三维重建模型的建立

介绍用三角形和点来构建物体三维模型的方法:第一:将体数据分割出所需显示的点,由此点构建显示表面。第二:MC算法及其改进方法。第三:点表面重构方法。     

与死神赛跑

如果问一名心脏科医生什么是最凶险的心血管疾病,他一定会告诉你,主动脉夹层是目前最凶险的心血管疾病,没有之一.2001年1月3日我国排球运动员朱刚不幸猝死于训练场,罪魁祸首正是主动脉夹层动脉破裂.为何主动脉夹层如此凶险？主动脉是人体靠近心脏的大动脉,血管壁有内、中、外三层膜。主动脉夹层是指主动脉壁内膜层破裂与中层分离,血液通过破口进入动脉壁内,使动脉壁撕裂形成夹层。     

经食道多平面超声心动图对急性胸主动脉夹层的快速诊断方法研究

目的 探讨应用急症快速多平面经食道超声心动图快速诊断急性胸主动脉夹层的方法学、适应症、并发症、安全性、准确性。方法 对急诊室中疑诊为急性胸主动脉夹层的病人进行急症快速多平面经食道超声心动图检查。结果 在29例疑诊急性胸主动脉夹层的患者,27例配合良好完成急症快速多平面经食道超声心动图检查,应用该法确诊急性胸主动脉夹层18例,其中典型的胸主动脉夹层13例(A型:9例,B型:4例);不典型的胸主动脉夹层(胸主动脉壁血肿)5例;9例患者无胸主动脉夹层。操作时间为平均182(69-352)秒,从入院到确诊时间36(20～100)分,急症快速多平面经食道超声心动图检查中无严重并发症。与常规经食道超声心动图技术比较,两种方法对诊断急性胸主动脉夹层无显著性差异,急症快速经食道超声心动图检查诊断急性胸主动脉夹层的敏感性为100％、特异性为100％。结论 应用急症快速多平面经食道超声心动图快速诊断急性胸主动脉夹层准确性高、安全、无明显并发症,可缩短确诊时间及入院时间,明显降低该病的死亡率。     

MSCT血管成像及后处理技术在主动脉夹层中的诊断价值

主动脉夹层是一种急症,是指由多种病因导致的主动脉内膜破裂,血液通过破裂口进入中层,随着血流压力的驱动,逐渐在主动脉中层内扩展,导致血管壁分层,形成异常通道或夹层血肿[1]。我们将MSCT血管成像及后处理技术应用于主动脉夹层的诊断中,效果满意,现报道如下。     

基于ITK和OpenGL的医学图像三维重建

目的:提出一种基于ITK和OpenGL开发的医学图像三维重建系统的新模式.方法:在VC++6.0的MFC环境下缟程,设计交互性强、灵活实用的用户界面;集成ITK类库实现医学图像的读写、分割、等值面提取,并利用OpenGL进行三维表面的绘制和渲染.结果:设计并实现了一个医学图像三维重建系统.结论:基于ITK和OpenGL模式开发医学图像三维重建系统,不仅可以解决ITK不具备可视功能、不提供用户界面的缺点,同时可以利用OpenGL强大的三维绘制和渲染功能使三维场景更加逼真.     

腹主动脉假性动脉瘤腔内修复术围手术期患者的护理

腹主动脉假性动脉瘤,多因外伤引起腹主动脉管壁全层破裂.血液进入血管壁外,由较厚的软组织包绕形成的局限性血肿,有搏动,瘤体大,开口小,瘤壁不光滑[1].近年来国内相继报道腹主动脉假性动脉瘤行腔内修复术治疗以来,以其微创、并发症少、病死率低、恢复迅速,使一部分高龄、高危患者得到了救治.     

一种简捷的眼眶三维图像分割方法

目的:将眼眶从头颅整体的三维图像中分割出来,以便独立研究.方法:通过对人体头颅进行CT扫描并进行三维重建,得到包含眼眶的头颅图像,采用基于分割目标形态的技术,将头颅三维图像中眼眶的三维分割出来.结果:该方法可以将眼眶整体从头颅三维图像中分离开采,为眼眶三维结构的研究奠定了基础.结论:该分割方法简捷直观,分割效果明显,可满足对眼眶进行独立研究的要求.     

1例主动脉夹层(StandfordA型)合并妊娠患者的临床观察和护理

主动脉夹层是指血液渗入主动脉壁损伤其中层并在中层和外层之间形成夹层血肿,并可沿主动脉壁延伸剥离导致心血管严重损伤的一种急症。范围可局限在升主动脉或降主动脉,但也可广泛涉及整个胸主动脉,降主动脉及分支血管。一般表现为剧烈疼痛,休克以及压迫症状。发病率一般男     

带膜血管内支架置入治疗胸主动脉夹层临床分析

目的:研究分析带膜血管内支架置入术用于胸主动脉夹层的治疗效果。方法:择取我院在2013.06-2014.06期间接收诊治的16例胸主动脉夹层患者,通过CT增强扫描检查确诊。均采用带膜血管内支架置入术加以治疗。结果:全部患者支架置入术成功,手术后即刻造影,14例患者未发现内漏,2例患者出现少量的内漏。降主动脉、腹主动脉真腔显著性扩大,远端分支、降主动脉供血均得到不同程度的缓解。随访发现,降主动脉、腹主动脉真腔均有所扩大,2例造影有少量内漏者,没有加重;14例患者近端夹层动脉已经消失,在假腔中出现血栓。结论:带膜血管内支架置入用于胸主动脉夹层治疗效果较为满意。     

七问主动脉夹层：带您认识血管里的“炸弹”

<正>第一问：什么是主动脉夹层了解主动脉夹层之前要先认识主动脉。主动脉是连接心脏的大血管,从心脏发出后,依次为升主动脉、主动脉弓和降主动脉,降主动脉在胸部称为胸主动脉,到达腹部后称为腹主动脉,血液通过主动脉输送到全身各个器官。打一个形象的比喻,心脏是我们的自来水厂,而主动脉就是连接水厂和千家万户的自来水主管道。主动脉壁由三层结构组成,分别为内膜、中层和外膜,正常情况下,三者紧密贴合,确保血液只在血管内流动。当出现各种病理因素（先天性血管发育不良、高血压、动脉粥样硬化等）时,     

醋酸铅暴露对雄性大鼠心血管系统功能的影响

目的探讨醋酸铅经口暴露对雄性大鼠心血管系统功能的影响。方法 40只SPF级Wistar雄性大鼠随机分为低、中、高3个醋酸铅剂量组灌胃法染毒(分别给予45、90、180 mg/kg醋酸铅),对照组(灌服等量蒸馏水),每组10只,每周5次,共染毒60 d。每组随机选取6只大鼠,尾袖法测定末次染毒12 h后血压和心率水平;末次染毒24 h后摘眼球收集血液,脱颈处死大鼠,分离心脏和胸主动脉。石墨炉原子吸收光谱法测定全血血铅水平;全自动生化分析仪测定外周血血清心肌酶水平;酶联免疫吸附法(ELISA)检测外周血血清氧化应激指标GSH、SOD和MDA水平;HE染色法观察大鼠心脏和胸主动脉组织病理学变化。结果染毒之初各组大鼠体重差异无统计学意义,随染毒时间增加,与对照组相比,各染毒组大鼠体重增长量呈下降趋势;各染毒组大鼠血铅水平均显著高于对照组(P0.05),且与染毒剂量呈显著正相关(r=0.614,P0.05);染毒组大鼠收缩压(SBP)水平均显著高于对照组(P0.05),舒张压、平均动脉压和心率在各组间差异无统计学意义(P0.05);中、高剂量染毒组大鼠CKMB和C反应蛋白(CRP)水平显著高于对照组,各染毒组大鼠外周血血清LDH和HBDH水平均显著高于对照组(P0.05),MDA水平显著高于对照组(P0.01),低、中剂量染毒组大鼠GSH水平低于对照组(P0.05);病理组织学检查发现,随醋酸铅染毒剂量的增加,大鼠心肌细胞肥大,胞核染色变深,变形、聚集,排列紊乱,心肌间质增宽,并出现炎细胞浸润,心肌纤维多处肿胀断裂,肌横纹消失;胸主动脉未见明显病理变化。结论醋酸铅暴露可引起雄性大鼠的血压升高、心肌酶谱改变及氧化损伤,直接损伤心肌组织。     

Effects of different sampling points on evaluation of fetal descending aortic flow

BACKGROUND: Widespread use of fetal aortic blood flow velocity measurements for assessment of fetal circulatory status has been precluded by difficulties in achieving an adequate Doppler insonation angle at particular sampling points. The goal of this study was to evaluate the differences in resistance index (RI) and systolic peak velocity (Vmax) of fetal aortic blood flow velocity waveforms throughout gestation among various Doppler sampling points. METHODS: A total of 551 normal women between 18-41 weeks of pregnancy participated in this study. Pulsed Doppler flow velocity waveforms were acquired from three different aortic sampling points (thoracic portion, beneath the diaphragm, and abdominal portion) of the fetal descending aorta. The Vmax and RI were calculated at the respective sampling points. RESULTS: The Vmax were significantly lower in abdominal portion than those in thoracic portion at every time point (from 69 +/- 11 cm/second in thoracic to 49 +/- 8 cm/second in abdominal portion at 18-19 gestational weeks, p<0.0001), and RI were also lower (from 0.84 +/- 0.05 in thoracic portion to 0.76 +/- 0.05 in abdominal portion at 18-19 gestational weeks, p<0.0001). Significant increase in the Vmax was seen until third trimester (from 58+/-10 cm/second at 18-19 gestational weeks to 113 +/- 13 cm/second at 38-39 gestational weeks beneath the diaphragm, p<0.0001), while the RI remained stable (0.79 +/- 0.04 at 18-19 gestational weeks; 0.80 +/- 0.05 at 38-39 gestational weeks beneath the diaphragm). CONCLUSIONS: In measuring the fetal circulatory status, these data demonstrate that the sampling point should be considered when evaluating the maximum systolic velocity and the resistance index of the fetal descending aorta.     

Evaluation of various deformable image registration algorithms for thoracic images

We evaluated the accuracy of one commercially available and three publicly available deformable image registration (DIR) algorithms for thoracic four-dimensional (4D) computed tomography (CT) images. Five patients with esophagus cancer were studied. Datasets of the five patients were provided by DIR-lab (dir-lab.com) and consisted of thoracic 4D CT images and a coordinate list of anatomical landmarks that had been manually identified. Expert landmark correspondence was used for evaluating DIR spatial accuracy. First, the manually measured displacement vector field (mDVF) was obtained from the coordinate list of anatomical landmarks. Then the automatically calculated displacement vector field (aDVF) was calculated by using the following four DIR algorithms: B-spine implemented in Velocity AI (Velocity Medical, Atlanta, GA, USA), free-form deformation (FFD), Horn–Schunk optical flow (OF) and Demons in DIRART of MATLAB software. Registration error is defined as the difference between mDVF and aDVF. The mean 3D registration errors were 2.7 ± 0.8 mm for B-spline, 3.6 ± 1.0 mm for FFD, 2.4 ± 0.9 mm for OF and 2.4 ± 1.2 mm for Demons. The results showed that reasonable accuracy was achieved in B-spline, OF and Demons, and that these algorithms have the potential to be used for 4D dose calculation, automatic image segmentation and 4D CT ventilation imaging in patients with thoracic cancer. However, for all algorithms, the accuracy might be improved by using the optimized parameter setting. Furthermore, for B-spline in Velocity AI, the 3D registration error was small with displacements of less than ∼10 mm, indicating that this software may be useful in this range of displacements.     

模拟60 m空气潜水引起大鼠的氧化应激状态

目的观察模拟60m空气潜水引起大鼠的氧化应激状态。方法将大鼠置于动物加压舱内,暴露于700kPa压缩空气下60min,每天2次,连续3d。于暴露后第1、3、5天915断头取血。用化学比色法测定循环血浆中超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化物酶、谷胱甘肽转硫酶的活力和谷胱甘肽、丙二醛的含量。结果经高压空气多次暴露后,大鼠血浆抗氧化酶活力显著降低(P<0.05或P<0.01),但在暴露后3～5d全部恢复正常;谷胱甘肽含量在暴露后第3天时明显降低(P<0.01),第5天恢复正常;丙二醛含量在多次暴露后显著增高(P<0.01),第5天时降至正常水平。147kPa纯氧暴露后各指标变化类似于700kPa空气暴露。常氧高氮处理后各指标无显著改变。结论60m模拟空气潜水引起大鼠明显的氧化应激,但能在3～5d内恢复;上述变化可能与压缩空气中的高分压氧有关。     

心尖轴流泵的解剖相容性及对心肌损伤的动物实验观察

目的：通过动物体内植入实验观察笔者研制的心尖微型轴流泵式心脏辅助装置的可植入性及对动物机体的损伤。方法：动物实验采用的心尖微型轴流泵呈圆柱形,外壳由钛合金制成,直径为18.4～20.6mm。实验动物采用普通家猪,质量为（65±5）kg。全麻下经右侧第5肋间开胸,用12mm直径人造血管与胸降主动脉行＂端-侧＂吻合。然后切开心包,在左心尖部用特制的环形刀将直径约为15mm的心肌切除,肝素化后将泵通过切口插入左心室,使入口与心室相通。间断缝合泵的环状缝合裙与心肌后严密止血。开始启动血泵后去除人造血管的阻断钳。调节泵转速,测定心腔压力。结果：总共6只动物均顺利完成手术植入,术中未发生不可控制的大出血。表明在非体外循环下植入心尖轴流泵的方法安全可靠。动物实验的压力测试表明：血泵可充分降低左心室压力负荷,维持稳定的外周血压。结论：心尖轴流泵结构设计可行,体积与质量小,可植入性和流体力学特性基本达到实用要求。     

孤立型脉络膜血管瘤的氩激光治疗观察

目的 总结孤立型脉络膜血管瘤激光治疗的经验及疗效。方法 回顾性分析11例孤立型脉络膜血管瘤的临床特征、治疗方法及疗效。结果 11例孤立型脉络膜血管瘤进行氩激光治疗，其中2例联合冷冻治疗后，瘤体基本萎缩5例，不同程度缩小6例，5例合并下方视网膜脱离患眼，4例视网膜下液全吸收，视网膜平复。随访6个月～3年，所有病例均显示肿瘤表面瘢痕形成，无瘤体复发。治疗并发症包括：血管改变；黄斑异常。结论 孤立型脉络膜血管瘤采用氩激光治疗可获满意疗效，当瘤体较大时，有时需联合冷冻治疗。     

Lead-induced dysregulation of superoxide dismutases, catalase, glutathione peroxidase, and guanylate cyclase

Previous studies from this laboratory have demonstrated the presence of oxidative stress and its role in the pathogenesis of lead-induced hypertension. This study was designed to determine whether oxidative stress in animals with lead-induced hypertension is associated with dysregulation of the activities of the main antioxidant enzymes, namely superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX). In addition, we aimed to determine the effect of lead on the regulation of guanylate cyclase (GC) expression. Male Sprague-Dawley rats were randomly assigned to control and lead-exposed groups, and immunodetectable Cu/Zn SOD, Mn SOD, CAT, and GPX were determined by immunoblotting in the thoracic aorta. Additionally, the activities of these enzymes were measured in the renal cortex, medulla, and thoracic aorta. Furthermore, immunodetectable GC was determined in the thoracic aorta. In the thoracic aorta, lead exposure resulted in significant upregulation of aortic Cu/Zn SOD activity, while CAT and GPX activity and CuZn SOD, Mn SOD, and CAT protein abundance were unchanged. Conversely, GC protein abundance was decreased in thoracic aorta. In renal cortex and medulla, CAT and Cu/Zn SOD activities were increased, while GPX activity was unchanged. Lead-exposed animals exhibited upregulation of some antioxidant enzyme activities, most likely as a compensatory response to lead exposure. However, other enzymes did not compensate in the face of oxidative stress, suggestive of an antioxidant/oxidant imbalance. These findings, combined with decrease in aortic GC protein abundance, provide further evidence for dysregulation of antioxidant/oxidant balance and hypertension in this model.     

经耻骨上尿道中段吊带术治疗女性压力性尿失禁的影像尿动力学评价

目的 采用影像尿动力学检查对经耻骨上尿道中段吊带术(SPARC)治疗女性压力性尿失禁的临床疗效进行评价.方法 对2007年1月至2008年10月收治的35例女性压力性尿失禁患者行SPARC.于术前、术后3个月、术后6个月进行国际尿失禁问卷简表(ICI-Q-SF)症状评分、术后1h尿垫试验、影像尿动力学检查并评价疗效.结果 32例患者获得有效随访,随访时间6～20个月,31例患者术后尿控满意,1例有轻度尿失禁.影像尿动力学检查:术后3、6个月最大膀胱容量(MCC)、残余尿(RU)、最大尿流率时逼尿肌压力(Pdet,Qmax)与术前比较差异无统计学意义(P＞0.05).术后3个月,腹压漏点压力(ALPP)与术前比较差异有统计学意义(P值为0.000).术后6个月,最大尿流率(Qmax)、ALPP与术前比较差异有统计学意义(P值分别为0.003、0.000).静态尿道压力图手术前后参数术前、术后3个月、术后6个月,最大尿道关闭压力(MUCP)分别为(35.2±20.4)、(53.1±22.5)、(62.3±19.8)cm H2O(1 cm H2O=0.098 kPa),功能尿道长度(FUL)分别为(3.5±1.3)、(3.9±0.9)、(4.2±1.1)cm,术后6个月MUCP、FUL与术前比较差异有统计学意义(P值分别为0.000和0.002).影像学方面比较,术后显示在增加腹压或咳嗽试验时,膀胱颈及后尿道活动度下降,中段尿道相对固定,尿道闭合.结论通过影像尿动力学评价,SPARC是治疗女性压力性尿失禁的有效方法之一,6个月内影像尿动力学评价提示手术能提高尿道压力,加强控尿功能,同时对膀胱功能无显著影响.     

A new design and computational fluid dynamics study of an implantable axial blood pump

Considering small thoracic space, using implantable ventricular assist device requires reduction in a pump size. Among many available blood pumps, axial blood pumps have attracted greatly because of their small size. In this article, a new miniature axial blood pump has been designed and studied which can be easily implanted in the human body. In this design, the pump overall length decreased by a little increasing in the pump diameter, and new blade geometry is used to produce a streamlined, idealized, and nonobstructing blood flow path in the pump. By means of computational fluid dynamic, the flow pattern through the pump has been predicted and overall pump performance and efficiency has been computed. Also, to ensure a reliable VAD design, two methods for checking wall shear stress were used to confirm that this pump wouldn’t cause serious blood damage.     

40例女性压力性尿失禁患者经超声诊断的价值探讨

目的：探讨二维及三维超声在压力性尿失禁患者中的诊断价值。方法选择2014年10月至2015年12月在西安交通大学第二附属医院泌尿外科门诊就诊的压力性尿失禁患者40名,选取同期健康女性40例为正常对照组,所有受检者均分别行二维及三维盆底超声检查,测量并记录数据。结果压力性尿失禁组与对照组二维测量参数比较,最大Valsalva动作后压力性尿失禁患者膀胱颈向后下方移位,膀胱颈移动度显著大于对照组（ t＝2．31,P＜0．05）;静息状态及最大Valsalva动作后膀胱尿道后角显著大于对照组（t值分别为2．57、3．09,均P＜0．05）;最大Valsalva动作后尿道旋转度显著大于对照组（t＝2．67,P＜0．05）;静息状态下压力性尿失禁组与对照组的尿道长度及尿道倾斜角,差异均无统计学意义（ t值分别为1．26、1．91,均P＞0．05）。三维超声观察耻骨内脏肌及盆膈裂孔结构清晰可辨,最大Valsalva状态下,耻骨内脏肌厚度,尿失禁组显著小于对照组（ t＝2．98,P＜0．05）,盆膈裂孔面积尿失禁组显著大于对照组（t＝5．01,P＜0．05）。结论压力性尿失禁发生的主要机制是膀胱颈和尿道支持结构的异常,经会阴二维及三维超声可良好评价不同状态下上述支持结构的改变。