肝窦阻塞综合征的超声影像学特征分析

目的描述肝窦阻塞综合征（HSOS）的多模态超声表现，并探讨超声在HSOS诊断中的应用价值。 方法回顾性分析2014年9月至2018年6月在复旦大学附属中山医院就诊的33例HSOS患者的临床特征和超声影像学特征，其中5例行超声造影和剪切波弹性成像检查，观察肝脏大小、肝区回声、肝静脉、门静脉、下腔静脉、胆囊、脾、体腔积液、肝弹性模量等情况；并用Cochran-Armitage趋势检验分析不同严重程度患者的超声征象阳性率。 结果患者中25例（75.8%）有土三七服药史，临床症状主要以腹胀、肝区痛、腹水和肝功能明显异常就诊。灰阶超声特征为16例（48.5%）肝肿大，10例（30.3%）肝区回声增强增粗，11例（33.3%）胆囊壁增厚，14例（42.4%）脾大，31例（93.9%）腹水，9例（27.3%）胸水，7例（21.2%）盆腔积液；彩色多普勒表现为20例（60.6%）肝静脉细窄，18例（54.5%）肝静脉频谱异常，5例（15.2%）门静脉细窄，门静脉平均流速（0.14±0.03）m/s，6例（18.2%）出现门静脉反流；超声造影表现为5例（100.0%）动脉期呈"花斑样"不均匀增强，肝动脉-肝静脉渡越时间和门静脉-肝静脉渡越时间分别为（22.3±3.3）s和（13.0±2.2）s；三维超声造影显示：肝动、静脉、门静脉充盈缓慢及节段性充盈缺损；肝弹性模量（54.0±10.1）kPa。肝肿大、肝静脉细窄和肝静脉频谱异常的阳性率与病情严重程度存在相关性（Z=2.830、2.171、2.840，P均<0.05）。 结论HSOS与服用中药土三七密切相关，超声造影及剪切波弹性成像对HSOS的诊断具有潜在的应用价值。     

甲状腺超声弹性成像结合颈部淋巴结彩超探查在诊断甲状腺良恶性病变中的应用

目的 探讨甲状腺超声弹性成像结合颈部淋巴结彩超探查在诊断甲状腺良恶性病变中的应用价值。 方法 收集来我院进行甲状腺弹性成像检查并检出颈部淋巴结的95例患者资料,共119个结节病灶,所有病例经外科手术或超声引导下穿刺活检确诊,应用超声弹性成像技术结合颈部淋巴结探查判断甲状腺结节的良恶性,并与病理诊断进行对比研究,评价此方法的诊断价值。 结果 甲状腺超声弹性成像结合颈部淋巴结彩超探查诊断弹性3分并淋巴结肿大的甲状腺结节灵敏度80%,特异度91.7%,诊断弹性4分并淋巴结肿大的结节灵敏度94.1%,特异度75%,诊断弹性5分并淋巴结肿大的结节灵敏度94.7%,特异度100%,与单纯的甲状腺弹性评分相比较,对评分3分、5分结节灵敏度及特异度明显提高,对评分4分的结节灵敏度明显提高(P<0.01)。结论 将弹性超声技术与颈部淋巴结探查相结合,可明显提高甲状腺结节良恶性病变诊断的准确性,具有广阔的临床应用前景。     

Improvement in diagnosis of breast tumour using ultrasound elastography and echography: A phantom based analysis

Due to the isoechoic nature of lesions and their poor contrast with neighbouring tissue, a lesion may remain undetected in ultrasound B mode imaging for cancerous tissue. Imaging of the elastic properties of tissue provides new information which is collateral to tissue pathology. This study provides quantitative analysis of improvements in tumour diagnosis when the ultrasound B mode imaging is combined with elastography. Quantification was based on the textural parameters measured from the ultrasound B mode image and strain measured from the elastogram. The ability of a parameter to discriminate between diseased cases and normal cases was evaluated using receiver operating characteristic (ROC) analysis. Polyacrylamide gel based tissue mimicking phantoms with embedded inclusions of varying stiffness were used for the analysis.     

超声弹性成像与传统超声对乳腺病变鉴别诊断的对照研究

目的:对比超声弹性成像(UE)及传统超声(CUS,包括灰阶超声、彩色多普勒血流显像、频谱多普勒超声)在乳腺良恶性病灶鉴别诊断方面的价值.方法:对我院135个乳腺病灶进行超声弹性、传统超声图像的回顾性分析,以手术后组织学诊断为参考标准,对比两者在诊断乳腺良恶性病变的准确性.结果:超声弹性成像诊断乳腺恶性病变的敏感度、特异...     

Improving B mode ultrasound evaluation of breast lesions with real-time ultrasound elastography--a clinical approach

Ultrasound elastography using the extended combined auto-correlation method of tissue elasticity allows for real-time strain image visualisation using a free-hand probe with concurrent conventional B mode imaging. Four hundred and fifteen consecutive women with 550 breast lesions confirmed on B mode ultrasound were assessed with elastography using the elasticity score. There were 119 malignant and 431 benign lesions. The elastography sensitivity was 78.0%, specificity was 98.5% and overall accuracy was 93.8%. The median score for malignancy was 5 and that for benign lesions was 2. There was good correlation with B mode BIRADS category. 98.6% of lesions with an elasticity score of 2 or below (95%CI=96.8-99.4) were benign. BIRADS 3 lesions with an elasticity score of 2 or below may be re-classified as BIRADS 2 lesions. We found that 15.3% of BIRADS 2 and 3 lesions with an elasticity score of 3 were malignant. Real-time ultrasound elastography is user-friendly with a high accuracy rate, thereby improving B mode ultrasound assessment.     

Anthropomorphic phantoms for assessment of strain imaging methods involving saline-infused sonohysterography

Two anthropomorphic uterine phantoms were developed that allow assessment and comparison of strain imaging systems adapted for use with saline-infused sonohysterography (SIS). Tissue-mimicking (TM) materials consist of dispersions of safflower oil in gelatin. TM fibroids are stiffer than the TM myometrium/cervix, and TM polyps are softer. The first uterine phantom has 3-mm-diameter TM fibroids distributed randomly in TM myometrium. The second uterine phantom has a 5-mm and 8-mm spherical TM fibroid, in addition to a 5-mm spherical and a 12.5-mm-long (medicine capsule-shaped) TM endometrial polyp protruding into the endometrial cavity; also, a 10-mm spherical TM fibroid projects from the serosal surface. Strain images using the first phantom show the stiffer 3-mm TM fibroids in the myometrium. Results from the second uterine phantom show that, as expected, parts of inclusions projecting into the uterine cavity will appear very stiff, whether they are stiff or soft. Results from both phantoms show that although there is a five-fold difference in the Young's moduli values, there is not a significant difference in the strain in the transition from the TM myometrium to the TM fat. These phantoms allow for realistic comparison and evolution of SIS strain imaging techniques and can aid clinical personnel to develop skills for SIS strain imaging.     

Propagation velocity and attenuation of a shear wave pulse measured by ultrasound detection in agarose and polyacrylamide gels

The aim of our research was to measure and analyze phase velocity and pulse attenuation of a shear wave in two media: well-known agarose-gelatin gel and seldom-used polyacrylamide gel. These quantities were determined at three temperatures by the method of transmission sonoelastography described by Catheline et al. (1999). The shear wave was generated with a shaker stimulated by an electric pulse, with a length of one sinusoidal period with a preset frequency. The calculation method is based on a cross-correlation algorithm used for consecutive A-scans of signals of backwards scattered ultrasonic pulses. It allows determination of the local displacement of scattering elements in the medium, caused by a propagating shear wave, and determination of viscoelastic properties of gels. The results of the measurements of shear wave phase velocity and attenuation, obtained for agarose-gelatin and polyacrylamide gels that simulate biological systems depending on frequency and amplitude of vibrations, are presented. The comparison of the measured characteristic properties of gels has revealed that polyacrylamide gel is more useful in viscoelastic investigations of tissue-like phantoms.     

Estimation of the transverse strain tensor in the arterial wall using IVUS image registration

Intravascular ultrasound (IVUS) elastography is an imaging technique that obtains the local mechanical properties of the artery wall and atherosclerotic plaques through strain measurements using IVUS. Knowledge of these mechanical properties may provide crucial information that can help in estimating plaque composition and its vulnerability. Here, we present a new method to estimate the transverse strain tensor of the arterial wall based on nonrigid image registration using IVUS images. This method registers a pair of images acquired at a vessel site under different levels of luminal pressure. The 2-D displacement field in the vessel cross-section is estimated from image registration; then the displacement field is used to calculate the 2-D local strain tensor. From the strain tensor, the strain in any direction in the cross-section can be obtained; here, the radial and circumferential strain distributions are presented. This strain estimation method has been validated with synthetic motion IVUS images and evaluated using the IVUS images of a polyvinyl alcohol cryogel phantom. The accuracy of the estimated strain and the ability of the method to overcome IVUS system noise are demonstrated.     

Freehand ultrasound elastography with a 3-D probe

This paper presents the first near-real-time freehand ultrasound elastography system using a (3-D) mechanical probe. Acquisition is complete within two sec, and only an additional 20 sec are required for generation of a full 3-D strain volume. The strain is axial, with estimates of lateral and elevational tissue movement used to increase the accuracy of the axial strain measurement. This is the first time all system components have been extended to 3-D, i.e., 3-D windows are used to track displacement, which is tracked in all directions, and 3-D kernels are used for least-squares gradient estimates. Normalization of the freehand 3-D strain data is also applied across the whole volume. The system is tested using a novel research 3-D radiofrequency (RF) system with real-time control over the stepper motor driving the ultrasound probe, and real-time streaming of RF ultrasound data. The paper proves the concept, rather than making significant comments on the achievable accuracy in 3-D, although we demonstrate that the high performance of the 2-D techniques that we extend appears to carry through to in-vitro and in-vivo 3-D data. The result is a fast and high-resolution 3-D image of normalized axial strain. (E-mail: gmt11@eng.cam.ac.uk).     

Evaluation of prostate cancer detection with ultrasound real-time elastography: a comparison with step section pathological analysis after radical prostatectomy

BACKGROUND: Conventional gray scale ultrasound has a low sensitivity and specificity for prostate cancer detection. Better imaging modalities are needed. OBJECTIVE: To determine sensitivity and specificity for prostate cancer detection with ultrasound-based real-time elastography (elastography) in patients scheduled for radical prostatectomy (RP). DESIGN, SETTING, AND PARTICIPANTS: Between July and October 2007, 109 patients with biopsy-proven localized prostate cancer (PCa) underwent elastography before RP. The investigator was blinded to clinical data. MEASUREMENTS: A EUB-6500HV ultrasound system with a V53W 7.5MHz end-fire transrectal probe was used preoperatively. Areas found to be suspicious for PCa were recorded for left and right side of the apex, mid-gland, and base. These findings were correlated with the obtained whole-mount sections after RP. RESULTS AND LIMITATIONS: Sensitivity and specificity for detecting PCa were 75.4% and 76.6%, respectively. A total of 439 suspicious areas in elastography were recorded, and 451 cancerous areas were found in the RP specimens. Positive predictive value, negative predictive value, and accuracy for elastography were 87.8%, 59%, and 76%, respectively. Nevertheless, there are limitations to our studies because we investigated specific patients scheduled for RP with apparent PCa. Whether elastography is practical as a diagnostic tool or can be used to target a biopsy and be at least as sensitive in tumor detection as extended biopsy schemes has yet to be determined. CONCLUSION: Elastography can detect prostate cancer foci within the prostate with good accuracy and has potential to increase ultrasound-based PCa detection. Further studies need to be done to approve these data and to evaluate whether tumor detection can be increased by elastography-guided biopsies.