类保幼激素对三带喙库蚊幼期发育的影响

本文报告用亚致死剂量的 S—31183(类保幼激素)处理三带喙库蚊幼虫对其发育影响的研究,结果表明处理后蛹期死亡率明显高于幼虫期,并且与剂量大小有关。S—31183处理幼虫并不影响幼虫的发育时间,但可使幼虫化蛹时蜕皮受阻与羽化受到一定的抑制。     

Histologic mimics of inflammatory bowel disease

This review summarizes a variety of clinical and histologic mimics of idiopathic inflammatory bowel disease. All the entities that are included demonstrate one or more histologic features typical of idiopathic inflammatory bowel disease that may lead to potential diagnostic confusion and misinterpretation by the pathologist. The elements of the clinical history, laboratory test results, and endoscopic findings that are helpful to the surgical pathologist in considering a diagnosis other than idiopathic inflammatory bowel disease are emphasized. On occasion, a poor response to standard treatment for idiopathic inflammatory bowel disease is the clue that prompts reconsideration of the initial diagnosis. Subtle histologic features, special stains, or other diagnostic methodologies that can aid in proper diagnosis are also discussed.     

Dental age estimation in Malaysian adults based on volumetric analysis of pulp/tooth ratio using CBCT data

Forensic odontology plays an important role in human identification and dental age estimation is an integral part of this process. The aim of the study was to investigate the association between chronological age and pulp/tooth volume ratio in a Malaysian population (Malays and Chinese) from cone-beam computed tomography (CBCT) scans, enhanced with Mimics software. Three hundred CBCT scans of 153 males and 147 females, aged between 16 and 65 years were divided into 5 age groups. Volumetric analysis of the pulp/tooth ratio was performed in maxillary left canines, maxillary right canines and maxillary right central incisors. Simple linear regression and Pearson correlation analysis indicated the strongest coefficient of correlation (R) values for maxillary right central incisors (0.83) followed by maxillary right canines (0.74) and maxillary left canines (0.73). Fisher’s Z test indicated that dental age estimation is gender independent. The derived regression equations were further validated on an independent group of 126 teeth. The results indicated mean absolute error (MAE) values of 6.48 and 8.58 years for maxillary right central incisors and maxillary canines respectively. It was also noticed that MAE values were higher among the age groups ranging from 46 to 65 years. This study showed that a volumetric change in the pulp cavity with age is a valuable assessment method for dental age estimation among Malaysian population.     

数字化技术辅助手术治疗 Pilon 骨折疗效分析

目的研究数字化技术辅助手术治疗 Pilon 骨折的疗效。方法选取30例 Pilon 骨折患者,随机分为 A 组和 B 组（各15例）。A 组采用数字化技术辅助手术,将患者计算机断层扫描（CT）数据导入Mimics10．01软件进行三维重建,选择合适术式行模拟复位手术,再进行手术治疗;B 组则采用传统的非数字化技术辅助手术。术后第2天,采用放射学疗效评价标准（Burwell-Charnley 标准）评估患者术后骨折复位情况;术后6个月、12个月,采用临床疗效评价标准（Olerud-Molander 主观评分标准）评估患者术后踝关节功能恢复情况。结果术后第2天,A 组解剖复位及功能复位例数多于 B 组,差异有统计学意义（P＜0．05）;术后6个月、12个月,A 组踝关节功能评分高于 B 组,差异有统计学意义（P＜0．05）。结论数字化技术辅助手术治疗 Pilon 骨折可使骨折块更好复位,术后踝关节功能恢复更好。     

颅腔三维模型的建立及其变形的有限元方法分析

目的建立真实的人体颅腔三维模型,通过有限元方法分析人体颅腔随颅内压(ICP)变化的应变规律。方法以1例成年健康男性的颅腔CT扫描图像为基础,利用逆向工程软件Mimics 13.0建立人体颅腔三维模型,并通过ANSYS软件模拟临床ICP变化范围2.0～6.0kPa,分析三维颅腔表面的变形情况。结果利用Mimics软件建立了与真实人体颅腔几何结构和材料属性均高度相似的三维颅腔有限元模型,该模型相较于其他简化模型和普通计算机辅助设计(CAD)建模软件建立的模型具有细节更逼真、材料属性更贴切的特点,更具有普遍应用的价值。而且通过ANSYS有限元模拟分析,随着ICP的增高,颅腔表面应变呈上升趋势,在2.0～6.0kPa ICP变化范围内,颅腔表面应变范围为1.27～3.67με。随ICP变化,人体颅腔表面的应变规律和范围与前期研究的计算结果基本一致。结论建立的真实人体颅腔三维模型和模拟颅腔随ICP变化的变形规律具有较高的可信度,为临床研究颅腔变形提供了可靠的数据依据。     

对Mimics V10.0软件的三维实体重建方法的研究

目的对Mimics V10.0软件的三维实体重建方法及重建原理加以研究。方法利用GELightspeed 16排螺旋CT对一个正常头颅,一个正常左膝关节以及一个有严重骨质增生的左膝关节分别以层厚5或10 mm,间隔5或10 mm的方式进行扫描,随后在GE后处理工作站进一步获得1.25 mm层厚的薄层后重建图像。Mimics直接读入Dicom格式后重建图像,运用阈值选取技术、三维区域增长技术,获得新蒙罩,以此新蒙罩为基础经三维重建后获得头颅及左膝关节三维实体模型。结果在Mimics中得到的三维实体模型能旋转、剖割及拆分,图像轮廓清晰,方便测量,其梯状伪影较小。对多种原因引起左膝关节间隙两侧骨端的骨质相接触时,其三维模型显示左股骨下端及胫骨上端连接在一起。结论Mimics软件中三维区域增长技术的原理是基于空间连接性演算,其三维实体重建采用表面遮盖重建技术。多个专业的临床医生利用Mimics软件可以得到人体组织、器官逼真的立体显示,且该软件还可用于考古学、体质学等研究。     

Mimics软件在胫骨平台骨折分类及术前计划的初步应用

目的:探讨Mimics软件在胫骨平台骨折Schatzker分类及术前计划中的价值.方法:将临床胫骨平台骨折患者CT扫描图像数据导入Mimics10.01软件,三维重建胫骨平台骨折可视模型,并按Schatzker提出的标准进行分类.选取胫骨平台塌陷型骨折三维模型进行三维数据测量、开窗复位手术的初步计算机模拟、立体显示、植骨量估算.结果:重建的胫骨平台骨折三维可视模型可准确反映出骨折特点、骨折移位的方向和程度,并可进行任意旋转观察,初步实现了胫骨平台骨折术前手术设计、开窗手术的模拟、植骨量估算及三维数据测量.结论:Mimics软件重建的胫骨平台三维骨折模型可清楚显示骨折情况并明确Schatzker分类,为术前的手术设计、开窗复位的模拟、植骨量估算、三维数据测量等提供了依据.     

Ultrasound transmission loss across transverse and oblique bone fractures: an in vitro study

An axial transmission technique has been used to investigate the changes in the first arrival time and signal amplitude of 200 kHz ultrasonic waves travelling across different fracture geometries. Results taken from intact bovine femora were compared with those produced when a transverse and an oblique fracture were simulated. The arrival time and signal amplitude displayed a different variation with receiver position for the two geometries and a given fracture gap width. A comparison between this work and a previous study suggested that the marrow does not play a significant role in the mechanisms causing the change in arrival time and signal amplitude. Numerical modelling revealed that an oblique fracture caused a reduction in the extra time delay of the propagating wave compared with the transverse case, but a decrease in the corresponding signal amplitude, i.e., greater signal loss. The angle of the oblique fracture was investigated and results suggested that decreasing the fracture angle relative to the wave propagation direction caused a decrease in the extra time delay and an increase in signal loss. These findings are important for determining the sensitivity of systems for monitoring fracture healing using ultrasound arrival time and signal amplitude. (E-mail: spd@inorbit.com).     

中、下段胸椎侧前方植入物内固定时的椎体数字化测量

背景：有关成人椎体钉进钉点的报道较多,但都只有一般性的描述,且由于不同种族、节段等差异,椎体形态变异较大,其置钉位置的选择也不一致。目的：通过CT扫描结合逆向工程软件建立下胸椎三维立体模型,数字化测量成年国人中下段胸椎侧前方椎骨相关解剖位置CT数据。方法：收集非脊柱疾患病例CT资料,利用Mimics软件建立国人完整中下段胸椎（T4-T12）三维立体模型,测量椎体正中冠状面左、右缘高度,正中矢状面前、中、后缘高度,椎体上终板矢状径及横径,椎体下板终矢状径及横径。结果与结论：国人中下段胸椎椎体上、下终板矢状径及横径均随椎序的增加而增人。在中、下段胸椎椎体卜缘置钉,椎体螺钉的选择有一定的规律;由于椎体的横径始终大于矢状径（3．0—4．0mm）,建议在取材和修剪移植松质骨块时应将骨块修成横行的长方体（长大于宽3．0—4．0mm）。临床中下胸椎侧前方固定时应参考以上数据选择合适的纵行棒进行固定。