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.     

Freehand three‐dimensional ultrasound to assess semitendinosus muscle morphology

In several neurological disorders and muscle injuries, morphological changes of the m. semitendinosus (ST) are presumed to contribute to movement limitations around the knee. Freehand three‐dimensional (3D) ultrasound (US), using position tracking of two‐dimensional US images to reconstruct a 3D voxel array, can be used to assess muscle morphology in vivo. The aims of this study were: (i) to introduce a newly developed 3D US protocol for ST; and (ii) provide a first comparison of morphological characteristics determined by 3D US with those measured on dissected cadaveric muscles. Morphological characteristics of ST (e.g. muscle belly length, tendon length, fascicle length and whole muscle volume, and volumes of both compartments) were assessed in six cadavers using a 3D US protocol. Subsequently, ST muscles were removed from the body to measure the same morphological characteristics. Mean differences between morphological characteristics measured by 3D US and after dissection were smaller than 10%. Intra‐class correlation coefficients (ICCs) were higher than 0.75 for all variables except for the lengths of proximal fascicles (ICC = 0.58). Measurement of the volume of proximal compartment by 3D US was not feasible, due to low US image quality proximally. We conclude that the presented 3D US protocol allows for reasonably accurate measurements of key morphological characteristics of ST muscle.     

右肺门支气管和血管在横断面上的配布特点

目的：探讨有肺门支气管、肺动脉和肺静脉在横断面上的配布特点。方法：在44例成人胸部连续横断层标本和5例螺旋CT图像上，追踪观察了有侧第一、二、三肺门处支气管、肺动脉和肺静脉的分支(或属支)及其毗邻关系。结果：从气管权开始，至底段上、下静脉出现，以7个典型横断面便可清晰显示有肺门管道结构的配布规律：①在气管权层面，尖段动脉、尖段支气管和后段静脉于奇静脉弓右侧由内向外依次排列；②在右肺上叶支气管层面，后段静脉居后段支气管与前段支气管之间；③在中间支气管层面，右肺上叶动脉上行于中间支气管前方，两者的深面为尖段静脉、前段静脉和后段静脉；④在叶间动脉层面，右肺上叶静脉、叶间动脉和中间支气管由前向后依次排列，在33例(75％)标本中可见到下叶上段动脉的起源；⑤于中间支气管权层面，中、下叶动脉走行于中、下叶支气管外侧；⑥于基底干支气管层面，在11例(25％)标本中可见中叶静脉直接汇入左心房，内侧底段支气管常与上段静脉段问支同时出现；⑦于底段上、下静脉层面，以各底段支气管为中心，相应动脉呈周围性分布，底段上、下静脉呈向心性走行。结论：通过寻找标志性结构，在横断面上可准确识别有肺门处肺叶和肺段的支气管、肺动脉和肺静脉。     

Vortical flow in human elbow joints: a three‐dimensional computed tomography modeling study

The human elbow joint has been regarded as a loose hinge joint, with a unique helical motion of the axis during extension–flexion. This study was designed to identify the helical axis in the ulnohumeral joint during elbow extension–flexion by tracking the midpoint between the coronoid tip and the olecranon tip of the proximal ulna in a three‐dimensional (3D) computed tomography (CT) image model. The elbows of four volunteers were CT‐scanned at four flexion angles (0°, 45°, 90°, and 130°) at neutral rotation with a custom‐made holding device to control any motion during scanning. Three‐dimensional models of each elbow were reconstructed and a 3D ulnohumeral joint at 45°, 90°, and 130° was superimposed onto a fully extended joint (0°) by rotating and translating each 3D ulnohumeral joint along the axes. The midpoints of the olecranon and coronoid tips were interpolated using cubic spline technique and the dynamic elbow motion was plotted to determine the motion of the helical axis. The means and standard deviations were subsequently calculated. The average midpoint pattern of joint motion from extension to flexion was elliptical‐orbit‐like when projected onto a sagittal plane and continuously translated a mean 2.14 ± 0.34 mm (range, 1.83–2.52 mm) to the lateral side during elbow extension–flexion. In 3D space, the average midpoint pattern of the ulnohumeral joint resembles a vortical flow, spinning along an imaginary axis, with an inconsistent radius from 0° to 130° flexion. The ulnohumeral joint axis both rotates and translates during elbow extension–flexion, with a vortex‐flow motion occurring during flexion in 3D model analysis. This motion should be considered when performing hinged external fixation, total elbow replacement and medial collateral ligament reconstruction surgery.     

A three‐dimensional microcomputed tomographic study of site‐specific variation in trabecular microarchitecture in the human second metacarpal

Variation in trabecular microarchitecture is widely accepted as being regulated by both functional (mechanical loading) and genetic parameters, although the relative influence of each is unclear. Studies reporting inter‐site differences in trabecular morphology (volume, number and structure) reveal a complex interaction at the gene–environment interface. We report inter‐ and intra‐site variation in trabecular anatomy using a novel model of contralateral (left vs right) and ipsilateral (head vs base) comparisons for the human second metacarpal in a sample of n = 29 historically known 19th century EuroCanadians. Measures of bone volume fraction, structure model index, connectivity, trabecular number, spacing and thickness as well as degree of anisotropy were obtained from 5‐mm volumes of interest using three‐dimensional microcomputed tomography. We hypothesized that: (i) the more diverse loading environment of metacarpal heads should produce a more robust trabecular architecture than corresponding bases within sides and (ii) the ipsilateral differences between epiphyses will be larger on the right side than on the left side, as a function of handedness. Analysis of covariance (Side × Epiphysis) with Age as covariate revealed a clear dichotomy between labile and constrained architectures within and among anatomical sites. The predicted variation in loading was accommodated by changes in trabecular volume, whereas trabecular structure did not vary significantly by side or by epiphysis within sides. Age was a significant covariate only for females. We conclude that environmental and genetic regulation of bone adaptation may act through distinct pathways and local anatomies to ensure an integrated lattice of sufficient mass to meet normal functional demands.     

A three‐dimensional measurement approach for the morphology of the femoral head

The hip joint is one of the most frequent sites of osteoarthritis. Advances in diagnosis and clinical treatment have progressed dramatically in the last few decades; however, there are limitations associated with the lack of reliable measures for quantifying hip joint morphology. Current diagnostic measures of the hip are performed with pre-determined measures, typically lengths and angles, on 2D radiographic planes. The current measurement techniques do not utilize the inherent 3D nature of CT and MR imaging and do not necessarily quantify the relevant clinical pathologies. A valid and reliable measurement modality that measures the surface geometry of the femoral head is necessary for early diagnosis and treatment of hip disease. The purpose of this study was to establish a method to quantify femoral head morphology using a three-dimensional model. A novel measurement approach was applied to 45 cadaveric femurs (23 right; 22 left; nine female, 17 male) and their digitally reconstructed 3D CT models. The mean difference between the cadaveric and digital measures was −2.04 mm with 95% confidence limits (CI) of 13.67 mm and −17.75 mm, respectively. The digital measurement approach was found to have excellent intraobserver reliability (ICC = 0.99, CI 0.98–0.99) and interobserver reliability (ICC = 0.98, CI 0.93–0.99). This valid and reliable novel digital measurement approach enables quantification of the 3D surface geometry of the femoral head and is able to measure individual variations and potentially detect abnormalities. This method may be used to assist future studies to establish valid diagnostic measurements for femoral head and head–neck junction pathologies.     

Beveled posteromedial corner of the radial head: a three‐dimensional micro‐computed tomography modeling study

The posteromedial quadrant of the radial head is known to be different from the other quadrants. However, the explanation of this unique anatomical feature remains elusive. Hence, this study was designed to address this unique anatomical variance using three‐dimensional μCT (micro‐computed tomography) analysis. Nine fresh cadaveric radial heads were scanned using μCT. Three‐dimensional subchondral bone and cartilage models were rendered. Both models were separated into the four quadrants at both the periphery (rim) and the articulating dish (fovea): anteromedial (AM), posteromedial (PM), posterolateral (PL), and anterolateral (AL). Each quadrant was analyzed in terms of (1) subchondral bone porosity (SBP), (2) mean subchondral bone thickness (MSBT), and (3) mean cartilage thickness (MCT). There was a significant difference between the fovea and the rim in terms of its microarchitectural features. Although within the fovea, the PM quadrant did not differ significantly from the other quadrants, a significant difference was found within the rim. In terms of SBP, PM, AM, PL and AL were calculated as 33, 37, 36 and 35%, respectively. In terms of MSBT, PM, AM, PL and AL were calculated as 0.11, 0.10, 0.09, and 0.09 mm, respectively. In terms of MCT, PM, AM, PL and AL were calculated 1.09, 0.81, 0.84 and 0.83 mm, respectively. The PM corner of the radial head between the 8 and 9 o'clock positions, was beveled. This might explain why the PM quadrant of the rim differed significantly from the other quadrants in terms of its microarchitectural features.     

Anatomy and three‐dimensional reconstructions of the brain of a bottlenose dolphin (Tursiops truncatus) from magnetic resonance images

Cetacean (dolphin, whale, and porpoise) brains are among the least studied mammalian brains because of the formidability of collecting and histologically preparing such relatively rare and large specimens. Magnetic resonance imaging offers a means of observing the internal structure of the brain when traditional histological procedures are not practical. Furthermore, internal structures can be analyzed in their precise anatomic positions, which is difficult to accomplish after the spatial distortions often accompanying histological processing. In this study, images of the brain of an adult bottlenose dolphin, Tursiops truncatus, were scanned in the coronal plane at 148 antero‐posterior levels. From these scans a computer‐generated three‐dimensional model was constructed using the programs VoxelView and VoxelMath (Vital Images, Inc.). This model, wherein details of internal and external morphology are represented in three‐dimensional space, was then resectioned in orthogonal planes to produce corresponding series of virtual sections in the horizontal and sagittal planes. Sections in all three planes display the sizes and positions of major neuroanatomical features such as the arrangement of cortical lobes and subcortical structures such as the inferior and superior colliculi, and demonstrate the utility of MRI for neuroanatomical investigations of dolphin brains. Anat Rec 264:397–414, 2001. © 2001 Wiley‐Liss, Inc.     

Rapid automated landmarking for morphometric analysis of three‐dimensional facial scans

Automated phenotyping is essential for the creation of large, highly standardized datasets from anatomical imaging data. Such datasets can support large‐scale studies of complex traits or clinical studies related to precision medicine or clinical trials. We have developed a method that generates three‐dimensional landmark data that meet the requirements of standard geometric morphometric analyses. The method is robust and can be implemented without high‐performance computing resources. We validated the method using both direct comparison to manual landmarking on the same individuals and also analyses of the variation patterns and outlier patterns in a large dataset of automated and manual landmark data. Direct comparison of manual and automated landmarks reveals that automated landmark data are less variable, but more highly integrated and reproducible. Automated data produce covariation structure that closely resembles that of manual landmarks. We further find that while our method does produce some landmarking errors, they tend to be readily detectable and can be fixed by adjusting parameters used in the registration and control‐point steps. Data generated using the method described here have been successfully used to study the genomic architecture of facial shape in two different genome‐wide association studies of facial shape.     

High‐resolution three‐dimensional digital imaging of the human renal microcirculation: An aid to evaluating microvascular alterations in chronic kidney disease in humans

We have developed a new virtual microscopy method, with two‐ and three‐dimensional (2D, 3D) synchronization, that enables visualization of the human renal microvasculature. The method was used to evaluate 120–150 serially cut sections of paraffin‐embedded human renal tissue from nephrectomized samples. Virtual microscopy images of sections double‐immunostained with antibodies against CD34 (an endothelium marker) and smooth muscle actin (an arterial media marker) and stained with periodic acid‐Schiff were processed using digital imaging analysis software. Image registration was conducted to generate 3D displays with red–green–blue color segmentation. The reconstructed images of the microvasculature, including the interlobular arteries and the glomeruli, allowed visualization of 3D structures and direct glomerular connections. Synchronizing these 3D images with the corresponding 2D images revealed the relationships between arteriosclerotic lesions and downstream glomeruli. Thus, interlobular arteries with moderate intimal thickening and afferent arterioles with segmental hyalinosis/sclerosis, as seen on the 2D images, exhibited wall irregularities on the corresponding 3D images. However, these lesions were not directly influenced by lesions in downstream glomeruli, such as sclerotic lesions. Our virtual‐slide method based on 2D and 3D image synchronization provides a comprehensive view of the renal microcirculation and therefore novel insights into the pathogenesis of vascular‐associated renal diseases.     

Clinical structural anatomy of the inferior pyramidal space reconstructed from the living heart: Three‐dimensional visualization using multidetector‐row computed tomography

The inferior pyramidal space (IPS) comprises the epicardial visceral adipose tissue wedged between the bottoms of the four cardiac chambers from the postero‐inferior epicardial surface of the heart. Understanding the complex anatomy around the IPS is important for clinical cardiologists. Although leading anatomists and radiologists have clarified the anatomy of the IPS in detail, few studies have demonstrated this anatomy in three dimensions. The aim of this study was to visualize the three‐dimensional anatomy of the IPS reconstructed from the living heart using multidetector‐row computed tomography. We also developed an original paper model of the IPS to enhance understanding of its intricate structure. Clin. Anat. 28:878–887, 2015. © 2014 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.     

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.     

Hitherto unknown detailed muscle anatomy in an 8‐week‐old embryo

Congenital muscle diseases, such as myopathies or dystrophies, occur relatively frequently, with estimated incidences of up to 4.7 per 100 000 newborns. To diagnose congenital diseases in the early stages of pregnancy, and to interpret the results of increasingly advanced in utero imaging techniques, a profound knowledge of normal human morphological development of the locomotor system and the nervous system is necessary. Muscular development, however, is an often neglected topic or is only described in a general way in embryology textbooks and papers. To provide the required detailed and updated comprehensive picture of embryologic muscular anatomy, three‐dimensional (3D) reconstructions were created based on serial histological sections of a human embryo at Carnegie stage 23 (8 weeks of development, crown–rump length of 23.8 mm), using Amira reconstruction software. Reconstructed muscles, tendons, bones and nerves were exported in a 3D‐PDF file to permit interactive viewing. Almost all adult skeletal muscles of the trunk and limbs could be individually identified in their relative adult position. The pectoralis major muscle was divided in three separate muscle heads. The reconstructions showed remarkable highly developed extraocular, infrahyoid and suprahyoid muscles at this age but surprisingly also absence of the facial muscles that have been described to be present at this stage of development. The overall stage of muscle development suggests heterochrony of skeletal muscle development. Several individual muscle groups were found to be developed earlier and in more detail than described in current literature.     

Three‐dimensional structure of efferent and epididymal ducts in mice

The aim of the present study was to clarify the detailed morphology of efferent and epididymal ducts in adult mice using three‐dimensional (3D) analysis. We reconstructed efferent and epididymal ducts in three adult mice using serial paraffin sections and high‐performance 3D reconstruction software to draw the core lines of all ducts. By comparing the 3D core lines with the histological features in serial sections, we obtained detailed information on the gross characteristics of the ducts and identified the duct divisions accurately. The intra‐testicular rete testis penetrated the tunica albuginea at one place and turned into the extra‐testicular rete testis, which branched once or twice to give rise to four efferent ducts within 0.5 mm from the tunica albuginea. As these ducts approached the epididymis, they converged into one again and changed abruptly into the initial segment (IS) of the epididymis. The average length from the tunica albuginea to the IS was 19.7 ± 3.1 mm. In one mouse, we found four additional efferent ducts diverging from the common region with blind ends. The epididymal duct was a single highly convoluted duct with no branch and an average length of 767 ± 26 mm. By dividing the epididymal duct into five regions based on its cytological features and periodic acid‐Schiff stainability, we calculated the length and diameter of individual regions accurately. Furthermore, we clearly showed locations of the connective tissue septa that divide the head epididymis into several segments. The epididymal duct followed a complicated, winding path within each segment while drawing a large spiral overall along the circumference of the epididymis. Sometimes the direction of this spiral reversed between adjacent segments. The present study revealed the detailed 3D structures of efferent and epididymal ducts in adult mice.     

A morphometric study of the inferior orbital fissure using three‐dimensional anatomical landmarks: Application to orbital surgery

The inferior orbital fissure (IOF) is an important structure during orbital surgery, however, neither its anatomical features nor the procedures necessary to expose the IOF have been examined in detail. A morphometric analysis of the IOF was performed on 232 orbits using computer software. The longest and shortest borders of the IOF were 18.2 ± 4.9 and 1.9 ± 1.3 mm, respectively. The outer and the inner angles were 138.9 ± 32.7° and 38.4 ± 24.7°, respectively. The perimeter of the IOF was 50.6 ± 13.5 mm and its area was 61.3 ± 39.1 mm². Eight types of IOF were observed. Type 1 IOF was observed in 42.2% and the Type 2 IOF was identified in 15.9%. A statistically significant relation was found between the longest edge and area and the widest edge and area of the IOF. The findings of our study suggest that the removal of the lateral wall should begin inferiorly, just lateral to the IOF and extended superolaterally. These data may be useful during surgical approaches to the orbit. Clin. Anat. 22:649–654, 2009. © 2009 Wiley‐Liss, Inc.