scholarly journals Correlations between fabric tensors computed on cone beam and micro computed tomography images

2013 ◽  
pp. 411-416 ◽  
Keyword(s):  
Computed Tomography ◽  
Cone Beam ◽  
Micro Computed Tomography ◽  
Computed Tomography Images ◽  
Fabric Tensors

scholarly journals Longitudinal Imaging of Liver Cancer Using MicroCT and Nanoparticle Contrast Agents in CRISPR/Cas9-Induced Liver Cancer Mouse Model

2021 ◽  
Vol 20 ◽  
pp. 153303382110164
Author(s):  
Sang Bu An ◽  
Kwangmo Yang ◽  
Chang Won Kim ◽  
Si Ho Choi ◽  
Eunji Kim ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Liver Cancer ◽  
Contrast Agents ◽  
Kupffer Cells ◽  
Micro Computed Tomography ◽  
Hepatic Parenchyma ◽  
Heterogeneous Distribution ◽  
Computed Tomography Images ◽  
Longitudinal Imaging ◽  
Over Time

Introduction: Micro-computed tomography with nanoparticle contrast agents may be a suitable tool for monitoring the time course of the development and progression of tumors. Here, we suggest a practical and convenient experimental method for generating and longitudinally imaging murine liver cancer models. Methods: Liver cancer was induced in 6 experimental mice by injecting clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeats-associated protein 9 plasmids causing mutations in genes expressed by hepatocytes. Nanoparticle agents are captured by Kupffer cells and detected by micro-computed tomography, thereby enabling longitudinal imaging. A total of 9 mice were used for the experiment. Six mice were injected with both plasmids and contrast, 2 injected with contrast alone, and one not injected with either agent. Micro-computed tomography images were acquired every 2- up to 14-weeks after cancer induction. Results: Liver cancer was first detected by micro-computed tomography at 8 weeks. The mean value of hepatic parenchymal attenuation remained almost unchanged over time, although the standard deviation of attenuation, reflecting heterogeneous contrast enhancement of the hepatic parenchyma, increased slowly over time in all mice. Histopathologically, heterogeneous distribution and aggregation of Kupffer cells was more prominent in the experimental group than in the control group. Heterogeneous enhancement of hepatic parenchyma, which could cause image quality deterioration and image misinterpretation, was observed and could be due to variation in Kupffer cells distribution. Conclusion: Micro-computed tomography with nanoparticle contrast is useful in evaluating the induction and characteristics of liver cancer, determining appropriate size of liver cancer for testing, and confirming therapeutic response.

Automatic Knot Detection in Coarse-Resolution Cone-Beam Computed Tomography Images of Softwood Logs

2019 ◽  
Vol 69 (3) ◽  
pp. 185-187
Author(s):  
Magnus Fredriksson ◽  
Julie Cool ◽  
Stavros Avramidis
Keyword(s):  
Computed Tomography ◽  
Exploratory Study ◽  
Ct Scanning ◽  
Detection Algorithm ◽  
Cone Beam ◽  
X Ray ◽  
Coarse Resolution ◽  
Computed Tomography Images ◽  
X Ray Computed ◽  
Accurate Position

Abstract X-ray computed tomography (CT) scanning of sawmill logs is associated with costly and complex machines. An alternative scanning solution was developed, but its data have not been evaluated regarding detection of internal features. In this exploratory study, a knot detection algorithm was applied to images of four logs to evaluate its performance in terms of knot position and size. The results were a detection rate of 67 percent, accurate position, and inaccurate size. Although the sample size was small, it was concluded that automatic knot detection in coarse resolution CT images of softwoods is feasible, albeit for knots of sufficient size.

scholarly journals PREVALENCE OF MANDIBULAR ASYMMETRY IN SKELETAL CLASS I ADULT PATIENTS

2014 ◽  
Vol 2 (2) ◽  
pp. 189 ◽  
Author(s):  
Bruno Frazão Gribel ◽  
Guilherme Thiesen ◽  
Tássia Silvana Borges ◽  
Maria Perpétua Mota Freitas
Keyword(s):  
Computed Tomography ◽  
Calculation Method ◽  
Significant Error ◽  
Adult Patients ◽  
Class I ◽  
Cone Beam ◽  
Skeletal Class ◽  
Mandibular Asymmetry ◽  
Computed Tomography Images ◽  
Significant Difference

AIM: The objective of this study was evaluating the prevalence of mandibular asymmetry in skeletal Class I adult patients. MATERIALS AND METHODS: The sample was composed by cone-beam computed tomography images of 250 skeletal Class I patients with age from 18 to 70 years old. The side deviation of mandibular asymmetry was evaluated (right and left), as well as the intensity of this asymmetry. People with gnathic deviation until 2mm were considered as patients with slight asymmetry; deviation between 2 and 5mm was considered moderate asymmetry and those higher than 5mm as severe asymmetries. The error calculation method was performed and there was not significant error in the measurements. To verify the association between the prevalence of mandibular asymmetry and the gender of individuals, the Χ2 was carried out and the significant level adopted was 5% (p<0.05). RESULTS: The results showed that mandibular deviation occurred more frequently to the left side in both genders (male 56.5% e female 58.2%), without statistically significant difference between them (p=0.792). Besides, the prevalence of slight, moderate and severe asymmetries were, respectively 61%, 27% and 12% for males and 54%, 28% and 18% for female; and there was not statistically significant difference (p=0.366) between the gender of the sample evaluated. CONCLUSION: In this study, both deviation and intensity of mandibular asymmetry did not present preference regarding to the gender.

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