超声造影在脾脏局灶性占位病变诊断中的价值

目的：探讨脾脏局灶性病变的超声造影特征及良恶性病变的差异。 方法：回顾性分析我院经手术或经皮穿刺活检病理确诊的24例脾脏局灶性病变患者的超声声像图特征,并比较良恶性病灶最大径、病灶数目、回声、边界、形态、动脉期及静脉期增强程度、动脉期增强病灶3min内有无明显廓清方面有无差异。 结果：共纳入24例患者的24个脾脏局灶性病变,包括15个良性病灶和9个恶性病灶。3个良性病灶超声造影表现为始终无增强,余 21个病灶均有增强,其中良性12个,恶性9个。动脉期增强病灶3min内有无明显廓清方面比较差异有统计学意义(P<0.05),良恶性病灶最大径、病灶数目、回声、边界、形态、动脉期及静脉期增强程度等指标比较差异均无统计学意义。 结论：脾脏局灶性病变具有一定超声造影特征,其中造影剂3min内是否有明显廓清对鉴别良恶性有借鉴意义。     

超声造影在肝脏局灶性病变定性诊断中的应用研究

目的探讨不同性质之肝脏局灶性病变（FLLs）的超声造影（CEUS）特征表现。方法对60例肝脏局灶性病变患者进行超声造影检查,并与增强CT、病理结果进行对照。结果超声造影后各种FLLs显示不同的造影特点。CEUS定性诊断率与增强CT对照差别无统计学意义。结论CEUS能显示局灶性病变内微小血管的血流灌注情况,对FLLs的定性诊断具有重要的意义。     

常规超声和超声造影对肝脏局灶性病变定性诊断的有用性评估

目的评估常规超声(B型超声 彩色多普勒超声)和超声造影(CEUS)在肝脏局灶性病变(FLL)定性诊断中的有用性。方法模拟日常超声检查工作情景检测常规超声和CEUS对305例FLL的定性诊断性能和诊断者的信心强度。CEUS采用造影剂SonoVue和对比脉冲序列成像技术。结果常规超声和CEUS的诊断正确率对肝细胞性肝癌分别为86.8%、88.6%,对转移性肝癌分别为97.6%、99.2%。对肝内胆管癌、血管瘤、局灶性结节增生、肝硬化结节、不均匀脂肪肝和其他病变,诊断正确率常规超声为26.2%～71.9%,CEUS为46.4%～92.9%,可相应提高19～25个百分点。对所有病变,CEUS均较大幅度地增强了诊断者的信心强度。结论在病灶回声表现典型、同时存在有力支持诊断的临床资料和伴随声像的条件下,常规超声定性诊断FLL的准确程度与CEUS相当,并不一定需要做造影检查。如不具备上述条件,CEUS是值得推荐的。     

肝脏局灶性病灶的超声造影定量分析

目的探讨良恶性肝脏局灶性病灶（focal liver lesions，FLL）超声造影（contrast-enhanced ultrasound，CEUs）的时间一强度曲线（time-intensity curve，TIC）形态和声学定量参数变化特征。方法应用反向脉冲谐波显像（pulse inversion harmonic imaging，PIH）技术对94例FLL行实时CEUS检查，以声学定量分析软件绘制不同FLL的TIC，对比分析良恶性病灶的TIC形态和定量参数变化特征。结果良性病灶TIC形态呈慢上慢下型，恶性病灶呈快上快下型。恶性病灶的声学定量参数包括始增时间、增强时间、达峰时间、始消时间、降支减半时间均早于良性病灶，上升支斜率、50％清除斜率大于良性病灶（P〈0.05，P〈0.001）。动脉相早期恶性病灶呈高灌注型，良性病灶呈低灌注型，门脉相及延迟相恶性者呈低灌注型，良性者呈高灌注型。结论CEUS的TIC形态和定量参数变化特征对FLL的良恶性鉴别有重要价值。     

应用低机械指数连续超声造影鉴别诊断肝脏局灶性病变

目的探讨低机械指数连续超声造影技术鉴别肝脏局灶性病变(FLL)良、恶性的应用价值。方法采用对比脉冲序列成像(CPS)技术和造影剂SonoVue对200例FLL作超声造影检查。以动脉期病灶增强,门脉期及延迟期增强消退,回声低于肝组织作为恶性FLL的诊断标准,以诊断试验评估其诊断效能。结果超声造影诊断恶性FLL的敏感性、特异性、阳性预测值、阴性预测值和准确性分别为95%(122/128)、86%(62/72)、92%(122/132)、91%(62/68)和92%(184/200)。结论低机械指数连续超声造影可作为FLL鉴别诊断的重要方法。     

肝局灶性病变声学造影早期动脉相增强类型及临床意义

目的探讨肝局灶性病变声学造影早期动脉相增强类型及相关临床意义。 方法利用SonoVue超声造影剂，对肝局灶性病变107例患者137个病灶进行低机械指数实时谐波造影，重点观察早期动脉相病灶有无增强及增强形态特征。 结果107例患者（137个病灶），在动脉期除28个病灶无增强外，余109个病灶均有不同程度，不同类型增强，实时观察在动脉期超声造影增强表现为5种增强类型：（1）向心性团状增强；（2）离心性团状增强；（3）环状增强；（4）周边结节状增强；（5）片状增强。不同病变声学造影动脉期增强表现不同，部分具有特征性表现，部分存在重叠。 结论肿瘤的血供特点与超声造影的表现密切相关，典型肝局灶性病变病例根据动脉期增强特征结合临床表现可作出初步诊断，动脉期增强可显著提高对肝内富血管肿瘤检出及鉴别诊断。     

超声造影在肝脏局灶性病变检测中的价值

随着新的超声造影剂及声学技术的发展,超声造影对肝脏局灶性病变的诊断有较高的准确性,为临床肝病的检测提供了新的应用前景。本文就低机械指数超声造影与常规超声、增强CT/MRI对比在检测各种肝局灶性病变的诊断及其诊断潜力方面作一综述。     

Use of Contrast-Enhanced Ultrasound in the Assessment of Uterine Fibroids: A Feasibility Study

Contrast-enhanced ultrasound (CEUS) is an innovative ultrasound technique capable of visualizing both the macro- and microvasculature of tissues. In this prospective pilot study, we evaluated the feasibility of using CEUS to visualize the microvasculature of uterine fibroids and compared CEUS with conventional ultrasound. Four women with fibroids underwent gray-scale ultrasound, sonoelastography and power/color Doppler scans followed by CEUS examination. Analysis of CEUS images revealed initial perfusion of the peripheral rim, that is, a pseudo-capsule, followed by enhancement of the entire lesion through vessels traveling from the exterior to the interior of the fibroid. The pseudo-capsules exhibited slight hyper-enhancement, making a clear delineation of the fibroids possible. The centers of three fibroids exhibited areas lacking vascularization, information not obtainable with the other imaging techniques. CEUS is a feasible technique for imaging and quantifying the microvasculature of fibroids. In comparison with conventional ultrasound imaging modalities, CEUS can provide additional diagnostic information based on the microvasculature.     

Value of Contrast-Enhanced Ultrasound Using Perflubutane Microbubbles for Diagnosing Liver Fibrosis and Cirrhosis in Rats

We determined the ability of contrast-enhanced ultrasound (CEUS) using perflubutane microbubbles to diagnose liver fibrosis and cirrhosis in rats using histology as the reference standard. Fibrosis was induced by oral administration of carbon tetrachloride to 32 Wistar rats. Features with baseline ultrasound (US) and enhancement level of liver and spleen with CEUS were obtained. In the post-vascular phase of CEUS, images of normal livers (n = 5) were significantly brighter than images of fibrotic (n = 6) and cirrhotic livers (n = 13) by quantitative analysis (all p < 0.05). The contrast between livers and spleens in rats with cirrhosis was quantitatively greater than that in normal rats and rats with fibrosis (all p < 0.05). Compared with US, CEUS improved sensitivity from 63% to 84% and accuracy from 71% to 88%. Specificity was 100% for both. The increased value of CEUS in diagnosing liver fibrosis and cirrhosis in rats supports its evaluation in clinical trials.     

Contrast-Enhanced Ultrasound Using Perfluorobutane-Containing Microbubbles in the Assessment of Liver Allograft Damage: An Exploratory Prospective Study

This prospective study investigated the usefulness of contrast (perfluorobutane-containing microbubbles)-enhanced ultrasound in the non-invasive assessment of liver allograft damage. Forty-one liver recipients underwent contrast-enhanced ultrasound followed by a liver biopsy. The hepatic filling rate (time between the arrival of contrast agent in the right hepatic artery and the maximum intensity of hepatic parenchyma) and parenchymal intensity difference before and after instantaneous high-power emission in the Kupffer phase were measured. Patients with allograft damage had higher hepatic filling rates and lower parenchymal intensity differences than those without damage (42.0 ± 16.9 vs. 30.5 ± 7.7 s, p = 0.005; 6.1 ± 7.4 vs. 16.6 ± 16.1 dB, p = 0.047, respectively). In the diagnosis of liver allograft damage, hepatic filling rate and parenchymal intensity difference had sensitivities of 61.5% and 90.9% and specificities of 92.6% and 63.6% using cutoffs of >38.5 s and ≤10.3 dB, respectively. In conclusion, contrast-enhanced ultrasound may be a promising tool in the detection of liver allograft damage.     

A Temporal and Spatial Analysis Approach to Automated Segmentation of Microbubble Signals in Contrast-Enhanced Ultrasound Images: Application to Quantification of Active Vascular Density in Human Lower Limbs

Contrast-enhanced ultrasound (CEUS) using microbubble contrast agents has shown great promise in visualising and quantifying active vascular density. Most existing approaches for vascular density quantification using CEUS are calculated based on image intensity and are susceptible to confounding factors and imaging artefact. Poor reproducibility is a key challenge to clinical translation. In this study, a new automated temporal and spatial signal analysis approach is developed for reproducible microbubble segmentation and quantification of contrast enhancement in human lower limbs. The approach is evaluated in vitro on phantoms and in vivo in lower limbs of healthy volunteers before and after physical exercise. In this approach, vascular density is quantified based on the relative areas microbubbles occupy instead of their image intensity. Temporal features of the CEUS image sequences are used to identify pixels that contain microbubble signals. A microbubble track density (MTD) measure, the ratio of the segmented microbubble area to the whole tissue area, is calculated as a surrogate for active capillary density. In vitro results reveal a good correlation (r² = 0.89) between the calculated MTD measure and the known bubble concentration. For in vivo results, a significant increase (129% in average) in the MTD measure is found in lower limbs of healthy volunteers after exercise, with excellent repeatability over a series of days (intra-class correlation coefficient = 0.96). This compares to the existing state-of-the-art approach of destruction and replenishment analysis on the same patients (intra-class correlation coefficient ≤0.78). The proposed new approach shows great potential as an accurate and highly reproducible clinical tool for quantification of active vascular density.     

超声引导及重复活检在CT/MR LR-4/5类肝局灶性小病变穿刺活检的应用价值

目的探讨超声引导及重复活检在CT/MR LR-4/5类肝局灶性小病变穿刺活检中的应用价值。方法收集<2 cm且CT/MR LR-4/5类的251个病灶行超声引导下肝局灶性病变活检,共241例患者。分为US和CEUS引导下穿刺活检,每次活检穿1~2针。恶性病变经活检或手术切除后病理确诊。良性病变的最终诊断是依靠重复活检或至少6个月的影像学检查无变化。结果超声引导下穿刺活检成功率100%;218个灶病变最终确诊为恶性。CT/MR LR-4/5类与超声引导下穿刺活检的定性诊断率为86.85%和98.01%。US组及CEUS组引导下首次活检定性诊断率为78.10%和90.35%;40个灶首次活检病理未明确病变性质的病变经重复活检后定性诊断率100%;重复穿刺后,两组穿刺活检定性诊断率为96.35%和100%。首次活检及重复活检的定性诊断率为83.67%和100%。结论超声引导下穿刺活检能提高CT/MR LR-4/5对肝内局灶性小病变的诊断效能,重复活检能提高常规超声引导下穿刺活检定性诊断率的临床价值。     

Liver Ultrasound Elastography: An Update to the World Federation for Ultrasound in Medicine and Biology Guidelines and Recommendations

The World Federation for Ultrasound in Medicine and Biology has produced these guidelines for the use of elastography techniques in liver diseases. For each available technique, the reproducibility, results and limitations are analyzed, and recommendations are given. This set of guidelines updates the first version, published in 2015. Since the prior guidelines, there have been several advances in technology. The recommendations are based on the international published literature, and the strength of each recommendation is judged according to the Oxford Centre for Evidence-Based Medicine. The document has a clinical perspective and is aimed at assessing the usefulness of elastography in the management of liver diseases.     

Differential Intensity Projection for Visualisation and Quantification of Plaque Neovascularisation in Contrast-Enhanced Ultrasound Images of Carotid Arteries

Studies have reported that intraplaque neovascularisation (IPN) is closely correlated with plaque vulnerability. In this study, a new image processing approach, differential intensity projection (DIP), was developed to visualise and quantify IPN in contrast-enhanced non-linear ultrasound image sequences of carotid arteries. DIP used the difference between the local temporal maximum and the local temporal average signals to identify bubbles against tissue non-linear artefact and noise. The total absolute and relative areas occupied by bubbles within each plaque were calculated to quantify IPN. In vitro measurements on a laboratory phantom were made, followed by in vivo measurements in which 24 contrast-enhanced non-linear ultrasound image sequences of carotid arteries from 48 patients were selected and motion corrected. The results using DIP were compared with those obtained by maximum intensity projection (MIP) and visual assessment. The results indicated that DIP can significantly reduce non-linear propagation tissue artefacts and is much more specific in detecting bubble signals than MIP, being able to reveal microbubble signals that are buried in tissue artefacts in the corresponding MIP image. A good correlation was found between microvascular area (MVA) (r = 0.83, p < 0.001)/microvascular density (r = 0.77, p < 0.001) obtained using DIP and the corresponding expert visual grades, comparing favourably to r = 0.26 and 0.23 obtained using MIP on the same data. In conclusion, the proposed method exhibits great potential in quantification of IPN in contrast-enhanced ultrasound images of carotid arteries.     

Assessment of a New Mathematical Model for the Computation of Numerical Parameters Related to Renal Cortical Blood Flow and Fractional Blood Volume by Contrast-Enhanced Ultrasound

We analyzed the value of a new mathematical model for the quantification of renal cortical blood flow and fractional blood volume by contrast-enhanced ultrasound after the injection of sulfur hexafluoride–filled microbubbles. A vessel-mimicking phantom experiment was preliminarily performed which showed that the effect of microbubble diffusion is negligible compared with the effect of liquid drag. Twelve healthy volunteers (7 male, 5 female; 27 to 48 years [n = 6; group 1], and 61 to 80 years [n = 6; group 2], respectively), with normal renal and cardiac function and not undergoing any pharmacologic treatment, were examined. In each volunteer, both kidneys were scanned after intravenous injection of sulfur hexafluoride–filled microbubbles at a slow rate (4.8 mL at a flow of 4.0 mL/min), and the refill kinetics of the renal cortex after microbubble destruction was evaluated by echo-signal intensity quantification. The progressive replenishment of the renal vessels was approximated both by standard negative exponential function and by the piecewise linear function resulting from our mathematical model. A better dataset approximation was provided by piecewise linear versus standard negative exponential function (overall mean square error: 0.44 vs. 0.51; p < 0.05, Wilcoxon test). The piecewise linear function provided a curve composed of four linear tracts (n = 3 volunteers; 2 from group 1 and 1 from group 2), three linear tracts (n = 6 volunteers; 3 from group 1 and 3 from group 2) or two linear tracts (n = 3 volunteers; 1 from group 1 and 2 from group 2). The piecewise linear function versus standard negative exponential function improved data approximation for the computation of numerical values related to renal cortical blood flow velocity and fractional blood volume. (E-mail: quaia@univ.trieste.it)     

超声造影及DSA对肝移植术后脾动脉窃血综合征诊断的对照研究

目的 探讨超声造影对肝移植术后脾动脉窃血综合征的诊断价值.方法 肝移植术后10例患者在超声造影诊断为肝移植术后脾动脉窃血综合征后,即刻进行DSA造影,将两者检查结果进行统计分析.结果 超声造影见移植肝肝动脉内造影剂增强信号微弱,肝动脉内径偏细.DSA造影见肝动脉纤细,造影剂染色稀薄暗淡,脾动脉明显增粗,两者诊断结果无统计学意义.结论 超声造影应常规作为肝移植术后的可疑移植肝血管系统异常的无创检查手段,具有极高的应用价值.     

Reliability of Contrast-Enhanced Ultrasound for the Assessment of Muscle Perfusion in Health and Peripheral Arterial Disease

We investigated the reliability of contrast-enhanced ultrasound (CEUS) in assessing calf muscle microvascular perfusion in health and disease. Response to a post-occlusive reactive hyperaemia test was repeated on two occasions >48 h apart in healthy young (28 ± 7 y) and elderly controls (70 ± 5 y), and in peripheral arterial disease patients (PAD, 69 ± 7 y; n = 10, 9 and 8 respectively). Overall, within-individual reliability was poor (coefficient of variation [CV] range: 15–87%); the most reliable parameter was time to peak (TTP, 15–48% CV). Nevertheless, TTP was twice as long in elderly controls and PAD compared to young (19.3 ± 10.4 and 22.0 ± 8.6 vs. 8.9 ± 6.2 s respectively; p < 0.01), and area under the curve for contrast intensity post-occlusion (a reflection of blood volume) was ∼50% lower in elderly controls (p < 0.01 versus PAD and young). Thus, CEUS assessment of muscle perfusion during reactive hyperaemia demonstrated poor reliability, yet still distinguished differences between PAD patients, elderly and young controls.