Robust 3-D/2-D registration of CT and MR to X-ray images based on gradient reconstruction

Objective  A novel 3-D/2-D registration method based on matching 3-D pre-interventional image gradients and coarsely reconstructed 3-D gradients from intra-interventional 2-D images is presented. Material and methods  The novel method establishes correspondences between two sets of gradients by searching for correspondences along normals to anatomical structures in 3-D images, while the final correspondences are established in an iterative process, combining the robust random sample consensus algorithm (RANSAC) and a special gradient matching criterion function. The proposed method was evaluated by the publicly available standardized evaluation methodology for 3-D/2-D registration, consisting of 3-D rotational X-ray, computed tomography (CT), magnetic resonance (MR), and 2-D X-ray images of two spine segments, and evaluation criteria. Results  Preliminary results show significant improve- ment in robustness (capture range and success rate) over three well established intensity-based, gradient-based, and reconstruction-based methods. Conclusion  The 3-D/2-D gradient reconstruction-based registration method efficiently combines the advantages of gradient and reconstruction-based methods, thereby enabling robust registration of CT and MR to only two X-ray images, while keeping the computational demands low.     

The impact of registration accuracy on imaging validation study design: A novel statistical power calculation

Novel imaging modalities are pushing the boundaries of what is possible in medical imaging, but their signal properties are not always well understood. The evaluation of these novel imaging modalities is critical to achieving their research and clinical potential.Image registration of novel modalities to accepted reference standard modalities is an important part of characterizing the modalities and elucidating the effect of underlying focal disease on the imaging signal. The strengths of the conclusions drawn from these analyses are limited by statistical power. Based on the observation that in this context, statistical power depends in part on uncertainty arising from registration error, we derive a power calculation formula relating registration error, number of subjects, and the minimum detectable difference between normal and pathologic regions on imaging, for an imaging validation study design that accommodates signal correlations within image regions.Monte Carlo simulations were used to evaluate the derived models and test the strength of their assumptions, showing that the model yielded predictions of the power, the number of subjects, and the minimum detectable difference of simulated experiments accurate to within a maximum error of 1% when the assumptions of the derivation were met, and characterizing sensitivities of the model to violations of the assumptions. The use of these formulae is illustrated through a calculation of the number of subjects required for a case study, modeled closely after a prostate cancer imaging validation study currently taking place at our institution.The power calculation formulae address three central questions in the design of imaging validation studies: (1) What is the maximum acceptable registration error? (2) How many subjects are needed? (3) What is the minimum detectable difference between normal and pathologic image regions?     

SharpMean: groupwise registration guided by sharp mean image and tree-based registration

Groupwise registration has become more and more popular due to its attractiveness for unbiased analysis of population data. One of the most popular approaches for groupwise registration is to iteratively calculate the group mean image and then register all subject images towards the latest estimated group mean image. However, its performance might be undermined by the fuzzy mean image estimated in the very beginning of groupwise registration procedure, because all subject images are far from being well-aligned at that moment. In this paper, we first point out the significance of always keeping the group mean image sharp and clear throughout the entire groupwise registration procedure, which is intuitively important but has not been explored in the literature yet. To achieve this, we resort to developing the robust mean-image estimator by the adaptive weighting strategy, where the weights are adaptive across not only the individual subject images but also all spatial locations in the image domain. On the other hand, we notice that some subjects might have large anatomical variations from the group mean image, which challenges most of the state-of-the-art registration algorithms. To ensure good registration results in each iteration, we explore the manifold of subject images and build a minimal spanning tree (MST) with the group mean image as the root of the MST. Therefore, each subject image is only registered to its parent node often with similar shapes, and its overall transformation to the group mean image space is obtained by concatenating all deformations along the paths connecting itself to the root of the MST (the group mean image). As a result, all the subjects will be well aligned to the group mean image adaptively. Our method has been evaluated in both real and simulated datasets. In all experiments, our method outperforms the conventional algorithm which generally produces a fuzzy group mean image throughout the entire groupwise registration.     

Towards image guided robotic surgery: multi-arm tracking through hybrid localization

Objective  Use of the robotic assisted surgery has been increasing in recent years, due both the continuous increase in the number of applications and the clinical benefits that surgical robots can provide. Currently robotic assisted surgery relies on endoscopic video for navigation, providing only surface visualization, thus limiting subsurface vision. To be able to visualize and identify subsurface information, techniques in image-guidance can be used. As part of designing an image guidance system, all arms of the robot need to be co-localized in a common coordinate system. Methods  In order to track multiple arms in a common coordinate space, intrinsic and extrinsic tracking methods can be used. First, the intrinsic tracking of the daVinci, specifically of the setup joints is analyzed. Because of the inadequacy of the setup joints for co-localization a hybrid tracking method is designed and implemented to mitigate the inaccuracy of the setup joints. Different both optical and magnetic tracking methods are examined for setup joint localization. Results  The hybrid localization method improved the localization accuracy of the setup joints. The inter-arm accuracy in hybrid localization was improved to 3.02 mm. This inter-arm error value was shown to be further reduced when the arms are co-registered, thus reducing common error.     

Non-rigid multi-frame registration of cell nuclei in live cell fluorescence microscopy image data

The analysis of the motion of subcellular particles in live cell microscopy images is essential for understanding biological processes within cells. For accurate quantification of the particle motion, compensation of the motion and deformation of the cell nucleus is required. We introduce a non-rigid multi-frame registration approach for live cell fluorescence microscopy image data. Compared to existing approaches using pairwise registration, our approach exploits information from multiple consecutive images simultaneously to improve the registration accuracy. We present three intensity-based variants of the multi-frame registration approach and we investigate two different temporal weighting schemes. The approach has been successfully applied to synthetic and live cell microscopy image sequences, and an experimental comparison with non-rigid pairwise registration has been carried out.     

超声与磁共振融合虚拟导航技术在乳腺病变定位中的初步研究

目的探讨超声融合磁共振成像（MRI）虚拟导航技术对仅MRI发现的乳腺病变定位的临床价值。 方法选取2016年6月至2018年12月于浙江大学医学院附属杭州市第一人民医院就诊的21例患者,均行超声及乳腺MRI检查,MRI发现22个超声上未显示的病灶且乳腺影像报告与数据系统（BI-RADS）评估为4类及以上,在俯卧位下行超声与MRI融合虚拟导航下定位,分别对病灶进行穿刺活检或定位后手术切除,与病理结果相对照,以及MRI术前/后对比,统计病变检出率,并分析此类病变的MRI特征及病理类型。 结果22个病灶中共计20个在虚拟导航下完成定位,检出率为91%。术后病理显示18个（90%）为良性病变,2个（10%）为恶性病变。22个病变中,MRI显示20个（91%）为非肿块样强化,仅2个（9%）为肿块型强化。 结论超声融合MRI虚拟导航可以有效提高超声隐匿性乳腺病变的检出率,通过超声引导下穿刺活检具有实时、便捷等特点,可在临床推广应用。     

Revised Acute Physiology and Chronic Health Evaluation score as a predictor of neurosurgery intensive care unit readmission: A case-controlled study

Purpose

Patients with neurologic system problems are among the most common patients readmitted to the intensive care unit (ICU). Readmission predictors for neurologic ICU patients have not been established. Previous research suggests that the Revised Acute Physiology and Chronic Health Evaluation (APACHE II) score is one indication of the critical status of ICU-admitted patients; however, the ability of the discharge APACHE II to predict readmission to the ICU requires further study. The purpose of this study was to investigate the ability of the APACHE II scoring system to predict ICU readmission of neurosurgical and ICU patients.

Materials and Methods

A retrospective case-controlled comparison study and a review of patient records for all patients admitted to 8 ICUs from January 2003 to June 2005 (N = 753) were conducted. Readmitted neurosurgery ICU patients were matched with 58 randomly selected nonreadmitted patients.

Results

Nine variables were significantly different between the readmission and case-controlled group. The APACHE II discharge score was the only significant predictor and was able to predict 18.6% of neurologic ICU readmissions. The risk of ICU readmission increased when the APACHE II score at the time of discharge exceeded 8.5 points.

Conclusions

The risk of ICU readmission of neurologic ICU patients can be predicted by determining APACHE II score upon ICU discharge.     

A hybrid method to improve target registration accuracy in surgical navigation

Background: The accuracy of surgical navigation depends greatly on that of registration between the patient and the medical image. Point-based registration has been the most common and reliable method, which typically uses skin markers. Unfortunately, high registration accuracy around the markers is not sustained at targets deeply seated within the body. To address such increase in target registration error (TRE), we proposed a hybrid point-based registration method that incorporates anatomical landmarks near the target. Material and methods: Ultrasound calibration is performed with an optical tracker for coordinate frame conversion of image coordinates into the real world. With the calibrated ultrasound probe, we could non-invasively obtain landmark positions near the target, being used together with skin markers for registration. Results: In the experiment, we examined registration accuracies achieved with and without use of an anatomical landmark. We confirmed that using an additional anatomical landmark in registration resulted in an increase in fiducial regsitration error (FRE), but a significant decrease in TRE (p < 0.001). Conclusion: We proposed and demonstrated the effectiveness of a hybrid method that uses both artificial and anatomical landmarks for patient-to-image registration. The experimental results confirmed that an improvement in TRE was evident by the proposed method, suggesting its feasibility in various spinal surgeries.     

加温输液在神经外科手术中对脑代谢影响的观察

目的:探讨加温(37°C)输液在神经外科手术中应用的意义。方法:将60例行开颅肿瘤切除术患者随机分为非加温输液组与加温输液组各30例,分别于全身麻醉诱导后、术中1 h、术中2 h、术中3 h、手术结束即刻测定颈内静脉球部及桡动脉血乳酸含量。结果:两组患者颈内静脉部血乳酸(VL)、动静脉血乳酸差值(ADVL)于术中2 h至术后即刻统计学差异有显著性(P<0.05);两组患者ADVL随手术时间推移而增大,且非加温输液组高于同期加温输液组。结论:围手术期患者应用加温液体输液通过人体正常代谢调节,可保障脑组织的有氧代谢,减少并发症的发生。     

Narcotrend监测用于神经外科开颅手术的临床观察

目的:探讨Narcotrend系统在神经外科开颅手术患者中应用的可行性和安全性。方法:择期开颅脑肿瘤切除患者50例,随机分入A组(Narcotrend监测组)和B组(临床组),每组25例。术中分别根据NI值及临床体征和临床经验调整丙泊酚和雷米芬太尼用量。两组分别记录不同时点的丙泊酚效应室浓度(Ceo Prop)、HR、MAP,A组再记录Narcotrend Index(NI)值;记录苏醒时间和听从指令时间、不良反应及术后并发症。结果:NI值随着丙泊酚效应室浓度的增加而降低,呈负相关。两组患者麻醉恢复情况差异有统计学意义,A组呼之睁眼和听从指令时间明显缩短。A组术后恶心呕吐发生率明显降低,差异有统计学意义。结论:NI值随着丙泊酚效应室浓度增加而下降,呈负相关,能较好地反映麻醉深度变化;Narcotrend用于神经外科肿瘤切除手术,有利于对麻醉深度的调控,促进患者术后的尽早复苏,降低术后恶心、呕吐等不良反应的发生率。     

临床路径在神经外科护理进修带教中的应用

目的：探讨临床路径在神经外科护理进修带教中的应用效果。方法选择2009年3月-2010年12月进修的护士36人为对照组,2011年3月-2012年12月进修的护士36人为观察组。对照组采取传统教学法带教,观察组应用临床路径法带教。进修时间为3个月,于每月末分别给予相关的理论和操作考试,测评进修护士每个阶段学习质量,并于进修结束时测评进修护士对教学满意度。结果观察组进修护士理论知识、护理操作、综合素质能力评分分别为（93．51±177;4．61）,（93．46±177;2．94）,（91．57±177;3．71）分,对照组分别为（91．07±177;3．88）,（91．29±177;2．87）,（88．44±177;4．28）分,两组比较差异均有统计学意义（t值分别为2．435,3．173,3．319;P＜0．05）。观察组进修护士对教学的满意度为100．00％（36/36）,对照组为83．33％（30/36）,两组比较差异有统计学意义（P＜0．05）。结论临床教学路径能提高临床教学质量,调动带教教师和进修护士的主动性和积极性,提高进修护士对教学的满意度。     

乳腺区域淋巴结的超声定位显像及临床应用

目的研究超声定位显像乳腺区域淋巴结的可行性,并与术中直视下淋巴结定位结果进行对比。方法对1例乳腺癌伴腋窝淋巴结转移接受改良根治术的患者行术中超声检查,对比超声切面定位和直视下腋窝淋巴结定位(外科定位),确定腋窝淋巴结分组的超声切面标志。然后对50例乳腺癌患者行术前乳腺区域淋巴结常规超声分组(腋下、中、上)定位,与手术中淋巴结清扫结果进行对比,研究超声定位显像淋巴结的可靠性和标准切面。结果常规超声锁骨下横切面可以清楚的显示并区分胸大肌、胸小肌、腋血管3个重要分组定位解剖结构,可以对腋窝淋巴结进行分组定位。胸骨旁纵切面可以清晰显示内乳动脉长轴和肋间软组织,可以定位内乳淋巴结,与术中所见淋巴结部位均存在极好的关联性(P0.01)。结论常规超声检查可以对乳腺区域淋巴结进行准确分组定位。     

神经外科护理危机成因分析与防范策略

目的分析神经外科护理危机事件的成因,提出防范策略,规避护理风险,保证护理安全。方法对主动上报的38例神经外科危机事件进行分析,寻找构成原因。结果因疾病及护理人员因素造成的危机事件各占事件总数的31．59％,患者因素占事件总数的23．68％,环境及药物因素分别占事件总数的5．26％和7．89％。结论神经外科护理危机事件是由多重原因造成的,需要通过预警评估、提高可视度、动态人力调配、维护环境安全、注重培训、物品规范化管理等一系列护理防范措施,达到控制神经外科护理危机事件发生的目的。     

联合刚性和B样条弹性配准的超声弹性成像

目的 设计一种基于图像数据的超声弹性成像方法.方法 联合刚性和B样条弹性配准方法对压缩前后的超声图像进行运动估计.首先进行全局的刚性配准,然后进行局部弹性配准,进而得出组织的运动位移,对纵向位移进行微分,求出组织的纵向应变.结果通过对一实测超声体模数据进行估计,获得了准确的应变信息.结论联合刚性和B样条弹性配准方法可以...     

门诊挂号过程中存在的问题分析与对策

目的：提高挂号窗口服务质量,满足患者就诊需要,从而提高挂号质量。方法：通过抽取门诊患者满意度调查表和意见投诉本中客观反映的挂号过程中存在的问题,就存在的问题进行分析并提出相应的对策。结果：缩短了患者的排队时间,提高了分诊准确率;提高了挂号成功率;减少了纠纷与投诉的发生,患者满意度调查达到95%以上。结论：挂号质量和工作效率的提高,有利于建立良好的医患关系,对于增强医院的核心竞争力起到了重要的作用。     

脑外科护士心理健康状况调查与分析

目的：调查脑外科护士心理健康状况，分析其心理健康问题的影响因素。方法：采用症状自评量表（SCL-90）分别对38名脑外科护士和38名内科护士进行测评。结果：脑外科护士SCL-90各因子平均分均明显高于内科护士和中国常模，组间比较差异有统计学意义（均P〈0．05）；内科护士除了抑郁、焦虑两个因子分明显高于中国常模以外（P〈0．05），其余SCL-90因子分与中国常模比较差异均无统计学意义（P均〉0．05）。结论：脑外科护士心理健康问题既比内科护士严重，又比一般人群更加突出，应针对脑外科护士的职业特点，开展多种形式的心理健康教育，以消除职业环境的不良影响。     

优质护理服务在神经外科中的实践及评价

目的:探讨优质护理服务在神经外科中应用,并客观评价优质护理服务的实践效果。方法:2010年对我院神经外科进行优质护理服务模式试行,调查实施优质护理服务一年后患者的满意度情况,正确评价优质护理服务在神经外科护理工作中的实施效果。结果:患者总满意率为99.34%。结论:优质护理服务是提高护理工作水平、加强服务意识的重要保障,可有效提升患者满意度。     

神经外科护理专业实习生学习手册的设计与使用

为提高神经外科临床教学质量,该文介绍了神经外科实习生学习手册的设计与使用方法.该手册为表格式,分为4部分,阶段式学习任务与考核内容解决了神经外科学习内容多而复杂的难题,师生互评表和师生互动平台实现了互动教学和按需教学,实习生档案为教学和科研积累了宝贵的资料.该手册得到了带教教师和实习生的共同肯定,提高了实习生的学习效率.     

神经外科标准化质控管理的应用及效果

目的探讨病区一级质控实施标准化管理的具体做法与实施效果,寻求严谨的护理质控方法,提高护理质量,确保护理安全。方法组建病区一级质控小组,制定规范的质量检查方法及检查频率,建立合理的监管机制,以层级管理的模式进行周查、月查,并进行总结、反馈、追踪,对质量检查实行环节控制。结果通过对比发现,三级质控结果与一级质控结果呈反比关系,标准化管理模式下护士缺陷及时修改率提高至59．60％,与2009年统计结果33．65％比较,差异具有统计学意义（x2=5．35,P〈0．05）。处罚后完成率降至Oi55％,与2009年统计结果11．22％比较,差异具有统计学意义（x2=53．49,P〈0．05）。结论一级质控标准化管理模式是一种无缝隙管理模式,有利于提高护理人员的管理能力,促进护理工作质量持续改进,确保护理安全。     

神经外科ICU患者身体约束分级管理方案的构建及应用

目的 构建神经外科ICU患者身体约束分级管理方案并探讨其应用效果.方法 组建研究团队并进行文献检索及相关问题讨论,制订神经外科ICU患者身体约束分级管理方案.采用便利抽样法,选择2019年4月-9月北京市某三级甲等医院神经外科ICU收治的患者304例,按入院时间将其分为试验组156例和对照组148例.试验组采用身体约束...