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。     

超声弹性成像在甲状腺结节鉴别诊断中的临床价值

目的 评估超声弹性成像在鉴别甲状腺结节性质方面的临床价值.方法 对90个甲状腺结节的常规超声特征和超声弹性成像分级情况进行分析,并与病理检查结果进行比较.结果 共有66个结节病理检查结果提示为良性,24个结节病理检查结果提示为恶性.而且,相对于良性结节,恶性结节大多数形态不规则、边界欠清晰、结节内有微钙化、纵横比＞1、且超声弹性分级多位于Ⅲ～Ⅳ级.按超声弹性成像分级Ⅲ～Ⅳ级判断甲状腺恶性结节的敏感性和特异性分别为95.45％和87.50％.结论 超声弹性成像在甲状腺良、恶性结节鉴别诊断中有较高的临床使用价值.     

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.     

CDFI与实时组织弹性成像联合监测在肝硬化经颈静脉肝内门体分流术术后疗效的临床价值

目的 探讨CDFI和实时组织弹性成像(RTE)联合监测在肝硬化经颈静脉肝内门体分流术(TIPSS)术后疗效的临床价值.方法 对临床46例肝硬化门脉高压经TIPSS术前、术后进行CDFI和RTE检查.观察门静脉、脾静脉内径和血流变化情况;通过组织弥散定量分析软件分析肝硬化弥散指标变化情况.结果 TIPSS术后门静脉内径变小,门静脉、脾静脉流速增快,与术前比较差异有统计学意义(P＜0.05),脾静脉内径改变不明显,与术前比较差异无统计学意义.TIPSS术后蓝色领域百分比增高,复杂度、峰度、偏度减低,与术前比较差异均有统计学意义(均P＜0.05),TIPSS术前、后应变均值、标准偏差、对比度、均等性、杂乱度、一致性及相关性改变不明显.结论 CDFI技术在观察TIPSS术前后血管内径、血流速方面改变比较明显;RTE能观察到肝硬化TIPSS术后肝硬度的改变情况.二者联合诊断肝硬化TIPSS术后价值更高.     

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。     

直肠腔内剪切波弹性成像对局部进展期直肠癌新辅助放化疗后T分期的价值

目的探讨经直肠腔内超声弹性成像对局部进展期直肠癌新辅助放化疗后T分期的应用价值。 方法收集就诊于中国医学科学院肿瘤医院的局部进展期直肠癌患者57例,均于术前接受新辅助放化疗,并进行根治性手术。所有患者新辅助放化疗前后行经直肠腔内超声（ERUS）及剪切波弹性成像（SWE）检查。以术后病理为金标准,评价ERUS及SWE对直肠癌新辅助放化疗后T分期的准确性。 结果ERUS对局部进展期直肠癌新辅助放化疗后T分期的诊断准确率为59.6%（34/57）。ERUS判断肿瘤局限于肠壁（T0~T2）的准确性为39.3%（11/28）。46.2%（6/13）的ypT0期患者被过高分期。放化疗前后,杨氏模量最大值（Emax）平均值分别为（103.27±29.23）kPa、（49.91±32.67）kPa,差异有统计学意义（t=6.236,P<0.001）。新辅助治疗后病理T分期越高,Emax平均值随之升高。以放化疗后病灶Emax构建ROC曲线,选取58 kPa作为最佳诊断临界点时,诊断放化疗后残余病变局限于肠壁内的敏感性、特异性、准确性分别为76.2%、86.4%、78.9%;以43 kPa为最佳诊断临界点,诊断ypT0期的敏感性、特异性、准确性分别为100%、84.6%、89.7%,均较ERUS有改善,说明SWE可提高新辅助治疗后直肠癌再分期的准确性,有助于临床治疗方案的制定。 结论经直肠腔内SWE可提高局部进展期直肠癌新辅助放化疗后T分期的准确性,可丰富现有影像检查方法。     

Transient elastography in DAA era. Relation between post‐SVR LSM and histology

The natural history of HCV chronic infection has drastically changed after direct‐acting antiviral treatment. Due to the high sustained virological response (SVR) achieved, noninvasive estimation of liver fibrosis regression has become a major key point. The present study tries to evaluate the relation between liver histology and liver stiffness measurement (LSM) by transient elastography (TE) after SVR.     

The stratification of cirrhosis

Cirrhosis is traditionally seen as an irreversible stage of chronic liver disease although its clinical course may last several years. Overall, the clinical management of patients with cirrhosis is based on the observation of clinical events mostly related to complications of portal hypertension. Each event of cirrhosis decompensation has clear prognostic implications although it is not precisely predictable. In practice, the advancement in the knowledge of the mechanisms responsible for disease progression is not yet translated in clinical tools allowing the stratification of the cirrhotic stage according to pathophysiological mechanisms. This article provides a review of the main clinical and histopathological features of liver cirrhosis that are relevant for its clinical stratification together with the advancements provided by the introduction of non‐invasive measures of portal hypertension. Other clinical aspects that have a major impact on the quality of life and the possibility of liver transplantation are also discussed.