目的:运用过程能力分析方法对CT设备长期稳定性进行分析.方法:依据国家标准《X射线计算机断层摄影装置质量保证检测规范》(GB17589-2011),利用Minitab 17.0软件对3台CT设备(CT-1、CT-2和CT-3)的长期稳定性进行过程能力分析,检测项目包括水的CT值、均匀性、噪声、CT值线性、低对比度分辨力、CT剂量指数(CTDIw)和重建层厚偏差.采用时间序列图对空间分辨力进行分析.结果:所有检测项目的测量值均符合GB17589-2011标准限值要求;大部分检测项目的长期质量控制过程处于Ⅱ级及以上水平,且过程性能指数(Pp)≥1.33;重建层厚偏差(s≤2 mm)的过程能力处于Ⅲ级及以下水平(Pp<1.33);CT-3的长期稳定性优于CT-2.结论:通过过程能力分析,可以客观地判断CT性能的长期稳定性情况.对于每台CT设备,通过定期执行稳定性检测,并利用过程能力分析检测结果的变化情况,可以判断其维护保养是否到位,更好的保障设备性能和诊疗质量.

目的:探索新型冠状病毒肺炎(COVID-19)疫情防控常态化管理期间网络教学的应用前景,保证临床医学教学效果.方法:通过远程网络平台—腾讯视频,采用云查房、专题讲座、技能培训以及基于案例的学习(CBL)方法进行在线授课;自行设计教师教学评价调查问卷,利用远程平台问卷星系统,调查回收2020年2-8月医院急诊科实习学生的395份调查问卷,并对问卷内容进行分析,评价教师远程网络教学情况.结果:问卷中教师教学效果的20个问题具有较高的内在一致性,评价结果具有较好的可信度,Cronbach'sα=0.945;多元Logistic回归寻找影响学生满意度的主要因素有授课准时、教师教学水平、对授课重点进行总结复习、理论联系实际、因材施教、教学授课量适中和中英文结合7个因素;通过百分制对教师测评,受试者工作特征(ROC)曲线提示其最佳预测截点91,灵敏度为89.5％,特异度为70.1％,阳性预测值为90.19％,阴性预测值为68.49％.结论:COVID-19防控常态化管理期间,应用远程网络平台进行网络教学可以帮助学生建立临床思维,提高学生的主观能动性,对非常时期临床实习有一定的弥补作用.

Objective: To explore the construction of medical radiation protection curriculum system in clinical teaching of biomedical engineering undergraduate, and put forward the knowledge points, teaching mode and method of radiation protection education. Methods: According to the relevant national laws and regulations, to analyze the problems existing in the teaching of radiation protection for biomedical engineering undergraduate and the harm caused by improper radiological protection in medical practice. Combining with the protection features of X ray diagnostics, interventional radiology, radiation therapy and nuclear medicine, to extract the main points of knowledge of radiation protection teaching for biomedical engineering undergraduates and then create the curriculum system, besides, add radiation protection teaching content in this curriculum system. Results: According to the characteristics of the different application of ionizing radiation and the work of Biomedical engineering graduates in hospitals, awareness rate of radiation protection for students and practitioners increased from 34.88%-51.38% to 87.55%-91.63% and the annual average effective dose of occupational exposure for radiologic staffs reduced from (0.98±0.08)mSv to (0.53±0.09)mSv after relevant training. Conclusion: Strengthening the radiation protection course for undergraduate majoring in biomedical engineering is an important part of clinical teaching knowledge system. It is great significance that students masters the basic knowledge of radiation protection and apply protective measures in medical treatment, teaching and scientific research, so as to avoid unnecessary ionizing radiation.

Objective: A three-dimensional energy distribution over the whole brain will be displayed by analyzing the brain magnetic data, so as to reflect the neurological activity of the brain accurately. Methods:The brain magnetic signal was processed with wavelet function to get frequency domain data. The energy information is mapped to the corresponding sensors’ position. In order to show the energy distribution, the author interpolated between sensors, created three-dimensional patches. For the purpose of validating, MEG data from a finger exercise testing subject was analyzed. Moreover, data of particular frequency was discussed also. Results: What it shows is consistent with description on event related synchronization. Actually the movements activated contralateral primary motor cortex (MI), bilateral supplementary motor area (SMA). Conclusion:Because of reflecting neurological activity accurately, it is said this method provides a valuable reference to analyze brain activity and locate neural activity.

Objective:To offer guarantee for clinical operation through Quality Control(QC) of medical equipments.Methods:QC is introduced into the full life circle of medical equipments and enforced in the process of equipment argumentation,acquisition,acceptance,application,maintenance,preventative maintenance,measurement and abandonment.Results:Under the efficient quality control,the failure rate has been reduced during the equipment usage.The security,accuracy and validity of the clinical examination are guaranteed.Conclusion:QC in the full life circle of medical equipments provides safe and effective examination/treatment for patients,as well as effectively reduces the risk of adverse events.

Lots of studies implicate that pathological high-frequency oscillation(HFO) was associated with epilepsy.In recent years,new recording technologies have advanced such that,at high temporal and spatial resolutions,high-frequency oscillation can be recorded in partial epilepsy by intracranial electrodes.More and more researchers focus on the study of high frequency oscillation.The techniques,which were used to record,automatic mine,analysis and quantify high-frequency oscillation,are develop quickly.As a new biomarker of epilepsy,high-frequency oscillation can reflect the epileptic form activity.The HFO has a great value in localization of human epileptic brain and epilepsy surgery.

Objective:To discuss the performance of different methods in multi-modal image registration for subdural electrode localization.Methods:Mean Squares and the Mattes Mutual Information metric methods were employed to align the post-implantation CT volume and the pre-implantation MR volume.Results:Both methods performed well in the determination of the rotation center.Rotation angles of different image pairs of the same volume pair fluctuated a lot.The mean rotation angles of images within one data set are approximate to the manual results that are considered to be the actual result for registration despite their fluctuation range.Conclusion:The average value of the registration results of the images sampled to implement the process could be used to align the whole volume pair and get a relatively good match.

Objective To accurately locate the intracranial electrode with the application of multimodal medical image registration after intracranial electrode embedding.Methods The intracranial electrode was accurately located in the magnetic resonance imaging(MRI) images by registration of MRI images before electrode embedding with CT images after electrode embedding and insight segmentation and registration toolkit(ITK),and established the relationship between electrode location and brain anatomy.Results Ten pairs of slice images were used to evaluate the efficacy of the method and the data from the difference images after registration showed a good match,while the evaluation given by experts showed that the accuracy of image fusion was clinically acceptable.Conclusion It is demonstrated that multimode image registration is useful to localize the intracranial electrodes,providing physicians with a more intuitive and complete information.

目的:通过对配备RFID标签的标准体模进行核磁成像,评估RFID标签在高磁场下应用的安全性.方法:基于标准的Magphan体模,通过在不同距离放置不同封装类型的13.56M无源RFID标签,对体模在1.5T核磁下成像,从两方面进行RFID在高磁场下应用安全性的验证:一方面对获取的MR图像,测量图像的信号、噪声水平、均匀度、高对比度分辨率和几何失真度,量化评价RFID标签对MR成像质量是否存在影响；另一方面对经过扫描试验的RFID标签进行读识别,检查高磁场是否影响标签的正常工作.结果:临近成像区域的RFID标签对图像信号和噪声水平的影响与未放置RFID标签及远离成像区域的影响有显著差异(P＜0.05).目测可以看出临近成像区域的RFID标签对对附近的组织产生伪影.RFID标签在1.5T的磁场中放置一小时左右,不影响RFID标签的可识别性.结论:13.56M无源RFID标签作为患者标识,在1.5T磁场下持续使用对自身安全正确使用没有影响,但是其可能影响核磁成像的信号及噪声水平.

目的:验证重心频率能否有效量化癫痫患者脑磁图中的高频振荡成分.方法:选择1例典型颞叶癫痫患者的脑磁图数据,采用短时傅里叶变换进行分解,用重心频率对高频振荡进行量化,并计算平均重心频率,比较左、右颞的重心频率差异.结果:在静息状态下,患侧的梯度计采集到的MEG信号在80～ 250 Hz范围内即时重心频率和平均重心频率都比健侧高.结论:采用重心频率能够有效的量化信号的高频振荡,同时能够有效的区分出健侧和患侧信号之间的高频振荡差异.

The moment technique is an effective method for image feature description and is widely used in various fields of image processing. Zernike moments are one kind of continuous orthogonal moments. They can be used to describe the global shape features of the image. The most significant property of Zernike moments is rotation-invariance. Any high order Zernike moments can be constructed. And image reconstruction from Zernike moments can be easily achieved. Zernike moments have the minimum information redundancy and are robust and insensitive to noise. In medical image processing, Zernike moments are mainly used in edge detection and image registration. Literature survey shows that sub-pixel level edge position can be achieved based on Zernike moments and the algorithms have high noise immunity. The registration merit functions based on Zernike moments reduce the degrees of freedom needed to be optimized, and the number of iteration necessary for registration can be significantly reduced. Algorithms with Zernike moments as feature point descriptor show good registration results in the presence of image scale and rotation.

Objective To improve the three-dimensional(3D) visualization effect of magnetic source image(MSI).Methods The MRI volume was segmented and the segment result of gray matter was 3D reconstructed using visualization Toolkit(VTK) functions.Based on 3 landmark points(left ear former nest,right ear former nest and nasion) defined before magnetoencephalography(MEG) test,the information of dipoles exported from the source analysis software was visualized in 3D render window after coordinate transformation.Results The abnormal discharge sources,important functional brain areas as well as the spatial relationship with neighbor tissues were rendered on 3D image.Conclusion It is demonstrated that the 3D rendering effect of MSI could provide more intuitive and better information for doctors.

Objective:To evaluate the validity of the time-frequency analysis based on Morlet wavelet transform used for event-related MEG.Methods:According to the basic principle of Morlet wavelet transform and character of time-frequency analysis base on Morlet wavelet transform,the MEG data was processed.The time-frequency energy distribution and phase-locked factor were used to present the MEG data.Results:The phase-locked energy and non phase-locked energy power could be extracted effectively.Conclusion:The time-frequency analysis base on Morlet wavelet transform is powerful and the interest information in MEG can be obtained easily.

Objective：Collecting the electric signal of spinal cord in the process of surgery curing brachial plexus avulsion pain patients and analyzeing it to guide the surgery.Methods：The data were analyzed with wave transform.The results were described using time-frequency analysis method.Results：Comparing with uninjured side and affected side after surgeries,the signal of affected side before surgery had difference in 20 Hz range.It had a higher energy.Conclusion：Surgery can be guided by measuring and anglicizing electric signal of spinal cord.

据统计,我国癫(癎)的患病率为7‰[1],目前约有900万名癫(癎)患者.癫(癎)死亡率和猝死发生率均较高,且有40%的患者出现行为、精神及认知功能的损害,失去升学和就业的机会,给家庭和社会增加了严重的负担. 目前国内外对于癫(癎)的治疗以药物治疗为主,随着经典抗癫(癎)药物的合理应用以及新药的不断涌现,70%的癫(癎)患者能够满意地控制发作,但约50%的患者出现明显的药物副作用而影响生活质量;30%的患者对各种药物均不敏感.虽然外科手术治疗的有效率已达60%～90%,但仍有50%的药物难治性癫(癎)患者,因癫(癎)灶难以精确定位或处于重要功能区,手术的高风险及价格昂贵等因素而不适合手术治疗[2].所以亟待开发出一些新的有效、安全、简便的治疗措施,为难治性癫(癎)的治疗开拓新的方向.

Objective To discuss a method for extracting ectocinerea from brain magnetic resonance imaging(MRI) image.Methods Threshold segmentation was used to preprocess the MRI images.The seed point was artificial selected.An 18-neighborhood three-dimensional(3D) region growing algorithm was used to extract ectocinerea from MRI;Finally,an erosion and dilation algorithm was applied to make up for the shortage of region growing.Results Five sets of MRI images were used,and achieved satisfactory ectocinerea images.The ectocinerea images were 3D reconstructed by means of surface rendering algorithm provided by VTK,and the high-quality cerebral cortex images were obtained.Conclusion It is demonstrated that the method can obtain satisfactory extraction of ectocinerea.

难治性癫痫的手术有时需要通过植入颅内电极进行脑电检测来确定致痫灶,为了准确定位致痫灶,医生需要知道电极的位置,但目前缺乏有效的电极定位方法.本文开发了一种利用植入电极后CT 图像序列进行电极定位的方法.首先使用面绘制三维重建出电极序列图像,并对各个电极进行识别和标识,然后将面绘制重建的颅骨图像叠加到电极图像上,建立电极的位置信息与人体解剖结构的联系,最后实现颅内电极定位.经过对10套植入电极后的CT图像进行定位检测,证实基于CT图像三维重建的电极定位方法与目前已有的定位方法比较具有明显优势.

Realizes the 3D reconstruction of several medical image datasets based on MITK. Studies two types of rendering methods, surface rendering and volume rendering, in which the marching cubes algorithm is used for surface rendering and the ray casting volume rendering methods are used for volume rendering. And compares their characteristics of two rendering methods. The results of the study on 3D reconstruction for medical images show that MITK as a reconstruction and medical imaging process tool,it has powerful function and it is very easy to be used for medical image processing and 3D reconstruction.