实时剪切波超声弹性成像技术评估肌肉减少症患者骨骼肌弹性模量的研究

摘 要 目的 研究肌肉减少症患者股四头肌、腘绳肌和肱二头肌长轴剪切波速度（SWV）值特征,探讨实时剪切波超声弹性成像技术（SWE）评估肌肉减少症患者肌肉状态的应用价值。方法 选择22例肌肉减少症患者（病变组）和21例同期年龄、性别匹配的健康体检者（对照组）,应用剪切波超声弹性成像技术,获取病变组和对照组优势侧的股四头肌4块肌肉［股外侧肌（VL）,股直肌（RF）,股内侧肌（VM）和股中间肌（VI）］,腘绳肌3块肌肉［股二头肌（BF）,半腱肌（ST）和半膜肌（SM）］和肱二头肌（BB）松弛状态下长轴SWV值,并进行对比分析。结果 松弛状态下病变组与对照组的VL、RF、VM、VI、BF、ST、SM和BB肌肉的SWV数值差异有显著统计学意义(均P＜0.001)。松弛状态下病变组与对照组比较,VL、RF、VM、VI、BF、ST、SM和BB肌肉的SWV数值分别降低7.8%、7.0%、7.3%、7.3%、7.1%、7.3%、6.5%和6.7%。与对照组比较,病变组SM长轴的SWV值降低最小,VL长轴的SWV值降低最为显著。年龄和BMI指数均为老年人骨骼肌弹性模量的影响因素。结论 实时剪切波超声弹性成像技术可检测肌肉减少症患者较大骨骼肌弹性差异,为评估肌肉减少症患者肌肉状态提供了一种新的检测方法。     

健康人群四肢近端肌肉剪切波弹性成像测量的初步研究

目的测量健康人群四肢近端肌肉剪切波速度,分析与其相关的因素。 方法选取2019年1月至2020年12月在四川大学华西医院招募的健康志愿者88例,记录受检者的性别、年龄、体质量指数（BMI）及运动习惯。测量不同肌肉（三角肌、肱二头肌、股直肌、股外侧肌）左右两侧及相同肌肉不同断面、不同位置及不同体位的剪切波速度,并对不同性别、年龄、BMI及运动状态的肌肉剪切波速度进行比较。随机抽取20例受试者,计算三角肌及股直肌剪切波速度测量的观察者间及观察者内一致性。 结果各肌肉纵断面剪切波速度左、右两侧比较,差异无统计学意义（P均＞0.05）。各肌肉剪切波速度纵断面均大于横断面（P均＜0.05）。肱二头肌伸直位纵断面,其剪切波速度肌腹外侧大于肌腹内侧（P均＜0.05）。肱二头肌剪切波速度伸直位均大于屈曲位（P均＜0.05）。三角肌、肱二头肌剪切波速度男性高于女性（P均＜0.05）。股外侧肌剪切波速度18~49岁组高于50~70岁组（P＜0.05）。肱二头肌剪切波速度BMI＜18.5 kg/m²组及18.5 kg/m²≤BMI＜24 kg/m²组均高于BMI≥24 kg/m²组,差异均有统计学意义（P均＜0.05）。三角肌剪切波速度规律运动者高于少运动者,差异有统计学意义（P＜0.05）。三角肌及股直肌的剪切波速度观察者内及观察者间一致性均为良好或优秀（ICC均＞0.88）。 结论剪切波弹性成像（SWE）能够用于定量测量健康人群肌肉的硬度值,肌肉的断面和部位及受检者的体位、性别、年龄、BMI和运动习惯为与其相关的因素,研究结果为特发性炎性肌病的进一步研究提供了依据。     

A profile of reference data for shear modulus for lower limb muscles in typically developing children

BackgroundShear wave elastography can measure shear wave speed in muscles, which is used to estimate shear modulus. Normative values and standardized methodology are needed for children. Study aims were to: estimate shear modulus behavior of lower limb muscles of typically developing children; and establish a profile of reference data and recommendations for clinical assessment.MethodsForty-one typically developing children (mean 9.7 y, SD 1.9 y) completed assessment of resting shear modulus of rectus femoris, biceps femoris, gastrocnemius lateralis and tibialis anterior at short and long lengths using shear wave elastography. Effects of muscle length, age, sex and BMI were examined. Then, our data and data from a scoping review for typical individuals were collated according to Net-Longitudinal Tension Angle (net proximal and distal joint angles).FindingsShear modulus was: higher at long versus short muscle lengths for all four muscles (P < 0.001); correlated with increasing age for tibialis anterior at short (r = 0.39) and long lengths (r = 0.42) (both P = 0.01); but not related to sex or BMI. Shear modulus: tended to increase with increasing Net-Longitudinal Tension Angle for 18 lower limb muscles; and was higher for children than adults for some muscles (e.g. tibialis anterior and gastrocnemius lateralis, both P < 0.001).InterpretationIn typically developing children, shear modulus of lower limb muscles increases with increasing Net-Longitudinal Tension Angle. Recommendations enable comparison of values across different test positions and populations. Some relation between shear modulus and age was identified, but more research is needed.     

实时剪切波弹性成像评价腰椎间盘突出症患者腓肠肌弹性

目的 探讨实时剪切波弹性成像评价腰椎间盘突出症患者腓肠肌弹性的价值。方法 选取临床确诊为单侧腰椎间盘突出症且接受侧隐窝入路选择性神经根阻滞联合臭氧消融术及脉冲射频治疗的患者100例,采用实时剪切波弹性成像技术检测治疗前后紧张状态下双侧小腿腓肠肌的平均（EMean）及最大（EMax）弹性模量值（kPa）,并进行统计分析。结果 治疗前患侧紧张状态腓肠肌EMean为（11.28±2.60）kPa,EMax为（15.26±2.63）kPa,均较健侧减低（t=78.241、64.634,P均<0.001）。治疗后患侧紧张状态腓肠肌EMean为（13.18±2.38）kPa,EMax为（17.63±2.73）kPa,均较治疗前增高（t=6.407、14.815,P均<0.001）。不同肌力状态下,治疗前和治疗后紧张状态腓肠肌的EMean、EMax值差异均有统计学意义（P均<0.001）。治疗前及治疗后当肌力增加时,紧张状态腓肠肌EMean、EMax值亦增加,不同肌力间两两比较差异均有统计学意义（P均<0.05）。结论 通过实时剪切波弹性成像技术检测腰椎间盘突出患者治疗前后紧张状态下腓肠肌的EMean和EMax,可定量分析肌肉组织恢复情况。     

A Method for Characterization of Tissue Elastic Properties Combining Ultrasonic Computed Tomography With Elastography

Objective. The correlation between various diseases and the change in the local mechanical properties of soft tissues has been long known. Over the past 20 years, there have been increasing research efforts to characterize mechanical properties of biological tissues using ultrasonic elastography. However, most of these works were based on characterization of only 1 type of waves (longitudinal or shear). The goal of this work was to devise a comprehensive ultrasound‐based imaging method capable of measuring elastic parameters by combining both backscattered elastography and through‐transmitted ultrasonic computed tomography. Methods. Our suggested technique provides measurements of both longitudinal and shear wave velocities. This enables the noninvasive computation of several tissue elasticity parameters such as Young's and shear moduli, Poisson's ratio, and, more importantly, the bulk modulus, the determination of which requires both wave velocities. Four different phantom types were examined: agar‐gelatin–based phantoms and porcine fat tissue, turkey breast tissue, and bovine liver tissue in vitro specimens. The values of Young's modulus, the shear modulus, and Poisson's ratio were estimated and were consistent with values published in the literature. Results. The average bulk modulus values of the phantoms ± SD were 2.83 ± 0.001, 2.25 ± 0.01, 2.48 ± 0.01, and 2.53 ± 0.02 GPa, respectively. A statistically significant difference (P < .001) in the values of the bulk modulus of the different phantoms was found. Conclusions. The bulk modulus is suitable for differentiation between different tissue types. The obtained results show the feasibility of using a comprehensive ultrasonic imaging technique for noninvasive quantitative tissue characterization.     

Quantitative Assessment of Healthy Skin Elasticity: Reliability and Feasibility of Shear Wave Elastography

The goal of this study was to investigate the reliability and feasibility of shear wave elastography by assessing the elasticity of the healthy skin of 40 volunteers. Young's moduli for bilateral fingers, forearms, anterior chest (sternum), and anterior abdomen were determined with both transverse and longitudinal sectional measurements. Reliability of measurements was evaluated using intra- and inter-class correlation coefficients with two observers. Our results revealed that the elastic modulus values of the skin between symmetric parts of fingers and forearms did not statistically different. No differences were found between the transverse and longitudinal sections of forearms, anterior chest, and abdomen (p > 0.05), except for middle fingers (p = 0.004). Inter-observer and intra-observer repeatability (inter- and intra-class correlation coefficients) varied from moderate to excellent depending on the skin site (0.62–0.91). In conclusion, shear wave elastography reached a good consistency in measuring healthy skin elasticity. Further studies are needed to provide more information on the factors that influence the reliability of shear wave elastography measurements in both healthy and diseased skin.     

剪切波弹性成像评价乳腺癌新辅助化疗的疗效

目的 探讨剪切波弹性成像技术在评价乳腺癌新辅助化疗(NAC)疗效中的价值。方法 对49例(NAC)患者在化疗前后均进行剪切波弹性成像。记录并将化疗前肿瘤的二维超声及弹性成像指标与实体瘤治疗疗效评价标准指标(RECIST指标)进行单因素及多因素回归分析。结果 化疗前后剪切波弹性模量的最大值、平均值、最小值、比值差异均有统计学意义(P均<0.05)。单因素分析显示年龄、边缘、肿块化疗前后大小差值、化疗前弹性模量参数(最大值、平均值、最小值)均与实体瘤治疗疗效评价标准评价指标有相关性(P均<0.05)。多因素分析显示年龄、边缘、肿块化疗前后大小差值、化疗前最大值与RECIST评价指标有相关性(P均<0.05)。结论 采用剪切波弹性成像技术可以反映乳腺肿块化疗前后的变化,化疗前肿块弹性成像的最大值可用于预测浸润性导管癌NAC效果。     

2型糖尿病患者骨骼肌厚度和弹性变化及其影响因素

目的 观察2型糖尿病患者骨骼肌厚度和弹性变化及其影响因素。方法 前瞻性招募62例2型糖尿病患者（T2DM组）及60名健康成年人（HC组）,以剪切波弹性成像（SWE）技术检测其放松及收缩状态下腹直肌和腓肠肌最大杨氏模量（E_max）,比较组间2种状态下骨骼肌厚度及弹性模量,并采用多重线性回归分析影响腹直肌和腓肠肌弹性模量的因素。结果 组间放松及收缩状态下腹直肌和腓肠肌厚度差异均无统计学意义（P均>0.05）;T2DM组放松及收缩状态下腹直肌及腓肠肌E_max均低于HC组（P均<0.05）。多重线性回归分析显示,T2DM组放松及收缩状态下腹直肌及腓肠肌弹性模量均随病程、空腹血糖（FBG）及糖化血红蛋白（HbA1c）而呈线性降低（P均<0.05）。结论 2型糖尿病患者骨骼肌弹性模量降低,且随病程、FBG及HbA1c而呈线性下降。     

探头扫查平面与肌纤维走行方向夹角对剪切波传播速度的影响

目的 探讨探头扫查平面与肱二头肌肌纤维走行方向夹角对剪切波传播速度的影响。方法 随机选取健康志愿者20名。采用实时剪切波弹性成像技术, 探头方向与肌纤维方向夹角分别为0°、30°、60°、90°,测量距体表深度1.7 cm、2.5 cm处同一位点的剪切波传播速度,并进行统计学分析。结果 深度为1.7 cm和2.5 cm,剪切波传播方向与肌纤维夹角为0°、30°、60°、90°时,剪切波传播速度差异均有统计学意义(P均<0.05)。分别取剪切波方向与人体肌纤维排列的夹角为0°、30°、60°、90°时,不同深度剪切波传播速度差异无统计学意义(P均>0.05)。结论 探头扫查平面与肌纤维走行方向夹角影响剪切波的传播速度,深度相同时,随着剪切波传播方向与人体肌纤维排列方向夹角增大,剪切波速度有递减趋势。传播方向一致时,剪切波在人体肱二头肌中的传播速度与深度无明显关系。     

Supersonic shear imaging provides a reliable measurement of resting muscle shear elastic modulus

The aim of the present study was to assess the reliability of shear elastic modulus measurements performed using supersonic shear imaging (SSI) in nine resting muscles (i.e. gastrocnemius medialis, tibialis anterior, vastus lateralis, rectus femoris, triceps brachii, biceps brachii, brachioradialis, adductor pollicis obliquus and abductor digiti minimi) of different architectures and typologies. Thirty healthy subjects were randomly assigned to the intra-session reliability (n = 20), inter-day reliability (n = 21) and the inter-observer reliability (n = 16) experiments. Muscle shear elastic modulus ranged from 2.99 (gastrocnemius medialis) to 4.50 kPa (adductor digiti minimi and tibialis anterior). On the whole, very good reliability was observed, with a coefficient of variation (CV) ranging from 4.6% to 8%, except for the inter-operator reliability of adductor pollicis obliquus (CV = 11.5%). The intraclass correlation coefficients were good (0.871 ± 0.045 for the intra-session reliability, 0.815 ± 0.065 for the inter-day reliability and 0.709 ± 0.141 for the inter-observer reliability). Both the reliability and the ease of use of SSI make it a potentially interesting technique that would be of benefit to fundamental, applied and clinical research projects that need an accurate assessment of muscle mechanical properties.     

Muscle Ultrasound Changes Correlate With Functional Impairment in Spinal Muscular Atrophy

ObjectiveWe investigated ultrasound patterns of muscle involvement in different types of spinal muscular atrophy (SMA) and their correlation with functional status to determine the pattern of muscle compromise in patients with SMA and the potential role of ultrasound to evaluate disease progression.MethodsWe examined muscles (biceps brachii, rectus femoris, diaphragm, intercostals and thoracic multifidus) of 41 patients with SMA (types 1 to 4) and 46 healthy age- and sex-matched control individuals using B-mode ultrasound for gray-scale analysis (GSA), area (biceps brachii and rectus femoris) and diaphragm thickening ratio. Functional scales were applied to patients only. We analyzed ultrasound abnormalities in specific clinical subtypes and correlated findings with functional status.ResultsCompared with controls, patients had reduced muscle area and increased mean GSA for all muscles (p < 0.001), with an established correlation between the increase in GSA and the severity of SMA for biceps brachii, rectus femoris and intercostals (p = 0.03, 0.01 and 0.004 respectively) when using the Hammersmith Functional Motor Scale Expanded. Diaphragm thickening ratio was normal in the majority of patients, and intercostal muscles had higher GSA than diaphragm in relation to the controls.ConclusionUltrasound is useful for quantifying muscular changes in SMA and correlates with functional status. Diaphragm thickening ratio can be normal even with severe compromise of respiratory muscles in quantitative analysis, and intercostal muscles were more affected than diaphragm.     

Shear wave elastography potential to characterize spastic muscles in stroke survivors: Literature review

BackgroundPost-stroke spasticity contributes to impairments, disabilities and decline in quality of life. Quantitative measurements of spasticity are needed in order to assess the impact of specific treatments and to choose the more accurate technique for each patient. The aim of this review is to examine the use of shear wave ultrasound elastography as a quantitative tool for monitoring biomechanical muscle properties such as stiffness and to determine whether it is a reliable method to assess spastic muscle in stroke survivors.MethodsStudies were sought from Academic Search Complete, CINAHL, PubMed/Medline, Scopus and SportDiscus with the following keywords: shear wave elastography, spasticity, stiffness, elasticity, hardness, stroke, cerebrovascular accident, cerebral vascular event and transient ischaemic attack. Titles and abstracts were screened, and relevant full-text articles were retrieved for further review.FindingsOf the 76 screened studies, nine captured elastography data of the spastic biceps brachii (n = 6) or the plantar flexors (n = 3) with stroke victims. All consulted studies had a different way of utilizing this technology which was expected considering no guidelines had been developed. Shear wave speed values obtained are compared and discussed with clinical measures. Reliability of the devices is also discussed.InterpretationShear wave ultrasound elastography can provide useful quantitative information on the mechanical properties of the spastic muscles in post-stroke patients. Nevertheless, new studies using common terminology and parameters are needed to develop reliable methods that could help in assessing treatment efficiency.     

Leg Muscle Activation and Distance Setting of the Leg Cycle Ergometer for Use by the Elderly

[Purpose] This study verified the leg muscle activities of elderly subjects performing leg cycle ergometer exercise. [Subjects] Forty-one elderly persons were the subjects of this study. [Methods] For the three distances corresponding to knee flexion angles of 15, 45, and 70, the muscle activities of the rectus femoris, biceps femoris, tibialis anterior and lateral gastrocnemius were measured while the subjects exercised on a cycle ergometer. [Results] The rectus femoris and biceps femoris showed statistically significant increases as the distance between the cycle ergometer and the body increased, and the lateral gastrocnemius muscle activation showed a statistically significant increase as the distance from the body to the cycle ergometer decreased. [Conclusion] When the elderly have limb muscle weakness, leg cycle ergometer distances should be adjusted.Key words: Cycle ergometer, Electromyography, Selective muscle strengthening     

Do Fitflops™ increase lower limb muscle activity?

Background

Fitness toning shoes are becoming increasingly popular, they aim to increase muscle activity, raise energy expenditure and improve overall health while wearing them. Yet there is a lack of consensus in the literature regarding their effectiveness. One such shoe on the market is the Fitflop™ designed to activate leg muscles through density shifts in the shoe's sole. The purpose of this study was to investigate the effect of wearing Fitflops^TM on the muscle activity of the lower limb.

Methods

Twenty three females (age 20.8 (1.3)years, mass 62.9 (11.9)kg, height 165.4 (5.6)cm) participated in the study. Muscle activity of the medial gastrocnemius, biceps femoris, rectus femoris and gluteus maximus of the participants' right limb were recorded using surface electromyography during participation in three different tasks to simulate daily living activities. These were a) treadmill walking b) stair climbing and c) zigzag walking around cones. The participants completed the tasks barefoot, while wearing Fitflops™ and while wearing regular flip flops so that comparisons between muscle activity in the different shoe conditions could be made.

Findings

The results show that there was no significant difference in the activity of the medial gastrocnemius, biceps femoris, rectus femoris and gluteus maximus muscles across all shoe conditions and simulated daily activities (P > 0.05).

Interpretation

Based on these results, the use of Fitflops™ is not recommended as a means of increasing muscle activity of the medial gastrocnemius, biceps femoris, rectus femoris and gluteus maximus during activities of daily living in a healthy recreationally active female population.     

Sonoelastography of the trunk and lower extremity muscles in a case of Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a rare genetic disorder typically presenting with muscle weakness and reduced tone of trunk and lower extremities. The sonoelastographic properties of DMD are poorly understood. We describe sonoelastographic characteristics of a patient’s trunk and lower extremity musculature. An 8-year-old male presented with a 5-year history of DMD. Sonoelastographic measures of the gluteus maximus and medius, lumbar erector spinae, rectus abdominis, rectus femoris, biceps femoris, tibialis anterior, medial and lateral gastrocnemius muscles were obtained. Sonoelastography demonstrated increased elasticity by elevated kiloPascals (kPa) across all muscles, except the lumbar erector spinae. Patient values were compared to an age-matched healthy control. These abnormal sonoelastographic findings reflected the pathological mechanical properties of DMD. Sonoelastography was valuable for characterizing the mechanical properties of normal and abnormal muscle tissue. There is limited information on the sonoelastography application to DMD. Sonoelastography may serve as a useful measure for diagnosis and monitoring clinical outcomes for DMD.     

Reliability of Muscle Quantity and Quality Measured With Extended-Field-of-View Ultrasound at Nine Body Sites

ObjectiveMeasuring muscle quantity and quality is very important because the loss of muscle quantity and quality is associated with several adverse effects specifically in older people. Ultrasound is a method widely used to measure muscle quantity and quality. One problem with ultrasound is its limited field of view, which makes it impossible to measure the muscle quantity and quality of certain muscles. In this study, we aimed to evaluate the intra- and inter-rater reliability of extended-field-of-view (EFOV) ultrasound for the measurement of muscle quantity and quality in nine muscles of the limbs and trunk.MethodsTwo examiners took two ultrasound EFOV images with a linear probe from each of the muscle sites. The intraclass correlation coefficient (ICC) was used, and the standard error of measurement and coefficient of variation were calculated.ResultsIntra-rater reliability was good to excellent (ICC = 0.2–1.00) for all muscle measurements. The inter-rater reliability for most of the muscle measurements was good to excellent (ICC = 0.82–0.98). Inter-rater reliability was moderate (0.58–0.72) for some muscle quantity measurements of the tibialis anterior, gastrocnemius, rectus femoris, biceps femoris and triceps brachii muscles.ConclusionMuscle quantity and quality can be measured reliably using EFOV US.     

Effects of hyperlipidemia on patellar tendon stiffness: A shear wave elastography study

BackgroundRecent studies presented that increased adiposity and hyperlipidemia may cause tendon pathology. The aim of this study was to evaluate the effect of hyperlipidemia on the patellar tendon stiffness by shear wave elastography.MethodsA total of 51 participants (19 female, 32 male) were included. Participants were divided into two groups, according to their low-density lipoprotein levels, as the study group (hyperlipidemia, n = 24) and the control group (non-hyperlipidemia, n = 27). The patellar tendon and rectus femoris muscle shear wave velocities were measured by shear wave elastography.FindingsPatellar tendon shear wave velocities was 5.02 (SD: 0.78) m/s in the control group and 5.98 (SD: 1.19) m/s in the hyperlipidemia group (ES = 0.95, P = .001). There was a positive moderate statistically significant correlation between patellar tendon shear wave velocity and low-density lipoprotein (r = 0.432, p < .002). In the multiple linear regression analysis, only low-density lipoprotein was found as a significant predictor of patellar tendon shear wave velocity (CI: 0.005–0.028, P = .007).InterpretationWe evaluated the effects of hyperlipidemia and body mass index on patellar tendon mechanical properties with shear wave elastography. We found that the blood low-density lipoprotein level had an impact on patellar tendon stiffness independently of body mass index. Accordingly, it is important to evaluate individuals' low-density lipoprotein levels when examining risk factors for tendon pathology.     

Use of MMG Signals for the Control of Powered Orthotic Devices: Development of a Rectus Femoris Measurement Protocol

ABSTRACT

A test protocol is defined for the purpose of measuring rectus femoris mechanomyographic (MMG) signals. The protocol is specified in terms of the following: measurement equipment, signal processing requirements, human postural requirements, test rig, sensor placement, sensor dermal fixation, and test procedure. Preliminary tests of the statistical nature of rectus femoris MMG signals were performed, and Gaussianity was evaluated by means of a two-sided Kolmogorov-Smirnov test. For all 100 MMG data sets obtained from the testing of two volunteers, the null hypothesis of Gaussianity was rejected at the 1%, 5%, and 10%?significance levels. Most skewness values were found to be greater than 0.0, while all kurtosis values were found to be greater than 3.0. A statistical convergence analysis also performed on the same 100 MMG data sets suggested that 25 MMG acquisitions should prove sufficient to statistically characterize rectus femoris MMG. This conclusion is supported by the qualitative characteristics of the mean rectus femoris MMG power spectral densities obtained using 25 averages.     

Evaluation of viscoelastic parameters of the skeletal muscles in junior triathletes

Five male triathletes of the Estonian national junior team were observed during a seven-week competition period. The Myoton-2 equipment was used to describe the viscoelastic parameters of the skeletal muscles. The frequency of damped mechanical oscillation of the muscle tissue (Hz - indicating the tension in the muscle), logarithmic decrement of the oscillations (Theta - indicating the elasticity of the muscle) and stiffness (N m(-1)) of the muscle tissue were registered bilaterally in eight muscles in both the relaxed and the contracted states: BB - biceps brachii (caput longum); TB - triceps brachii (caput longum); BF - biceps femoris (caput longum); RF - rectus femoris; TA - tibialis anterior; GC - gastrocnemius (caput mediale); LD - latissimus dorsi; PM - pectoralis major (pars sternocostalis). A portable massage table was used for the subject to rest on during the measuring. For the measurement of the anterior muscles, the subject lay supine; for the posterior muscles the prone position was used. The (isometric) contraction was standardized simply by the same measuring position of the limb-the subject raised his arm or leg to an angle of 45 degrees from the horizontal level, using a 2.3 kg dumb-bell as an additional weight for the upper limb. The tarsal dorsiflexion and plantarflexion was performed against a fixed table to contract the crural muscles. The elasticity of the skeletal muscle is higher for the contracted state with respect to the relaxed one (p < 0.0001) and is described by decline of the value of logarithmic decrement, the stiffness and the tension in the muscle increases (p < 0.0001 for both parameters). The measured skeletal muscles differ significantly (p < 0.0018) by the viscoelastic properties in the relaxed state. In the relaxed state, TA was the most elastic (mean +/- SD; Theta-0.74 +/- 0.13), stiff (mean +/- SD; 346.68 +/- 60.34 N m(-1)) and tense muscle (mean +/- SD; 18.72 +/- 1.55 Hz). In the contracted state, the elasticity of TA did not change (0.76 +/- 0.14) while the stiffness and the tension in this muscle rose significantly (93% and 38%, accordingly). Personal differences (p < 0.005) exist if pooled data from the muscles are compared between the subjects.     

实时剪切波弹性成像检测急性肝炎肝脏弹性

目的 应用实时剪切波弹性技术测量急性肝炎患者肝脏弹性, 探讨其与肝功能的相关性。方法 对50例急性肝炎患者(急性肝炎组)及50名健康志愿者(正常组)行肝脏实时剪切波弹性测量, 比较急性肝炎组与正常组、急性病毒性肝炎与急性药物性肝炎患者肝脏弹性值差异, 对急性肝炎组肝脏剪切波弹性值与肝功能指标进行相关性分析。结果 急性肝炎组剪切波弹性值明显高于正常组[10.12±3.63] vs [4.96±0.72]kPa, P <0.05)];急性病毒性肝炎与急性药物性肝炎患者肝脏剪切波弹性值差异无统计学意义[9.11±3.03] vs [10.86±3.89]。急性肝炎组剪切波弹性值与总胆红素和直接胆红素之间呈正相关(r=0.305、0.304, P均 <0.05), 与肝功能其他指标间无相关性(P均 >0.05)。结论 急性肝炎中肝脏硬度增加, 实时剪切波弹性成像可通过检测剪切波弹性值对其进行定量评估, 为临床诊断急性肝炎提供有价值的参考。