Wireless Capsule Endoscopy Indication as a Predictor of Study Quality

PURPOSE: The aim of the study was to assess whether specific indications are associated with poor visualization during wireless capsule endoscopy (WCE) studies . Four hundred consecutive WCE studies performed at our institute were analyzed retrospectively. RESULTS: Data was available on cases involving 176 males and 224 females. About 23 capsules failed to exit the stomach (excluded from the study). Poor visualization was reported in 66 (17%) WCE studies. The most common indications were gastrointestinal (GI) blood loss (271 cases; 72%), abdominal pain and/or diarrhea (73 cases; 19%), and suspected inflammatory bowel disease (46 cases; 12%). Of the 271 patients suffering GI bleeding, visualization was reported to be poor in 53 (19%) patients; among those showing other indications, visualization was poor in 13 (11%) patients (P = 0.02). After controlling for secondary indications and age, GI bleeding was associated with a higher rate of poor visualization compared to all other indications (odds ratio 2.6; 95% confidence interval 1.4-6.8). CONCLUSIONS: Gastrointestinal bleeding as study indication for WCE is associated with a higher rate of poor visualization.     

Does a New Ultrasound Flow Modality Improve Visualization of Neonatal Pulmonary Veins?

Background: Blood flow imaging is a new ultrasound modality that supplements color Doppler imaging with angle‐independent information of flow direction that is not influenced by velocity aliasing. This is done by visualizing the blood speckle movement superimposed on the color Doppler images. This study aimed to investigate whether this method improves the visualization of the pulmonary veins in neonates. Methods: Twenty‐six neonates with suspected congenital heart disease were prospectively examined with echocardiography and blood flow imaging of the pulmonary veins after parental consent. For each patient, blood flow imaging and color Doppler imaging cine loops were presented to four observers (pediatric cardiologist/cardiologists) in a random order. Questions regarding the pulmonary venous connections and the overall quality of the pulmonary vein imaging were evaluated on a visual analogue scale from 0 (worst) to 100 (best). The methods were compared within each observer using the Wilcoxon's exact signed‐rank test. Results: Blood flow imaging (color Doppler imaging combined with the blood speckle movement) was consistently ranked as better than conventional color Doppler imaging for visualization of the pulmonary veins for all observers (all P‐values < 0.002). Conclusion: Blood flow imaging may improve the visualization of the pulmonary veins in neonates. (Echocardiography 2010;27:1113‐1119)     

基于三维图形化数据挖掘方法的四物汤类方配伍规律研究

目的:研究用于不同血瘀证证型的四物汤类方的配伍特点,从组方药物性味归经及功效等属性研究各类方之间的共同特征。方法:在本实验室开发的二维方剂图形化挖掘方法的基础上,进一步增加了药物的功效属性,分别以性味、归经、功效属性为坐标,将方剂信息表现在三维图形上。分别将用于各类血瘀证型的方剂转化为三维图形,并寻找各类血瘀证型方剂对图形中的共同节点,分析四物汤类方治疗血瘀证的用药特点。结果:通过适用于不同证型的各类方间的三维方剂图形比较,发现了部分四物汤类方治疗血虚血瘀证的部分共同特征。组方药味性味以辛、甘、温为多,大多归肝、心、脾经,功效以补血、活血、止痛为主。这类节点在各证型类方中均出现较多,平均每方出现0.5～1.5次。这些节点可代表四物汤类方治疗血瘀证的一般特点,与传统理论相符。结论:三维图形化数据挖掘方法具有直观、形象的特点,便于从复杂数据中发现规律,非常适用于类方数据挖掘研究。     

《伤寒论》方证对应规律的数学三维解析

目的:在建立《伤寒论》常用73味"药力"的基础上,根据"药证相应"、"方证相应"原理,将《伤寒论》中药、方、证全部放到一个具有客观的相对精确数据要求的数学模型中,试图用现代数学语言解析中医的临床经验、药物性能和辨证术语,客观展现抽象的中医概念,可视化方证对应规律。方法:应用数学方法、计算机模型法和计算机软件技术对《伤寒论》方证质点对应规律进行空间描述并进行数学三维解析及量化表达。结果:在获得有关《伤寒论》药、方、证量化数据的基础上,将《伤寒论》方证对应质点图形化、量化显示在模型软件的空间坐标系中,通过数学三维解析使传统的中医方证对应规律图形化、量化表达。结论:利用模型软件可以清晰地演示《伤寒论》中药、方、证质点在三维空间的变化轨迹,可视化方证对应规律的同时,也客观展示了中医辨证论治的思辨过程,为中医的量化模式研究开辟了一条新的路径。     

虚拟肝段模型在肝脏超声教学中的应用

肝脏超声是超声影像学教学的重要内容。建立在中国可视化人体基础上的虚拟肝段模型具有操作简便、人机交互性好、清晰显示肝脏超声任意切面上的肝裂和肝段等优点,有助于医学生和临床医师学习和掌握超声图像上肝内解剖结构,包括各个肝段和肝裂的准确位置,为肝脏超声的教学提供了一种新的方法。     

数字人脑可视化平台的构建研究

目的 建立数字人脑可视化平台.方法 选取中国可视化人(Chinese visible human,CVH)的脑部切片图像,在Windows平台上以Visual C++为开发工具,结合可视化类库VTK,进行数字人脑可视化平台的框架构建、摹于MarchingCube(MC)算法的三维重建及基于3D Widget的三维模型交互式虚拟削切等可视化展示.结果 建立了数字人脑可视化平台,实现了多值面绘制和体绘制重建、精确的交互式三维剖切、任意方位虚拟切片的动态观察及三维场景渲染参数动态设置等多种功能.结论 数字人脑可视化平台能真实展示人脑的解剖特征,可为人脑解剖教学和脑外科手术计划制定等各种临床应用提供平台支持.     

Effects of leaflet geometry on the flow field in three bileaflet valves when installed in a pneumatic ventricular assist device

Our group is currently developing a pneumatic ventricular assist device (PVAD). In this study, in order to select the optimal bileaflet valve for our PVAD, three kinds of bileaflet valve were installed and the flow was visualized downstream of the outlet valve using the particle image velocimetry (PIV) method. To carry out flow visualization inside the blood pump and near the valve, we designed a model pump that had the same configuration as our PVAD. The three bileaflet valves tested were a 21-mm ATS valve, a 21-mm St. Jude valve, and a 21-mm Sorin Bicarbon valve. The mechanical heart valves were mounted at the aortic position of the model pump and the flow was visualized by using the PIV method. The maximum flow velocity was measured at three distances (0, 10, and 30 mm) from the valve plane. The maximum flow velocity of the Sorin Bicarbon valve was less than that of the other two valves; however, it decreased slightly with increasing distance it the X-Y plane in all three valves. Although different bileaflet valves are very similar in design, the geometry of the leaflet is an important factor when selecting a mechanical heart valve for use in an artificial heart.     

Model-based erosion spotting and visualization in rheumatoid arthritis

RATIONALE AND OBJECTIVES: A method for the automatic detection and the visualization of erosions caused by rheumatoid arthritis is investigated. Erosion-enhanced viewing is a contribution to the computer-aided diagnosis of rheumatoid arthritis. It supports the clinician by providing the automatic marking of erosions and the visualization of any deviations from intact anatomy for a concise reviewing interface. MATERIALS AND METHODS: A generative appearance model is used to capture the variability of intact bone and erosions. The algorithm marks erosions on hand radiographs using this model, and visualizes these erosions with the help of the residual appearance error after fitting the model built from intact bone texture. The algorithm was evaluated on 17 hand radiographs. The standard of reference was an annotation of the erosions by a musculoskeletal radiologist. RESULTS: Detection results from the algorithm are reported for a set of 17 radiographs of moderately diseased hands. With a specificity of 84%, the detection of unequivocal erosions achieved a sensitivity of 85%. A receiver operating characteristic analysis yields an area under the curve of 0.92. The visualization provided a clear representation of the erosions as determined by two musculoskeletal radiologists. CONCLUSION: The automatic spotting of erosions provides promising results, and the visualization of the deviation from healthy anatomy aids clinicians in the evaluation of the erosions and in the reviewing of automatic detection results.     

Image guidance in pelvic and acetabular surgery--expectations, success and limitations

During the last decade navigation techniques in pelvic and acetabular surgery have been described. Nowadays, available techniques include CT-based navigation, 2D C-arm navigation and 3D C-arm navigation. The main indication is the navigated percutaneous SI screw fixation, but acetabular screw fixations are also reported. In this article, based upon a literature review and our own clinical experiences, the indications for and limitations of navigated techniques in pelvic and acetabular surgery are described.     

Database Analysis of Simulated and Recorded Electrophysiological Datasets with PANDORA’s Toolbox

Neuronal recordings and computer simulations produce ever growing amounts of data, impeding conventional analysis methods from keeping pace. Such large datasets can be automatically analyzed by taking advantage of the well-established relational database paradigm. Raw electrophysiology data can be entered into a database by extracting its interesting characteristics (e.g., firing rate). Compared to storing the raw data directly, this database representation is several orders of magnitude higher efficient in storage space and processing time. Using two large electrophysiology recording and simulation datasets, we demonstrate that the database can be queried, transformed and analyzed. This process is relatively simple and easy to learn because it takes place entirely in Matlab, using our database analysis toolbox, PANDORA. It is capable of acquiring data from common recording and simulation platforms and exchanging data with external database engines and other analysis toolboxes, which make analysis simpler and highly interoperable. PANDORA is available to be freely used and modified because it is open-source (). Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.