The most common methods for three-dimensional reconstruction of peripheral nerve fascicles include histological and radiology techniques. Histological techniques have many drawbacks including an enormous manual worklo...The most common methods for three-dimensional reconstruction of peripheral nerve fascicles include histological and radiology techniques. Histological techniques have many drawbacks including an enormous manual workload and poor image registration. Micro-magnetic resonance imaging（Micro-MRI）, an emerging radiology technique, has been used to report results in the brain, liver and tumor tissues. However, micro-MRI usage for obtaining intraneural structures has not been reported. The aim of this study was to present a new imaging method for three-dimensional reconstruction of peripheral nerve fascicles by ~1T micro-MRI. Freshly harvested sciatic nerve samples from an amputated limb were divided into four groups. Two different scanning conditions（Mannerist Solution/GD-DTPA contrast agent, distilled water） were selected, and both T1 and T2 phases programmed for each scanning condition. Three clinical surgeons evaluated the quality of the images via a standardized scale. Moreover, to analyze deformation of the two-dimensional image, the nerve diameter and total area of the micro-MRI images were compared after hematoxylin-eosin staining. The results show that rapid micro-MRI imaging method can be used for three-dimensional reconstruction of the fascicle structure. Nerve sample immersed in contrast agent（Mannerist Solution/GD-DTPA） and scanned in the T1 phase was the best. Moreover, the nerve sample was scanned freshly and can be recycled for other procedures. MRI images show better stability and smaller deformation compared with histological images. In conclusion, micro-MRI provides a feasible and rapid method for three-dimensional reconstruction of peripheral nerve fascicles, which can clearly show the internal structure of the peripheral nerve.展开更多
Heart diseases remain the top threat to human health,and the treatment of heart diseases changes with each passing day.Convincing evidence shows that three-dimensional(3D)printing allows for a more precise understandi...Heart diseases remain the top threat to human health,and the treatment of heart diseases changes with each passing day.Convincing evidence shows that three-dimensional(3D)printing allows for a more precise understanding of the complex anatomy associated with various heart diseases.In addition,3D-printed models of cardiac diseases may serve as effective educational tools and for hands-on simulation of surgical interventions.We introduce examples of the clinical applications of different types of 3D printing based on specific cases and clinical application scenarios of 3D printing in treating heart diseases.We also discuss the limitations and clinically unmet needs of 3D printing in this context.展开更多
The estimation of shear strength of rock mass discontinuity is always a focal, but difficult, problem in the field of geotechnical engineering. Considering the disadvantages and limitation of exist- ing estimation met...The estimation of shear strength of rock mass discontinuity is always a focal, but difficult, problem in the field of geotechnical engineering. Considering the disadvantages and limitation of exist- ing estimation methods, a new approach based on the shadow area percentage （SAP） that can be used to quantify surface roughness is proposed in this article. Firstly, by the help of laser scanning technique, the three-dimensional model of the surface of rock discontinuity was established. Secondly, a light source was simulated, and there would be some shadows produced on the model surface. Thirdly, to obtain the value of SAP of each specimen, the shadow detection technique was introduced for use. Fourthly, compared with the result from direct shear testing and based on statistics, an empirical for- mula was found among SAP, normal stress, and shear strength. Data of Yujian （~ River were used as an example, and the following conclusions have been made. （1） In the case of equal normal stress, the peak shear stress is positively proportional to the SAP. （2） The formula for estimating was derived, and the predictions of peak-shear strength made with this equation well agreed with the experimental re- suits obtained in laboratory tests.展开更多
Developments of digital technology and three-dimensional(3D)reconstruction allowed a precise description of anatomic structures.With the introduction of Visible Human Project and Virtual Chinese Human(VCH)techniques,m...Developments of digital technology and three-dimensional(3D)reconstruction allowed a precise description of anatomic structures.With the introduction of Visible Human Project and Virtual Chinese Human(VCH)techniques,more detailed anatomic images could be obtained.Digitized visible models of these structures can be applied as a useful tool in clinical training.The aim of this study was to reconstruct the normal structures of thoracodorsal artery in 3D images and to establish the digitized visible models of latissimus dorsi myocutaneous(LDM)flap.The cross-sectional images from the four VCH datasets were reviewed to study LDM and thoraco-dorsal artery structures on a section-by-section basis.Next,two adult fresh cadaver specimens were perfused with lead oxide-gelatine mixture and subject to radio-graphic CT scanning on their torsos.The cross-sectional images from the CT images were reviewed to study thor-acodorsal artery structures.Three-dimensional computer-ized reconstructions of LDM flap structures were conducted from these datasets by using Amira 3.1(TGS)software respectively.The 3D reconstructed visible models established from these datasets perfectly displayed the anatomic characteristics of LDM flap.展开更多
基金supported by grants from the National Key Research and Development Plan of China,No.31670986(to QTZ)the Science and Technology Project of Guangdong Province of China,No.2014B020227001,2017A050501017(to QTZ)the Science and Technology Project of Guangzhou of China,No.201807010082(to QTZ),201704030041(to JQ)
文摘The most common methods for three-dimensional reconstruction of peripheral nerve fascicles include histological and radiology techniques. Histological techniques have many drawbacks including an enormous manual workload and poor image registration. Micro-magnetic resonance imaging（Micro-MRI）, an emerging radiology technique, has been used to report results in the brain, liver and tumor tissues. However, micro-MRI usage for obtaining intraneural structures has not been reported. The aim of this study was to present a new imaging method for three-dimensional reconstruction of peripheral nerve fascicles by ~1T micro-MRI. Freshly harvested sciatic nerve samples from an amputated limb were divided into four groups. Two different scanning conditions（Mannerist Solution/GD-DTPA contrast agent, distilled water） were selected, and both T1 and T2 phases programmed for each scanning condition. Three clinical surgeons evaluated the quality of the images via a standardized scale. Moreover, to analyze deformation of the two-dimensional image, the nerve diameter and total area of the micro-MRI images were compared after hematoxylin-eosin staining. The results show that rapid micro-MRI imaging method can be used for three-dimensional reconstruction of the fascicle structure. Nerve sample immersed in contrast agent（Mannerist Solution/GD-DTPA） and scanned in the T1 phase was the best. Moreover, the nerve sample was scanned freshly and can be recycled for other procedures. MRI images show better stability and smaller deformation compared with histological images. In conclusion, micro-MRI provides a feasible and rapid method for three-dimensional reconstruction of peripheral nerve fascicles, which can clearly show the internal structure of the peripheral nerve.
基金This study was supported by the National key R&D plan(No.2020YFC2008100)the Science and Technology Innovation Team Project of the Shaanxi Innovation Capability Support Plan(No.S2020-ZC-TD-0029)the Science Foundation for Distinguished Young Scholars of Shaanxi Natural Science Basic Research Program(No.S2018-JC-JQ-0094)。
文摘Heart diseases remain the top threat to human health,and the treatment of heart diseases changes with each passing day.Convincing evidence shows that three-dimensional(3D)printing allows for a more precise understanding of the complex anatomy associated with various heart diseases.In addition,3D-printed models of cardiac diseases may serve as effective educational tools and for hands-on simulation of surgical interventions.We introduce examples of the clinical applications of different types of 3D printing based on specific cases and clinical application scenarios of 3D printing in treating heart diseases.We also discuss the limitations and clinically unmet needs of 3D printing in this context.
基金supported by the China Geological Survey (No.1212011014030)the Major State Basic Research Development Program of China (973 Program) (No.2011CB710600)
文摘The estimation of shear strength of rock mass discontinuity is always a focal, but difficult, problem in the field of geotechnical engineering. Considering the disadvantages and limitation of exist- ing estimation methods, a new approach based on the shadow area percentage （SAP） that can be used to quantify surface roughness is proposed in this article. Firstly, by the help of laser scanning technique, the three-dimensional model of the surface of rock discontinuity was established. Secondly, a light source was simulated, and there would be some shadows produced on the model surface. Thirdly, to obtain the value of SAP of each specimen, the shadow detection technique was introduced for use. Fourthly, compared with the result from direct shear testing and based on statistics, an empirical for- mula was found among SAP, normal stress, and shear strength. Data of Yujian （~ River were used as an example, and the following conclusions have been made. （1） In the case of equal normal stress, the peak shear stress is positively proportional to the SAP. （2） The formula for estimating was derived, and the predictions of peak-shear strength made with this equation well agreed with the experimental re- suits obtained in laboratory tests.
文摘Developments of digital technology and three-dimensional(3D)reconstruction allowed a precise description of anatomic structures.With the introduction of Visible Human Project and Virtual Chinese Human(VCH)techniques,more detailed anatomic images could be obtained.Digitized visible models of these structures can be applied as a useful tool in clinical training.The aim of this study was to reconstruct the normal structures of thoracodorsal artery in 3D images and to establish the digitized visible models of latissimus dorsi myocutaneous(LDM)flap.The cross-sectional images from the four VCH datasets were reviewed to study LDM and thoraco-dorsal artery structures on a section-by-section basis.Next,two adult fresh cadaver specimens were perfused with lead oxide-gelatine mixture and subject to radio-graphic CT scanning on their torsos.The cross-sectional images from the CT images were reviewed to study thor-acodorsal artery structures.Three-dimensional computer-ized reconstructions of LDM flap structures were conducted from these datasets by using Amira 3.1(TGS)software respectively.The 3D reconstructed visible models established from these datasets perfectly displayed the anatomic characteristics of LDM flap.
