Standard Coordinate System Research Articles

Searching for the GD-1 stream progenitor inGaiaDR2 with directN-body simulations

We perform a large suite of direct N-body simulations aimed at revealing the location of the progenitor, or its remnant, of the GD-1 stream. Data from \gaia\ DR2 reveals the GD-1 stream extends over $\approx 100^\circ$, allowing us to determine the stream's leading and trailing ends. Our models suggest the length of the stream is consistent with a dynamical age of between 2-3 Gyr and the exact length, width and location of the GD-1 stream correspond to the stream's progenitor being located between $-30^\circ < \phi_{1,\mathrm{pro}} < -45^{\circ}$ in the standard GD-1 coordinate system. The model stream density profiles reveal that intact progenitors leave a strong over-density, recently-dissolved progenitors appear as gaps in the stream as escaped stars continue to move away from the remnant progenitor's location, and long-dissolved progenitors leave no observational signature on the remaining stream. Comparing our models to the GD-1 stream yields two possible scenarios for its progenitor's history: a) the progenitor reached dissolution approximately 500 Myr ago during the cluster's previous perigalactic pass and is both located at and responsible for the observed gap at $\phi_1=-40^{\circ}$ or b) the progenitor reached dissolution over 2.5 Gyr ago, the fully-dissolved remnant is at $-30^\circ < \phi_1 < -45^{\circ}$, and an observational signature of its location no longer exists. That the dissolved progenitor is in the range $-30^\circ < \phi_1 < -45^{\circ}$ implies that density fluctuations outside of this range, e.g., a deep gap at $\phi_1 \approx -20^\circ$, are likely produced by compact baryonic or dark-matter perturbers.

An active texture-based digital atlas enables automated mapping of structures and markers across brains.

Brain atlases enable the mapping of labeled cells and projections from different brains onto a standard coordinate system. We address two issues in the construction and use of atlases. First, expert neuroanatomists ascertain the fine-scale pattern of brain tissue, the 'texture' formed by cellular organization, to define cytoarchitectural borders. We automate the processes of localizing landmark structures and alignment of brains to a reference atlas using machine learning and training data derived from expert annotations. Second, we construct an atlas that is active; that is, augmented with each use. We show that the alignment of new brains to a reference atlas can continuously refine the coordinate system and associated variance. We apply this approach to the adult murine brainstem and achieve a precise alignment of projections in cytoarchitecturally ill-defined regions across brains from different animals.

Construction of Indian human brain atlas.

A brain magnetic resonanace imaging (MRI) atlas plays an important role in many neuroimage analysis tasks as it provides an atlas with a standard coordinate system which is needed for spatial normalization of a brain MRI. Ideally, this atlas should be as near to the average brain of the population being studied as possible. The aim of this study is to construct and validate the Indian brain MRI atlas of young Indian population and the corresponding structure probability maps. This was a population-specific atlas generation and validation process. 100 young healthy adults (M/F = 50/50), aged 21-30 years, were recruited for the study. Three different 1.5-T scanners were used for image acquisition. The atlas and structure maps were created using nonrigid groupwise registration and label-transfer techniques. The generated atlas was compared against other atlases to study the population-specific trends. The atlas-based comparison indicated a signifi cant difference between the global size of Indian and Caucasian brains. This difference was noteworthy for all three global measures, namely, length, width, and height. Such a comparison with the Chinese and Korean brain templates indicate all 3 to be comparable in length but signifi cantly different (smaller) in terms of height and width. The findings confirm that there is significant difference in brain morphology between Indian, Chinese, and Caucasian populations.

A stereotaxic MRI template set of mouse brain with fine sub-anatomical delineations: Application to MEMRI studies of 5XFAD mice

PurposeManganese-enhanced magnetic resonance imaging (MEMRI) can help us trace the active neurons and neuronal pathway in transgenic mouse AD model. 5XFAD has been widespread accepted as a valuable model system for studying brain dysfunction progresses in the courses of AD. To further understand the development of AD at early stages, an effective and objective data analysis platform for MEMRI studies should be constructed. Materials and methodsA set of stereotaxic templates of mouse brain in Paxinos and Franklin space, “the Institute of High Energy Physics Mouse Template”, or IMT for short, was constructed by iteratively registration and averaging. An atlas image was reconstructed from the Paxinos and Franklin atlas figures and each sub-anatomical segmentation was assigning a unique integer. An analysis SPM plug-in toolbox was further created, that automates and standardizes the time-consuming processes of brain extraction, tissue segmentation, and statistical analysis for MEMRI scans. ResultsThe IMT comprised a T2WI template image, a MEMRI template image, intracranial tissue segmentations, and accompany with a digital mouse brain atlas image, in which 707 sub-anatomical brain regions are delineated. Data analyses were performed on groups of developing 5XFAD mice to demonstrate the usage of IMT, and the results shows that abnormal neuronal activity occurs at early stage in 5XFAD mice. ConclusionWe have constructed a stereotaxic template set of mouse brain named IMT with fine delineations of sub-anatomical structures, which is compatible with SPM. It will give a widely range of researchers a standardized coordinate system for localization of any mouse brain related data.

Five-Level Inverter-Fed Space Vector Based Direct Torque Control of Open-End Winding Induction Motor Drive

This work proposes a space vector based direct torque control scheme implemented on an open-end winding type induction motor fed by a five-level inverter. The modulation algorithm uses a 60-degree coordinate system to avoid fractional arithmetic as present in the standard Cartesian coordinate system, which reduces the arithmetic calculation complexity. Making use of the natural fractal structure of a hexagonal space vector diagram of the multilevel inverter, this scheme uses a fractal-based algorithm for sector identification and switching vector generation. In this scheme, three-phase signals to the space vector modulator are generated based on a torque-flux error by means of transformation logic. Two three-level inverters are fed from both open ends of an induction motor for realizing a five-level inverter. The scheme includes implementation of different levels of inverter-fed direct torque control drive. The control scheme is implemented on a laboratory prototype 2hp induction motor through a TMS320F240 DSP processor based dSPACE DS-1104 controller. The inverter gating signals are generated by using a Virtex-II FPGA board. The hardware results of different direct torque control configurations are presented for validating the algorithm and all the measurements are done under closed-loop operation.

Gravitational Scattering of a Quantum Particle and the Privileged Coordinate System

In gravitational scattering the quantum particle probes the Fourier-transforms of a metric. I evaluate the Fourier-transforms of Schwarzschild metrics in standard, harmonic and other coordinate systems in linear and $G^2-$approximations. In general different coordinate systems lead to different scattering. This opens up the possibility to choose the privileged coordinate system which should lead to scattering in agreement with experiment.

Three-dimensional craniofacial reconstruction of an ancient Qihe human skull

In 2011, a Qihe human skull with the mandible, dating to about 10000 years ago, was found in Zhangping, Fujian Province. The skull exhibits mixed physical characteristics of both Neolithic Southern and Neolithic Northern populations, together with some primitive traits of Late Pleistocene human fossils; therefore, it has become one of the most important materials to investigate Neolithic southern human physical characteristics and migration in the Late Pleistocene to Holocene transition. There are significant morphological differences between the Qihe and recent humans; for example, the Qihe skull has a long cranial vault, a larger cranial cavity, a higher and narrower face, a wider and shorter nose bone, and lower orbits. In this paper, we propose a novel method to generate the 3D facial appearance of the Qihe human skull based on the craniofacial morphology relationship of recent human and anthropologist’s findings. Our method consisted of three steps. (1) High-resolution computed tomography (CT) was used to acquire series of images, and commercial software Mimics 16.0 was used to create the digital model of the Qihe skull. Because Qihe skull had been divided into the maxilla and mandible, we interactively reassembled these two parts and transformed the whole skull into a standardized Frankfurt Horizontal coordinate system. After exterior point clouds of Qihe skull were extracted, the Iterative Closest Point (ICP) algorithm and generic thin-plate spline (TPS) non-rigid algorithm were used to alignment the Qihe skull with one average skull from the recent human database. The dense corresponding point clouds of the Qihe skull were used to perform the craniofacial reconstruction. (2) We then applied principal component analysis (PCA) to reduce data dimensions and to calculate parameters of the skull and face of each sample in the recent human database. Least square regression was used to quantitatively represent the craniofacial morphology of the recent human. Then, the parameters of Qihe skull were input to predict three-dimensional facial appearance. Facial generation face of this step was found to be consistent and objective. (3) Because craniofacial morphology of the Qihe and recent human was similar but inconsistent, we developed an easy-to-use interactive tool to edit the facial appearance based on statistical shape model and an anthropologist’s findings. PCA was again used to construct a facial statistical shape model based on the dense corresponding point clouds. Variations in these point clouds, which were captured in every principal component (PC), were analyzed to observe shape variability. We changed the coefficients of corresponding PCs to produce multiple facial appearances and choose the best three-dimensional facial appearance. Finally, the geometric shape of the neurocranium and facial morphological characters of the Neolithic human were vividly shown in a handmade drawing. In comparison to manual craniofacial reconstruction, our method is faster, easier, and more efficient for producing facial appearance of Qihe skull via craniofacial morphology and anthropologist’s finds. Using the proposed method, the facial appearance of Qihe skull is displayed. Furthermore, our method provides efficient technical support and references for craniofacial reconstruction of ancient human skulls, which may further be applicable for other fossils and skeletons.

A stereotaxic breed-averaged, symmetric T2w canine brain atlas including detailed morphological and volumetrical data sets

Stereotaxic systems and automatic tissue segmentation routines enable neuronavigation as well as reproducible processing of neuroimage datasets. Such systems have been developed for humans, non-human-primates, sheep, and rodents, but not for dogs. Although dogs share important neurofunctional and -anatomical features with humans, and in spite of their importance in translational neuroscience, little is known about the variability of the canine brain morphology and, possibly related, function. Moreover, we lack templates, tissue probability maps (TPM), and stereotaxic brain labels for implementation in standard software utilities such as Statistical Parametric Mapping (SPM). Hence, objective and reproducible, image-based investigations are currently impeded in dogs. We have created a detailed stereotaxic reference frame for dogs including TPM and tissue labels, enabling inter-individual and cross-study neuroimage analysis.T2w datasets were acquired from 16 neurologically inconspicuous dogs of different breeds by 3T MRI. The datasets were averaged after initial preprocessing using linear and nonlinear registration algorithms as implemented in SPM8. TPM for gray (GM) and white matter (WM) as well as cerebrospinal fluid (CSF) were created. Different cortical, subcortical, medullary, and CSF regions were manually labeled to create a spatial binary atlas being aligned with the template. A proof-of-concept for automatic determination of morphological and volumetrical characteristics was performed using additional canine datasets (n = 64) including a subgroup of laboratory beagles (n = 24).Overall, 21 brain regions were labeled using the segmented tissue classes of the brain template. The proof-of-concept trial revealed excellent suitability of the created tools for image processing and subsequent analysis. There was high intra-breed variability in frontal lobe and hippocampus volumes, and noticeable inter-breed corpus callosum volume variation.The T2w brain template provides important, breed-averaged canine brain anatomy features in a spatial standard coordinate system. TPM allows automatic tissue segmentation using SPM and enables unbiased automatic image processing or morphological characterization in different canine breeds. The reported volumetric and morphometric results may serve as a starting point for further research aimed at in vivo analysis of canine brain anatomy and function.

Matrix Fusion Factory

The current trend in mass personalization is making it ever-more important to achieve a smooth transition towards a more flexible production process to keep up with global competition. IFF has therefore developed the concept of the Matrix Fusion Factory (MFF). MFF fuses the standardized coordinate system developed by IFF with the real factory, thus linking physical factories with their digital images. It is based on modularized, mobile machines capable of configuring and positioning themselves according to the tasks and context concerned. The necessary information, such as machine areas or work instructions, is gathered practically in realtime depending on location, time, order and equipment, and made available within the factory in a context-based manner.In the MFF, this information is considered as being part of the physical factory. This allows the impact of the available information on the production system to be identified and simulated and, the availability of information to be adjusted. This mutual dependence between the physical and the digital factory can only be achieved through fusion. The end-result is a digital-physical factory that enables efficient and flexible value-adding processes in modularized mobile factories.

A surface-based approach to determine key spatial parameters of the acetabulum in a standardized pelvic coordinate system

Accurately determining the spatial relationship between the pelvis and acetabulum is challenging due to their inherently complex three-dimensional (3D) anatomy. A standardized 3D pelvic coordinate system (PCS) and the precise assessment of acetabular orientation would enable the relationship to be determined. We present a surface-based method to establish a reliable PCS and develop software for semi-automatic measurement of acetabular spatial parameters. Vertices on the acetabular rim were manually extracted as an eigenpoint set after 3D models were imported into the software. A reliable PCS consisting of the anterior pelvic plane, midsagittal pelvic plane, and transverse pelvic plane was then computed by iteration on mesh data. A spatial circle was fitted as a succinct description of the acetabular rim. Finally, a series of mutual spatial parameters between the pelvis and acetabulum were determined semi-automatically, including the center of rotation, radius, and acetabular orientation. Pelvic models were reconstructed based on high-resolution computed tomography images. Inter- and intra-rater correlations for measurements of mutual spatial parameters were almost perfect, showing our method affords very reproducible measurements. The approach will thus be useful for analyzing anatomic data and has potential applications for preoperative planning in individuals receiving total hip arthroplasty.

Catlas: An magnetic resonance imaging-based three-dimensional cortical atlas and tissue probability maps for the domestic cat (Felis catus).

Brain atlases play an important role in effectively communicating results from neuroimaging studies in a standardized coordinate system. Furthermore, brain atlases extend analysis of functional magnetic resonance imaging (MRI) data by delineating regions of interest over which to evaluate the extent of functional activation as well as measures of inter-regional connectivity. Here, we introduce a three-dimensional atlas of the cat cerebral cortex based on established cytoarchitectonic and electrophysiological findings. In total, 71 cerebral areas were mapped onto the gray matter (GM) of an averaged T1-weighted structural MRI acquired at 7 T from eight adult domestic cats. In addition, a nonlinear registration procedure was used to generate a common template brain as well as GM, white matter, and cerebral spinal fluid tissue probability maps to facilitate tissue segmentation as part of the standard preprocessing pipeline for MRI data analysis. The atlas and associated files can also be used for planning stereotaxic surgery and for didactic purposes.

Higher Occurrence Rates Of Foot Sesamoids And Accessory Bones In Wrestlers By Ct And 3d-reconstruction

The sesamoids and accessory bones of feet are complicated and small but important in regulating pressure, frictions and direction of muscular traction. Multi-slice CT and 3D reconstruction becomes available for exhibiting bones’ morghology. PURPOSE: To investigate the morphological features of podalic sesamoids and accessory bones in professional wrestlers by CT and 3D reconstruction. METHODS: 9 male Guangdong wrestlers served as subjects (height: 168.2±2.1 cm; weight: 66.8±4.2 kg; age: 18.3±2.4 y) lying on back, and their feet were scanned by 64-slice spiral CT continuously along both feet transect for cross-sections of bones according the set: bone tissue window, 140kv power, 0.656mm pixel size,0.45mm layer distance. Based on the data with the Dicom3.0 standard, the 3D model was constructed by Mimics (Version 10) through the processing of standardized coordinate system of bone, reconstruction, threshold-value segmentation, regional growth, edge segmentation and alternative editing, etc). RESULTS: 53 sesamoids and 10 accessory bones are in the 18 feet. 36 sesamoids bones are below the first metatarsal bones while 17 in the great toe joints, with 2 to 3 sesamoids per foot. In 89% of the feet, the outer-side sesamoids of the first metatarsal bone are larger than the inner-side ones. The sesamoids occurrence rate of the first metatarsal is 100% and the interphalangeal joint is 94.4%, which is much higher than those of other studies. The occurrence rate of accessory navicular bone is 16.7% and that of the triquetral sesamoids is 22.2%. The average volume of the outer-side sesamoids is 434.87mm3, while the inner-side is 386.94mm3. The average surface area of the outer-side sesamoids is 298.8294m2, while the inner-side ones is 274.15 m2. The average volume of sesamoids on the toe joints is 55.49 mm3 with average surface area of 74.24 m2. The average volume of triquetral bones is 703.01 mm3 with average surface area of 417.41 m2. In all accessory bones, the triquetral bone in the right foot is biggest with volume 941.21 mm3, while the interphalangeal bone is smallest with 45.98 mm3. CONCLUSIONS: CT and 3D reconstruction may be effective for investigating the small bones. The sesamoids and accessory bones in feet of wrestlers could be common than no sportsmen, which is related to the acquired influence of Professional training.

Comparison of XPM and UCAC4 catalogues in the galactic coordinate system

This paper presents the results of the comparison of the galactic reference frames realized by the catalogues XPM and UCAC4. Based on about 40 million stars common to both catalogues, the systematic differences of the galactic coordinates and proper motions have been derived for 12 magnitudes in 0.5m width bins with the mean J‐values from 10m.25 to 15m.75. The systematic differences were represented by vector spherical harmonics, with the magnitude equation taken into consideration. The mutual orientation of the frames was found to be at the level of 10 mas. It is concluded that these differences are negligible in comparison with the accuracy of the implementation of the standard galactic coordinate system MAS 1958. We investigated two features of the XPM catalogue. First, unlike the HCRF and UCAC4 catalogues, whose proper motions are tied to the quasars and galaxies, the XPM catalogue implements a reference system based only on galaxies. Second, the XPM catalogue has two systems of proper motions—XPMx and XPMp, referred to the two galaxy sub‐catalogues of the project 2MASS—PSC and XSC. The study of the differences XPMx−XPMp showed that they are free of the magnitude equation. The speed of relative rotation of XPMx over XPMp was found to be ω=0.453±0.003 mas/year, which exceeds the residual rotation of the HCRF (0.25 mas/year). Analysis of systematic differences XPMx−UCAC4 and XPMp−UCAC4 showed that both frames XPMx and XPMp have an appreciable rotation speed relative to the UCAC4 (hence the ICRF), especially large (up to 2 mas/year) for the brightest stars in our range. This shows that a relatively high speed of rotation of the two frames XPMx and XPMp with respect to the UCAC4 is a consequence of the transition from a combined “quasar‐galaxy” to a purely “galactic” reference system. It is shown that the systematic difference between the proper motions of stars can be interpreted within the Ogorodnikov–Milne kinematic model of the velocity field.

Standardized Coordinate System for Factory and Production Planning

The Institute of Industrial Manufacturing and Management IFF, which is affiliated with the University of Stuttgart in Germany, has developed a continuous factory coordinate system for adaptable production systems and implemented it in the learning factory “advanced Industrial Engineering” aIE. The factory coordinate system merges the digital image of the factory (digital shadow) with the real production process practically in realtime and independent of scale. To achieve this, diverse data acquisition systems are grouped into a classification system on the basis of the degree of accuracy required; depending on the degree of resolution, the data collected is then merged chronologically in a standardized coordinate system according to time. The resulting digital shadow of the complete production plant enables the complexity of tasks in the system to be reduced. Any decisions that need to be made in the near future can be aided by performing centralized or decentralized simulations with realtime data. This enables systems to be adapted to new restrictions faster and more cost-effectively. By projecting the digital shadow onto the real production system, any discrepancies are identified immediately, any problems rectified and downtimes reduced even before they arise. This strengthens and safeguards the competitiveness of networked factories in the future.

A Novel Method for Quantitative Serial Autofluorescence Analysis in Retinitis Pigmentosa Using Image Characteristics.

PurposeIdentifying potential biomarkers for disease progression in retinitis pigmentosa (RP) is highly relevant now that gene therapy and other treatments are in clinical trial. Here we report a novel technique for analysis of short-wavelength autofluorescence (AF) imaging to quantify defined regions of AF in RP patients. MethodsFifty-five–degree AF images were acquired from 12 participants with RP over a 12-month period. Of these, five were identified as having a hyperfluorescent annulus. A standard Cartesian coordinate system was superimposed on images with the fovea as the origin and eight bisecting lines traversing the center at 45 degrees to each other. Spatial extraction software was programmed to highlight pixels corresponding to varying degrees of percentile fluorescence such that the parafoveal AF ring was mapped. Distance between the fovea and midpoint of the AF ring was measured. Percentage of low luminance areas was utilized as a measure of atrophy.ResultsThe hyperfluorescent ring was most accurately mapped using the 70th percentile of fluorescence. Both the AF ring and peripheral hypofluorescence showed robust repeatability at all time points noted (P = 0.93).ConclusionsBoth a hypofluorescent ring and retinal pigment epithelium atrophy were present on a significant proportion of RP patients and were consistently mapped over a 12-month period. There is potential extrapolation of this methodology to wide-field imaging as well as other retinal dystrophies. This anatomical change may provide a useful anatomical biomarker for assessing treatment end points in RP.Translational RelevanceSpatial extraction software can be a valuable tool in the assessment of ophthalmic imaging data.

Analysis of the global financial crisis using statistical moments

In this paper, we investigate the impacts of the global financial crisis on the statistical properties of the stock market indices. And we also suggest a possible warning signal of the global financial crisis from the changes in the statistical properties. In order to do that, we treat the world stock markets as a web of relations, which is described by a distribution in the standardized normalization coordinate system: Quarterly world stock-market indices are standardized by re-scaling each index and then normalizing the whole time-series so that every sample of standardized indices has the same mean and variance. By plotting the higher moments of this normalized series, it is possible to identify singularities which might have warned of the dotcom bubble crash in 2002, the 2008 financial crisis, and the European sovereign debt crisis of 2009–10.

THE GENERATION OF BUILDING FLOOR PLANS USING PORTABLE AND UNMANNED AERIAL VEHICLE MAPPING SYSTEMS

Indoor navigation or positioning systems have been widely developed for Location-Based Services (LBS) applications and they come along with a keen demand of indoor floor plans for displaying results even improving the positioning performance. Generally, the floor plans produced by robot mapping focus on perceiving the environment to avoid obstacles and using the feature landmarks to update the robot position in the relative coordinate frame. These maps are not accurate enough to incorporate to the indoor positioning system. This study aims at developing Indoor Mobile Mapping System (Indoor MMS) and concentrates on generating the highly accurate floor plans based on the robot mapping technique using the portable, robot and Unmanned Aerial Vehicles (UAV) platform. The proposed portable mapping system prototype can be used in the chest package and the handheld approach. In order to evaluate and correct the generated floor plans from robot mapping techniques, this study builds the testing and calibration field using the outdoor control survey method implemented in the indoor environments. Based on control points and check points from control survey, this study presents the map rectification method that uses the affine transformation to solve the scale and deformation problems and also transfer the local coordinate system into world standard coordinate system. The preliminary results illustrate that the final version of the building floor plan reach 1 meter absolute positioning accuracy using the proposed mapping systems that combines with the novel map rectification approach proposed. These maps are well geo-referenced with world coordinate system thus it can be applied for future seamless navigation applications including indoor and outdoor scenarios.

THE GENERATION OF BUILDING FLOOR PLANS USING PORTABLE AND UNMANNED AERIAL VEHICLE MAPPING SYSTEMS

Abstract. Indoor navigation or positioning systems have been widely developed for Location-Based Services (LBS) applications and they come along with a keen demand of indoor floor plans for displaying results even improving the positioning performance. Generally, the floor plans produced by robot mapping focus on perceiving the environment to avoid obstacles and using the feature landmarks to update the robot position in the relative coordinate frame. These maps are not accurate enough to incorporate to the indoor positioning system. This study aims at developing Indoor Mobile Mapping System (Indoor MMS) and concentrates on generating the highly accurate floor plans based on the robot mapping technique using the portable, robot and Unmanned Aerial Vehicles (UAV) platform. The proposed portable mapping system prototype can be used in the chest package and the handheld approach. In order to evaluate and correct the generated floor plans from robot mapping techniques, this study builds the testing and calibration field using the outdoor control survey method implemented in the indoor environments. Based on control points and check points from control survey, this study presents the map rectification method that uses the affine transformation to solve the scale and deformation problems and also transfer the local coordinate system into world standard coordinate system. The preliminary results illustrate that the final version of the building floor plan reach 1 meter absolute positioning accuracy using the proposed mapping systems that combines with the novel map rectification approach proposed. These maps are well geo-referenced with world coordinate system thus it can be applied for future seamless navigation applications including indoor and outdoor scenarios.

Study of BPPV precise manipulation treatment

Objective:To explore the effect of the BPPV precision manipulation treatment. Method:With 3D SLICER software we segment structure such as semicircular canal, eye ball, orbital and ear rod from MRI or CT volume data of patients which underwent MRI or CT scaning of inner ear, for measuring the spatial direction of semicircular canals and building semicircular canal modules with standard space coordinate system and embedding into 3D PDF files. Result:With the slice that divide the semicircular canal equally as the semicircular canal plane and the eyeball as reference object to determine whether it is symmetric, it is not only intuitive but also reliable for measuring the angle between the posterior semicircular canal. 3D PDF is intuitive, rotation angle can be adjusted according to the individual differences in the process of manipulation treatment, to observe and demonstrate the theoretical reduction effect before the actual operation. Conclusion:By reconstruction the three-dimensional semicircular canal structure from the inner ear image data of patients and measurement of the semicircular canal space direction, it is of a certain significance for BPPV precision manipulation treatment.

A 3D high resolution ex vivo white matter atlas of the common squirrel monkey (Saimiri sciureus) based on diffusion tensor imaging.

Modern magnetic resonance imaging (MRI) brain atlases are high quality 3-D volumes with specific structures labeled in the volume. Atlases are essential in providing a common space for interpretation of results across studies, for anatomical education, and providing quantitative image-based navigation. Extensive work has been devoted to atlas construction for humans, macaque, and several non-primate species (e.g., rat). One notable gap in the literature is the common squirrel monkey - for which the primary published atlases date from the 1960's. The common squirrel monkey has been used extensively as surrogate for humans in biomedical studies, given its anatomical neuro-system similarities and practical considerations. This work describes the continued development of a multi-modal MRI atlas for the common squirrel monkey, for which a structural imaging space and gray matter parcels have been previously constructed. This study adds white matter tracts to the atlas. The new atlas includes 49 white matter (WM) tracts, defined using diffusion tensor imaging (DTI) in three animals and combines these data to define the anatomical locations of these tracks in a standardized coordinate system compatible with previous development. An anatomist reviewed the resulting tracts and the inter-animal reproducibility (i.e., the Dice index of each WM parcel across animals in common space) was assessed. The Dice indices range from 0.05 to 0.80 due to differences of local registration quality and the variation of WM tract position across individuals. However, the combined WM labels from the 3 animals represent the general locations of WM parcels, adding basic connectivity information to the atlas.