Three-dimensional Reconstruction Technology Research Articles

Application of Sensitivity Encoding Reconstruction for MRI with BOLD Signal

The work of this paper analyzes the performance of Sensitivity Encoding (SENSE) through actual data sets and determines the problem of computational efficiency. It corrects the error of the detection signal through the calibration function of the percentage signal change, and uses the three-dimensional sensor image reconstruction technology to calibrate the sensitivity of the blood to the magnetic change, enhances the sensitivity of the magnetic susceptibility gradient, and reduces the scanning time of the MRI experiment. The actual data set handles the image resolution. The performance and experimental results of SENSE are analyzed through actual data sets.

Application of 3D Navigation and Vascular Reconstruction Technology in Precision Resection of Lung Segment

With the rapid development of imaging technology and the improvement of people's health awareness, more early lung cancers are found. For very early lung cancer (mainly manifested as ground glass nodules), lobectomy is still the standard surgical treatment for lung cancer, and segmental resection has been used clinically as a treatment method. 3D navigation is an effective tool for precise lung segment and sub-segment resection. Three-dimensional vascular reconstruction technology is an advanced imaging technology. Accurate segment resection under thoracoscopy is considered the best surgical treatment for early stage lung cancer. It is difficult to accurately estimate the morphology, nature and other characteristics of the tumor and its surroundings by two-dimensional imaging alone. Therefore, the precise resection operation adds great difficulty and risk to the surgeon. In recent years, 3D navigation and vascular reconstruction techniques have been widely developed and applied in the medical field, and they are rarely used in thoracic surgery. This article has conducted a more in-depth study on the application of 3D navigation technology and vascular reconstruction technology in precision lung resection, and has achieved certain research results.

3D-RVP: A method for 3D object reconstruction from a single depth view using voxel and point

Three-dimensional object reconstruction technology has a wide range of applications such as augment reality, virtual reality, industrial manufacturing and intelligent robotics. Although deep learning-based 3D object reconstruction technology has developed rapidly in recent years, there remain important problems to be solved. One of them is that the resolution of reconstructed 3D models is hard to improve because of the limitation of memory and computational efficiency when deployed on resource-limited devices. In this paper, we propose 3D-RVP to reconstruct a complete and accurate 3D geometry from a single depth view, where R, V and P represent Reconstruction, Voxel and Point, respectively. It is a novel two-stage method that combines a 3D encoder-decoder network with a point prediction network. In the first stage, we propose a 3D encoder-decoder network with residual learning to output coarse prediction results. In the second stage, we propose an iterative subdivision algorithm to predict the labels of adaptively selected points. The proposed method can output high-resolution 3D models by increasing a small number of parameters. Experiments are conducted on widely used benchmarks of a ShapeNet dataset in which four categories of models are selected to test the performance of neural networks. Experimental results show that our proposed method outperforms the state-of-the-arts, and achieves about 2.7% improvement in terms of the intersection-over-union metric.

Explosion propagation and characteristics of rock damage in decoupled charge blasting based on computed tomography scanning

Blasting in rocks typically causes the remaining rock mass to be subjected to varying degrees of damage and failure, leading to a decline in the mechanical properties and bearing capacity of the surrounding rock. In this study, a decoupled charge blasting experiment for small-charge small-scale red sandstone specimens was conducted in a laboratory; the damaged specimens (after blasting) were scanned and reconstructed using computed tomography (CT) scanning and three-dimensional reconstruction technology. The relationship between the gray-scale change characteristics of the CT images and the decoupling coefficient was analyzed. Additionally, the analysis dimensions and damage degree of the damaged specimens (after blasting) were calculated and the damage degree of the indoor small-scale samples (after blasting) was quantitatively evaluated. Furthermore, the relationship between the decoupling coefficient and the blasting action was examined using the LS-DYNA simulation software. The results indicated that the gray-scale value tended to increase with the decoupled coefficient, and the decoupled coefficient demonstrated a significant influence on the blasting action. Thus, the proposed method serves as a suitable means for the evaluation of the failure mechanism through the reconstruction of the spatial distribution of internal cracks.

Influence of freeze-thaw cycles on microstructure and hydraulic conductivity of saline intact loess

In this paper, influence of freeze-thaw (F-T) cycles on the microstructure and hydraulic conductivity were investigated on saline intact loess specimens by infiltrating sodium sulfate. X-Ray computed micro tomography (Micro-CT), and triaxial permeability tests were carried out to understand the relationship between the soil microstructure and hydraulic conductivity. The CT scan images suggest tiny holes in the soil structure expand to form cracks due to F-T cycles; these cracks were more pronounced in specimens with higher salt contents. The soil morphology was reconstructed using three-dimensional (3D) reconstruction technology, which highlights the significant influence of salt weathering on the microstructure of saline intact loess. Triaxial permeability test results suggest that the void ratio and hydraulic conductivity of saline intact loess both increase after F-T cycles or at higher sodium sulfate contents, which are consistent with the changes of the porosity of the 3D reconstructed model. Finally, an empirical relationship between hydraulic conductivity and void ratio was proposed incorporating the influence of F-T cycles and salt content. There is a good comparison between the calculated and measured data that establishes the rationality and validity of the proposed equation.

Occurrence modes of water in gasification fine slag filter cake and drying behavior analysis——A case study

Coal gasification fine slag is one of the major industrial wastes produced from coal gasification technology and its landfill disposal of the high-moisture product has brought harmful environmental impacts. The characteristic of water occurrence modes in gasification slag filter cake has positive effects on guiding high-efficiency dewatering processes which benefits to the environment. Gasification fine slag particles and water exist simultaneously in the gasification fine slag filter cake, and the physicochemical properties of the gasification fine slag have significant influences on the water occurrence mode and the effective dewatering process. The hydrophilic components and abundant macropores in the gasification slag are favorable for water occurrence. The water in the gasification fine slag filter cake was classified according to the freezing types and size distribution by low-temperature DSC and LF-NMR, respectively. ∼86 wt% of total water corresponding to the free water form which would be removed first during drying process. The visualization of water was determined by three-dimensional reconstruction technology, there are distinct water channels in the gasification fine slag filter cake from the direction in which the filter cake is formed, and the volume of water was estimated at ∼56 %. The drying behaviors were tested by TGA with the heating rates of 2, 7, and 15 K/min, and the maximum drying rate and critical water content increased as the increasing heating rates. The two-dimensional growth kinetic model was applied for describing the drying kinetic process, and the activation energy decreased as the increasing heating rate, and the drying rate reduction stage has higher activation energy compare to the increasing and constant drying stage.

Application of three-dimensional reconstruction and virtual reality technology in liver surgery

Application of three-dimensional reconstruction and virtual reality technology in liver surgery

Application of DynaCT angiographic reconstruction in balloon pulmonary angioplasty.

To investigate the feasibility and accuracy of balloon pulmonary angioplasty (BPA) using DynaCT angiographic reconstruction guidance. Thirty-four BPAs (23 CTEPH patients) targeting 175 pulmonary arteries were included. Eleven BPAs (2D group) were guided by DSA two-dimensional angiography. Another twenty-three BPAs (3D group) were guided using DynaCT angiographic reconstruction. The volume rendering (VR) method was used to obtain a three-dimensional image of the blood vessels. This image was used as a reference to continue BPA treatment under the guidance of vascular three-dimensional reconstruction technology. Procedure durations and radiation exposure data were compared between the two groups using Mann-Whitney U test. Using the DynaCT angiographic reconstruction technique, more target vessels were treated in a single BPA procedure (5.83 ± 2.33 vs 3.73 ± 1.10 vessels per BPA, p = 0.008) in a shorter operation time (3.58 ± 0.61 vs 4.49 ± 0.91h, p = 0.002). Overall, the dose area product (DAP) was significantly higher for the 2D group than for the 3D group (13,901.82 ± 5549.69 vs 4682.82 ± 1950.64, p < 0.001). The use of the DynaCT angiographic reconstruction technique to guide BPA required a lower dose of contrast agent (225.22 ± 48.70 vs 292.73 ± 76.82mL, p = 0.013) and less radiation exposure. The use of DynaCT angiographic reconstruction guidance in patients undergoing BPA is feasible and accurate. Images of DynaCT angiographic reconstruction may be beneficial for optimizing the operative process in BPA with reduced radiation exposure. • BPA guidance by DynaCT angiographic reconstruction is feasible and accurate. • DynaCT angiographic reconstruction may be beneficial for optimizing the operative process. • DynaCT angiographic reconstruction can reduce patient radiation dose due to multi-times of BPA sessions.

A new technique for the 3D reconstruction of the incisional hernia: A pilot study

PurposeThis study aimed to accurately evaluate incisional hernias with a new three-dimensional (3D) reconstruction technology, proving surgeons more information for intuitive and accurate judgments about incisional hernia to minimize the perioperative complications and recurrence rate. MethodThis was a pilot study using a new technique, 3D reconstruction, based on computed tomography (CT) scans to measure abdominal wall defect, herniary area, herniary volume, abdominal cavity volume, and the volume of transverse, oblique, and recti abdominis in three patients with incisional hernias. ResultsThe 3D reconstruction technique made automated segmentation of the bony skeleton, skin, outer abdominal wall, vessel, and hernia sac. The hernia sac, abdominal muscles, and their anatomic relationship were clearly illustrated in 3D reconstruction images. Moreover, abdominal cavity volume; herniary diameter, area, and volume; and the volume of transverse, oblique, and recti muscles could be evaluated through 3D reconstruction images. Surgeons can also freely combine, rotate, scale, and move the 3D reconstruction mode, modify the name and transparency of the 3D reconstruction model, and observe the internal structure of the tissue and the size, shape, and location of the lesion from multiple angles for better and accurate judgments. ConclusionThe herniary diameter, area, and volume and the volume of transverse, oblique, and recti abdominis can be accurately calculated through this 3D reconstruction technology. A three-dimensional vision of the abdomen through this technology can objectively and quantitatively evaluate the situation of incisional hernia, providing a more realistic means for diagnosis and treatment of incisional hernias.

Three-dimensional reconstruction of the dribble track of soccer robot based on heterogeneous binocular vision

With the rapid development of science and technology, as an important branch of the computer. Binocular vision technology has also been greatly improved and improved. It has been applied to many fields of production and life, medical information, industrial manufacturing, and service industries. Heterogeneous binocular vision typically uses a camera to simulate the sensory acquisition process of humans. To process the target information, multiple viewpoints observe the same motion scene. Finally, multiple pairs of images are obtained from different viewpoints. Three-dimensional reconstruction has long been one of the important research fields of computer vision. It has great application value in robot autonomous navigation vision, self-driving vehicle, and automatic detection field and freedom degree mechanical device control. In the robot application of visual positioning technology, with the development needs, the level of intelligence of the robot is also gradually increasing. The three-dimensional reconstruction technology combined with the principle of heterogeneous binocular vision has important practical significance for completing the technique of the dribble track of soccer robots. Based on the RoboCup soccer robot competition, this paper uses the heterogeneous binocular vision technology to analyze the kinematics of the soccer robot in detail. By analyzing the basic motion characteristics of soccer robots, a three-dimensional reconstruction technology model of its dribble trajectory is established, and the reliability, practicability and rationality of the design are verified.

Evaluation of Three-Dimensional Printing-Assisted Laparoscopic Cryoablation of Small Renal Tumors: A Preliminary Report.

This study aimed to explore the security and feasibility of three-dimensional (3D) printing technology- assisted laparoscopic cryoablation to treat small renal tumors. Four patients recruited from our hospital from April 2016 to August 2017 underwent 3D printing technology-assisted laparoscopic cryoablation. Three-dimensional reconstruction technology was used to mimic cryoablation treatment before operations to determine the number of needles needed for the operation and the depth and angle required for needle insertion into the tumor to preserve nephron integrity. CT scans were used to assess the treatment's efficacy after operation during regular follow-up. The operation was performed successfully in all cases and all patients recovered without major complications. The operation times ranged from 106 to 118 minutes and blood loss ranged from 50 to 100 mL. The follow-up times were between 8-16 months and the mean time was 13.3 months. Follow-up surveys were conducted regularly based on a standard outpatient protocol. Results showed no abnormal reinforcing signals in cryoablation treated areas. 3D printing technology-assisted laparoscopic cryoablation is a feasible method for the treatment of renal tumors and may be a way to better preserve nephrons, especially in elderly patients and/or those with comorbidities.

Three-dimensional mechanical parts reconstruction technology based on two-dimensional image

With the development of computer technology and three-dimensional reconstruction technology, three-dimensional reconstruction based on visual images has become one of the research hotspots in computer graphics. Three-dimensional reconstruction based on visual image can be divided into three-dimensional reconstruction based on single photo and video. As an indirect three-dimensional modeling technology, this method is widely used in the fields of film and television production, cultural relics restoration, mechanical manufacturing, and medical health. This article studies and designs a stereo vision system based on two-dimensional image modeling technology. The system can be divided into image processing, camera calibration, stereo matching, three-dimensional point reconstruction, and model reconstruction. In the part of image processing, common image processing methods, feature point extraction algorithm, and edge extraction algorithm are studied. On this basis, interactive local corner extraction algorithm and interactive local edge detection algorithm are proposed. It is found that the Harris algorithm can effectively remove the features of less information and easy to generate clustering phenomenon. At the same time, the method of limit constraints is used to match the feature points extracted from the image. This method has high matching accuracy and short time. The experimental research has achieved good matching results. Using the platform of binocular stereo vision system, each step in the process of three-dimensional reconstruction has achieved high accuracy, thus achieving the three-dimensional reconstruction of the target object. Finally, based on the research of three-dimensional reconstruction of mechanical parts and the designed binocular stereo vision system platform, the experimental results of edge detection, camera calibration, stereo matching, and three-dimensional model reconstruction in the process of three-dimensional reconstruction are obtained, and the full text is summarized, analyzed, and prospected.

Application of three-dimensional reconstruction simulation to define the starting point of lumbar cortical bone trajectory

CT three-dimensional reconstruction technology was used to simulate the placement of the lumbar cortical bone trajectory (CBT), to determine the starting point and direction of the screw trajectory. Between February 2017 and April 2018, 24 patients with lumbar CT were selected as the study object. There were 7 males and 17 females, with an average age of 50.4 years (range, 37-68 years). The CT DICOM data of patients were imported into Mimics 16.0 software, and the three-dimensional model of lumbar spine was established. A 5 mm diameter cylinder was set up to simulate the CBT by using Mimics 16.0 software. According to the different implant schemes, the study was divided into groups A, B, and C, the track of the screw respectively passed through the upper edge, the medial edge, and the lower edge of the isthmus of the pedicle. The intersection of simulated screw and lumbar spine was marked as region of interest (ROI) and a mask was generated. The average CT value [Hounsfield unit (HU)] and the screw length of ROI were automatically measured by Mimics 16.0 software. In addition, the head inclination angle and head camber angle of the screw were measured respectively. Point F was the intersection of the level of the lowest edge of the transverse process and the lumbar isthmus periphery. The horizontal and vertical distance between point F and the starting point were measured, and the relationship between the three schemes and the position of the zygapophysial joint and spinous process was observed. Plan A has the highest ROI average HU, with the maximum value appearing in L 4; plan B has the longest screw length, with the maximum value appearing in L 5; plan C has the largest nail track head inclination angle, with the maximum value appearing in L 4; plan B has the largest nail track head camber angle, with the maximum value appearing in L 3. The screw length and head camber angle of the nail in group B were significantly greater than those in groups A and C ( P<0.05); the head inclination angle in groups A, B, and C was gradually increased, showing significant differences ( P<0.05); there was no significant difference in the average HU value of ROI between the 3 groups ( P>0.05). In plan A, 74.48% (143/192) screws had a horizontal distance of -2 to 4 mm from point F, a vertical distance of 6-14 mm from point F, a head inclination angle of (14.64±2.77)°, and a head camber angle of (6.55±2.09)°, respectively; in plan B, 84.58% (203/240) screws had a horizontal distance of 1-6 mm from point F, a vertical distance of 1-5 mm from point F, a head inclination angle of (26.93±2.21)°, and a head camber angle of (10.29±2.46)°, respectively; in plan C, 85.94% (165/192) screws had a horizontal distance of -2 to 3 mm from point F, a vertical distance of -2 to 4 mm from point F, a head inclination angle of (33.50±3.69)°, and a head camber angle of (6.47±2.48)°, respectively. Plan B should be selected as the starting point of the L 1-L 5 CBT implant. It is located at the intersection of the lowest horizontal line of the transverse process root and the lateral edge of the lumbar isthmus, which is 1-6 mm horizontally inward, 1-5 mm vertically upward, with a head inclination angle of (26.93±2.21)°, and a head camber angle of (10.29±2.46)°, respectively.

Investigation on preferential path of fluid flow by using topological network model of permeable asphalt mixture

The void structures in permeable asphalt pavements are capable of creating space for fluid flow, and the preferential paths of fluid most significantly impact its flow features. In the present study, the aim was to investigate the preferential path of fluid flow using topological network model of permeable asphalt mixtures. Permeable asphalt mixtures were produced in the laboratory, and their internal structure images were captured with the computed tomography. To eliminate the interference of noise and defects in the image, reasonable image processing methods of image de-noising and defect processing were identified. The Otsu method and three-dimensional reconstruction technology were employed to build the three-dimensional structure of the voids. The void contents calculated in the experiment were adopted to verify the feasibility of the void reconstruction. On that basis, the topological network model of the void was further built by morphological processing. Subsequently, Dijkstra algorithm was adopted for comparing the flow resistance of different paths in the topological network, as well as for the determination of the preferential path of flow. The computational fluid dynamics model was employed to verify the feasibility of the preferential flow path by analyzing the distribution rules of flow velocity and streamline of fluid.

Clinical application of CT measurement in primary total hip arthroplasty of DDH patients

Objective To investigate the clinical effect of preoperative computed tomography (CT) measurement of acetabulum femoral neck combined anteversion in primary total hip arthroplasty (THA). Methods From March 2016 to may 2018, 48 patients (90 hips) with developmental dysplasia of the hip (DDH) who were treated with THA in the orthopaedic department of Jiangmen Central Hospital were measured by X-ray and spiral CT three-dimensional reconstruction technology before operation, and the best combined anteversion angle of acetabulum was determined before implementing THA, which was CT group; the remaining 42 patients were not measured by CT before operation, which was X-ray group. The difference of acetabulum cup anteversion angle, acetabulum femoral neck combined anteversion angle and preoperation angle were evaluated by three-dimensional computed tomography (3D-CT) in CT group. Results There was no significant difference in operative time, intraoperative blood loss, time of getting out of bed and length of lower limbs between the two groups (P>0.05). In CT group, the acetabulum cup anteversion and acetabulum femoral neck anteversion were close to the pre-operative angle at 2 and 3 months postoperatively (P>0.05). The Harris hip score of CT group was significantly higher than that of X-ray group at 2 and 3 months after operation, and the incidence of deep vein thrombosis was 6.25%, significantly lower than that of X-ray group (21.43%) (P 0.05). Conclusions For DDH patients who received THA for the first time, preoperative CT measurement of acetabulum femoral neck combined with anteversion is conducive to the formulation of the best combined anteversion adjustment scheme, which can obtain the maximum initial stability, improve the surgical effect and reduce the occurrence of dislocation of prosthesis. Key words: Tomography, X-ray computed; Acetabulum; Femur neck; Hip dysplasia; Arthroplasty, replacement, hip

Application of 3D reconstruction for midline glossectomy in OSA patients.

To explore the application of three-dimensional (3D) reconstruction technology for midline glossectomy in patients with obstructive sleep apnea (OSA). Fifteen patients with OSA were included in this study. Each of them received computed tomography angiography (CTA) examination of lingual arteries in the resting tongue position and fully extended tongue position respectively. The two-dimensional CTA images were converted to 3D models using 3D reconstruction technology. We simulated the midline glossectomy in different tongue positions with a safe margin of 3mm. The differences in the distances between bilateral lingual arteries, the depths of the lingual arteries and the surgical resectable volumes of the tongue were compared between different tongue positions in 3D models. The depths of the lingual arteries, the distances between bilateral lingual arteries based on three measuring sections and the surgical resectable volumes of the tongue in the fully extended tongue position were significantly smaller than those in the resting tongue position (P < 0.01 or 0.05). The 3D reconstruction technology can show the course of lingual artery stereoscopically and visually, and can be more beneficial to guide surgery than two-dimensional examination. Lingual artery examination in the fully extended tongue position has higher specificity in displaying intraoperative actual situation.

基于光纤光栅传感器的板状结构形态感知与三维重构技术

基于光纤光栅传感器的板状结构形态感知与三维重构技术

熔融石英光学元件亚表面缺陷三维重构技术

熔融石英光学元件亚表面缺陷三维重构技术

Application of three-dimensional reconstruction to improve the preoperative measurement accuracy and applicability of femoral neck torsion angle.

Conventional methods have limitations in measuring femoral neck torsion angle (FNTA) of patients with femoral deformities. A new method of three-dimensional (3D) reconstruction technology based on computer tomography (CT) was proposed to enhance measurement accuracy and applicability in this study.Bilateral FNTA of 50 developmental dysplasia of the hip (DDH) patients (DDH group) and 81 volunteers (normal group) were measured by Mimics software based on CT data with the marker lines determined by centerline and curvature. Each FNTA was measured by observer A and observer B for twice separately. 50 DDH patients were classified into 3 groups (group I, II, III) according to Hartofilakidis classification. The statistical analysis of the differences was made among the measurements of the FNTA.The FNTA values were 27.56° ± 12.48° in DDH group and 21.22° ± 8.14° in normal group with significant difference (t = 4.516, P < .001). The FNTA values were 24.53° ± 2.40° in group I, 29.78° ± 1.83° in group II and 39.08° ± 3.13° in group III, with significant difference (F = 7.568, P = .001).The accuracy, reliability and applicable scope of FNTA measurement can be improved by 3D reconstruction in clinical practice. The applicable scope of this method included normal people and patients with femoral deformities. The FNTA of DDH patients is significantly larger than normal volunteers with a positive correlation between the severity of classification. This study will also provide references for preoperative design of Chinese population.

Application effects of enhanced computed tomography and three-dimensional reconstruction technology in reconstruction of pediatric post-burn scars with expanded flaps

Objective: To explore the application effects of enhanced computed tomography (CT) and three-dimensional reconstruction technology in the reconstruction of pediatric post-burn scars with expanded flaps. Methods: From May 2016 to March 2019, 19 children with hypertrophic scars after thermal injuries were admitted to our unit, including 10 boys and 9 girls, aged from 4 years and 5 months to 15 years and 11 months. The area of scars ranged from 5 cm×4 cm to 23 cm×9 cm. One or more skin and soft tissue expanders with suitable volume and shape were implanted into the normal skin area around scar of children. Three to six months later, enhanced CT and three-dimensional reconstruction were performed before the second stage operation to obtain three-dimensional images of the vascular branches in the donor site for expanded flaps to be cut, so as to determine the course and distribution of the vascular branches and guide the design of expanded flaps. According to the design scheme, the resection of scar, removal of expanders, and excision and transfer of flaps were performed to repair the wounds after scar resection. The area of flaps ranged from 6 cm×4 cm to 25 cm×10 cm. The donor site was closed directly. The number of flaps was counted. The anatomical structure, vascular distribution, and adverse reactions during enhanced CT and three-dimensional reconstruction of site for expanded flaps to be cut, the survival of expanded flaps and the follow-up after the second-stage operation were observed. Results: A total of 48 expanded flaps were designed and excised in 19 children. The anatomical structure of the site for expanded flaps to be cut and the adjacent spatial position relationship were visually observed through the three-dimensional reconstruction after enhanced CT, and no adverse reactions were observed. Arterial branch blood supply or venous return was observed in 29 sites for expanded flaps to be cut. All the expanded flaps survived well without blood supply disorder after the second stage operation. The children were followed up for 6 months to 1 year and 6 months after the second stage operation. The appearance of the flaps was natural, and the color and thickness of the flaps were similar to those of the surrounding normal skin, except for one child with obvious linear scar. Conclusions: Enhanced CT and three-dimensional reconstruction can assist the vascular assessment of the expended flaps, which is helpful for rational design of the flap excision and transfer protocol to improve the survival rate of flaps. Thus, it has certain clinical application value in the reconstruction of post-burn scar in children with expanded flaps.