咀嚼肌表面电极肌电图重复性检验和参考值的建立

目的:对成年人咀嚼肌表面电极采集的肌电信号加以分析,研究下颌在6种不同运动状态下咀嚼肌肌电信号的可重复性,并取得正常参考值。方法:30名22-44岁受试者进行咀嚼肌表面电极肌电图检查,记录下颌姿势位、牙尖交错位和扣齿运动时双侧咬肌、颞肌前束和二腹肌前腹的肌电活动,每个受试者在3个不同时段各测试一次。结果:3次测试的咀嚼肌峰值电位之间无统计学差异(P>0.05)。下颌姿势位时,右侧咬肌峰值电位95%正常参考值为0-0.1,左侧为0-0.13,右侧颞肌前束为0-0.67,左侧颞肌前束为0-0.1,右侧二腹肌前腹为0-0.13,左侧二腹肌前腹为0-0.1;牙尖交错位时,右侧咬肌峰值电位95%正常参考值为0.33-2.53,左侧为0.47-2.5,右侧颞肌前束为0.23-2.23,左侧颞肌前束为0.2-3.67,右侧二腹肌前腹为0.13-1.07,左侧二腹肌前腹为0.1-0.87;扣齿运动时右侧咬肌峰值电位95%正常参考值为0.5-2.5,左侧为0.73-2.3,右侧颞肌前束为0.4-3.47,左侧颞肌前束为0.3-3.63,右侧二腹肌前腹为0.2-1.07,左侧二腹肌前腹为0.13-0.97。结论:表面电极采集的双侧咬肌、颞肌前束和二腹肌前腹的肌电活动具有一定的可重复性。     

Improved spectral resolution and high reliability of in vivo 1H MRS at 7 T allow the characterization of the effect of acute exercise on carnosine in skeletal muscle

The aims of this study were to observe the behavior of carnosine peaks in human soleus (SOL) and gastrocnemius (GM) muscles following acute exercise, to determine the relaxation times and to assess the repeatability of carnosine quantification by ¹H MRS at 7 T. Relaxation constants in GM and SOL were measured by a stimulated echo acquisition mode (STEAM) localization sequence. For T₁ measurement, an inversion recovery sequence was used. The repeatability of the measurement and the absolute quantification of carnosine were determined in both muscles in five healthy volunteers. For absolute quantification, an internal water reference signal was used. The effect of acute exercise on carnosine levels and resonance lines was tested in eight recreational runners/cyclists. The defined carnosine measurement protocol was applied three times – before and twice after (approximately 20 and 40 min) a 1‐h submaximal street run and additional toe‐hopping. The measured T₁ relaxation times for the C2‐H carnosine peak at 7 T were 2002 ± 94 and 1997 ± 259 ms for GM and SOL, respectively, and the T₂ times were 95.8 ± 9.4 and 81.0 ± 21.8 ms for GM and SOL, respectively. The coefficient of variation of the carnosine quantification measurement was 9.1% for GM and 6.3% for SOL, showing high repeatability, and the intraclass correlation coefficients (ICCs) of 0.93 for GM and 0.98 for SOL indicate the high reliability of the measurement. Acute exercise did not change the concentration of carnosine in the muscle, but affected the shape of the resonance lines, in terms of the shifting and splitting into doublets. Carnosine measurement by ¹H MRS at 7 T in skeletal muscle exhibits high repeatability and reliability. The observed effects of acute exercise were more prominent in GM, probably as a result of the larger portion of glycolytic fibers in this muscle and the more pronounced exercise‐induced change in pH. Our results support the application of the MRS‐based assessment of carnosine for pH measurement in muscle compartments. © 2015 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd.     

多层螺旋 CT 肺动脉造影对急性肺栓塞右心功能相关参数的可重复性研究

目的：评价不同观察者间及同一观察者在不同时间对肺栓塞患者CT相关右心功能参数定量测量的可重复性。方法回顾性分析行多层螺旋CT肺动脉成像且影像质量良好的肺栓塞患者50例,对肺动脉栓塞患者CT有关右心室的相关参数进行定量评价,包括：室间隔位置、腔静脉回流、轴位及四腔层面右、左心室内径比（ RVD／LVD）、四腔心层面右、左心室截面积比（ RVA／LVA）。统计分析使用kappa统计、Pearson等级相关系数和Bland-Alt-man分析。结果同一观察者前、后2次测量室间隔位置（κ＝0 X．754）及腔静脉返流（κ＝0．865）一致性较好。 Pearson分析前、后2次测量 RVD-ax／LVD-ax、RVD-4ch／LVD-4ch、RVA／LVA间相关系数分别为0．959、0．932、0．987（ P ＝0．000）。不同观察者测量室间隔位置（κ＝0．384）及腔静脉返流（κ＝0．503）一致性尚可。 Pearson 分析二人测量RVD-ax／LVD-ax、RVD-4ch／LVD-4ch、RVA／LVA间相关系数分别为0．556、0．652、0．793（ P ＝0．000）。结论同一观察者对急性肺栓塞患者右心功能参数的重复测量一致性较好;而不同观察者间测量结果存在较大差异。采用左、右室截面积比是诊断肺动脉栓塞右心室功能较客观的指标。     

Comparison axial length measurements from three biometric instruments in high myopia

AIM: To compare the axial lengths (ALs) measured with Lenstar, IOLMaster and A-scan contact ultrasound (Ultrasound) in normal and high myopia (HM). METHODS: Eighty-four normal eyes and 49 HM eyes were included. Three consecutive measurements were performed on each eye in the following order: Lenstar, IOLMaster, and Ultrasound. The repeatabilities of the AL measurements for each instrument were assessed by calculating the pooled coefficients of variation (CVs) of 18 eyes in each group. Comparisons between the HM and normal groups were made with independent sample t-tests. The inter-device agreements were evaluated with Bland-Altman analyses and paired two-tailed t-tests. RESULTS: For normal group, the CVs of the AL measurements taken with the Lenstar, IOLMaster and Ultrasound were 0.001%, 0.01% and 0.14%, respectively. The corresponding CVs for the HM group were 0.005%, 0.02% and 0.15%, respectively. There was significant difference between the Lenstar and the IOLMaster in normal group (P=0.031) but not in HM group (P=0.100). In the two groups, the Lenstar and the IOLMaster produced higher values than did the Ultrasound (all P<0.001). All three instruments exhibited good agreement in terms of AL values. For the intraocular lens (IOL) power calculation using SRK II formula, the Lenstar and the IOLMaster showed 0.5 D higher than Ultrasound in both groups (all P<0.001). No significant difference existed between the Lenstar and the IOLMaster for the IOL power calculation in both normal (P=0.474) and HM group (P=0.103). CONCLUSION: The three devices exhibited excellent intra-visit repeatabilities in the AL measurements. The AL and IOL power difference between partial coherence interferometry and ultrasound instruments should be noticed.     

Optic Nerve Head Parameters Measured with Spectral-Domain Optical Coherence Tomography in Healthy Turkish Children: Normal Values,Repeatability, and Interocular Symmetry

To determine normal values, repeatability, and interocular symmetry of optic nerve head measurements, three spectral-domain optical coherence tomography (SD-OCT) scans were obtained from 128 healthy Turkish children aged 5–17 years consecutively and prospectively. The mean disc area, rim area, cup volume, cup to disc area ratio, and vertical and horizontal cup to disc ratios were 2.30 ± 0.42 mm², 1.84 ± 0.45 mm², 0.09 ± 0.10 mm³, 0.20 ± 0.13, 0.37 ± 0.17, and 0.45 ± 0.20, respectively. The intraclass correlation coefficients were >0.9 for repeatability and >0.75 for interocular correlation. Interocular differences were not statistically significant (p > 0.05). Normal paediatric SD-OCT measurements of the optic nerve head are presented, which showed excellent repeatability and no interocular difference.     

眼睑压力测量仪的初步临床应用

目的 采用新型眼睑压力测量仪对正常人和蒸发过强型干眼患者进行上眼睑压力测量,并分析眼睑压力的影响因素。设计 前瞻性病例系列。研究对象 北京同仁医院干眼患者62例,平均年龄（48.31±3.42）岁;正常人对照42例,平均年龄（45.72±5.33）岁。均将右眼纳入研究。方法 设计新型眼睑压力测量仪,测量正常人和蒸发过强型干眼患者的上眼睑压力及干眼指标,分析眼睑压力的影响因素。每位受试者测量3次,观察仪器的准确性和重复性。随访受试者的症状和体征,观察仪器的安全性。主要指标 上眼睑压力。结果 正常受试者和干眼患者的上眼睑压力值分别为（0.40±0.13）牛顿（N）和（0.55±0.21）N（t=2.561,P=0.026）;每位受试者测量3次,每组结果之间的差异无统计学意义（t=1.22,P>0.05）;所有受试者测量后均未出现眼部异常。正常受试者上眼睑压力与年龄呈负相关（r=-0.372,P=0.02）。干眼患者上眼睑压力与BUT、SchirmerⅠ之间呈明显负相关（r=-0.262、-0.235,P<0.05）,与角膜染色评分之间未见明显相关（r=0.205,P=0.063）。结论 新型眼睑压力测量仪可安全、有效地检测上眼睑压力。随着年龄的增长,正常人上眼睑施于眼球的压力逐渐下降。与正常人相比,干眼患者眼睑压力升高。 眼睑压力与眼表上皮细胞病变之间的关系尚待进一步研究。     

可视化角膜生物力学分析仪测量青少年儿童中央角膜厚度的重复性及与扫频光源OCT的一致性分析

目的：评估可视化角膜生物力学分析仪（Corvis ST）测量青少年儿童中央角膜厚度（CCT）的重复性,并与前节CASIA SS-1000光学相干断层扫描仪（OCT）测量结果进行一致性分析。方法：系列病例研究。纳入2015年1-4月来温州医科大学附属眼视光医院进行视光检查的儿童44名,年龄8～14岁,除近视外无其他眼部疾病,先采用Corvis ST测量CCT,再采用SS-1000 OCT进行测量。仅分析右眼数据。组内相关系数（ICC）、Bland-Altman及重复测量方差分析用于评估Corvis ST测量CCT的重复性,配对t检验及Bland-Altman用于评估Corvis ST与SS-1000 OCT测量的一致性。结果：Corvis ST重复3次测量CCT的ICC为0.987,3次测量之间一致性界限分别是-15.6～16.2 μm、-15.7～13.4 μm、-16.0～13.1 μm。重复测量方差分析显示3次测量的差异无统计学意义。CorvisST与SS-1000 OCT测量CCT的均值分别为（553±28）μm和（540±28）μm,其中Corvis ST测得的CCT值比SS-1000 OCT厚13 μm,差异有统计学意义（t=-6.037,P<0.001）。2种仪器测量CCT的95%一致性界限为-15.2～41.6 μm。结论：Corvis ST测量儿童CCT具有很好的重复性,与SS-1000 OCT一致性较好,但是在临床工作中,还应考虑到其测量值的差异,不可直接替代。     

18F-FDG PET/CT代谢的可重复性研究进展

18F-脱氧葡萄糖(18F-FDG)PET／CT在恶性肿瘤的早期诊断、临床分期、疗效评价、监测复发及肿瘤放疗靶区定位中具有重要价值。为了使PET/CT能够更准确地进行恶性肿瘤的疗效评价,18F-FDG PET／CT代谢的可重复性研究显得尤为重要。本文就传统临床代谢参数值标准化摄取值（SUV）、代谢活性肿瘤体积（MATV）、总病灶糖酵解（TLG）、肿瘤与肝脏比率（TLR）、肿瘤与血液比率(SUR)及近年新兴的PET图像纹理分析等方面的可重复性研究进行概述。     

Reproducibility of liver stiffness measurements in hepatitis C virus (HCV)-infected patients in Egypt

Summary. Elastometry has demonstrated good accuracy, but little is known about its reproducibility. The aim of this study was to assess the intra‐ and inter‐operator reproducibility of liver stiffness measurement among hepatitis C virus (HCV)‐infected patients in Egypt. The study was conducted among HCV‐infected patients referred for treatment evaluation in two hepatitis treatment centres of Cairo. Two operators took liver stiffness measurement two times per patient the same day. Intra‐ and inter‐reproducibility were estimated by different methods: Bland and Altman graphics, variation coefficient, intraclass correlation coefficient and Kappa coefficient; 7.1 kPa was used as the threshold of significant (≥F2) fibrosis whenever needed. Fifty‐eight patients were included in the study, and 216 measurements were taken. Failure rate was 7% and associated with overweight. For a value of 7.1 kPa, the inter‐operator 95% limits of agreement were estimated at ±2.88 kPa. Intra‐ and inter‐operator coefficients of variation ranged between 11% and 15%, intraclass correlation coefficients [95% confidence interval] between 0.94 [0.86–0.97] and 0.97 [0.95–0.99], and Kappa coefficients between 0.65 [0.44–0.88] and 0.92 [0.81–1.00]. The reliability of liver stiffness measurement is questionable when considering the decision to initiate antiviral therapy because of the percentage of discordance between measurements is notable, especially in the intermediate fibrosis stages.