痉挛性脑瘫患儿起步过程步态特征的生物力学分析

目的:对痉挛性脑瘫患儿与正常儿童起步过程步态的生物力学参数进行分析,为痉挛性脑瘫患儿步行能力的评价提供参考。方法:采用三维运动捕捉系统和测力台,运用分析软件采集观察组28例痉挛性脑瘫患儿和对照组24例正常儿童起步过程时-空、运动学和动力学数据。时空参数包括第一步步长、第一步时间、双支撑时间、第一步步速;运动学参数包括膝、踝关节活动度;动力学参数包括向前动量和垂直轴、额状轴及矢状轴地面反力峰值。采用独立样本均数t检验比较两组各参数的差异。结果:(1)起步过程中两组时-空各参数均有显著性差异(P<0.05)。(2)起步过程中两组运动学参数支撑脚踝关节活动度有显著性差异(P<0.05)。(3)除右脚为起步脚的额状轴GRFs峰值外,起步过程中两组其余动力学参数均有显著性差异(P<0.05)。结论:起步过程的时-空各参数、支撑脚踝关节活动度、动力学各参数的分析对痉挛性脑瘫患儿步行能力的评价有一定参考价值。     

脑性瘫痪的MRI特征

目的:探讨脑性瘫痪(脑瘫)患儿的头颅MRI表现及其与脑瘫类型的关系。方法:回顾性分析81例脑瘫患儿的临床资料与MRI表现。结果:81例脑瘫患儿MRI异常率为85.2%,痉挛型双瘫、四肢瘫、偏瘫、不随意运动型脑瘫、共济失调型脑瘫、肌张力低下型脑瘫和混合型脑瘫MRI异常率分别为92.9%、100%、100%、60%、87.5%、50%和81.8%。各类型脑瘫的MRI异常表现不同,痉挛型双瘫以脑室周围白质软化(PRL)为主,偏瘫型突出表现为单侧脑损伤,四肢瘫表现为广泛、弥漫、双侧脑损伤,不随意运动型表现为基底节病变或PVL,共济失调型绝大部分存在先天性小脑发育不全。结论:MRI有助于评价各型脑瘫的病理特点,对脑瘫病因的推测有帮助。     

3.0T MR正常肾脏短期重复DWI扫描：ADC值及IVIM参数值的可重复性分析

【摘要】目的：探讨正常肾脏的ADC值及体素内不相干运动（IVIM）参数值在短期重复扫描时的可重复性。方法：对17例年轻志愿者短期内(间隔15分钟)进行2次双肾3.0T磁共振IVIM-DWI扫描。由2位测量者分别在ADC和IVIM图像上选取肾门层面测量肾皮质的ADC值和D、D*和f值。采用配对t检验（正态分布数据）或Wilcoxon检验（非正态分布数据）比较不同测量者和两次扫描获得的各参数的差异。对各参数值的测量者间一致性及两次扫描数据的可重复性采用组内相关系数（ICC）和Bland-Altman法进行评价。结果：重复扫描和两位医师重复测量获得的ADC和IVIM相关参数值的差异均无统计学意义（P＞0.05）。双侧肾脏各参数测量值的差异均无统计学意义（P＞0.05）。所有参数均表现出较好的测量者间一致性（ICC=0.703~0.973）。两次扫描时以ADC和D值的可重复性较好（ICC分别为0.756~0.866和0.779~0.876）,D*和f值的可重复性较差（ICC分别为0.274~0.700和0.499~0.664）。结论：肾脏IVIM-DWI短期重复扫描时,以ADC和D值的可重复性较好。仍需要优化IVIM扫描方案和改进后处理算法,提高D*和f值的测量可重复性。     

基于肩关节骨性关节盂后下部最大拟合圆采用径线缺损比例法评价关节盂形态的可靠性研究

目的:评估基于肩关节骨性关节盂后下部最大拟合圆的关节盂形态评价方法的可靠性,为提高临床工作及相关研究的准确性提供依据。方法:入组人群为成年人,无肩关节脱位病史,无肩关节畸形等其他可能导致关节盂形态异常的因素。共40例患者(80例关节盂)纳入本研究。入组人群因非脱位导致的肩关节不适进行包含双侧肩关节盂的CT检查。对层厚、层间距为1 mm的关节盂图像进行VR重建,旋转至En-face位。对图像采用径线缺损比例法进行评价。3位资历不同的医师基于关节盂后下部绘制拟合圆,测量并记录拟合圆的半径(R)、关节盂前缘距圆心最近点的距离(D),计算径线缺损量与拟合圆直径之比[F=(R-D)/2R*100%]。测量3次取平均值作为该测量者该次关节盂测量结果。上述测量共进行2次,测量间隔3个月以上。采用组内相关系数分析比较同一医师不同次测量及各医师间测量结果的差异,ICC值大于0.75认为可靠性良好,ICC值小于0.4认为可靠性不佳,ICC值介于0.4与0.75之间认为可靠性一般。结果:共40名患者(80个关节盂)纳入研究。采用组内相关系数分析,每名医师不同次测量中各参数ICC大于0.9,可靠性好;各医师间测量结果R、D的ICC值介于0.4至0.75之间,可靠性一般;F的ICC值小于0.2,可靠性不佳。结论:基于关节盂后下部最大拟合圆采用径线缺损比例法评价关节盂形态这一方法,同一测量者测量可重复性好,但测量者间可靠性不佳。可采用多名测量者测量并求取均值方案以保证结果的可信度。通过测量径线缺损比例的方法不能真实准确地反映关节盂缺损情况,在临床工作及研究中应谨慎使用。     

组织多普勒应变与二维应变检测左心室壁应变可靠性对比分析

目的:评价以组织多普勒技术为基础的应变(DT-ST)及以斑点追踪技术为基础的二维应变(2D-ST)测量左室壁应变的可靠性。方法:随机抽取40例作左室壁DT-ST及2D-ST分析,并选取同期40例正常人作为对照组。左室壁应变测量由2名观察者独立完成,每名观察者对每例患者用组织多普勒应变及二维应变析各测量2次。同一名观察者测量2次间及2名观察者间测量差异用重复检测方差分析比较,一致性用组里相关系数(ICC)描述,2名观察者间测量可靠性用Cronbach’s alpha系数描述。结果:①除观察者甲冠心病组的室间隔心尖段DT-ST 2次测量结果、观察者间对照组的左室侧壁中间段、心尖段DT-ST及观察者间冠心病组左室侧壁基底段及心尖段DT-ST测量结果差异有统计学意义外(P值均<0.05),余观察者内及观察者间各节段重复测量结果之间均无显著差异;②观察者内可靠性:对照组2D-STICC与DT-STICC相近,或略大于DT-STICC;而冠心病组除观察者乙室间隔中间段ICC外,余各节段2D-ST ICC均大于DT-STICC;③观察者间可靠性:冠心病组及对照组左室壁各节段2D-ST的Cronbach’s alpha系数均大于DT-ST Cron-bach’s alpha系数。结论:组织多普勒应变及二维应变检测室壁应变均具有较高可靠性,但二维应变法具有更高的观察者间可靠性。     

脑瘫儿认知功能损害的3T多模态脑功能MR成像

目的:探索BOLD及DKI磁共振功能成像技术在认知功能损害脑瘫儿的应用。方法:选取伴有认知功能障碍脑瘫患儿(CP组)52例及正常小儿(CG组)50例,使用PhilipsIngenia3.0T多模态磁共振功能成像技术,在静息状态下行高分辨T1WI、BOLD及可行性DKI扫描,采集统计及分析MR功能数据。结果:CP组与CG组比较:①BOLD成像ALFF值:左丘脑、左壳核、左楔前回及右角回、右扣带回后部的ALFF值升高(P <0.05)。②ReHo值:左额上回、左岛叶皮质、左枕回、右额中回、右颞上回Reho值降低(P<0.05);左额叶白质、左顶下小叶、左丘脑、右额叶白质、右扣带回Reho值升高(P <0.05)。③DKI成像MK值:CP组双额叶、双顶叶、双枕叶MK值均低于CG组(P <0.05)。结论:RS-fMRI为无创性敏感研究认知功能障碍脑瘫儿脑灰白质功能、微观结构及病损的重要影像学方法。     

基于步态触觉参数的青少年运动能耗估算公式的建立

目的:建立基于步态触觉参数的青少年体力活动估算公式,为能耗评估方法和青少年健康促进的研究提供参考。方法:11～14岁青少年为受试者,测量其身体基本数据(身高、体重、腿长、体脂率)后,穿着课题组自主研发的数字化跑鞋在可变速跑台上,分别以3、4、5、6、7、8 km/h的速度进行走或跑步运动,同时采用K4b2心肺功能测试仪采集数据,测定运动能量消耗。根据数字化跑鞋采集的运动足底压力和加速度信号参数测算步频,推算步频值与运动能量消耗的关联,再综合个体参数,采用多元逐步回归建立运动能耗代谢公式,最后将公式带入事先抽出、未参与建模的数据进行验证。结果:(1)步频值和单位体重运动能耗的代谢率的皮尔森指数为0.86,有显著性差异;两者之间线性拟合与二次曲线拟合的R2值均约为0.73。(2)通过多元逐步回归得到了基于青少年运动步频和身体参数的单位体重运动能耗代谢率的估算公式:AEE=1.913×SF-2.079×BMI+10.755×Sex-4.211×Age-42.312(R2=0.75),其中,AEE:每公斤体重每分钟运动消耗的能量,单位为cal/min/kg;SF:步频,单位为steps/min;BMI单位为kg/m2;Sex:性别,男生=1,女生=0;Age:年龄,单位为周岁。通过验证,该公式准确度为83%。结论:基于生物力学步态触觉参数得到的步频值和身体参数可较准确地估测初中阶段青少年的运动能量代谢量,并得到运动代谢计算公式,采用步态触觉参数评估能耗代谢有良好的应用发展前景。     

实性孤立性肺结节CT影像组学参数测量的可重复性研究

【摘要】目的：探讨实性孤立性肺结节（SPN）两种兴趣区（ROI）画取方式获得的影像组学参数的一致性,并对良、恶性结节两组间的参数进行比较。方法：回顾性分析49例SPN患者的术前CT资料,由两位高年资主治医生在Imagej软件上进行图像处理及参数测量,其中一位测量者间隔12个月重复测试一次。方案一：（半）自动化全局法,使用Ostu阈值二值化图像,区域生长法获得结节边界,分割效果不佳者辅以手工修剪边缘。方案二：结节中心画取,在结节内部选取圆形ROI。测量一致性采用组内相关系数（ICC）进行分析。选择ICC均＞0.6的参数,取两位测量者首次测量的平均值用于统计学分析。结果：方案一中测量一致性均很好的参数有11个,ICC范围分别为0.810～0.998（不同观察者间）和0.804～0.997（同一观察者内）。方案二中测量一致性均很好的参数有4个,ICC范围为0.820～0.954（不同观察者间）和0.950～0.960（同一观察者内）。两方案灰度共生矩阵（GLCM）参数中,相关性参数的测量一致性均最低,ICC介于0.721～0.843。良性组与恶性组SPN进行比较,方案一中的结节短径、平均径、圆度、角二阶矩及熵在两组中差异均有统计学意义（P＜0.05）。结论：（半）自动化分割SPN获取的影像组学参数的可重复性较高,并能为良、恶性结节的鉴别诊断提供客观、稳定的信息。     

肺癌短期重复扫描ADC值和IVIM参数值的测量可重复性

目的:前瞻性评估肺癌短期重复扫描的ADC值及体素内不相干运动(IVIM)参数值的测量可重复性.方法:27个肺癌患者(27个病灶)进行2次自由呼吸DWI(b=0,300,800 s/mm2)及IVIM(10个b值,b=0～1000 s/mm2)扫描(间隔30～60min).2名独立测量者分别在ADC图、IVIM图上通过勾勒病灶获得ADC均值和D、D*、f值.采用配对样本t检验(正态分布)或Wilcoxon检验(非正态分布)比较重复测量、不同测量者和重复扫描的误差.各参数值的测量者内可重复性、测量者间一致性以及两次扫描的测量可重复性采用组内相关系数(ICC)、组间变异系数(WCV)和Bland-Altman法评价.结果:重复测量和重复扫描所得ADC均值、IVIM参数值差异均无统计学意义(P＞0.05).所有参数显示出好的测量者内可重复性和测量者间一致性,除了D*(WCV＞30％).重复扫描D值的可重复性最佳(ICC为0.905、0.883,WCV为7.63％、8.46％),ADC值的可重复性较好(ICC为0.829、0.823,WCV为10.65％、11.13％),而D*和f的可重复性相对较差(ICC为0.639～0.802;WCV为39.50％～58.14％).结论:当运用DWI或IVIM来监测肺癌疗效时,若ADC值、D、D*和f值的变化分别小于21.81％、16.58％、113.95％和84.77％,则很可能是由测量误差引起.需要改进IVIM扫描技术和后处理算法,提高D*和f的测量可重复性.     

非卧床性脑瘫病人脊椎滑脱的发病率

作者在Boston儿童医院连续进行了50例非卧床性脑瘫病人脊椎滑脱的预测性研究。除3例曾经做过手术的病例外,其余47例中,21例为痉挛性四肢瘫痪;15例为痉挛性偏瘫;11例为痉挛性双瘫。47例中22例女性,25例男性,平均年龄为16.8岁(7～30岁)。每例特别注意询问背痛问题,所有病例均有完整的矫形外科体检资料。屈曲性髋挛缩应用修改的Thomas试验进行临床测量。全部病例均拍摄腰椎站立前后位片。测量骶股角方法为:侧位片骶骨上面与股骨干轴线之夹角。正常人站立位骶股角为50°～65°,伴有脊椎滑脱者应用Meyerding方法测量。     

Gait asymmetries in children with cerebral palsy: do they deteriorate with running?

In children with cerebral palsy (CP) analysis of gait asymmetry can provide insight into the control of walking and may help in guiding the clinician's treatment decisions. Running is more difficult that walking for the musculoskeletal system, however, in the literature it has been shown that gait deviations associated with CP maybe better tolerated during running. This leads us to the hypothesis that running might increase gait symmetry in patients with CP. Therefore the purpose of this study was to investigate the effect of running on asymmetries in spatio-temporal, kinematic and kinetic gait parameters for children with CP. Twenty-four children with diplegia and 25 with hemiplegia were examined using 3D gait analysis during running and walking. MANOVA on two factors: diagnosis (hemiplegic, diplegic) and movement (walking, running) was conducted on a total of 22 gait parameters. The MANOVA revealed a significant difference in symmetry between walking and running (p<0.001) and between patients groups (p=0.004). The detailed analysis of gait parameters demonstrated a significant decrease of symmetry in 13 of the 22 gait parameters investigated, only symmetry of step time was significantly increased. Therefore the hypothesis that gait symmetry improved with running in children with CP can be rejected. Based on the results of this study, asymmetries masked during walking might appear during running. Therefore, analysis of asymmetry of walking and running gives a more comprehensive assessment of the gait pathology for clinical decision making.     

The characteristics of sit-to-stand transfer in young children with spastic cerebral palsy based on kinematic and kinetic data

The aim of this study is to investigate the kinetic and kinematic characteristics of sit-to-stand transfer in children with spastic cerebral palsy (CP) in comparison with normal children. Fifteen spastic diplegic children, 12 spastic hemiplegic children and 21 normally developed children participated in this study. The sit-to-stand task was evaluated using a Motion analyzer (Vicon 370 MA with six infrared cameras). The consistent pattern of sit-to-stand transfer and six transitional points were identified in normal children. The motion analysis of sit-to-stand in children with CP showed slowness in the task, increased anterior pelvic tilting, and hip flexion during the task. An early abrupt knee extension was noted in diplegic children, as compared with normal controls. Decreased maximal knee extensor moment and decreased extensor power generation of the hip and knee joints were the major kinetic characteristics of the involved limbs of both diplegic and hemiplegic CP.     

Single-session reliability of discrete gait parameters in ambulatory children with cerebral palsy based on GMFCS level

The single-session reliability of 28 discrete spatiotemporal and kinematic variables was evaluated from computerized gait analysis (CGA) in 33 ambulatory children with cerebral palsy (CP), subcategorized according to Gross Motor Function Classification System (GMFCS) Levels I (n = 11), II (n = 12) and III (n = 10). Nineteen boys and 14 girls participated, mean age = 8 years 1 month (S.D. = 3 years 0 month). Intraclass correlation coefficients (ICCs) estimated reliability, and the number of strides required to obtain an ICC of at least 0.90 was determined. The reliability of discrete gait parameters was dependent upon GMFCS level, with children in GMFCS Level I exhibiting the highest reliability (ICC range = 0.70–0.96). GMFCS Levels II and III had lower levels of reliability with ICC values varying from 0.54 to 0.95 and 0.45 to 0.98, respectively. With the exclusion of pelvis range of motion (ROM), an average of four strides provided a reliability estimate of at least 0.90 for GMFCS Level I, while six strides were needed for children in Levels II and III. On the basis of the intrasession reliability results from the present study, further work is recommended to examine the test–retest reliability of these gait parameters in children with CP.     

Determination of gait patterns in children with spastic diplegic cerebral palsy using principal components

This study developed an objective graphical classification method of spastic diplegic cerebral palsy (CP) gait patterns based on principal component analysis (PCA). Gait analyses of 20 healthy and 20 spastic diplegic CP children were examined to define gait characteristics. PCA was used to reduce the dimensionality of 27 parameters (26 selected kinematics variables and age of the children) for the 40 subjects in order to identify the dominant variability in the data. Fuzzy C-mean cluster analysis was performed plotting the first three principal components, which accounted for 61% of the total variability. Results indicated that only the healthy children formed a distinct cluster; however it was possible to recognise gait patterns in overlapping clusters in children with spastic diplegia. This study demonstrates that it is possible to quantitatively classify gait types in CP using PCA. Graphical classification of gait types could assist in clinical evaluation of the children and serve as a validation of clinical reports as well as aid treatment planning.     

Leg lengthening as part of gait improvement surgery in cerebral palsy: an evaluation using gait analysis

Eleven children with hemiplegic or an asymmetric diplegic cerebral palsy who had a preoperative leg length discrepancy of more than 2.5 cm underwent gait improvement surgery which included leg length equalisation. Sagittal plane kinematics and kinetics before and about 3 years after surgery for the lengthened limb and contralateral limb were evaluated. Preoperatively the unaffected limb had excessive stance phase flexion at the hip and knee, and dorsal flexion at the ankle joint. These changes could be partially reversed to produce a kinematic gait pattern comparable to age matched normal controls on the uninvolved side after equalisation of leg length.     

Gait initiation in children with cerebral palsy

The task of gait initiation (GI), or taking a first step from a static standing position requires the development of forward momentum while maintaining dynamic balance as the body's center of mass (COM) moves forward and outside the base of support. The dynamics of GI in children (aged 7-12 years) with hemiplegic cerebral palsy (CP), diplegic CP and children with typical development (TD) were compared to characterize the mechanics and control of this task. Ground reaction forces (GRFs) and muscle activity were collected during GI at three different self-selected speeds (slow, moderate and fast). Movement of a sacral marker was also tracked to estimate downward shifting of the body during the GI task. Results demonstrate the presence of a motor sequence characterized by increased forward momentum development with increased GI speed for all groups of children. Anticipatory movements of children with CP were different when compared to children with TD. Children with hemiplegic CP demonstrated decreased lateral shifting while children with diplegic CP demonstrated a trend of decreased downward shifting of the body compared to children of TD. Analysis of the GI motor sequence in children provides a means to characterize coordination and motor control of a functional ambulatory task in children with CP compared to children with TD.     

Hip deformities in walking patients with cerebral palsy

Hip deformities in walking patients with cerebral palsy are rare. Nineteen diplegic and four hemiplegic patients with unilateral hip subluxation were studied to determine whether or not characteristic gait patterns could be identified. All were examined clinically and radiologically as well as undergoing observational and instrumented three dimensional gait analysis. Twenty one of the patients compensated for the subluxation with an ipsilateral trunk lean and contralateral pelvic drop. These patterns were quantified in the kinematic and kinetic variables measured. We conclude that hip abductor weakness should be considered as the cause of the deformity.     

Test-retest reliability of spatial and temporal gait parameters in children with cerebral palsy as measured by an electronic walkway

PURPOSE: The purpose of this study was to examine test-retest reliability of seven selected temporal and spatial gait parameters and asymmetry measures in children with cerebral palsy. METHOD: Seventeen children with CP between 3 and 13 years of age walked at three different speeds across an electronic walkway of 5.2m. The tests were repeated after approximately 25 min. The scores were normalized to a walking speed of 1.1m/s to avoid the confounding effect of gait speed on speed dependent gait parameters. Intraclass correlation coefficients (ICC(1,1) and ICC(3,1)) with 95% confidence intervals, within-subject standard deviation (S(w)) and smallest detectable difference (SDD) were calculated. RESULTS: The relative reliability of cadence, step length, stride length and single stance time was high to excellent (ICC(1,1) between 0.73 and 0.95), while it was poor for step width (ICC(1,1)=0.27 and 0.35). The relative reliability for two calculated asymmetry measures were high for the step length index (ICC(1,1)=0.82) and moderate for the single stance time index (ICC(1,1)=0.49). The absolute reliability values for all gait parameters are reported. CONCLUSIONS: Five of seven gait parameters measured by an electronic walkway and normalized to a common walking speed, appear to be highly repeatable in a short-term time span in children with CP who were able to walk without assistive walking devices, provided sufficient cognitive function.     

Validation of a visual gait assessment scale for children with hemiplegic cerebral palsy

This study reports the experience of reliability testing and validation of a visual assessment of gait based on the Physician Rating Scale in children with hemiplegic cerebral palsy. Comparison with three-dimensional gait analysis showed excellent correlation between observers and full gait analysis for sagittal plane motion at the knee in stance. Inter and intra-rater reliability showed moderate to almost perfect agreement for foot contact characteristics and ankle in stance. Use of this scale may be helpful in assessment of children where frequent analysis of these characteristics is needed.