The practical value of 3-dimensional computed tomography on diagnosis of bladder tumor

Objective To study the practical value of 3-dimensional computed tomography on diagnosis of bladder tumor, Methods Fifteen patients with bladder masses were examined by thin-layer computed tomography. The results of 3-dimensional reconstructed images were compared with the final diagnosis and the pathological stages. Results According to 3-dimensional reconstructed images, among the 15 cases, 12 cases of bladder cancer were diagnosed, and the pathological types were transitional carcinoma. Two cases were diagnosed as benign tumor (leiomyoma), and the other one was colon cancer, which invaded bladder. The accuracy was 100% . The clinical stages were determined. Of the 12 bladder carcinomas,5 was in stage T1, 3 in T2,, 3 in T3 and 1 in T4.The accuracy of staging was up to 83% (10/12) compared with pathological stages. Conclusion The 3-dimensional reconstructed technology may improve the accuracy of staging of bladder carcinoma, and to provide important evidence for surgery options. 3 refs,2 figs.

Effects of dry-wet cycles on three-dimensional pore structure and permeability characteristics of granite residual soil using X-ray micro computed tomography

Due to seasonal climate alterations,the microstructure and permeability of granite residual soil are easily affected by multiple dry-wet cycles.The X-ray micro computed tomography(micro-CT)acted as a nondestructive tool for characterizing the microstructure of soil samples exposed to a range of damage levels induced by dry-wet cycles.Subsequently,the variations of pore distribution and permeability due to drywet cycling effects were revealed based on three-dimensional(3D)pore distribution analysis and seepage simulations.According to the results,granite residual soils could be separated into four different components,namely,pores,clay,quartz,and hematite,from micro-CT images.The reconstructed 3D pore models dynamically demonstrated the expanding and connecting patterns of pore structures during drywet cycles.The values of porosity and connectivity are positively correlated with the number of dry-wet cycles,which were expressed by exponential and linear functions,respectively.The pore volume probability distribution curves of granite residual soil coincide with the χ^(2)distribution curve,which verifies the effectiveness of the assumption of χ^(2)distribution probability.The pore volume distribution curves suggest that the pores in soils were divided into four types based on their volumes,i.e.micropores,mesopores,macropores,and cracks.From a quantitative and visual perspective,considerable small pores are gradually transformed into cracks with a large volume and a high connectivity.Under the action of dry-wet cycles,the number of seepage flow streamlines which contribute to water permeation in seepage simulation increases distinctly,as well as the permeability and hydraulic conductivity.The calculated hydraulic conductivity is comparable with measured ones with an acceptable error margin in general,verifying the accuracy of seepage simulations based on micro-CT results.

3D characterization and analysis of pore structure of packed ore particle beds based on computed tomography images

Methods and procedures of three-dimensional （3D） characterization of the pore structure features in the packed ore particle bed are focused. X-ray computed tomography was applied to deriving the cross-sectional images of specimens with single particle size of 1-2, 2-3, 3-4, 4-5, 5-6, 6-7, 7-8, 8-9, 9-10 ram. Based on the in-house developed 3D image analysis programs using Matlab, the volume porosity, pore size distribution and degree of connectivity were calculated and analyzed in detail. The results indicate that the volume porosity, the mean diameter of pores and the effective pore size （d50） increase with the increasing of particle size. Lognormal distribution or Gauss distribution is mostly suitable to model the pore size distribution. The degree of connectivity investigated on the basis of cluster-labeling algorithm also increases with increasing the particle size approximately.

Three-Tesla Magnetic Resonance and Computed Tomography Imaging in Three-Dimensional Conformal Radiotherapy for Localized Prostate Cancer

Aims and background: we evaluate CT-3Tesla MRI fusion in conformal radiotherapy for localized prostate cancer.Methods: 18 consecutive patients underwent a 3T MRI scan under radiotherapy planning conditions, after the CT scan. Bowel and bladder preparation were prescribed. CT and MR images were automatically fused;prostate and seminal vesicles were contoured on CT and on MRI, organs at risk were defined on CT-MRI fusion. Late rectal and sexual toxicity, differences in target volume between MRI and CT and differences in rectal and penile bulb dose distribution based on CT only or on CT-MRI fusion were evaluated.Results: one patient experienced a late rectal toxicity;no patient had sexual toxicity. The difference between the mean MRI and CT target volumes was statistically significant (p = 0.0001 paired Student's t-test). The dose-volume histogram (DVH) analysis shows a significant reduction of the dose received by the rectum and the penile bulb in MRI-plans compared to CT-plans.Conclusions: 3 Tesla MRI scan under radiotherapy planning conditions along with bowel preparation significantly improves the definition of the target volume sparing normal tissue irradiation.

Diagnostic Performance and Inter-Observer Agreement of 4-Dimensional Computed Tomography Parathyroid Scans in Patients with Primary and Secondary Hyperparathyroidism

Background: 4D-CT has been used to localize the parathyroid adenomas and hyperplasia since 2006 as a second line study after TC-99 m MIBI and ultrasonography. However, multiple studies have shown that 4D-CT is a robust imaging method with high diagnostic accuracy, becoming increasingly popular among surgeons and radiologists. Purpose: To assess the diagnostic performance of 4D-CT scans to identify the pathologic gland(s), using pathology and intraoperative findings as gold standards. Methods: We analyzed patients with primary and secondary hyperparathyroidism who had intraoperative reports, pathology, parathyroid hormone levels, and preoperative 4D-CT. Histology, surgical findings, and decreased parathyroid hormone levels were used as gold standards. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy and 95% confidence interval were calculated. Fleiss’ kappa was used to assess the inter-observer agreement. Results: Sixty-seven patients were included. Sixty-two patients had a single adenoma, and five patients had a multiple gland disease (adenomas or hyperplasia). A total of 72 glands were proven to have parathyroid adenomas or hyperplasia. The sensitivity, specificity, PPV, NPV and accuracy are 85%, 97%, 96%, 87% and 91% for lateralization and 76%, 96%, 85%, 92% and 90% for quadrant localization, respectively in single-gland disease. The sensitivity, specificity, PPV, NPV and accuracy are 88%, 100%, 100%, 50% and 90% for lateralization and 71%, 100%, 100%, 60% and 80% for quadrant localization respectively in multiple-gland disease. Fleiss’ kappa value is 5.6 (moderate inter-observer agreement). Conclusion: 4D-CT is a robust method in the localization of hyperfunctioning parathyroid glands with high accuracy and at least moderate inter-observer agreement.

Use of high-resolution X-ray computed tomography and 3D image analysis to quantify mineral dissemination and pore space in oxide copper ore particles

Mineral dissemination and pore space distribution in ore particles are important features that influence heap leaching performance. To quantify the mineral dissemination and pore space distribution of an ore particle, a cylindrical copper oxide ore sample (I center dot 4.6 mm x 5.6 mm) was scanned using high-resolution X-ray computed tomography (HRXCT), a nondestructive imaging technology, at a spatial resolution of 4.85 mu m. Combined with three-dimensional (3D) image analysis techniques, the main mineral phases and pore space were segmented and the volume fraction of each phase was calculated. In addition, the mass fraction of each mineral phase was estimated and the result was validated with that obtained using traditional techniques. Furthermore, the pore phase features, including the pore size distribution, pore surface area, pore fractal dimension, pore centerline, and the pore connectivity, were investigated quantitatively. The pore space analysis results indicate that the pore size distribution closely fits a log-normal distribution and that the pore space morphology is complicated, with a large surface area and low connectivity. This study demonstrates that the combination of HRXCT and 3D image analysis is an effective tool for acquiring 3D mineralogical and pore structural data.

Numerical analysis of the failure process of soil-rock mixtures through computed tomography and PFC3D models

Soil-rock mixture （SRM） is a unique type of geomaterial characterized by a heterogeneous composition and a complicated structure. It is intractable for the continuum-based soil and rock mechanics theories to accurately characterize and predict the SRM＇s mechanical properties. This study reports a novel numerical method incorporating microfocus computed tomography and PFC3D codes to probe the deformation and failure processes of SRM. The three-dimensional （3D） PFC models that represent the SRM＇s complex structures were built. By simulating the entire failure process in PFC3D, the SRM＇s strength, elastic modulus and crack growth were obtained. The influence of rock ratios on the SRM＇s strength, deformation and failure processes, as well as its internal mesoscale mechanism, were analyzed. By comparing simulation results with experimental data, it was verified that the 3D PFC models were in good agreement with SRM＇s real structure and the SRM＇s compression process, deformation and failure patterns; its intrinsic mesomechanism can be effectively analyzed based on such 3D PFC models.

Quantification of 3D macropore networks in forest soils in Touzhai valley(Yunnan,China)using X-ray computed tomography and image analysis

The three dimensional （3D） geometry of soil macropores largely controls preferential flow, which is a significant infiltrating mechanism for rainfall in forest soils and affects slope stability. However, detailed studies on the 3D geometry of macropore networks in forest soils are rare. The intense rainfall-triggered potentially unstable slopes were threatening the villages at the downstream of Touzhai valley （Yunnan, China）. We visualized and quantified the 3D macropore networks in undisturbed soil columns （Histosols） taken from a forest hillslope in Touzhai valley, and compared them with those in agricultural soils （corn and soybean in USA; barley, fodder beet and red fescue in Denmark） and grassland soils in USA. We took two large undisturbed soil columns （250 mm^25o mmxsoo mm）, and scanned the soil columns at in-situ soil water content conditions using X-ray computed tomography at a voxel resolution of 0.945 × 0.945 × 1.500o mm^3. After reconstruction and visualization, we quantified the characteristics of macropore networks. In the studied forest soils, the main types of maeropores were root channels, inter-aggregate voids, maeropores without knowing origin, root-soil interfaee and stone-soil interface. While maeropore networks tend to be more eomplex, larger, deeper and longer. The forest soils have high maeroporosity, total maeropore wall area density, node density, and large maeropore volume, hydraulie radius, mean maeropore length, angle, and low tortuosity. The findings suggest that maeropore networks in the forest soils have high inter- connectivity, vertical continuity, linearity and less vertically oriented.

X-ray Computed Tomography Characterization of 3D Tufted Twill Textile Composite for Aerostructures

Damage assessments in three dimensional (3D) textile composites subjected to mechanical loading can be performed by non-destructive and destructive techniques.This paper applies the two techniques to investigate the fracture behavior of 3D tufted textile composites.X-ray computed tomography as a non-destructive evaluation method is appropriate to detect damage locations and identify their progression in 3D textile composites.Destructive methods such as sectioning toward observing damage provide valuable information about damage patterns.The results of this research could be utilized to evaluate the initial cause of rupture in 3D tufted composites used in aerospace structures and analyze fracture modes and damage progression.

Femoroacetabular impingement with chronic acetabular rim fracture- 3D computed tomography, 3D magnetic resonance imaging and arthroscopic correlation

Femoroacetabular impingement is uncommonly associated with a large rim fragment of bone along the superolateral acetabulum. We report an unusual case of femoroacetabular impingement(FAI) with chronic acetabular rim fracture. Radiographic, 3D computed tomography, 3D magnetic resonance imaging and arthroscopy correlation is presented with discussion of relative advantages and disadvantages of various modalities in the context of FAI.

3D Reconstruction with Spiral Computed Tomography in Choroidal Osteoma

Choroidal osteoma (CO) is a rare, ossifying benign tumor originated in the choroid that typically occurs in otherwise healthy young women (1,2). It is characterized by a yellowish, well demarcated lesion in the juxtapapillary or macular area. The diagnosis is clinical and can be confirmed with the use of fluorescein or indocyanine angiography, optical coherence tomography, computed tomography or magnetic resonance imaging. Choroidal neovascularization or subretinal fluid, the main causes for vision loss, can be treated with laser therapy, photodynamic therapy or intravitreal antivascular endothelial growth factor therapy. We present a case of choroidal osteoma, showing the role of the high resolution 3D spiral computed tomography.

Evaluation of Airway Obstruction at Soft Palate Level in Male Patients with Obstructive Sleep Apnea/Hypopnea Syndrome:Dynamic 3-Dimensional CT Imaging of Upper Airway

This study examined the dynamic characteristics of upper airway collapse at soft palate level in patients with obstructive sleep apnea/hypopnea syndrome（OSAHS） by using dynamic 3-Dimensional（3-D） CT imaging.A total of 41 male patients who presented with 2 of the following symptoms,i.e.,daytime sleepiness and fatigue,frequent snoring,and apnea with witness,were diagnosed as having OSAHS.They underwent full-night polysomnography and then dynamic 3-D CT imaging of the upper airway during quiet breathing and in Muller＇s maneuver.The soft palate length（SPL）,the minimal cross-sectional area of the retropalatal region（mXSA-RP）,and the vertical distance from the hard palate to the upper posterior part of the hyoid（hhL） were compared between the two breathing states.These parameters,together with hard palate length（HPL）,were also compared between mild/moderate and severe OSAHS groups.Association of these parameters with the severity of OSAHS [as reflected by apnea hypopnea index（AHI） and the lowest saturation of blood oxygen（LSaO2）] was examined.The results showed that 31 patients had severe OSAHS,and 10 mild/moderate OSAHS.All the patients had airway obstruction at soft palate level.mXSA-RP was significantly decreased and SPL remarkably increased during Muller＇s maneuver as compared with the quiet breathing state.There were no significant differences in these airway parameters（except the position of the hyoid bone） between severe and mild/moderate OSAHS groups.And no significant correlation between these airway parameters and the severity of OSAHS was found.The position of hyoid was lower in the severe OSAHS group than in the mild/moderate OSAHS group.The patients in group with body mass index（BMI）≥26 had higher collapse ratio of mXSA-RP,greater neck circumference and smaller mXSA-RP in the Muller＇s maneuver than those in group with BMI26（P0.05 for all）.It was concluded that dynamic 3-D CT imaging could dynamically show the upper airway changes at soft palate level in OSAHS patients.All the OSAHS patients had airway obstruction of various degrees at soft palate level.But no correlation was observed between the airway change at soft palate level and the severity of OSAHS.The patients in group with BMI≥26 were more likely to develop airway obstruction at soft palate level than those with BMI26.

Characterization of microstructure evolution of cement paste by micro computed tomography

Micro computed tomography (Micro-CT) was applied to obtain three-dimensional images of the microstructure of cement paste (water-to-cement mass ratio of 0.5) at different ages. By using the Amira software, component phases of the cement paste such as pores, hydration products, and unhydrated clinker particles were segmented from each other based on their 3D image grey levels; their relative contents were also calculated with the software, and the data are 61.2%, 0% and 38.8% at the beginning of hydration and 11.8%, 78.5% and 9.7% at 28 d age, respectively. The hydration degree of cement paste at different ages was compared with the experimental data acquired by loss on ignition (LOI) tests. The results show that the calculated and measured data reasonably agree with each other, which indicates that micro-CT is a useful and reliable approach to characterize the micro structure evolution of hydrating cement paste.

Painleve Analysis and Determinant Solutions of a (3+1)-Dimensional Variable-Coefficient Kadomtsev-Petviashvili Equation in Wronskian and Grammian Form

In this paper, the investigation is focused on a （3＋1）-dimensional variable-coefficient Kadomtsev- Petviashvili （vcKP） equation, which can describe the realistic nonlinear phenomena in the fluid dynamics and plasma in three spatial dimensions. In order to study the integrability property of such an equation, the Painlevé analysis is performed on it. And then, based on the truncated Painlevé expansion, the bilinear form of the （3＋1）-dimensionaJ vcKP equation is obtained under certain coefficients constraint, and its solution in the Wronskian determinant form is constructed and verified by virtue of the Wronskian technique. Besides the Wronskian determinant solution, it is shown that the （3＋1）-dimensional vcKP equation also possesses a solution in the form of the Grammian determinant.

Extended symmetry transformation of (3+1)-dimensional generalized nonlinear Schrdinger equation with variable coefficients

In this paper, the extended symmetry transformation of （3＋1）-dimensional （3D） generalized nonlinear Schrodinger （NLS） equations with variable coefficients is investigated by using the extended symmetry approach and symbolic computation. Then based on the extended symmetry, some 3D variable coefficient NLS equations are reduced to other variable coefficient NLS equations or the constant coefficient 3D NLS equation. By using these symmetry transformations, abundant exact solutions of some 3D NLS equations with distributed dispersion, nonlinearity, and gain or loss are obtained from the constant coefficient 3D NLS equation.

CNN Ensemble Approach to Detect COVID-19 from Computed Tomography Chest Images

In January 2020,the World Health Organization declared a global health emergency concerning the spread of a new coronavirus disease,which was later named COVID-19.Early and fast diagnosis and isolation of COVID-19 patients have proven to be instrumental in limiting the spread of the disease.Computed tomography(CT)is a promising imaging method for fast diagnosis of COVID-19.In this study,we develop a unique preprocessing step to resize CT chest images to a fixed size(256×256 pixels)that preserves the aspect ratio and reduces image loss.Then,we present a deep learning(DL)method to classify CT chest images based on the light-weight pre-trained EfficientNet-B3 CNN model and ensemble techniques.The proposed method,which we refer to as EfficientNet-B3-GAP-Ensemble,comprises an ensemble of a modified version of the EfficientNet-B3.We build the ensemble using multiple runs and multiple training epochs.We test the EfficientNet-B3-GAPEnsemble on two common benchmark datasets,i.e.,the COVID19-CT and SARS-CoV-2-CT datasets.The proposed method has outperformed state-ofthe-art methods for both datasets.For the COVID19-CT dataset,it achieved 88.18%sensitivity,88.29%precision,88.18%accuracy,an F1-score of 88.15%,and AUC of 92.10%.With the SARS-CoV-2-CT dataset,we tested the proposed method under different train-test splits,i.e.,20%–80%,50%–50%,and 80%–20%.For the latter split,the proposed method achieved 99.72%accuracy,99.80%sensitivity,precision,and F1-scores,and an AUC score of 99.99%.

X-Ray Computed Tomography for Root Quantification

Soil cores from a field growing barley and barley mutants without root hairs under conventional and minimum tillage were sampled. They were X-ray scanned to produce a 3D image and then the roots were washed out and weight and length were determined by conventional means. Root volume and surface area were then calculated from the 3D images using state of the art software and methodology, and the measured and calculated measures were correlated. The only strong and significant correlation was between measured weight and calculated volume for mutants without root hairs. It is concluded that the software cannot segment out very small roots, but segmentation accuracy also depends on root structure in some unknown way. Any study using X-ray computed tomography to quantify roots as they grow in situ should start with a calibration for the conditions in question.

Phase II Clinical Study of Three-Dimensional Printed Coplanar Template Combined with CT-Guided Percutaneous Core Needle Biopsy of Pulmonary Nodules in Elderly Patients

Background: As the population age structure gradually ages, more and more elderly people were found to have pulmonary nodules during physical examinations. Most elderly people had underlying diseases such as heart, lung, brain and blood vessels and cannot tolerate surgery. Computed tomography (CT)-guided percutaneous core needle biopsy (CNB) was the first choice for pathological diagnosis and subsequent targeted drugs, immune drugs or ablation treatment. CT-guided percutaneous CNB requires clinicians with rich CNB experience to ensure high CNB accuracy, but it was easy to cause complications such as pneumothorax and hemorrhage. Three-dimensional (3D) printing coplanar template (PCT) combined with CT-guided percutaneous pulmonary CNB biopsy has been used in clinical practice, but there was no prospective, randomized controlled study. Methods: Elderly patients with lung nodules admitted to the Department of Oncology of our hospital from January 2019 to January 2023 were selected. A total of 225 elderly patients were screened, and 30 patients were included after screening. They were randomly divided into experimental group (Group A: 30 cases) and control group (Group B: 30 cases). Group A was given 3D-PCT combined with CT-guided percutaneous pulmonary CNB biopsy, Group B underwent CT-guided percutaneous pulmonary CNB. The primary outcome measure of this study was the accuracy of diagnostic CNB, and the secondary outcome measures were CNB time, number of CNB needles, number of pathological tissues and complications. Results: The diagnostic accuracy of group A and group B was 96.67% and 76.67%, respectively (P = 0.026). There were statistical differences between group A and group B in average CNB time (P = 0.001), number of CNB (1 vs more than 1, P = 0.029), and pathological tissue obtained by CNB (3 vs 1, P = 0.040). There was no statistical difference in the incidence of pneumothorax and hemorrhage between the two groups (P > 0.05). Conclusions: 3D-PCT combined with CT-guided percutaneous CNB can improve the puncture accuracy of elderly patients, shorten the puncture time, reduce the number of punctures, and increase the amount of puncture pathological tissue, without increasing pneumothorax and hemorrhage complications. We look forward to verifying this in a phase III randomized controlled clinical study. .

Differentiate Xp11.2 Translocation Renal Cell Carcinoma from Computed Tomography Images and Clinical Data with ResNet-18 CNN and XGBoost

This study aims to apply ResNet-18 convolutional neural network(CNN)and XGBoost to preoperative computed tomography(CT)images and clinical data for distinguishing Xp11.2 translocation renal cell carcinoma(Xp11.2 tRCC)from common subtypes of renal cell carcinoma(RCC)in order to provide patients with individualized treatment plans.Data from45 patients with Xp11.2 tRCC fromJanuary 2007 to December 2021 are collected.Clear cell RCC(ccRCC),papillary RCC(pRCC),or chromophobe RCC(chRCC)can be detected from each patient.CT images are acquired in the following three phases:unenhanced,corticomedullary,and nephrographic.A unified framework is proposed for the classification of renal masses.In this framework,ResNet-18 CNN is employed to classify renal cancers with CT images,while XGBoost is adopted with clinical data.Experiments demonstrate that,if applying ResNet-18 CNN or XGBoost singly,the latter outperforms the former,while the framework integrating both technologies performs similarly or better than urologists.Especially,the possibility of misclassifying Xp11.2 tRCC,pRCC,and chRCC as ccRCC by the proposed framework is much lower than urologists.

Three-dimensional simulation of pore scale fluid flow in granular ore media with realistic geometry

The images of granular ore media were captured by X-ray CT scanner. Combined with digital image processing and finite element techniques, the three-dimensional geometrical model, which represents the realistic pore structure of the media, was constructed. With this model, three dimensional pore scale fluid flow among particles was simulated. Then the distributions of fluid flow velocity and pressure were analyzed and the hydraulic conductivity was calculated. The simulation results indicate the fluid flow behaviors are mainly dominated by the volume and topological structure of pore space. There exist obvious preferential flow and leaching blind zones simultaneously in the medium. The highest velocities generally occur in those narrow pores with high pressure drops. The hydraulic conductivity obtained by simulation is the same order of magnitude as the laboratory test result, which denotes the validity of the model. The pore-scale and macro-scale are combined and the established geometrical model can be used for the simulations of other phenomena during heap leaching process.