This paper demonstrates an experiment on the generation of 3D virtual geographic environment on the basis of experimental flight laser scanning data by a set of algorithms and methods that were developed to automatica...This paper demonstrates an experiment on the generation of 3D virtual geographic environment on the basis of experimental flight laser scanning data by a set of algorithms and methods that were developed to automatically interpret range images for extracting geo-spatial features and then to reconstruct geo-objects. The algorithms and methods for the interpretation and modeling of laser scanner data include triangulated-irregular-network (TIN)-based range image interpolation; mathematical-morphology (MM)-based range image filtering, feature extraction and range image segmentation, feature generalization and optimization, 3D objects reconstruction and modeling; computer-graphics (CG)-based visualization and animation of geographic virtual reality environment.展开更多
The study of various medical conditions is limited by the current state of knowledge. New tech-nologies enable researchers to advance their understanding of various medical conditions and to advance their understandin...The study of various medical conditions is limited by the current state of knowledge. New tech-nologies enable researchers to advance their understanding of various medical conditions and to advance their understanding of particular pathologies. Strannik Virtual Scanning (SVS) is such a technology. SVS is able to determine the genetic and non-genetic components of every pathology in each of the 30 main organs, and it is able to determine the onset of pathologies at a much earlier stage than any other technologies or techniques. This makes it an ideal tool to screen for the onset and progression of pathologies which are implicated in multi-systemic conditions and to determine the spectrum of pathologies i.e. comorbidities which are involved in diabetes, cardiovascular disease, migraine, chronic fatigue syndrome, fibromyalgia, depression, chronic kidney disease, etc. This case study illustrates how the technology can be usefully and cost-effectively deployed to determine the spectrum of pathologies which characterise Reynaud’s phenomenon. This includes pathologies in the liver and kidneys e.g. portal hypertension, renal insufficiency, nephritis, liver insufficiency, pre-symptomatic onset of heart attack, presymptomatic indications of dementia, pancreatic cancer, and ovarian cancer, which are difficult to diagnose and/or for which there is currently an unmet clinical need.展开更多
Background This paper presents an intelligent path planner for lifting tasks by tower cranes in highly complex environments,such as old industrial plants that were built many decades ago and sites used as tentative st...Background This paper presents an intelligent path planner for lifting tasks by tower cranes in highly complex environments,such as old industrial plants that were built many decades ago and sites used as tentative storage spaces.Generally,these environments do not have workable digital models and 3 D representations are impractical.Methods The current investigation introduces the use of cutting edge laser scanning technology to convert real environments into virtualized versions of the construction sites or plants in the form of point clouds.The challenge is in dealing with the large point cloud datasets from the multiple scans needed to produce a complete virtualized model.The tower crane is also virtualized for the purpose of path planning.A parallelized genetic algorithm is employed to achieve intelligent path planning for the lifting task performed by tower cranes in complicated environments taking advantage of graphics processing unit technology,which has high computing performance yet low cost.Results Optimal lifting paths are generate d in several seconds.展开更多
The aim of this case report is to raise awareness about the use of 3-Dimentional Computed Tomography (3D-CT) virtual reality imaging as a routine pre-operative tool for evaluation of unusual anatomy such as Situs Inve...The aim of this case report is to raise awareness about the use of 3-Dimentional Computed Tomography (3D-CT) virtual reality imaging as a routine pre-operative tool for evaluation of unusual anatomy such as Situs Inversus Totalis (SIT). We present a case of presumed lung cancer in a 58 years old lady with SIT successfully treated by VATS lobectomy via an anterior approach. She presented with an incidental solitary pulmonary nodule in her right lower lobe, which had moderate FDG uptake on the PET scan. The nodule was too deep to permit safe wedge biopsy, due to proximity of a large pulmonary arterial branch. 3D-CT images were invaluable in pre-operative assessment of the anatomy and were the key to safe completion of right VATS lower lobectomy. Sectioning the lung after retrieval of the specimen suggested a chondroid hamartoma;therefore, systemic nodal dissection (SND) was not contemplated. The final histology confirmed the diagnosis of chondroid hamartoma. In an unusual anatomy such as SIT, 3D-CT allows construction of virtual reality models that can be viewed and manipulated before and during the operation to understand the anatomy better, highlight caveats around target structures and enable localisation of lesions unlikely to be palpated intra-operatively.展开更多
AIM: To evaluate the feasibility of a new computed virtual chromoendoscopy (CVC) device (M i-scan) in the diagnosis of gastric neoplasia. METHODS: Patients with superficial lesions no larger than 1.0 cm found during h...AIM: To evaluate the feasibility of a new computed virtual chromoendoscopy (CVC) device (M i-scan) in the diagnosis of gastric neoplasia. METHODS: Patients with superficial lesions no larger than 1.0 cm found during high definition endoscopy were included. Those with advanced or obviously protruded or depressed lesions, lesions larger than 1.0 cm and/or lesions which were not amenable to observation by zoom function were excluded. The endoscopist was required to give the real-time descriptions of surface pit patterns of the lesions, based on surface pattern classification of enhanced magnification endoscopy. According to previous reports, types Ⅰ-Ⅲ represent nonneoplastic lesions, and types Ⅳ-Ⅴ represent neoplastic lesions. Diagnosis with M i-scan and biopsy was performed before histopathological diagnosis. Magnified images of gastric lesions with and without enhancement were collected for further analysis. The diagnostic yield of real-time M i-scan and effects on magnification image quality by tone enhancement (TE), surface enhancement (SE) and color enhancement (CE) were calculated. The selected images were sent to another endoscopist. The endoscopist rated the image quality of each lesion at 3 levels. Ratings of image quality were based on visualization of pit pattern, vessel and demarcation line. RESULTS: One hundred and eighty-three patients were recruited. Five patients were excluded for advanced gastric lesions, 1 patient was excluded for poor preparation and 2 patients were excluded for superficial lesions larger than 1.0 cm; 132 patients were excluded for no lesions found by high definition endoscopy. In the end, 43 patients with 43 lesions were included. Histopathology revealed 10 inflammation, 14 atrophy, 10 metaplasia, 1 low grade dysplasia (LGD), 5 high grade dysplasia (HGD) and 3 cancers. For 7 lesions classified into type Ⅰ, histopathology revealed 6 atrophy and 1 metaplasia; for 10 lesions classified into type Ⅱ, histopathology revealed 2 inflammation, 7 atrophy and 1 metaplasia; for 10 lesions classified into type Ⅲ, histopathology revealed 1 inflammation, 8 metaplasia and 1 LGD; for 9 lesions classified into type Ⅳ, histopathology revealed 4 inflammation, 1 atrophy and 4 HGD; for 7 lesions classified into type Ⅴ, histopathology revealed 3 inflammation, 1 HGD and 3 cancers. A total of 172 still images, including 43 images by white light (MWL) and 129 images by M i-scan (43 with TE, 43 with SE and 43 with CE), were selected and sent to the endoscopist who did the analysis. General image quality of M i-scan with TE and SE was significantly better than that of MWL (TE, 4.55 ± 1.07; SE, 4.30 ± 1.02; MWL, 3.25 ± 0.99; P < 0.001). Visualization of pit pattern was significantly improved by M i-scan with SE (1.93 ± 0.25 vs 1.50 ± 0.50, P < 0.001). Microvessel visualization was significantly improved by M i-scan with TE (1.23 ± 0.78 vs 0.76 ± 0.73, P < 0.001). Demarcation line visualization was improved by M i-scan with both TE and SE (TE, 1.75 ± 0.52; SE, 1.56 ± 0.59; MWL, 0.98 ± 0.44; P < 0.001). M i-scan with CE did not show any significant improvements of image quality in general or in the 3 key parameters. Although M i-scan with TE and SE slightly increased the diagnostic yield of MWL, there was no significant difference (P > 0.1). CONCLUSION: Although digital enhancement improves the image quality of magnification endoscopy, its value in improving the diagnostic yield seems to be limited.展开更多
Objective To evaluate the feasibility of using gadopentetate dimeglumine(Gd-DTPA)for dual-energy computed tomography pulmonary angiography(CTPA).Methods Sixty-six patients were randomly divided into three groups and u...Objective To evaluate the feasibility of using gadopentetate dimeglumine(Gd-DTPA)for dual-energy computed tomography pulmonary angiography(CTPA).Methods Sixty-six patients were randomly divided into three groups and underwent CTPA.Group A had a turbo flash scan using an iohexol injection,Group B had a turbo flash scan using Gd-DTPA,and Group C had a dual-energy scan using Gd-DTPA.The original images of Group C were linearly blended with a blending factor of 0.5 or reconstructed at 40,50,60,70,80,90,100,and 110 keV,respectively.The groups were compared in terms of pulmonary artery CT value,image quality,and radiation dose.Results The pulmonary artery CT values were significantly higher in Group C40keV than in Groups B and C,but lower than in Group A.There was no significant difference in the image noise of Groups C40keV,B,and C.Moreover,Group A had the largest beam hardening artifacts of the superior vena cava(SVC),followed by Groups B and C.Group C40keV showed better vascular branching than the other three groups,among which Group B was superior to Group A.The subjective score of the image quality of Groups A,B,and C showed no significant difference,but the score was significantly higher in Group C40keV than in Groups A and B.The radiation dose was significantly lower in Group B than in Groups A and C.Conclusion Gd-CTPA is recommended to patients who are unsuitable for receiving an iodine-based CTPA.Furthermore,a turbo flash scan could surpass a dual-energy scan without consideration for virtual monoenergetic imaging.展开更多
This paper contributes to depict the current pattern of applications of digital 3D models for professional research and practice, and for broader dissemination of cultural heritage. Passing from a general review to th...This paper contributes to depict the current pattern of applications of digital 3D models for professional research and practice, and for broader dissemination of cultural heritage. Passing from a general review to the illustration of the background project, named MUSINT, the authors underline the objectives. The present case study primarily aims to share information about valuable archaeological collections which have little visibility. To enhance the project＇s contents, which include a whole set of different artifacts, the authors have reproduced high resolution, faithful and measurable digital models on one side, and on the other, lower resolution and geometrically simplified models are yet completed and very close to reality. The former are meant to implement a scholars＇ archive for further scientific activity. The latter to provide content for virtual exhibitions on the Web or on stand-alone interfaces situated in the actual physical museum spaces. The data acquisition and post-processing methods which have been tested and chosen are here briefly described. Hence, the authors then give an account of the most recurrent problematic issues of the established work-flow and how they should be solved. Touched instances are the delicate placing of the artifacts, which must be digitized, in relation to the triangulation-based laser scanner＇s functionality, the refining operations in order to build a coherent single polygon mesh, the most effective ways to deal with unavoidable missing parts or defected textures in the generated model and so on.展开更多
文摘This paper demonstrates an experiment on the generation of 3D virtual geographic environment on the basis of experimental flight laser scanning data by a set of algorithms and methods that were developed to automatically interpret range images for extracting geo-spatial features and then to reconstruct geo-objects. The algorithms and methods for the interpretation and modeling of laser scanner data include triangulated-irregular-network (TIN)-based range image interpolation; mathematical-morphology (MM)-based range image filtering, feature extraction and range image segmentation, feature generalization and optimization, 3D objects reconstruction and modeling; computer-graphics (CG)-based visualization and animation of geographic virtual reality environment.
文摘The study of various medical conditions is limited by the current state of knowledge. New tech-nologies enable researchers to advance their understanding of various medical conditions and to advance their understanding of particular pathologies. Strannik Virtual Scanning (SVS) is such a technology. SVS is able to determine the genetic and non-genetic components of every pathology in each of the 30 main organs, and it is able to determine the onset of pathologies at a much earlier stage than any other technologies or techniques. This makes it an ideal tool to screen for the onset and progression of pathologies which are implicated in multi-systemic conditions and to determine the spectrum of pathologies i.e. comorbidities which are involved in diabetes, cardiovascular disease, migraine, chronic fatigue syndrome, fibromyalgia, depression, chronic kidney disease, etc. This case study illustrates how the technology can be usefully and cost-effectively deployed to determine the spectrum of pathologies which characterise Reynaud’s phenomenon. This includes pathologies in the liver and kidneys e.g. portal hypertension, renal insufficiency, nephritis, liver insufficiency, pre-symptomatic onset of heart attack, presymptomatic indications of dementia, pancreatic cancer, and ovarian cancer, which are difficult to diagnose and/or for which there is currently an unmet clinical need.
文摘Background This paper presents an intelligent path planner for lifting tasks by tower cranes in highly complex environments,such as old industrial plants that were built many decades ago and sites used as tentative storage spaces.Generally,these environments do not have workable digital models and 3 D representations are impractical.Methods The current investigation introduces the use of cutting edge laser scanning technology to convert real environments into virtualized versions of the construction sites or plants in the form of point clouds.The challenge is in dealing with the large point cloud datasets from the multiple scans needed to produce a complete virtualized model.The tower crane is also virtualized for the purpose of path planning.A parallelized genetic algorithm is employed to achieve intelligent path planning for the lifting task performed by tower cranes in complicated environments taking advantage of graphics processing unit technology,which has high computing performance yet low cost.Results Optimal lifting paths are generate d in several seconds.
文摘The aim of this case report is to raise awareness about the use of 3-Dimentional Computed Tomography (3D-CT) virtual reality imaging as a routine pre-operative tool for evaluation of unusual anatomy such as Situs Inversus Totalis (SIT). We present a case of presumed lung cancer in a 58 years old lady with SIT successfully treated by VATS lobectomy via an anterior approach. She presented with an incidental solitary pulmonary nodule in her right lower lobe, which had moderate FDG uptake on the PET scan. The nodule was too deep to permit safe wedge biopsy, due to proximity of a large pulmonary arterial branch. 3D-CT images were invaluable in pre-operative assessment of the anatomy and were the key to safe completion of right VATS lower lobectomy. Sectioning the lung after retrieval of the specimen suggested a chondroid hamartoma;therefore, systemic nodal dissection (SND) was not contemplated. The final histology confirmed the diagnosis of chondroid hamartoma. In an unusual anatomy such as SIT, 3D-CT allows construction of virtual reality models that can be viewed and manipulated before and during the operation to understand the anatomy better, highlight caveats around target structures and enable localisation of lesions unlikely to be palpated intra-operatively.
基金Supported by The National Clinical Project from the Health Ministry of Chinathe Shandong Province Science and Technology Committee, No. 2010GSF10247National Natural Foundation of Science of China, No. NSFC81101098
文摘AIM: To evaluate the feasibility of a new computed virtual chromoendoscopy (CVC) device (M i-scan) in the diagnosis of gastric neoplasia. METHODS: Patients with superficial lesions no larger than 1.0 cm found during high definition endoscopy were included. Those with advanced or obviously protruded or depressed lesions, lesions larger than 1.0 cm and/or lesions which were not amenable to observation by zoom function were excluded. The endoscopist was required to give the real-time descriptions of surface pit patterns of the lesions, based on surface pattern classification of enhanced magnification endoscopy. According to previous reports, types Ⅰ-Ⅲ represent nonneoplastic lesions, and types Ⅳ-Ⅴ represent neoplastic lesions. Diagnosis with M i-scan and biopsy was performed before histopathological diagnosis. Magnified images of gastric lesions with and without enhancement were collected for further analysis. The diagnostic yield of real-time M i-scan and effects on magnification image quality by tone enhancement (TE), surface enhancement (SE) and color enhancement (CE) were calculated. The selected images were sent to another endoscopist. The endoscopist rated the image quality of each lesion at 3 levels. Ratings of image quality were based on visualization of pit pattern, vessel and demarcation line. RESULTS: One hundred and eighty-three patients were recruited. Five patients were excluded for advanced gastric lesions, 1 patient was excluded for poor preparation and 2 patients were excluded for superficial lesions larger than 1.0 cm; 132 patients were excluded for no lesions found by high definition endoscopy. In the end, 43 patients with 43 lesions were included. Histopathology revealed 10 inflammation, 14 atrophy, 10 metaplasia, 1 low grade dysplasia (LGD), 5 high grade dysplasia (HGD) and 3 cancers. For 7 lesions classified into type Ⅰ, histopathology revealed 6 atrophy and 1 metaplasia; for 10 lesions classified into type Ⅱ, histopathology revealed 2 inflammation, 7 atrophy and 1 metaplasia; for 10 lesions classified into type Ⅲ, histopathology revealed 1 inflammation, 8 metaplasia and 1 LGD; for 9 lesions classified into type Ⅳ, histopathology revealed 4 inflammation, 1 atrophy and 4 HGD; for 7 lesions classified into type Ⅴ, histopathology revealed 3 inflammation, 1 HGD and 3 cancers. A total of 172 still images, including 43 images by white light (MWL) and 129 images by M i-scan (43 with TE, 43 with SE and 43 with CE), were selected and sent to the endoscopist who did the analysis. General image quality of M i-scan with TE and SE was significantly better than that of MWL (TE, 4.55 ± 1.07; SE, 4.30 ± 1.02; MWL, 3.25 ± 0.99; P < 0.001). Visualization of pit pattern was significantly improved by M i-scan with SE (1.93 ± 0.25 vs 1.50 ± 0.50, P < 0.001). Microvessel visualization was significantly improved by M i-scan with TE (1.23 ± 0.78 vs 0.76 ± 0.73, P < 0.001). Demarcation line visualization was improved by M i-scan with both TE and SE (TE, 1.75 ± 0.52; SE, 1.56 ± 0.59; MWL, 0.98 ± 0.44; P < 0.001). M i-scan with CE did not show any significant improvements of image quality in general or in the 3 key parameters. Although M i-scan with TE and SE slightly increased the diagnostic yield of MWL, there was no significant difference (P > 0.1). CONCLUSION: Although digital enhancement improves the image quality of magnification endoscopy, its value in improving the diagnostic yield seems to be limited.
基金supported by grants from the Scientific Research Project of Hunan Health Commission in 2019(No.B2019071)the Scientific Research Project of Hunan Health Commission in 2020(No.B20200059).
文摘Objective To evaluate the feasibility of using gadopentetate dimeglumine(Gd-DTPA)for dual-energy computed tomography pulmonary angiography(CTPA).Methods Sixty-six patients were randomly divided into three groups and underwent CTPA.Group A had a turbo flash scan using an iohexol injection,Group B had a turbo flash scan using Gd-DTPA,and Group C had a dual-energy scan using Gd-DTPA.The original images of Group C were linearly blended with a blending factor of 0.5 or reconstructed at 40,50,60,70,80,90,100,and 110 keV,respectively.The groups were compared in terms of pulmonary artery CT value,image quality,and radiation dose.Results The pulmonary artery CT values were significantly higher in Group C40keV than in Groups B and C,but lower than in Group A.There was no significant difference in the image noise of Groups C40keV,B,and C.Moreover,Group A had the largest beam hardening artifacts of the superior vena cava(SVC),followed by Groups B and C.Group C40keV showed better vascular branching than the other three groups,among which Group B was superior to Group A.The subjective score of the image quality of Groups A,B,and C showed no significant difference,but the score was significantly higher in Group C40keV than in Groups A and B.The radiation dose was significantly lower in Group B than in Groups A and C.Conclusion Gd-CTPA is recommended to patients who are unsuitable for receiving an iodine-based CTPA.Furthermore,a turbo flash scan could surpass a dual-energy scan without consideration for virtual monoenergetic imaging.
文摘This paper contributes to depict the current pattern of applications of digital 3D models for professional research and practice, and for broader dissemination of cultural heritage. Passing from a general review to the illustration of the background project, named MUSINT, the authors underline the objectives. The present case study primarily aims to share information about valuable archaeological collections which have little visibility. To enhance the project＇s contents, which include a whole set of different artifacts, the authors have reproduced high resolution, faithful and measurable digital models on one side, and on the other, lower resolution and geometrically simplified models are yet completed and very close to reality. The former are meant to implement a scholars＇ archive for further scientific activity. The latter to provide content for virtual exhibitions on the Web or on stand-alone interfaces situated in the actual physical museum spaces. The data acquisition and post-processing methods which have been tested and chosen are here briefly described. Hence, the authors then give an account of the most recurrent problematic issues of the established work-flow and how they should be solved. Touched instances are the delicate placing of the artifacts, which must be digitized, in relation to the triangulation-based laser scanner＇s functionality, the refining operations in order to build a coherent single polygon mesh, the most effective ways to deal with unavoidable missing parts or defected textures in the generated model and so on.
