螺旋CT3D图像重建在鞍区肿瘤中的应用

目的：探讨螺旋CT血管造影（SCTA）3D重建图像技术在鞍区肿瘤治疗中的应用价值。方法：本组20例鞍区肿瘤经MRI明确诊断后，行SCTA螺旋CT重建3D图像。螺旋扫描层厚2.0mm，间距1.0mm，螺距1.0-1.25，以3.0ml s^-1速度注射对比剂120ml；用同遮盖法（SSD）重建三维图像，所建图像与MRI及手术对照。9例行伪彩SSD重建用以模拟手术入路。结果：螺旋CT3D重建图像能清楚显示鞍区肿瘤的形态及其与大血管、颅骨的三维关系并可显示邻近受压移位的血管；螺旋CT重建图像技术可为模拟手术入路提供重要信息。结论：作为常规二维影像的补充，螺旋CT重建图像技术可提供鞍区肿瘤与邻近血管及颅骨的三维空间图像，对临床治疗有重要指导价值。     

64层螺旋CT-3D技术在神经外科的应用价值

3D-CT是近年发展起来的用三维重建技术在计算机断层扫描基础上重构图像的一种CT技术,如配合静脉持续注入造影剂,来显示血管性病变时即CT血管造影(CTA)。随着螺旋CT的普及,特别是64层CT推出,高效、无创、快速、图像清晰等优     

螺旋CT多平面重建三维重建技术在小儿隐性脊柱裂诊断中的临床应用

目的探讨螺旋CT多平面重建技术(MPR)及三维重建(3D)技术在小儿隐性脊柱裂诊断中的应用。方法使用GEprospeedAI型螺旋CT机对80例小儿隐性脊柱裂扫描后进行MPR、3D重建观察,并与二维CT(2DCT)比较。结果MPR、3D重建图像清晰显示了脊柱裂的裂隙缝位置、范围及程度。结论螺旋CT的MPR、3D是诊断小儿脊柱裂的有效手段,有助于病变的早发现早治疗。     

螺旋CT资料建立颅面三维模型

背景：三维螺旋CT可以在胶片或计算机屏幕上展示多角度的立体图像,但复杂的三维解剖形态很难在二维的胶片或计算机屏幕上直观显示,颅颌面外科的手术模拟和方案设计往往更需要三维实体模型。 目的：用螺旋CT数据资料建立颅面三维模型,探讨该模型在颅颌面外科领域的应用。 方法：患者行螺旋CT扫描,层厚2 mm,螺距1.0 mm,利用工作站,进行扫描图像的容积三维重建后,重新间隔分层,利用CuteFTP 4.0软件以BMP格式下载。应用课题组自主开发的CT图象处理软件对已下载的二维图象进行过滤、筛减、降噪、校正失真等处理,对图像的边缘轮廓进行提取,得到面颅骨皮质骨边缘轮廓的矢量化线图,将该线图数据输入Surfacer 9.0重建软件,对轮廓曲线进行矢量叠加,从而得到面颅骨的三维三角形面片线框模型及实体模型。进一步在该模型上按镜像关系重构衬垫物的三维模型。 结果与结论：实验得到了颅面骨骼表面轮廓的三维实体模型,并在其上进行了整形手术的计算机辅助设计,通过快速成型技术加工出衬垫物模板。用螺旋CT数据资料可以建立颅面三维模型,该模型在颅颌面畸形损伤肿瘤等的诊断和治疗中将发挥重要作用。     

多层螺旋CT颅骨三维图像重建在颅骨骨折中的应用研究

目的分析和对比多层螺旋CT（Multi-slice Spiral Computed Tomography,MSCT）与多层螺旋cT颅骨三维图像重建（Three dimensional reconstruction）在颅骨骨折中的影像表现,探讨多层螺旋CT颅骨三维图像重建在颅骨骨折中的临床应用价值。方法收集2009年12月～2012年10月我院收治的300例急性颅脑外伤（traumatic brain injury TBI）检查资料,均于伤后6h内行多层螺旋CT及颅骨三维图像重建检查,检出颅骨骨折病例82例,将数据运用统计学方法分析,比较两种检查方法的差异。结果多层螺旋CT颅骨三维图像重建在颅顶骨折（P=0．026）、颅底骨折（P=0．004）的检出率高于常规多层螺旋CT,具有统计学差异（P〈0．05）,并且有较高的特异性及敏感性。结论螺旋CT颅骨三维图像重建在颅骨骨折的诊断中优于MSCT,具有可靠的临床价值。     

AutoCAD对ImageViewer界面完成的颈椎多平面重建CT图像行定量测量*☆

背景：Silver-PACS系统的功能尚不完善，其图像浏览软件ImageViewer可对序列原始横断面CT图像实施多平面重建，但对重建图像不具有定量电子测量功能。 目的：探索利用AutoCAD2006对ImageViewer重建的下颈椎多平面重建CT图像行定量测量，以弥补现有ImageViewer版本的功能不足。 设计、时间及地点：定量测量试验，2007-06/08在解放军海军总医院放射科完成原始图像扫描，后续定量测量在骨科实验室完成。 材料：8具自愿捐献新鲜下颈椎标本，GE公司的Lightspeed 16排螺旋CT。 方法：螺旋CT对俯卧位颈椎标本行5 mm层厚连续容积扫描，标本纵轴需同CT扫描轴相平行，在AW工作站以0.625 mm层厚、0.625 mm间隔内插法获得原始连续横断面图像。以Dicom格式存储后在ImageViewer界面打开，重建出满意的多平面重建CT图像；利用电脑的Prt Sc功能，在Adobe Photoshop软件中将重建好的带刻度标示的MPR图像转化为*. JPG格式保存；以光栅图像格式在AutoCAD软件中打开，完成定量电子测量。 主要观察指标：重建颈椎弓根内、外、上、下壁及上、下关节突前壁皮质厚度。 结果：在ImageViewer界面成功重建了下颈椎多平面重建CT图像，利用AutoCAD对重建图像成功进行颈椎弓根四壁皮质厚度及上下关节突前壁厚度的电子定量测量，发现颈椎弓根外壁皮质明显薄于其他各壁（P < 0.05）。 结论：以序列原始横断面CT图像为基础，ImageViewer界面可重建出满意的多平面重建CT图像，在AutoCAD中可对重建图像精确定量测量，弥补了ImageViewer软件现有版本的不足。     

多排螺旋CT多平面重建与表面遮盖显示肩胛骨复杂性骨折中的直观图像

背景：由于肩胛骨骨折结构复杂、重叠较多,X射线平片检查容易造成漏诊。随着多排螺旋CT及三维重建技术的应用,三维重建图像能够直观、立体、多方位地显示骨折特征。 目的：探讨多排螺旋CT多平面重建和表面遮盖显示重建后处理技术在肩胛骨复杂性骨折中的应用价值。 方法：使用多排螺旋CT对26例肩胛骨复杂性骨折的患者行薄层扫描,全部数据输入计算机工作站上进行多平面重建和表面遮盖显示重建后处理,得到肩胛骨骨折部位高清晰度的三维图像后,从不同角度观察骨折线走行、骨折移位及成角情况,依据三维图像进行骨折分型及模拟手术入路。 结果与结论：多排螺旋CT多平面重建和表面遮盖显示重建图像能多方位、立体、全面地显示肩胛骨骨折部位和程度,图像与手术中所见符合率为100%。26例均为2 处或2处以上复杂骨折,共有骨折81处。按Hardegger标准分型：肩胛骨体部骨折28处,肩胛颈骨折13处,盂缘骨折11处,盂窝中央横断骨折9处,肩峰骨折8处,肩胛冈骨折6处,喙突骨折6处。结果提示,多排螺旋CT多平面重建和表面遮盖显示重建图像显示肩胛骨复杂性骨折的图像直观,对于肩胛骨复杂性骨折的分型、手术入路及内固定器选择等方案的制定具有较高的应用价值,是诊断肩胛骨复杂性骨折的有效方法。     

多层螺旋CT与虚拟结肠镜在猪肠道重建中的应用

背景：在不影响检查结果的基础下合理降低CT扫描剂量是以后的发展趋势。低扫描剂量CT肠道重建是否可行是近年来探讨研究的热点。 目的：探讨低剂量扫描在多层螺旋CT肠道重建中的可行性。 方法：选用新鲜离体猪结肠制作36枚息肉模型。按设置参数不同随机分为3组：150 mA，100 mA， 50 mA。采用GE LightSpeed16排螺旋CT扫描。每组肠段均行3个角度扫描，即猪结肠纵轴与扫描架平面成0°，45°，90°扫描。在工作站上用仿真内镜技术进行肠道重建，根据图像诊断结果比较3组对息肉的灵敏度。 结果与结论：36枚息肉在150 mA，100 mA， 50 mA扫描强度下分别检出36枚，35枚，33枚，各自的灵敏度分别为100%，97.2%，91.7%，组间差异无显著性意义(P=0.162)。在0°，45°，90°不同扫描角度下检出的猪结肠息肉数分别为34枚，34枚，36枚，各自的灵敏度分别为94.4%，94.4%，100%，组间差异无显著性意义(P=0.354)。提示低剂量多层螺旋CT肠道重建图像可提供足够的诊断信息，可满足仅单纯查看结肠息肉的诊断需要。多层螺旋CT以50 mA的管电流扫描剂量遵循了X射线正当化，防护最优化的原则，在放射剂量和图像质量之间可以很好地建立平衡。     

64层CT后处理技术在关节骨折诊断中的价值

背景：多层螺旋CT结合图像后处理技术对骨折诊断的价值已得到肯定,其中安装有图像后处理软件,可用于各种骨关节外伤的诊断。 目的：评价64层螺旋CT后处理技术在关节骨折中的应用价值。 方法：对36例骨关节损伤患者全部进行X射线平片及多层螺旋CT扫描,并进行多平面重建及容积重建,分析平片、轴位、多平面重建及容积重建对骨折或脱位的显示情况。 结果与结论：所有受试者中,X 射线平片有明确骨折仅20例,容积重建图像可以立体显示骨折线的形态和走行,但容积重建图像对骨皮质轻微分离显示不佳、对关节腔内及椎管内游离骨折片显示困难。多平面重建可以准确显示骨折线以及骨折片的移位。3种方式对关节骨折诊断的阳性率比较有显著性差异。提示,64层螺旋CT后处理技术可以直观、立体、清晰、多角度地显示关节骨折;具有较高的临床应用价值。     

CT血管造影评价静脉血栓栓塞的特征★

目的：介绍多排螺旋CT血管造影诊断静脉血栓栓塞的扫描技术和影像学征象，评价其在静脉血栓栓塞早期诊断中应用价值和优势。 方法：应用计算机检索Medline 1998-01/2007-10与静脉血栓栓塞和肺血栓栓塞的诊断相关的英文文章，检索词“venous thromboembolism，pulmonary thromboembolism，CT angiography”；同时通过手工和计算机检索万方数据库2000-01/ 2007-10相关中文文章，检索词“静脉血栓栓塞，CT血管造影，诊断”。通过检索得到228篇相关文献，纳入24篇完全符合要求的文献。 结果：多排螺旋CT利用多排采集技术，结合高质量的三维重建图像，能清晰地显示肺动脉远端分支，使肺栓塞的诊断进一步达到了亚段水平。薄层螺旋CT诊断肺栓塞的敏感性与肺动脉血管造影相比没有显著差异，其敏感性和特异性都高于肺通气/灌注核素扫描，且在排除急性肺栓塞时，螺旋CT有可能替代核素扫描成为检查的首选。 结论：螺旋CT扫描速度快，图像清晰，不遗漏小病灶。螺旋CT血管造影是静脉血栓栓塞安全、迅速、无创伤的有效诊断方法。     

Children’s head motion during fMRI tasks is heritable and stable over time

Head motion during fMRI scans negatively impacts data quality, and as post-acquisition techniques for addressing motion become increasingly stringent, data retention decreases. Studies conducted with adult participants suggest that movement acts as a relatively stable, heritable phenotype that serves as a marker for other genetically influenced phenotypes. Whether these patterns extend downward to childhood has critical implications for the interpretation and generalizability of fMRI data acquired from children. We examined factors affecting scanner motion in two samples: a population-based twin sample of 73 participants (ages 7–12 years) and a case-control sample of 32 non-struggling and 78 struggling readers (ages 8–11 years), 30 of whom were scanned multiple times. Age, but not ADHD symptoms, was significantly related to scanner movement. Movement also varied as a function of task type, run length, and session length. Twin pair concordance for head motion was high for monozygotic twins and moderate for dizygotic twins. Cross-session test-retest reliability was high. Together, these findings suggest that children’s head motion is a genetically influenced trait that has the potential to systematically affect individual differences in BOLD changes within and across groups. We discuss recommendations for future work and best practices for pediatric neuroimaging.     

不同屈曲角度下膝关节主要韧带有限元模型的建立和验证

背景：随着计算机技术和有限元理论的发展,通过建立膝关节主要韧带的有限元模型进行生物力学研究开始成为最重要的研究方法之一,而如何建立不同屈曲角度下的精确而有效的膝关节模型也成为了研究者们关注的焦点。 目的：探索建立不同屈曲角度下膝关节主要韧带有限元模型的方法并进行验证。 方法：解剖膝关节标本,去除周围软组织并暴露主要韧带。将韧带用钢丝环绕标记后用CT机在不同屈曲角度下扫描,去除韧带组织后再将韧带止点打孔标记并用CT机扫描。将得到的图像数据导入到仿真软件MIMICS中进行三维重建。将三维模型进行必要的修饰和调整后导入有限元软件ANSYS中,在设置材料属性和划分网格后生成三维有限元模型。在有限元软件中对完全伸直角度下的有限元模型采用134 N前向力作用于胫骨,采集胫骨前移的数据并观察韧带受力情况以验证模型的有效性。 结果与结论：得到的模型外形精确逼真,包括股骨、胫骨、前后交叉韧带和内外侧副韧带,并且通过与其他学者的类似数据以及临床经验的比较验证了模型的有效性。实验所得到的模型具有较好的形态仿真和功能仿真,能够在不同屈曲角度下有效的模仿膝关节活动,可以用于开展进一步的生物力学研究。     

3D-CT颅骨重建技术在枕下乙状窦后入路开颅术中的应用

目的探讨3D-CT颅骨重建在枕下乙状窦后开颅术中的指导作用。方法回顾性分析2014年12月至2017年3月枕下乙状窦后入路手术治疗的40例桥小脑角区病变的临床资料,其中左侧开颅22例,右侧18例。术前应用3D-CT颅骨重建技术重建颅后窝骨质,明确横窦、乙状窦静脉窦沟及星点、顶乳缝前角、枕乳缝、二腹肌沟,在颅骨内表面借横窦乙状窦沟交界处设置"关键孔",颅骨外表面测量"关键孔"与顶乳缝前角、星点及二腹肌沟距离及角度。根据术前规划进行开颅。结果术中无静脉窦破裂出血,无明显骨质缺损,开颅快捷。"关键孔"能清晰暴露横窦乙状窦交界处有34例,未能清晰暴露6例。左侧星点与"关键孔"中心距离为6.7~20.6 mm,平均(14.0±3.6)mm;右侧6.9~19.4 mm,平均(13.9±3.7)mm。星点与"关键孔"中心连线及星点与二腹肌沟连线组成的角度左侧(4~45)°,平均(25±12)°;右侧(4~49)°,平均(24±13)°。结论应用3D-CT颅骨重建技术协助枕下乙状窦后入路开颅,操作简单快捷,骨瓣缺损少,有利于静脉窦保护。     

Real-time motion monitoring improves functional MRI data quality in infants

Imaging the infant brain with MRI has improved our understanding of early neurodevelopment. However, head motion during MRI acquisition is detrimental to both functional and structural MRI scan quality. Though infants are typically scanned while asleep, they commonly exhibit motion during scanning causing data loss. Our group has shown that providing MRI technicians with real-time motion estimates via Framewise Integrated Real-Time MRI Monitoring (FIRMM) software helps obtain high-quality, low motion fMRI data. By estimating head motion in real time and displaying motion metrics to the MR technician during an fMRI scan, FIRMM can improve scanning efficiency. Here, we compared average framewise displacement (FD), a proxy for head motion, and the amount of usable fMRI data (FD ≤ 0.2 mm) in infants scanned with (n = 407) and without FIRMM (n = 295). Using a mixed-effects model, we found that the addition of FIRMM to current state-of-the-art infant scanning protocols significantly increased the amount of usable fMRI data acquired per infant, demonstrating its value for research and clinical infant neuroimaging.     

BOLD fMRI activation induced by vagus nerve stimulation in seizure patients

OBJECTIVE: To identify the cerebral activated regions associated with the vagus nerve stimulation in epilepsy patients. DESIGN: Blood oxygenation level dependent functional magnetic resonance imaging (BOLD fMRI) was employed to detect areas of the brain activated by vagus nerve stimulation in five patients with documented complex partial seizures. METHODS: Functional MRI was done on a GE 1.5T Echospeed horizon scanner. Before each patient entered the scanner, the vagal nerve stimulator was set to a specific ON-OFF paradigm so that the data could be analysed using a box-car type of design. The brains were scanned both anatomically and functionally. The functional images were corrected for head motion and co-registered to the anatomical images. Maps of the activated areas were generated and analysed using the brain mapping software, SPM99. The threshold for activation was chosen as p < 0.001. RESULTS: All patients showed activation in the frontal and occipital lobes. However, activation in the thalamus was seen only in the two patients with improved seizure control. CONCLUSIONS: BOLD fMRI can detect activation associated with vagus nerve stimulation. There may be a relation between thalamic activation and a favourable clinical outcome.     

Assessment and prevention of head motion during imaging of patients with attention deficit hyperactivity disorder

The present study serves to detail the specific procedures for a mock scanner protocol, report on its use in the context of a multi-site study, and make suggestions for improving such protocols based on data acquired during study scanning. Specifically, a mock scanner compliance training protocol was used in a functional imaging study with a group of adolescents and adults with Attention Deficit Hyperactivity Disorder (ADHD) and a matched sample of healthy children and adults. Head motion was measured during mock and actual scanning. Participants across groups exhibited excess motion (>2 mm) on 43% of runs during the mock scanner. During actual scanning, excessive motion was limited to 10% of runs. There was a clear task-correlated head motion during a go/no-go task that occurred even after the compliance training: participants had a tendency to respond with increased head motion immediately after committing an error. This study illustrates the need to (1) report data attrition due to head motion, (2) assess task-related motion, and (3) consider mock scanner training in functional imaging protocols.     

Detecting default mode networks in utero by integrated 4D fMRI reconstruction and analysis

Recently, there has been considerable interest, especially for in utero imaging, in the detection of functional connectivity in subjects whose motion cannot be controlled while in the MRI scanner. These cases require two advances over current studies: (1) multiecho acquisitions and (2) post processing and reconstruction that can deal with significant between slice motion during multislice protocols to allow for the ability to detect temporal correlations introduced by spatial scattering of slices into account. This article focuses on the estimation of a spatially and temporally regular time series from motion scattered slices of multiecho fMRI datasets using a full four‐dimensional (4D) iterative image reconstruction framework. The framework which includes quantitative MRI methods for artifact correction is evaluated using adult studies with and without motion to both refine parameter settings and evaluate the analysis pipeline. ICA analysis is then applied to the 4D image reconstruction of both adult and in utero fetal studies where resting state activity is perturbed by motion. Results indicate quantitative improvements in reconstruction quality when compared to the conventional 3D reconstruction approach (using simulated adult data) and demonstrate the ability to detect the default mode network in moving adults and fetuses with single‐subject and group analysis. Hum Brain Mapp 37:4158–4178, 2016. © 2016 Wiley Periodicals, Inc.     

双源CT结合多平面重建与容积再现三维重建技术评价肋骨骨折

背景：依靠胸部摄片诊断肋骨骨折常导致误诊和漏诊。 目的：分析双源CT结合三维重建技术在肋骨骨折中的应用价值。 方法：使用双源CT对65例肋骨骨折患者进行薄层扫描,将数据发送至工作站行多平面重建、容积再现技术,得到肋骨骨折高清晰度的三维图像后,从不同角度观察骨折线走行、骨折移位及成角情况。 结果与结论：双源CT结合三维重建图像清晰显示65例患者286根骨折,其中52例保守治疗,其余13例行切开复位、内固定治疗。制定手术方案时均参考了三维重建图像,所显示的骨折部位、移位、成角等情况与术中所见一致。提示双源CT能明确诊断肋骨骨折,多平面重建和容积再现技术互相补充对诊断肋骨骨折及指导治疗方案有明显的优势。     

基于CT三维重建个体化股骨假体的计算机辅助设计

背景：由于人体的绝对个性化特点,标准人工假体与患者骨骼之间的误差使二者难以很好匹配。计算机辅助设计和制造个体化假体克服了其他假体的缺点,可有效地延长人工关节的使用寿命和使用质量,并可能解决人工关节的翻修问题。国内的研究尚处于起步阶段。 目的：基于CT图像的三维重建,探求个体化股骨假体计算机辅助设计在提高假体与病变骨骼匹配度中的作用。 方法：CT扫描对象为1例健康男性志愿者,排除髋关节疾患。采用GE Speed Light 16排螺旋CT对股骨中上段进行层厚3 mm扫描,得到CT数据的二维图像,利用自主开发的数据格式转换软件将CT图像转换为bmp格式。对位图编辑预处理,用Mimics8.1软件进行矢量化处理,提取股骨内外轮廓。然后输入Mimics8.1和Rapidform2004三维反求工程软件中,生成股骨内外轮廓的特征曲线,重建股骨三维模型。将股骨髓腔的特征轮廓曲线dxf文件输入计算机辅助设计建模软件Solidworks2004中,以此股骨髓腔轮廓为基础,完成个体化股骨假体的设计。 结果与结论：利用自主开发的数据格式转换软件,实现了CT图像信息的矢量转换。以CT二维图像为依据,进行三维反求,可获得精确的股骨内外轮廓三维实体模型。采用反求工程与正向计算机辅助设计相结合,可设计出匹配良好的个体化股骨假体。提示反求工程和计算机辅助设计技术为个体化假体的研制提供了一个有效可行的途径,解决假体与病变骨骼的良好匹配,可防止假体松动,提高其长期稳定性。     

Visual activation in functional magnetic resonance imaging at very high field (4 Tesla).

OBJECTIVES: Functional magnetic resonance imaging (fMRI) at very high field strengths provides functional brain mapping with the enhanced signal to noise ratio and the larger blood oxygenation level-dependent (BOLD) effect. We report activated areas in the standard space detected by fMRI at 4 Tesla (T) during simple visual stimulation. MATERIALS AND METHODS: Twelve healthy young subjects were scanned using a 4 T scanner during binocular flashing visual stimulation. Functional images were realigned to the first scan and then spatially normalized. Individual and group data analyses were performed to identify areas of visual activation. RESULTS: Activation of the bilateral primary visual cortex (V1/V2) was observed along the entire calcarine fissure in all subjects. The activated area extended to the extrastriate cortex in all subjects. Activation of the bilateral lateral geniculate nucleus (LGN) was detected in all subjects. The group data showed activation of the bilateral primary visual cortex and the bilateral lateral geniculate nucleus. CONCLUSIONS: Robust activation of the vision-related areas was successfully obtained in all subjects using a 4 T magnetic resonance scanner. These results suggest that fMRI at very high field strengths may be effective in showing visual system physiology, and that it can be a promising method to assess visual function of human subjects.