基于BP神经网络的CT图像骨皮质分割

目的在CT图像中通过对骨皮质的分割与测量,测定骨量、骨骼的几何形状以及骨强度,并计算相应的组织形态计量学参数。方法通过DCMTK解读CT图像,提取相应的图像信息。利用OpenCV对图像进行预处理,在感兴趣的区域(ROI)设置的基础上,提取图像的纹理特征作为输入向量;以对训练样本手工分割的结果作为导师信号,对BP神经网络进行训练;用训练好的网络对CT图像序列中的骨皮质进行分割,并对分割后的结果进行后处理及显示。结果骨皮质CT图像的神经网络分割效率符合实际应用的需求,分割结果形状明显,与周围组织区分度高,满足临床诊断需求。结论纹理特征明显的情况下,可以达到较为满意的分割效果。分割结果轮廓平滑,分割精度高、成功率高、适应性强;而且图像分割过程人工介入少,可以用于整套CT图像骨皮质的批量分割。不足之处在于此方法神经网络训练时间相对较长。     

Using Internet search engines to obtain medical information: a comparative study

Background

The Internet has become one of the most important means to obtain health and medical information. It is often the first step in checking for basic information about a disease and its treatment. The search results are often useful to general users. Various search engines such as Google, Yahoo!, Bing, and Ask.com can play an important role in obtaining medical information for both medical professionals and lay people. However, the usability and effectiveness of various search engines for medical information have not been comprehensively compared and evaluated.

Objective

To compare major Internet search engines in their usability of obtaining medical and health information.

Methods

We applied usability testing as a software engineering technique and a standard industry practice to compare the four major search engines (Google, Yahoo!, Bing, and Ask.com) in obtaining health and medical information. For this purpose, we searched the keyword breast cancer in Google, Yahoo!, Bing, and Ask.com and saved the results of the top 200 links from each search engine. We combined nonredundant links from the four search engines and gave them to volunteer users in an alphabetical order. The volunteer users evaluated the websites and scored each website from 0 to 10 (lowest to highest) based on the usefulness of the content relevant to breast cancer. A medical expert identified six well-known websites related to breast cancer in advance as standards. We also used five keywords associated with breast cancer defined in the latest release of Systematized Nomenclature of Medicine-Clinical Terms (SNOMED CT) and analyzed their occurrence in the websites.

Results

Each search engine provided rich information related to breast cancer in the search results. All six standard websites were among the top 30 in search results of all four search engines. Google had the best search validity (in terms of whether a website could be opened), followed by Bing, Ask.com, and Yahoo!. The search results highly overlapped between the search engines, and the overlap between any two search engines was about half or more. On the other hand, each search engine emphasized various types of content differently. In terms of user satisfaction analysis, volunteer users scored Bing the highest for its usefulness, followed by Yahoo!, Google, and Ask.com.

Conclusions

Google, Yahoo!, Bing, and Ask.com are by and large effective search engines for helping lay users get health and medical information. Nevertheless, the current ranking methods have some pitfalls and there is room for improvement to help users get more accurate and useful information. We suggest that search engine users explore multiple search engines to search different types of health information and medical knowledge for their own needs and get a professional consultation if necessary.     

Acceptability and preliminary feasibility of an internet/CD-ROM-based education and decision program for early-stage prostate cancer patients: randomized pilot study

Background

Prostate cancer is the most common cancer affecting men in the United States. Management options for localized disease exist, yet an evidence-based criterion standard for treatment still has to emerge. Although 5-year survival rates approach 98%, all treatment options carry the possibility for significant side effects, such as erectile dysfunction and urinary incontinence. It is therefore recommended that patients be actively involved in the treatment decision process. We have developed an Internet/CD-ROM-based multimedia Prostate Interactive Educational System (PIES) to enhance patients’ treatment decision making. PIES virtually mirrors a health center to provide patients with information about prostate cancer and its treatment through an intuitive interface, using videos, animations, graphics, and texts.

Objectives

(1) To examine the acceptability and feasibility of the PIES intervention and to report preliminary outcomes of the program in a pilot trial among patients with a new prostate cancer diagnosis, and (2) to explore the potential impact of tailoring PIES treatment information to participants’ information-seeking styles on study outcomes.

Methods

Participants (n = 72) were patients with newly diagnosed localized prostate cancer who had not made a treatment decision. Patients were randomly assigned to 3 experimental conditions: (1) control condition (providing information through standard National Cancer Institute brochures; 26%), and PIES (2) with tailoring (43%) and (3) without tailoring to a patient’s information-seeking style (31%). Questionnaires were administrated before (t1) and immediately after the intervention (t2). Measurements include evaluation and acceptability of the PIES intervention, monitoring/blunting information-seeking style, psychological distress, and decision-related variables (eg, decisional confidence, feeling informed about prostate cancer and treatment, and treatment preference).

Results

The PIES program was well accepted by patients and did not interfere with the clinical routine. About 79% of eligible patients (72/91) completed the pre- and post-PIES intervention assessments. Patients in the PIES groups compared with those in the control condition were significantly more likely to report higher levels of confidence in their treatment choices, higher levels of helpfulness of the information they received in making a treatment decision, and that the information they received was emotionally reassuring. Patients in the PIES groups compared with those in the control condition were significantly less likely to need more information about treatment options, were less anxious about their treatment choices, and thought the information they received was clear (P < .05). Tailoring PIES information to information-seeking style was not related to decision-making variables.

Conclusions

This pilot study confirms that the implementation of PIES within a clinical practice is feasible and acceptable to patients with a recent diagnosis of prostate cancer. PIES improved key decision-making process variables and reduced the emotional impact of a difficult medical decision.     

临床学院实时课表的开发与实践

在广泛分析各类课程表优缺点的基础上,介绍了用Visual FoxPro的滑尺控件类和“wait window nowait”语句开发实时课表软件的一些做法.指出该课表软件实现了在线同一界面一次查看当天或更远时间的课表内容,具有很大的实用性.同时,对该课表软件的后续研发提出了建议.     

位相对比乳腺摄影与全数字化乳腺摄影影像质量的比较研究

目的 探讨和比较位相对比乳腺摄影(Phase-contrast Mammography,PCM)与全数字化乳腺摄影(Full Field Digital Mammography,FFDM)的影像质量.方法 选用ACR RMI-156模型,分别于PCM乳腺摄影机与FFDM乳腺摄影机拍摄,除自动曝光条件,其余选用的曝光条件...     

基底动脉尖综合征临床特点研究

目的探讨基底动脉尖综合征（TOBS）的临床表现、影像学特征、治疗及预后转归。方法回顾性分析40例TOBS患者的临床资料。结果 TOBS的临床表现多样,以眩晕、眼动及瞳孔变化多见,伴或不伴有意识障碍、偏盲、偏瘫等症状。部分患者有进展性加重,治疗以抗凝抗栓为主,预后差,病死率高。影像学特征：病灶分布于后循环支配区域,多见于丘脑、小脑、枕叶、中脑、聂叶底面。结论诊断TOBS应结合临床和影像,预后转归取决于发病后的就诊时间及病灶范围,超早期溶栓治疗应考虑为首选方案。     

Gilliatt-Sumner hand or true neurogenic thoracic outlet syndrome. A report on seven operated cases

Background and purpose

The clinical picture of hand atrophy related to a cervical rib or elongated C7 transverse process was well described in the modern literature by Gilliatt and Sumner; in 1970, they reported a series of nine patients whose motor status was stabilized following brachial plexus decompression. We report here seven patients suffering from thoracic outlet syndrome (TOS), who developed hand atrophy, sometimes because of diagnostic delay.

Methods

The patient's charts were analysed retrospectively.

Results

The seven patients were all female; the mean age was 43 years. The first complaints were arm pain and paresthesias lasting six months to 5 years. Three patients were treated with C56/C67 discectomy plus disc prosthesis (one patient), ulnar neurolysis at the elbow (the same patient), carpal tunnel release (one patient), and intravenous immunoglobulins (one patient) before TOS diagnosis. Hand atrophy, severe in five patients, was present at presentation. All patients underwent brachial plexus decompression by the anterior (four), posterior (two), or transaxillary (one) approach. This last approach was completed 18 months later by brachial plexus neurolysis via the anterior approach. Postoperatively, motor deficit was improved in two patients and stabilized in five patients.

Conclusions

Physicians’ unfamiliarity with TOS diagnosis or their reluctance to accept the diagnosis without electrical confirmation can lead to hand atrophy. Brachial plexus decompression at this stage usually stabilizes the deficit.     

Preliminary investigation of foot pressure distribution variation in men and women adults while standing

Background

Women and men are anatomically and physiologically different in a number of ways. They differ in both shape and size. These differences could potentially mean foot pressure distribution variation in men and women. The purpose of this study was to analyze standing foot pressure image to obtain the foot pressure distribution parameter – power ratio variation between men and women using image processing in frequency domain.

Methods

We examined 28 healthy adult subjects (14 men and 14 women) aged between 20 and 45 years was recruited for our study. Foot pressure distribution patterns while standing are obtained by using a PedoPowerGraph plantar pressure measurement system for foot image formation, a digital camera for image capturing, a TV tuner PC-add on card, a WinDvr software for still capture and Matlab software with dedicated image processing algorithms have been developed. Various PedoPowerGraphic parameters such as percentage medial impulse (PMI), fore foot to hind foot pressure distribution ratio (F/H), big toe to fore foot pressure distribution ratio (B/F) and power ratio (PR) were evaluated.

Results

In men, contact area was significantly larger in all regions of the foot compared with women. There were significant differences in plantar pressure distribution but there was no significant difference in F/H and B/F ratio. Mean PR value was significantly greater in men than women under the hind foot and fore foot. PMI value was greater in women than men. As compared to men, women have maximum PR variations in the mid foot. Hence there is significant difference at level p < 0.05 in medial mid foot and mid foot PR of women as compared to men.

Conclusion

There was variation in plantar pressure distribution because the contact area of the men foot was larger than that of women foot. Hence knowledge of pressure distributions variation of both feet can provide suitable guidelines to biomedical engineers and doctor for designing orthotic devices for reliving the area of excessively high pressure.     

PET-MRI的临床研究进展

多模式显像技术PET-CT和SPECT-CT已经成为临床实践和基础生物医学研究常用的检查方法,并且技术日益成熟。但PET-CT作为有效的临床基本检查工具,仍然受到许多限制,为克服这些困难,目前研究的热点集中在PET和MRI融合技术上。PET-MRI是综合了多参数功能成像和高分辨率的显像技术,尤其适用于对软组织要求较高、...     

Fusion of dynamic contrast-enhanced magnetic resonance mammography at 3.0T with X-ray mammograms: pilot study evaluation using dedicated semi-automatic registration software

Rationale and objectives

To evaluate the semi-automatic image registration accuracy of X-ray-mammography (XR-M) with high-resolution high-field (3.0 T) MR-mammography (MR-M) in an initial pilot study.

Material and methods

MR-M was acquired on a high-field clinical scanner at 3.0 T (T1-weighted 3D VIBE ± Gd). XR-M was obtained with state-of-the-art full-field digital systems. Seven patients with clearly delineable mass lesions >10 mm both in XR-M and MR-M were enrolled (exclusion criteria: previous breast surgery; surgical intervention between XR-M and MR-M).XR-M and MR-M were matched using a dedicated image-registration algorithm allowing semi-automatic non-linear deformation of MR-M based on finite-element modeling. To identify registration errors (RE) a virtual craniocaudal 2D mammogram was calculated by the software from MR-M (with and w/o Gadodiamide/Gd) and matched with corresponding XR-M. To quantify REs the geometric center of the lesions in the virtual vs. conventional mammogram were subtracted. The robustness of registration was quantified by registration of X-MRs to both MR-Ms with and w/o Gadodiamide.

Results

Image registration was performed successfully for all patients. Overall RE was 8.2 mm (1 min after Gd; confidence interval/CI: 2.0-14.4 mm, standard deviation/SD: 6.7 mm) vs. 8.9 mm (no Gd; CI: 4.0-13.9 mm, SD: 5.4 mm). The mean difference between pre- vs. post-contrast was 0.7 mm (SD: 1.9 mm).

Conclusion

Image registration of high-field 3.0 T MR-mammography with X-ray-mammography is feasible. For this study applying a high-resolution protocol at 3.0 T, the registration was robust and the overall registration error was sufficient for clinical application.