) ◽

pp. L535-L545 ◽

Cited By ~ 42

Author(s):

Horst Detlef Litzlbauer ◽

Christoph Neuhaeuser ◽

Alexander Moell ◽

Susanne Greschus ◽

Andreas Breithecker ◽

...

Keyword(s):

Computed Tomography ◽

Three Dimensional ◽

Ct Scans ◽

Micro Ct ◽

Tissue Samples ◽

X Ray ◽

Ct Analysis ◽

X Ray Computed ◽

Mean Linear Intercept ◽

Alveolar Surface

We evaluated microfocal X-ray-computed tomography (micro-CT) as a method to visualize lung architecture two and three dimensionally and to obtain morphometric data. Inflated porcine lungs were fixed by formaldehyde ventilation. Tissue samples (8-mm diameter, 10-mm height) were stained with osmium tetroxide, and 400 projection images (1,024 × 1,024 pixel) were obtained. Continuous isometric micro-CT scans (voxel size 9 μm) were acquired to reconstruct two- and three-dimensional images. Tissue samples were sectioned (8-μm thickness) for histological analysis. Alveolar surface density and mean linear intercept were assessed by stereology-based morphometry in micro-CT scans and corresponding histological sections. Furthermore, stereology-based morphometry was compared with morphometric semi-automated micro-CT analysis within the same micro-CT scan. Agreement of methods was assessed by regression and Bland-Altman analysis. Comparing histology with micro-CT, alveolar surface densities (35.4 ± 2.4 vs. 33.4 ± 1.9/mm, P < 0.05) showed a correlation ( r = 0.72; P = 0.018) with an agreement of 2 ± 1.6/mm; the mean linear intercept (135.7 ± 14.5 vs. 135.8 ± 15 μm) correlated well ( r = 0.97; P < 0.0001) with an agreement of −0.1 ± 3.4 μm. Semi-automated micro-CT analysis resulted in smaller alveolar surface densities (33.4 ± 1.9 vs. 30.5 ± 1/mm; P < 0.01) with a correlation ( r = 0.70; P = 0.023) and agreement of 2.9 ± 1.4/mm. Non-destructive micro-CT scanning offers the advantage to visualize the spatial tissue architecture of small lung samples two and three dimensionally.

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A Radiologist's Art in CT Images

International Journal of User-Driven Healthcare ◽

10.4018/ijudh.2013100109 ◽

2013 ◽

Vol 3 (4) ◽

pp. 61-66

Author(s):

Piyu Deo Mahant

Keyword(s):

Computed Tomography ◽

Medical Imaging ◽

Human Body ◽

Ct Images ◽

Ct Scans ◽

X Rays ◽

Imaging Studies ◽

X Ray ◽

X Ray Computed

The story of medical imaging starts on 8 Nov, 1895, when Wilhelm Conrad Röntgen accidentally discovered X rays. Since then it has undergone great technological advancements helping physicians create images of the human body to reveal, diagnose, or examine disease (X-ray, n.d). CT scans combine the use of computers and x-rays to create virtual 'slices' of what is inside our body without cutting it open. Earlier many diseases could only be confirmed at autopsy. In 2010, more than 5 billion medical imaging studies were completed done worldwide (X-ray computed tomography, n.d).

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Investigating Machine Learning Based X-Ray Computed Tomography Reconstruction Methods to Enhance the Accuracy of CT Scans.

10.2172/1571551 ◽

2019 ◽

Author(s):

Carianne Martinez ◽

John P. Korbin ◽

Kevin Matthew Potter ◽

Emily Donahue ◽

Jeremy David Gamet ◽

...

Keyword(s):

Machine Learning ◽

Computed Tomography ◽

Ct Scans ◽

X Ray ◽

Reconstruction Methods ◽

X Ray Computed ◽

Tomography Reconstruction ◽

Computed Tomography Reconstruction

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Reducing metal artifacts by restricting negative pixels

Visual Computing for Industry Biomedicine and Art ◽

10.1186/s42492-021-00083-z ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Gengsheng L. Zeng ◽

Megan Zeng

Keyword(s):

Computed Tomography ◽

Objective Function ◽

Ct Scans ◽

Filtered Backprojection ◽

Beam Hardening ◽

Metal Artifacts ◽

X Ray ◽

X Ray Computed ◽

Set Up ◽

True Values

AbstractWhen the object contains metals, its x-ray computed tomography (CT) images are normally affected by streaking artifacts. These artifacts are mainly caused by the x-ray beam hardening effects, which deviate the measurements from their true values. One interesting observation of the metal artifacts is that certain regions of the metal artifacts often appear as negative pixel values. Our novel idea in this paper is to set up an objective function that restricts the negative pixel values in the image. We must point out that the naïve idea of setting the negative pixel values in the reconstructed image to zero does not give the same result. This paper proposes an iterative algorithm to optimize this objective function, and the unknowns are the metal affected projections. Once the metal affected projections are estimated, the filtered backprojection algorithm is used to reconstruct the final image. This paper applies the proposed algorithm to some airport bag CT scans. The bags all contain unknown metallic objects. The metal artifacts are effectively reduced by the proposed algorithm.

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