3D-EIT图像重建的研究进展

本文回顾了三维医学电阻抗成像(3D-EIT)图像重建技术近年来的研究进展,介绍了几个新的有效的成像模型,并指出了该项研究目前存在的主要问题.     

Distribution of the Purkinje fibres in the sheep heart

The aim of the present study was to advance our knowledge regarding the anatomy of the purkinje fibres from their origin, at the bundle branches, till their termination within the myocardium. Indian ink injections of the purkinje fibres were carried out in the left ventricle of 25 fresh sheep hearts and in the right ventricle of 20 hearts. Numerous samples were taken from the walls and papillary muscles of the two ventricles for histological analysis and determination of the mode of termination of the fibres. The ventricular conduction system could be injected as far proximally as the bundle branches, thus illustrating the bifascicular nature of the left bundle branch, with numerous interfascicular communications. The purkinje fibres were observed to form an extensive subendocardial network, forming a polygonal arrangement in the left ventricle with a characteristic pattern around the papillary muscles. Deep myocardial branches took origin from this network which penetrated the ventricular wall to reach the epicardium. Histological analysis demonstrated the characteristic features of the purkinje cells, and confirmed the presence of a perifascicular sheath of connective tissue which surrounded the purkinje fibres until their transition with working cardiomyocytes. The perifascicular connective tissue sheath is important in organising the contraction of the myocardium by preventing lateral spread of conduction and by permitting transmission of the impulse only at the termination of the purkinje fibre. The sheath may also protect the fibres from the stresses and strains originating from contraction of the surrounding myocardium. Anat Rec 254:92–97, 1999. © 1999 Wiley‐Liss, Inc.     

Technique of semiautomatic surface reconstruction of the visible Korean human data using commercial software

This article describes the technique of semiautomatic surface reconstruction of anatomic structures using widely available commercial software. This technique would enable researchers to promptly and objectively perform surface reconstruction, creating three-dimensional anatomic images without any assistance from computer engineers. To develop the technique, we used data from the Visible Korean Human project, which produced digitalized photographic serial images of an entire cadaver. We selected 114 anatomic structures (skin [1], bones [32], knee joint structures [7], muscles [60], arteries [7], and nerves [7]) from the 976 anatomic images which were generated from the left lower limb of the cadaver. Using Adobe Photoshop, the selected anatomic structures in each serial image were outlined, creating a segmented image. The Photoshop files were then converted into Adobe Illustrator files to prepare isolated segmented images, so that the contours of the structure could be viewed independent of the surrounding anatomy. Using Alias Maya, these isolated segmented images were then stacked to construct a contour image. Gaps between the contour lines were filled with surfaces, and three-dimensional surface reconstruction could be visualized with Rhinoceros. Surface imperfections were then corrected to complete the three-dimensional images in Alias Maya. We believe that the three-dimensional anatomic images created by these methods will have widespread application in both medical education and research.     

Reconfirmation of the right medial division of the portal venous system of liver

With the development of hepatic surgery and radiology, an increasing amount of researchers have reported discrepancies between the real distribution of the hepatic portal vein branches and Couinaud's segmentation, especially for further division of the right medial division. The present study investigated 25 cadaveric liver dissections and 30 three-dimensional reconstruction images of intrahepatic vessels. The ramifications, course, distribution and quantity of the portal branches were analyzed. An oblique fissure that had few vessels was found among third-order branches of the hepatic portal vein of the right medial division. The right medial division could be redivided into the ventral subsegment and dorsal subsegment by this oblique fissure. A hepatic vein coursed in the oblique fissure between the ventral subsegment and dorsal subsegment. The hepatic vein could serve as an anatomical landmark of the inter-subsegmental plane. This new method of identifying further division of the right medial division is a novel concept providing further information on conventional segmental anatomy.     

Development of the Mucosal Vascular System in the Distal Colon of the Fetal Mouse

The formation of the crypt in the distal colon of the mouse was investigated in association with the development of vascular networks. For histological observation, 1‐μm cross‐sections were made from the distal colon of fetal mice in 13 to 18 days of gestation. Three‐dimensional distributions of vascular networks in the organ were observed after perfusing fetuses with rhodamine isothiocyanate‐labeled gelatin and immunostaining for laminin to examine the boundary between the epithelium and the mesenchyme. At 13 days of gestation, the distal colon and its epithelium formed a cylindrical tube and a loose primary plexus of vessels was built in the mesenchyme. In the distal colon of 15 days of gestation, the caudal portion began to form the crypt and the vascular plexus built up from a few layers was situated apart from the boundary between the epithelium and the mesenchyme. As the development proceeded, the formation of the crypt occurred in the caudorostral direction. The developing crypt advanced into the vascular plexus, so that a few vessels situated in the mesenchyme between crypts. As the crypt elongated, these vessels formed a small plexus situated perpendicular to the primary plexus, while the primary plexus became monolayered and loosened. The new plexus was composed of ascending vessels and traversing ones, but the regular honeycomb‐like plexuses around openings of crypts have not established yet even in 18 days of gestation. The vascular system as well as the crypt in the distal colon will take further a few postnatal weeks to be completed. Anat Rec, 291:65–73, 2007. © 2007 Wiley‐Liss, Inc.     

Three‐dimensional structure of seminiferous tubules in the adult mouse

Seminiferous tubules develop from sex cords, which are embryonic structures with simple C‐shaped arches. Histologically, the epithelium of adult mouse seminiferous tubules has been divided into 12 stages based on the associations of spermatogenic cells in four cycles of spermatogenesis. However, the gross characteristics of the seminiferous tubules themselves, including their number, length, run, and mutual relationships remain largely unknown. In the present study, we analyzed all seminiferous tubules in a single adult mouse testis with high resolution using serial paraffin sections and high‐perfomance three‐dimensional reconstruction software. There were 11 seminiferous tubules with an average length of 140 mm. Each tubule ran along circular paths within the testis while making convolutions with cranial and caudal hairpin turns. The cranial turns of all tubules were in contact with the tunica albuginea, whereas the caudal turns were not, resulting in funnel‐shaped networks of these tubules with tapered caudal portions. The caudally located networks surrounded the preceding cranially located networks from the bottom and outside, similar to stacked paper cups. Five out of the 11 seminiferous tubules were continuous from one end to the other both connected with the rete testis (10 connection points). Nine branching points, one blind end, and 18 more connection points with the rete testis were detected in the remaining six seminiferous tubules, making the paths of these tubules complicated to various degrees. The present study revealed that the 3D structures of seminiferous tubules were highly regular as a whole in the adult mouse testis.     

Morphogenesis of the Middle Ear during Fetal Development as Observed Via Magnetic Resonance Imaging

Recently, our research group has utilized serial histological sections to investigate the morphogenesis of the middle ear, which corresponds to the period of middle ear ossicle (MEO) cartilage formation. However, research regarding middle ear development during the post‐embryonic period has been limited. In the present study, we investigated morphogenesis of the middle ear in human fetuses with a crown‐rump length (CRL) between 37 and 197 mm using high‐resolution magnetic resonance imaging (MRI). Our findings indicated that the morphology of the MEOs is similar during fetal development and adulthood; further, growth of the MEOs nearly ceases once a CRL of 150 mm is attained. In each MEO, ossification spreads from a single center. The malleus and Meckel's cartilage could be discriminated in samples exhibiting a CRL of 145 mm based on differences in MRI signal intensity. In samples with a CRL of 86 mm, the tympanic cavity (TC) appeared as a thin yet distinct structure attached to the external auditory meatus at the convex surface. Only the handle of the malleus was covered by the TC, while the incus and stapes contacted the cavity at the region of articulation between the two ossicles only, even after a CRL of 145 mm had been attained. Thus, although the TC increased in both diameter and thickness, coverage did not extend across all three MEOs during the observation period. These data are expected to provide a useful standard for morphogenesis and may aid researchers in distinguishing between normal and abnormal development. Anat Rec, 301:757–764, 2018. © 2017 Wiley Periodicals Inc.     

Variations of the Circle of Willis at the End of the Human Embryonic Period

Variations of the circle of Willis (CW) influence blood supply to the brain and adjacent structures in adults. We examined the formation of the CW in 20 human embryo samples at the end of the embryonic period using 3‐D reconstructions of serial histological sections. The CW was closed in all samples, and did not form in a single plane, but was composed of multiple stair‐like planes. The artery acutely curved at the caudal part of the CW, namely, at the inlet of the basilar artery and bifurcation of the P1 segment of the posterior cerebral artery (PCA), reflecting flexure of the mesencephalon and diencephalon at this stage. Variations were observed in 17 of 20 samples—only anterior parts (anterior communicating artery [Acom] and anterior cerebral artery [ACA]) in 10 samples, only posterior parts (posterior communicating artery [Pcom]) in one sample, and both anterior and posterior parts in six samples. Variations included the Acom formed as partially duplicated in three samples, duplicated in four, plexiform in three, and no channel as a result of a single azygos ACA in one. The ACA formed as duplicated in two, median ACA in two, and right hypoplasia in one. The Pcom formed in hypoplasia of either side in six samples. Variations observed in this study are similar to those observed in fetuses, neonates, and adults. The P1 segment of PCA was very large in all samples. The present observations indicate that variations in the CW are present from the initiation of CW formation. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc.     

Quantitative morphometry of the orbit in Chinese adults based on a three-dimensional reconstruction method

The three‐dimensional (3D) reconstruction technique serves as a practical tool in diagnosis, surgical planning, and outcome prediction of plastic and reconstructive surgery. In our study, the morphologic features of the Chinese adult orbit were described by 11 anatomic parameters using a 3D reconstruction technique. Sixty‐four Chinese adults were selected randomly from patients who had undergone craniofacial computed tomography (CT) scans to diagnose conditions other than craniofacial or orbital deformations. The morphologic parameters of orbit such as bony orbital volume, orbital foramen area and orbital rim perimeter were measured on 3D models using this technique. Differences between the two orbits and between the two sexes were investigated. The method of measurement showed high reproducibility of results. No difference between the two orbits was found. There were significant differences between men and women in all anatomic parameters other than orbital height. In men and women, respectively, mean bony orbital volume was 26.02 and 23.32 mL, mean orbital foramen area 11.80 and 11.10 cm², mean orbital rim perimeter 12.65 and 12.20 cm, mean orbital height 33.35 and 33.22 mm, mean orbital width 40.02 and 38.00 mm; mean orbital floor length 47.93 and 46.18 mm, mean orbital roof length 52.93 and 50.89 mm, mean medial orbital wall length 46.43 and 44.41 mm, mean lateral orbital wall length 48.38 and 46.91 mm, mean intraorbital distance 27.18 and 25.11 mm, mean extra‐orbital distance 98.77 and 93.69 mm. It is concluded that the measurements of these orbital parameters could be obtained from a 3D reconstruction method. The two orbits were symmetric based on orbital volume and other anatomic parameters. Orbital size was significantly smaller in women than in men; orbital height, however, was similar. The findings of the present study allow for quantification of the orbital features of Chinese adults and provide parameters for preoperative planning and prediction of postoperative outcome.     

Morphogenesis of the middle ear ossicles and spatial relationships with the external and inner ears during the embryonic period

We describe the three‐dimensional morphogenesis of the middle ear ossicles (MEOs) according to Carnegie stage (CS) in human embryos. Seventeen samples including 33 MEOs from CS18 to 23 were selected from the Kyoto Collection. The primordia of the MEOs and related structures were histologically observed and three‐dimensionally reconstructed from digital images. The timing of chondrogenesis was variable among structures. The stapes was recognizable as a vague condensation of the mesenchymal cells in all samples from CS18, whereas the malleus and incus were recognizable at CS19. Chondrogenesis of all MEOs was evident in all samples after CS21. The chondrocranium was recognizable in all samples by CS18, and the perichondrium border of the auricular cartilage and otic capsule was distinct in all samples at CS23. At CS19, the MEOs were positioned in the anterior to posterior direction, following the order malleus, incus, stapes, which adjusted gradually during development. The MEOs connected in all samples after CS22. The stapes was located close to the vestibular part of the inner ear, although the basal part was not differentiated into the “footplate” form, even at CS23. The handles of the malleus were close to the tubotympanic recess at CS23, but were distant from the external auditory meatus. Determining the timeline of the formation of MEOs and connection of the external and inner ears can be informative for understanding hearing loss caused by failure of this connection. These data may provide a useful standard for morphogenesis, and will contribute to distinguishing between normal and abnormal MEO development. Anat Rec, 299:1325–1337, 2016. © 2016 Wiley Periodicals, Inc.     

Congenital laryngeal atresia: two autopsy cases, one describing the use of computed tomography

Two autopsy cases of congenital laryngeal atresia (CLA) were studied. In the first case (a boy delivered at 37 weeks of gestation) the subglottic lumen was almost totally occupied by a dome shaped cricoid cartilage with a pharyngotracheal duct (PTD). No tracheoesophageal fistula (TEF) was found. In the second case (a girl born at 41 weeks of gestation) histology showed that the subglottic lumen was almost occluded by an epithelial lamina and a dome-shaped cricoid cartilage. Again no TEF was found. Both cases had PTD and showed normal development of the lungs. These deformities coincided with Smith & Bain's type II subglottic atresia. The anatomy of the lesion was confirmed by postmortem three-dimensional reconstruction CT, the use of which has not previously been reported.     

Computerized three‐dimensional analysis of the heart and great vessels in normal and holoprosencephalic human embryos

The developing heart and great vessels undergo drastic morphogenetic changes during the embryonic period. To analyze the normal and abnormal development of these organs, it is essential to visualize their structures in three and four dimensions, including the changes occurring with time. We have reconstructed the luminal structure of the hearts and great vessels of staged human embryos from serial histological sections to demonstrate their sequential morphological changes in three dimensions. The detailed structures of the embryonic heart and major arteries in normal and holoprosencephalic (HPE) human embryos could be reconstructed and visualized, and anatomical structures were analyzed using 3D images. By 3D analysis, cardiac anomalies such as double‐outlet right ventricle and malrotation of the heart tube were identified in HPE embryos, which were not easily diagnosed by histological observation. Reconstruction and analysis of 3D images are useful for the study of anatomical structures of developing embryos and for identifying their abnormalities. Anat Rec, 2007. © 2007 Wiley‐Liss, Inc.     

A New Technique to Map the Lymphatic Distribution and Alignment of the Penis

The present study was to examine the distribution of lymphatic vessels in the penis of normal adult males, which could provide an anatomical basis for improvement of incisions in penile lengthening surgery, and may also help to prevent postoperative refractory edema. Thirteen normal adult male volunteers were recruited for this study. Contrast agent was injected subcutaneously in the foreskin of the penis, and after two minutes magnetic resonance lymphangiography (MRL) was performed. The acquired magnetic resonance images were analyzed to determine the changes in the number and diameter of lymphatic vessels in different parts of the penis. Maximum intensity projections (MIP) and materializes interactive medical image control system (MIMICS) were applied to analyze the overall distribution of lymphatic vessels in the penis. Magnetic resonance imaging (MRI) showed that the lymphatic vessels were in conspicuous contrast with surrounding tissues and could be clearly identified. Penile lymphatic vessels were clearly visible in the root of the penis. At the junction of the penis and the abdominal wall, all lymphatic vessels were found to be concentrated in the dorsal part of the penis. MIP two‐dimensional reconstruction showed that the overall distribution of relatively large lymphatic vessels in the dorsal and ventral parts of the penis could be seen clearly on bilateral 45° position, but not inside the abdominal wall because some of lymphatic vessels were overlapped by other tissues in the abdomen. MIMICS three‐dimensional reconstruction was able to reveal the overall spatial distribution of lymphatic vessels in the penis from any angle. The reconstruction results showed that there were 1–2 main lymphatic vessels on the root of dorsal penis, which coursed along the cavernous to the first physiological curvature of the penis. Lymphatic vessels merged on both sides of the ventral penis. At the root of the penis, lymphatic vessels gradually coursed to the dorsal surface of the penis and folded at the abdominal wall to the outside, and finally merged into the inguinal lymph nodes. The changes in distribution, number and diameter of the lymphatic vessels in the penis were observed by MRI. MIP and MIMICS reconstructions directly revealed the anatomical features of penile lymphatic vessels such as spatial distribution, overall alignment, and the relations to adjacent structures, drainage and reflux. The study will provide the anatomical basis for penile surgery, penile lymphatic reflux disorders caused by trauma or lymphatic vessels obstruction, and lymph node metastasis in penile cancer. Anat Rec, 298:1465–1471, 2015. © 2014 Wiley Periodicals, Inc.     

Segmentation and Surface Reconstruction of the Detailed Ear Structures,Identified in Sectioned Images

The structure of the ear, which intervenes between gross anatomy and histology in size, can be best understood by means of three‐dimensional (3D) surface models on a computer. Furthermore, surface models are the source of interactive simulation for clinical trials, such as tympanoplasty. The objective of this research was to elaborate the surface models of detailed ear structures, which contribute to learning anatomy or the practice of otology. We produced sectioned images of a cadaver head (pixel size, 0.1 mm; 48‐bit color). In the sectioned images, the external, middle, and internal ear structures and other related components were delineated on Photoshop to acquire segmented images at 0.5‐mm intervals. Segmented images of each structure were stacked, and the surface was reconstructed to generate a 3D‐surface model on commercial software. Thirty surface models showed fine ear topographic anatomy (e.g., semicircular ducts), as expected. Herein, we present the corresponding sectioned images, segmented images, and surface models of ear structures that will be released together. It is hoped that these image data will stimulate the development of medical simulations. The efficient technique of segmentation and surface reconstruction enables the manufacture of surface models from other serial images (e.g., CTs and MRIs). Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.     

Three‐Dimensional Visualization of Developing Neurovascular Architecture in the Craniofacial Region of Embryonic Mice

Recent studies have highlighted the mechanism of vascular and axonal guidance to ensure proper morphogenesis and organogenesis. We aimed to perform global mapping of developing neurovascular networks during craniofacial development of embryonic mice. To this end, we developed histology‐based three‐dimensional (3D) reconstructions using paraffin‐embedded serial sections obtained from mouse embryos. All serial sections were dual‐immunolabeled with Pecam1 and Pgp9.5/Gap43 cocktail antibodies. All immunolabeled serial sections were digitized with virtual microscopy to acquire high spatial resolution images. The 3D reconstructs warranted superior positional accuracy to trace the long‐range connectivity of blood vessels and individual cranial nerve axons. It was feasible to depict simultaneously the details of angiogenic sprouting and axon terminal arborization and to assess quantitatively the locoregional proximity between blood vessels and cranial nerve axons. Notably, 3D views of the craniofacial region revealed the following: Branchial arch arteries and blood capillary plexi were formed without accompanying nerves at embryonic day (E) 9.5. Cranial nerve axons began to grow into the branchial arches, developing a labyrinth of small blood vessels at E10.5. Vascular remodeling occurred, and axon terminals of the maxillary, mandibular, chorda tympani, and hypoglossal nerve axons had arborized around the lateral lingual swellings at E11.5. The diverged patterning of trigeminal nerves and the arterial branches from the carotid artery became congruent at E11.5. The overall results support the advantage of dual‐immunolabeling and 3D reconstruction technology to document the architecture and wiring of the developing neurovascular networks in mouse embryos. Anat Rec, 298:1824–1835, 2015. © 2015 Wiley Periodicals, Inc.     

Apoptosis and epicardial contributions act as complementary factors in remodeling of the atrioventricular canal myocardium and atrioventricular conduction patterns in the embryonic chick heart

Background : During heart development, it has been hypothesized that apoptosis of atrioventricular canal myocardium and replacement by fibrous tissue derived from the epicardium are imperative to develop a mature atrioventricular conduction. To test this, apoptosis was blocked using an established caspase inhibitor and epicardial growth was delayed using the experimental epicardial inhibition model, both in chick embryonic hearts. Results : Chicken embryonic hearts were either treated with the peptide caspase inhibitor zVAD‐fmk by intrapericardial injection in ovo (ED4) or underwent epicardial inhibition (ED2.5). Spontaneously beating embryonic hearts isolated (ED7–ED8) were then stained with voltage‐sensitive dye Di‐4‐ANEPPS and imaged at 0.5–1 kHz. Apoptotic cells were quantified (ED5–ED7) by whole‐mount LysoTracker Red and anti‐active caspase 3 staining. zVAD‐treated hearts showed a significantly increased proportion of immature (base to apex) activation patterns at ED8, including ventricular activation originating from the right atrioventricular junction, a pattern never observed in control hearts. zVAD‐treated hearts showed decreased numbers of apoptotic cells in the atrioventricular canal myocardium at ED7. Hearts with delayed epicardial outgrowth showed also increased immature activation patterns at ED7.5 and ED8.5. However, the ventricular activation always originated from the left atrioventricular junction. Histological examination showed no changes in apoptosis rates, but a diminished presence of atrioventricular sulcus tissue compared with controls. Conclusions : Apoptosis in the atrioventricular canal myocardium and controlled replacement of this myocardium by epicardially derived HCN4‐/Trop1‐ sulcus tissue are essential determinants of mature ventricular activation pattern. Disruption can lead to persistence of accessory atrioventricular connections, forming a morphological substrate for ventricular pre‐excitation. Developmental Dynamics 247:1033‐1042, 2018. © 2018 Wiley Periodicals, Inc.     

The effect of scanning distance on the accuracy of intra‐oral scanners used in dentistry

The aim of this study was to evaluate the factors affecting intra‐oral scanner accuracy by analyzing variation in measurements of a dental model according to scanning distance. A dental cast, including a prepared left mandibular first molar, was used. Rectangular frames measuring 20 × 30 mm with heights of 2.5, 5.0, and 7.5 mm were made. The model was scanned 10 times with a reference scanner to obtain the true value. Scanning was performed 10 times at four distances of 0, 2.5, 5.0, and 7.5 mm with the frame of each height using the following intra‐oral scanners: TRIOS; CS 3500; and PlanScan. In the linear distance measurement method (2D), measurements were taken at five parameters using the Rapidform software. In the best‐fit alignment method (3D), using the Geomagic Control X, the root mean square values of the two scan images were calculated. In the 2D comparison, the different from the reference value was the smallest at 2.5 and 5.0 mm. In the 3D comparison, 2.5 and 5.0 mm were the most accurate, and 0 mm was the least accurate among the four distances. To the best of our knowledge, this study was the first to evaluate the accuracy of scanning distances, and found a difference between the accuracy of the scanning distance and the accuracy of the scanner. Moreover, the results of this study indicated that the scanning distance was a variable affecting accuracy. Clin. Anat. 32:430–438, 2019. © 2019 Wiley Periodicals, Inc.     

Cancer cell invasion and EMT marker expression: a three‐dimensional study of the human cancer–host interface

Cancer cell invasion takes place at the cancer–host interface and is a prerequisite for distant metastasis. The relationships between current biological and clinical concepts such as cell migration modes, tumour budding and epithelial–mesenchymal transition (EMT) remains unclear in several aspects, especially for the 'real' situation in human cancer. We developed a novel method that provides exact three‐dimensional (3D) information on both microscopic morphology and gene expression, over a virtually unlimited spatial range, by reconstruction from serial immunostained tissue slices. Quantitative 3D assessment of tumour budding at the cancer–host interface in human pancreatic, colorectal, lung and breast adenocarcinoma suggests collective cell migration as the mechanism of cancer cell invasion, while single cancer cell migration seems to be virtually absent. Budding tumour cells display a shift towards spindle‐like as well as a rounded morphology. This is associated with decreased E‐cadherin staining intensity and a shift from membranous to cytoplasmic staining, as well as increased nuclear ZEB1 expression. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.