THE VISIBLE ANIMAL PROJECT: A THREE-DIMENSIONAL, DIGITAL DATABASE FOR HIGH QUALITY THREE-DIMENSIONAL RECONSTRUCTIONS

The "Visible Animal Project" (VAP) is comprised of axial anatomic cryosections and corresponding CT and MR images of a mature dog. The digital database is used for the creation of three-dimensional computer graphics of canine anatomy. The technique of cryodissection is described in detail. The combining of the corresponding CT and MR images, and cryosections as well as the data processing for the creation of three-dimensional reconstructions is presented and examples are shown. For the first time a complete high-resolution three-dimensional database of a dog is available, which can be used as the base for further high quality three-dimensional reconstructions, similar to the "Visible Human Project" (VHP).     

Topographical Anatomy, Computed Tomography, and Surgical Approach of the Guttural Pouches of the Donkey

The guttural pouches of the donkey are a pair of pouches located dorsoposteriorly to the posterior pharynx. The pouches have a close contact rostrally with the sphenoid bone, ventrally with the pharynx and esophagus, and caudally with the atlantoaxial joint. The left and right guttural pouches have almost the same capacity. In this study, topographic anatomy, computed tomography (CT) examination, and a surgical approach were carried out in the heads of donkeys. Results of the CT examination, transverse and sagittal sections of the heads, revealed that the donkeys possessed large, symmetrical guttural pouches incompletely divided into medial and lateral compartments by the stylohyoid bone. Moreover, the right and left guttural pouches met each other at the median part to form a thin membranous septum. As CT sections approached the occipital condyle, the lateral compartment disappeared and the medial compartment gradually became smaller toward the base of the skull. Two cadaver heads were examined to assess the anatomic limits of the surgical approach and whether vital structures might be damaged. Direct access to the lateral compartment was performed using a modified Garm's technique, whereas direct access to the medial compartment was gained through Viborg's triangle.     

128层螺旋CT三维重建在外伤骨折成像的临床应用

目的研究128层螺旋CT三维重建在外伤骨折成像中的临床应用.方法对36例外伤患者进行128层螺旋CT扫描及三维重建.结果 128层螺旋CT对各个部位的骨折均能良好显示.结论 128层螺旋CT三维重建不仅精确地显示病变的立体形态,还能详细了解各解剖结构的空间关系,是目前诊断外伤骨折的理想方法.     

基于医学CT和工业CT扫描研究土壤大孔隙结构特征的区别

为探究医学CT与工业CT在土壤大孔隙特征扫描研究应用的区别,选取青海地区金露梅灌丛原状土壤样品,分别采用医学和工业2种CT对其进行扫描,通过对扫描图像的分析和处理,对比分析2种CT扫描的断层图像质量、土壤大孔隙三维图像以及孔隙度特征3个方面特征,分析2种CT研究土壤大孔隙特征的差异。研究结果表明:(1)从扫描土壤横断面图像质量来看,工业CT的图像质量要明显高于医学CT图像;(2)2种CT图像经处理堆栈出的三维图像在形态上相似,但是工业CT解析出的三维图能更好地体现出不同深度的土壤孔隙分布;(3)2种CT图像经处理得到的孔隙度,随着土壤深度的变化,其特征在整体趋势上大致相同,但工业CT能更准确地反映较深层次土壤的孔隙度。因此可以根据不同的需求选择适宜的CT。     

基于CT图像板材节子边缘检测的研究

板材CT图像的边缘提取是实现板材三维重建的关键步骤。针对板材CT图像低对比度、低动态范围、板材缺陷边缘提取困难等问题,采用数学形态学方法对板材二值化处理后的图像进行边缘提取,并与传统的Sobel、Prewitt、LoG和Canny算子对原始板材CT图像边缘提取效果进行对比。结果表明,这种方法能较好地检测出板材节子的边缘信息,提取的边缘清晰完整,准确性较高,能为后续的板材CT图像三维重构奠定基础。     

Investigation of 3D geometry of bulk wheat and pea pores using X-ray computed tomography images

Quantitative characterization of pore topology inside grain bulks is necessary to predict the air traverse time and the cooling or fumigation pattern for the design of storage management strategies. Quantification of 3D microarchitecture of the inter-granular airspace in the grain bulks can also contribute to the development of predictive models of insect movement and for designing acoustic systems for insect infestation detection. In this study, inter-connected 3D array of void spaces was characterized by geometrical quantities such as specific surface area, pore throat size and nodal pore volume. These features were obtained from a 13.1 cm × 13.1 cm × 5 cm volume of wheat and pea bulks. The grain bulks were imaged using a high resolution X-ray computed tomography system at 200 μm resolution. The spatial distributions were computed based on 3D medial axis analysis of the void space in the images using 3DMA-Rock software and a high performance Polaris computer. The other features calculated were medial axis tortuosity, throat surface area and porosity from the 3D images. Characterization of pore throat network provides reliable observation for facilitating realistic prediction of permeability and the nature of air and gas distribution inside grain bulks.     

囊性脑膜瘤的手术治疗

目的:探讨囊性脑膜瘤的病理、临床特点及手术方法。方法:对13例囊性脑膜瘤临床资料进行回顾性分析。结果:肿瘤实质及囊壁全切除9例,肿瘤实质全切加囊壁部分切除3例,肿瘤实质及囊壁部分切除1例,无手术死亡和严重并发症。结论:脑膜瘤由于急性囊变加速了病情发展,引起严重的临床症状,易误诊为其它性质的肿瘤,MRI可以提高诊断的准确率。应尽早手术,肿瘤结节与囊壁尽可能彻底切除以防复发。     

渠道边坡土壤裂隙网络的CT扫描与分形特征研究

为了从微观结构的角度深入研究南水北调中线工程渠道边坡土壤的渗透特性,对膨胀土开展显微CT扫描试验,得到了土样裂隙的二维图像和三维裂隙网络模型,并对裂隙的分形特征进行了系统分析。结果表明:膨胀土内部裂隙网络十分复杂,裂隙尺寸分布范围广泛,可以划分为大、中、小3类;由裂隙数量分布特点可看出膨胀土内部大裂隙的数量较少,但面积占比较大;按照形状可以将大裂隙分层4类,包括:扁平状、似椭圆多边形、长条状和树枝状,其中树枝状裂隙大多为连通裂隙,而连通裂隙是膨胀土吸水膨胀和失水干缩特点的先决条件;从分形几何的角度研究裂隙规则度,发现膨胀土内部的裂隙具有明显不均匀性,裂隙不均匀性可以作为影响渠道边坡稳定性的潜在因素。     

基于CT扫描的煤矿排土场土壤孔隙三维多重分形特征

土壤孔隙对水分、养分的运移起着重要作用,重构土壤孔隙状况反映着复垦土壤质量的高低。本研究基于Math Works Matlab(2009a)平台,在对土壤孔隙CT扫描图片三维重建的基础上,运用多重分形理论对安太堡露天煤矿不同复垦年限排土场重构土壤(23年、20年、0年)以及原地貌土壤进行三维多重分形定量表征,以探讨重构土壤孔隙空间分布规律。结果表明:重构土壤孔隙三维结构具有多重分形特征,信息熵维D1、广义维数谱曲线弯曲程度△D、多重分形谱谱宽△α随着复垦年限逐渐增大,土壤孔隙状况得到改善,土壤孔隙分布越趋于复杂,变异程度较高;重构土壤及原地貌土壤孔隙三维分布多重分形谱函数△f0,呈左钩状,大概率孔隙占主要地位,孔隙分布不均匀。多重分形参数D1、D0-D1、△D、△α、△f间具有较好的相关性,从不同角度上反映了土壤孔隙三维分布的非均质性。