In Vivo Measures of Shear Wave Speed as a Predictor of Tendon Elasticity and Strength

The purpose of this study was to assess the potential for ultrasound shear wave elastography (SWE) to measure tissue elasticity and ultimate stress in both intact and healing tendons. The lateral gastrocnemius (Achilles) tendons of 41 New Zealand white rabbits were surgically severed and repaired with growth factor coated sutures. SWE imaging was used to measure shear wave speed (SWS) in both the medial and lateral tendons pre-surgery, and at 2 and 4 wk post-surgery. Rabbits were euthanized at 4 wk, and both medial and lateral tendons underwent mechanical testing to failure. SWS significantly (p < 0.001) decreased an average of 17% between the intact and post-surgical state across all tendons. SWS was significantly (p < 0.001) correlated with both the tendon elastic modulus (r = 0.52) and ultimate stress (r = 0.58). Thus, ultrasound SWE is a potentially promising non-invasive technology for quantitatively assessing the mechanical integrity of pre-operative and post-operative tendons.     

Assessment of Diffuse Thyroid Disease by Strain Ratio in Ultrasound Elastography

The goal of this study was to explore the value of strain ratio from real-time elastography in the semi-quantitative assessment of diffuse thyroid disease. Fifty-one patients with primary hyperthyroidism, 70 with Hashimoto's thyroiditis, 8 with subacute thyroiditis and 43 with normal healthy thyroids were recruited to measure the strain ratio (SR) of thyroid tissue and sternocleidomastoid muscle (on the same side of the thyroid). SR values of all groups were subjected to statistical analysis. The SRs (mean ± standard deviation) of patients with hyperthyroidism, Hashimoto's thyroiditis and subacute thyroiditis were 2.30 ± 1.08, 7.04 ± 7.74 and 24.09 ± 13.56, respectively. The SR of the control group was 1.76 ± 0.54. SR values ranked in ascending order were control group < hyperthyroidism group < Hashimoto's thyroiditis group < subacute thyroiditis group. There were statistically significant (p < 0.05) differences in thyroid hardness between groups with different diffuse thyroid diseases. SR values of the hyperthyroidism and control groups did not statistically differ (p > 0.05). It is feasible to assess diffuse thyroid disease with strain ratios obtained with ultrasound elastography.     

Quantitative Shear Wave Velocity Measurement on Acoustic Radiation Force Impulse Elastography for Differential Diagnosis between Benign and Malignant Thyroid Nodules: A Meta-analysis

The aim of this study was to evaluate the diagnostic performance of quantitative shear wave velocity (SWV) measurement on acoustic radiation force impulse (ARFI) elastography for differentiation between benign and malignant thyroid nodules using meta-analysis. The databases of PubMed and the Web of Science were searched. Studies published in English on assessment of the sensitivity and specificity of ARFI elastography for the differentiation of thyroid nodules were collected. The quantitative measurement of ARFI elastography was evaluated by SWV (m/s). Meta-Disc Version 1.4 software was used to describe and calculate the sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio and summary receiver operating characteristic curves. We analyzed a total of 13 studies, which included 1,854 thyroid nodules (including 1,339 benign nodules and 515 malignant nodules) from 1,641 patients. The summary sensitivity and specificity for differential diagnosis between benign and malignant thyroid nodules by SWV were 0.81 (95% confidence interval [CI]: 0.77–0.84) and 0.84 (95% CI: 0.81–0.86), respectively. The pooled positive and negative likelihood ratios were 5.21 (95% CI: 3.56–7.62) and 0.23 (95% CI: 0.17–0.32), respectively. The pooled diagnostic odds ratio was 27.53 (95% CI: 14.58–52.01), and the area under the summary receiver operating characteristic curve was 0.91 (Q* = 0.84). In conclusion, SWV measurement on ARFI elastography has high sensitivity and specificity for differential diagnosis between benign and malignant thyroid nodules and can be used in combination with conventional ultrasound.     

实时剪切波弹性成像对甲状腺结节良恶性的诊断及影响因素分析

目的 探讨剪切波弹性成像(SWE)各参数对甲状腺结节良恶性鉴别诊断的临床价值。方法 应用SWE对拟接受手术或活检的221例甲状腺结节患者(265个结节)进行检查,测量结节的绝对弹性值。以病理结果为金标准,绘制ROC曲线,得到最优的诊断界点,并以此进行良恶性诊断。根据ROC曲线下面积评价各个SWE参数的诊断价值。同时,分析可能存在的影响因素。结果 265个甲状腺结节中,良性177个,恶性88个。恶性结节的杨氏模量均高于良性结节,差异有统计学意义(P均<0.05)。5个SWE参数(SWE_whole_mean、SWE_whole_min、SWE_mean、SWE_min、SWE_max)诊断结节良恶性的ROC曲线下面积分别为0.793、0.656、0.801、0.796和0.791。SWE_mean的ROC曲线下面积(AUC)面积最大,以最优的诊断界点为39.2 kPa进行良恶性诊断,诊断的敏感度和特异度分别为67.05% 和83.62%。各可能的影响因素中,结节内钙化会使测量到的杨氏模量值增加。SWE与常规超声联合应用的诊断敏感度为86.36%。结论 SWE有助于甲状腺结节良恶性的鉴别诊断。     

剪切波超声弹性成像的原理及临床应用现状

剪切波超声弹性成像(SWE)是一种用于评价活体组织硬度的新技术,具有实时、无创、定量等特点,目前的研究表明其具有良好的临床应用前景。本文旨在对该技术的原理以及临床应用现状进行综述。     

基于规则化位移场的弹性减影成像研究

目的：提出一种新的基于规则化位移场的弹性减影成像方法,探讨其在消融损伤成像监控中应用的可行性。方法分别进行有限元仿真和离体实验研究,对压缩量不同情况下的位移场进行规整化和减影处理,处理后的位移场在深度方向进行微分获得弹性减影图像。结果仿真和离体实验数据显示,在消融治疗中,基于规则化位移场的弹性减影成像在压缩量变化的情况下,可获得效果较好的弹性图像,比传统弹性成像更好地反映了损伤区域的情况。结论基于规则化位移场的弹性减影成像方法实现压缩量不同情况下的弹性减影成像,优于传统弹性成像方法,可以用于消融治疗的损伤监控。     

Transient elastography-derived liver stiffness measurements were found to be useful for predicting liver infiltration in a case of mature T-cell neoplasm involving liver dysfunction

Transient elastography (TE) is a novel, non-invasive imaging technique for measuring liver stiffness (LS). It is considered to be useful for predicting the severity of fibrosis and the risk of cirrhosis or hepatocellular carcinoma. However, the association between the presence of diffuse regions of increased cell density in the liver and elevated LS values has not been assessed. We experienced a case in which a mature T-cell neoplasm had invaded the liver, but the infiltrating lesion was not detected by contrast-enhanced computed tomography (CT) or fluorodeoxyglucose positron emission tomography/CT scans. Instead, the tumor’s presence was indicated by the change in the patient’s TE-derived LS values after chemotherapy. At diagnosis liver dysfunction was detected in a biochemical examination, and mean LS value was as high as 25.4 kPa [interquartile range (IQR): 0.3, success rate (SR):100%]. After chemotherapy, the patient’s mean LS value fell to 4.3 kPa (IQR: 0.8, SR:100%). A follow-up pathological investigation demonstrated that proliferating abnormal T-cells were no longer present in the patient’s liver. This is the first report to describe the use of LS data to support a diagnosis of liver infiltration by tumor cells exhibiting a portal and sinusoidal distribution pattern rather than a focal pattern. Elevated TE-derived LS values should lead to hepatic tumor infiltration being considered during initial examinations or a suspicion of recurrence during follow-up examination of lymphoma patients who achieve complete remission, even when radiological investigations do not detect abnormalities in the liver.     

The factors associated with longitudinal changes in liver stiffness in patients with chronic hepatitis B

Background/Aims

Liver stiffness (LS) as assessed by transient elastography (TE) can change longitudinally in patients with chronic hepatitis B (CHB). The aim of this study was to identify the factors that improve LS.

Methods

Between April 2007 and December 2012, 151 patients with CHB who underwent two TE procedures with an interval of about 2 years were enrolled. Ninety-six of the 151 patients were treated with nucleos(t)ide analogues [the antiviral therapy (+) group], while the remaining 55 patients were not [the antiviral therapy (-) group]. The two groups of patients were stratified according to whether they exhibited an improvement or a deterioration in LS during the study period (defined as an LS change of ≤0 or >0 kPa, respectively, over a 1-year period), and their data were compared.

Results

No differences were observed between the antiviral therapy (+) and (-) groups with respect to either their clinical characteristics or their initial LS. The observed LS improvement was significantly greater in the antiviral therapy (+) group than in the antiviral therapy (-) group (-3.0 vs. 0.98 kPa, P=0.011). In the antiviral therapy (+) group, the initial LS was higher in the LS improvement group (n=63) than in the LS deterioration group (n=33; 7.9 vs. 4.8 kPa, P<0.001). However, there were no differences in any other clinical characteristic. In the antiviral therapy (-) group, the initial LS was also higher in the LS improvement group (n=29) than in the LS deterioration group (n=26; 8.3 vs. 6.5 kPa, P=0.021), with no differences in any other clinical characteristic.

Conclusions

A higher initial LS was the only factor associated with LS improvement in patients with CHB in this study.     

两种超声弹性成像参数对乳腺良恶性肿瘤诊断价值的研究

目的：探讨两种超声弹性成像（ ultrasonic elastography,UE）参数直径变化率及面积比在鉴别乳腺良恶性肿瘤中的诊断价值。方法：对144个乳腺肿块进行弹性成像检查,以病理结果为金标准,分析乳腺良恶性病变弹性参数的差异。结果：乳腺病变在弹性分级＞4分者,恶性肿瘤出现率明显高于良性病变（ P ＜0．05）;肿块在弹性图与二维图的最大直径变化率和面积比参数在良、恶性组间比较差异均有统计学意义（ P ＜0．05）;比较2种参数的ROC曲线发现,肿块面积最大直径变化率在鉴别恶性方面准确性更大。结论：UE能客观评价乳腺肿块的相对弹性硬度,定量参数直径变化率和面积比有助于乳腺肿块良恶性的鉴别诊断,而面积比更为准确。