超声造影在局灶性肝脏病变定性诊断中的应用

局灶性肝脏病变(FLL)种类较多,如果病灶被发现,最根本的问题常是良恶性的鉴别.B型超声(B-US)和彩色多普勒超声检查(CDFI简称彩超)由于本身成像原理的局限,对肝脏局灶性病变的定性诊断相对较弱.超声造影(CEUS)是近年来发展起来的超声新技术,被誉为无创数字减影血管造影,可以实时动态观察和记录组织血流灌注情况,据此可对疾病进行定性诊断[1～3].本文通过回顾性分析23例局灶性肝脏病变超声造影图像特征,以探讨超声造影对局灶性肝脏病变的鉴别诊断价值.报道如下.     

肝脏局灶性小病变的超声造影研究

目的提高超声造影检查肝脏局灶性病变的诊断准确率。方法对46例肝脏局灶性小病变患者(直径≤3.0cm)行常规超声和超声造影检查,结果与病理检查和增强CT(15例)对比分析。结果常规超声检查显示,低回声29例,等回声4例,高回声12例,周围有声晕6例,漏诊肝细胞性肝癌1例。46例肝脏局灶性小病变的常规超声、超声造影及增强CT的诊断准确率分别为65.2%、95.6%及73.3%。肝脏局灶性小病变大部分病灶具有典型的增强模式。结论超声造影能够提供肝局灶性病变的血流灌注,明显优于常规超声,可作为定性诊断肝脏局灶性病变的一种可靠的新手段。     

超声造影对肝硬化癌变相关局灶性小结节的诊断研究

目的运用灰阶超声造影（CEUS）观察肝硬化癌变相关局灶性小结节（≤3cm）的显像特征,探讨不同性质病灶的造影增强模式的差异及其鉴别诊断价值。方法运用超声造影剂SonoVue及对比脉冲序列技术（CPS）研究68例肝硬化患者合并的75个肝脏实性局灶性小结节的CEUS显像特征。所有病灶均行穿刺活检或手术切除,病理证实为15个大再生结节（LRN）、27个增生不良结节（DN）和33个小肝癌（SHCC）,将各组结节的CEUS增强特征与常规超声和CT增强扫描进行对比。结果CEUS可持续观察病灶及邻近肝实质内造影剂进入直至消退的整个动态过程,可以更准确地反映病灶的微血管灌注及增强特点,CEUS准确判断肝硬化癌变相关局灶性小结节性质的能力优于常规超声（P〈0.01）,CEUS和增强CT对本组病灶不同时相增强显像结果一致（P〉0.05）。结论CEUS对于肝硬化癌变相关局灶性小结节具有较为准确的定性诊断价值,对病灶内血流灌注的评估优于增强CT。     

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。     

脉冲反向谐波实时超声造影与增强螺旋CT诊断肝占位病变的比较研究

目的 比较实时超声造影与增强螺旋CT显示肝占位病变血流灌注特点的能力，探讨超声造影在肝肿瘤鉴别诊断中的应用价值。方法 对109例经手术或超声引导穿刺活检病理确诊的肝占位（原发性肝癌61例，转移性肝癌15例，肝内胆管细胞癌5例，血管瘤12例，肝硬化增生结节5例，肝细胞腺瘤2例，胆管细胞腺瘤1例，局灶性结节增生3例，局灶性坏死4例，血管平滑肌脂肪瘤1例）术前分别进行实时超声造影和造影剂增强16层螺旋CT检查，将两种检查的术前诊断与术后病理结果进行比较分析。结果 超声造影漏诊原发性肝癌2例、转移性肝癌1例，误诊原发性肝癌5例、胆管癌1例、胆管腺瘤1例、肝硬化结节1例、血管瘤1例、局灶性结节增生1例。增强CT漏诊原发性肝癌3例、转移性肝癌2例、血管瘤1例、肝硬化增生结节1例，误诊原发性肝癌7例、胆管癌2例、胆管腺瘤1例、血管瘤3例、肝硬化结节2例、局灶性结节增生2例、局灶性坏死2例。超声造影诊断肝占位病变的检出率为97．25％，增强CT的检出率为93．58％；超声造影诊断肝肿瘤的准确性为90．83％，增强CT的准确性为82．57％。结论 实时超声造影对肝占位病变的诊断能力与增强螺旋CT相近，实时超声造影具有独立诊断价值，对于增强CT扫描阴性或未显示病灶血流灌注特点的病例，超声造影具有更重要的临床意义。     

超声造影对肝脏局灶性病变的诊断价值

目的：探讨超声造影对肝脏局灶性病变的诊断价值。方法：采用低机械指数实时连续成像技术和造影剂SonoVue对149例肝脏局灶性病变作超声造影检查。结果：149确肝脏局灶性病变中，肝脏恶性肿瘤具有较特征性的超声造影表现，而良性病变除血管瘤、局灶性增生结节、肝脏囊性占位具有特征性的改变易于诊断外，其他尚无特征性表现。结论：超声造影对肝脏局灶性病变具有较高的诊断价值，尤其是鉴别良恶性病变。     

肝肿瘤实时灰阶谐波超声造影与动态增强螺旋CT对照研究

目的 探讨实时灰阶谐波超声造影和动态增强螺旋CT对肝局灶性病变的诊断价值.方法 选择肝局灶性病变患者49例,共54个病灶.其中包括原发性肝癌29个,转移性肝癌4个,肝血管瘤11个,肝局灶性结节增生7个,肝硬化结节1个,肝脂肪浸润不均2个.分别进行实时灰阶谐波超声造影和动态增强螺旋CT检查,比较肝肿瘤在两种成像方法中的表现.结果 两种成像方法显示的肝肿瘤在不同时相的表现及在动脉相的增强类型相一致.超声造影鉴别诊断肝良恶性病变的敏感性、特异性和准确性分别为 90.9%（30/33）、90.5%（19/21）和 90.7%（49/54）;动态增强螺旋CT鉴别诊断肝良恶性病变的敏感性、特异性、准确性分别为 90.9%（30/33）、95.2%（20/21）和 92.6%（50/54）,二者鉴别肝局灶性病变良恶性的能力差异无显著性意义.结论 实时灰阶谐波超声造影和动态增强螺旋CT均能反映肝病变的血流动力学特性,均有助于肝肿瘤的鉴别诊断.     

超声造影对肝脏恶性局灶性病变的诊断价值

目的:探讨超声造影对恶性肝脏局灶性病变的诊断价值。方法:行超声造影的肝脏恶性局灶性占位病变33例,所有患者均进行了增强CT或增强MRI检查,25例经病理证实及随访观察。结果:33例肝脏恶性局灶性病变,包括肝细胞性肝癌23例、胆管细胞癌2例、转移性肝癌6例、门静脉癌栓6例(其中4例继发于肝细胞性肝癌)。肝细胞性肝癌、转移性肝癌和门静脉癌栓具有特征性的超声造影表现,而胆管细胞性肝癌的超声造影表现多样。结论:超声造影对肝脏恶性局灶性病变的诊断具有重要的价值,但对不典型病例,尤其是对胆管细胞性肝癌需进一步检查确诊。     

实时灰阶超声造影和螺旋CT诊断肝肿瘤的比较研究

目的比较实时超声造影和螺旋CT显示肝肿瘤血流信号的特点.方法对29例肝肿瘤(原发性肝癌16例,转移性肝癌2例,血管瘤6例和肝局灶性结节增生5例)分别进行超声造影和CT检查.结果超声造影显示肝恶性肿瘤的整体型、血管瘤的周边型及局灶性结节增生的中央型出现率显著高于其他病变(P<0.01).CT示恶性肿瘤中94.4%(17/18) 动脉期强化、门脉期低密度;血管瘤中83.3%(5/6)呈结节状强化;肝局灶性结节增生动脉期均明显强化.超声造影和CT鉴别肝肿瘤的能力无显著差异.结论超声造影和CT都能敏感地显示不同肝肿瘤的血供特征.     

超声造影在肝局灶性病变诊疗中的应用进展

超声检查被多国肝病指南推荐作为肝脏肿瘤早期筛查监测手段。基于常规超声的超声造影(contrast-enhanced ultrasound,CEUS)可以提供组织微循环灌注等方面的功能学相关信息,且较增强CT/MRI而言,具有实时、连续、动态、无放射性损伤等优势,其所用超声对比剂微泡经肺排泄,无心肾甲状腺毒性,适用于肾功能不全患者,过敏反应发生率极低。CEUS被多项国内和国际指南推荐作为诊断及鉴别肝脏局灶性病变(focal liver lesion,FLL)的一线增强影像学检查方式。相较于常规超声,CEUS可大幅度提高FLL病灶检出率和诊断及鉴别诊断能力。美国放射学院(American College of Radiology,ACR)发布的超声造影肝脏影像报告及数据系统(Liver Imaging Reporting And Data System,LI-RADS)可用于高危人群肝内病变全谱的描述及FLL危险程度分层和临床处理策略的推荐。在介入方面,CEUS有助于优化FLL穿刺活检路径和靶目标识别,提高穿刺成功率和标本阳性率,并应用于消融术中引导、即刻评估、长期疗效评估和术后随访等。除此之外,外科手术中应用CEUS检查可提高微小肝转移灶及化疗后常规影像显示消失的肝转移灶的检出率,从而帮助临床医师修订手术方案。CEUS对于肝脏恶性肿瘤患者全身系统治疗后疗的效评估也有一定的价值。     

Automatic Identification of the Optimal Reference Frame for Segmentation and Quantification of Focal Liver Lesions in Contrast-Enhanced Ultrasound

Post-examination interpretation of contrast-enhanced ultrasound (CEUS) cineloops of focal liver lesions (FLLs) requires offline manual assessment by experienced radiologists, which is time-consuming and generates subjective results. Such assessment usually starts by manually identifying a reference frame, where FLL and healthy parenchyma are well-distinguished. This study proposes an automatic computational method to objectively identify the optimal reference frame for distinguishing and hence delineating an FLL, by statistically analyzing the temporal intensity variation across the spatially discretized ultrasonographic image. Level of confidence and clinical value of the proposed method were quantitatively evaluated on retrospective multi-institutional data (n = 64) and compared with expert interpretations. Results support the proposed method for facilitating easier, quicker and reproducible assessment of FLLs, further increasing the radiologists' confidence in diagnostic decisions. Finally, our method yields a useful training tool for radiologists, widening CEUS use in non-specialist centers, potentially leading to reduced turnaround times and lower patient anxiety and healthcare costs.     

虚拟导航超声造影与常规超声造影定位检测肝局灶性病变的比较

目的 比较虚拟导航超声造影与常规超声造影检出二维超声显示困难肝局灶性病变的差异,探讨虚拟导航超声造影的应用价值.方法 47个CT或MR提示但二维超声无法显示的肝局灶性病变,分别行虚拟导航超声造影和常规超声造影,对比两种造影方法的病灶检出率.结果 常规超声造影和虚拟导航超声造影的病灶检出率分别为 36.2%(17/47)和 78.7%(37/47),后者明显高于前者(P<0.01).虚拟导航超声造影时图像融合成功率达100%,平均对位用时5 min.当病灶位于肝边缘受肋骨或肺气影响、肝实质背景杂乱及病灶异常灌注时相较短或灌注差异不明显时,虚拟导航超声造影比常规超声造影更容易定位并检出病灶.结论 虚拟导航超声造影可明显提高二维超声无法显示肝局灶性病变的造影检出率.

Abstract：

Objective To evaluate virtual navigation assisted contrast-enhanced ultrasound(VN-CEUS) by comparing VN-CEUS with routine CEUS in detecting focal liver lesion(FLL) invisible in B-mode ultrasound(BUS).Methods Forty-seven FLLs invisible in BUS were identified by CT/MR,and received VN-CEUS and routine CEUS respectively.Results The detection rate of VN-CEUS and routine CEUS were 78.7%(37/47) and 36.2%(17/47),the former was much higher than the later (P<0.01).In all the cases,fusion of CT/MR with ultrasound was achieved successfully and average time for image fusion was 5 min.compared with routine CEUS,VN-CEUS could more easily find FLLs shadowed by lung or ribs,FLLs in inhomogeneous liver background,and FLLs with brief or inapparent abnormal enhancement.ConclusionsVN-CEUS can greatly improve the detection rate of FLL that was invisible in BUS.     

超声造影诊断肝局灶性病变在县市级医院的应用

目的探讨超声造影对肝脏局灶性病变的诊断价值以及超声造影技术在县市级医院的可行性。方法125例常规超声检查不能完全明确诊断的肝脏局灶性病变患者，采用造影剂SonoVue进行超声造影。分析研究不同性质的肝脏局灶性病变在不同时相的增强表现。结果不同性质的肝脏局灶性病变都有其特征性的增强模式．从而有助于鉴别诊断。与增强CT或增强MRI对照，大多数病灶有相似的增强变化规律。超声造影的诊断准确率达到94．4％（118／125）。结论超声造影技术可明显提高对肝脏局灶性病变的诊断水平，而且在县市级医院开展此技术是可行的。     

超声造影对少罕见局灶性肝病变的诊断价值

目的探讨超声造影对少罕见局灶性肝病变（FLL）的诊断价值及“快进快出”造影模式对少罕见FLL超声造影的诊断价值。 方法回顾分析2012年1月至2019年8月在华中科技大学同济医学院附属同济医院就诊的FLL患者的超声造影资料，人群发病率＜0.05%的病变纳入本研究少罕见FLL组，共纳入61个少罕见FLL病灶，其中33个病灶经MRI/CT检查。以病理结果为金标准，采用四格表评价超声造影、MRI/CT检查以及两者联合对少罕见FLL良恶性的诊断效能，并采用χ²检验比较不同检查方式之间诊断准确性的差异。 结果61个少罕见FLL中，超声造影正确诊断病灶良恶性的敏感度为51.9%（28/54）、特异度为85.7%（6/7）、阳性预测值为96.6%（28/29）、阴性预测值为18.8%（6/32）、诊断准确性为55.7%（34/61）。33个同期行MRI/CT检查的少罕见FLL，超声造影良恶性诊断的诊断准确性略高于MRI/CT检查（48.5% vs 39.4%），但差异无统计学意义（P＞0.05）。超声造影+MRI/CT联合对少罕见FLL良恶性诊断的准确性（69.7%）高于单独MRI/CT检查或超声造影，差异均具有统计学意义（χ²=6.111，P=0.013；χ²=3.070，P=0.046）。对于呈现“快进快出”造影模式的少罕见FLL，超声造影诊断符合率为18.8%（6/32）。实际工作中，超声医师结合临床表现与实验室检查后超声诊断原始报告的诊断符合率为56.3%（18/32），高于单独超声造影诊断，差异具有统计学意义（χ²=9.600，P=0.002）。 结论超声造影对少罕见FLL具有一定诊断价值，与MRI/CT联合应用可提高诊断准确性。对于“快进快出”造影模式的少罕见FLL的诊断，结合临床表现与实验室检查有助于提高诊断符合率。     

Liver tumor characterization--review of the literature

Multicenter trials to assess contrast-enhanced ultrasound (CEUS) for the imaging of focal liver lesions (FLLs) have included more than 1000 patients. This article reviews the published literature pertaining to these trials to determine the role of CEUS in the characterization of FLL.     

Liver tumor characterization--comments and illustrations regarding guidelines

Contrast-enhanced ultrasound (CEUS) is a well established diagnostic imaging technique for a variety of indications and applications. One of the most important applications is in the liver where it is frequently a first-line technique for the detection and diagnosis (characterization) of focal liver lesions (FLLs). In this setting the accurate differentiation of benign lesions from malignant lesions is critical to ensure that the patient undergoes the appropriate therapeutic option. In this article the role of CEUS in the characterization of FLLs is described on the basis of recently published guidelines, in particular in terms of the enhancement patterns of the most common FLLs, e. g. hemangioma, focal nodular hyperplasia, hepatocellular adenoma and their differentiation from malignant lesions.     

Focal liver lesions: sinusoidal phase of CEUS

Ultrasound examination is the first imaging modality for hepatic study in neoplastic and chronic liver diseases. Focal liver lesions frequently cause diagnostic problems in terms of characterization, especially when small and hypoechoic to the rest of the parenchyma. Contrast- enhanced ultrasonography (CEUS) has shown its value in the characterization of focal liver lesions. This study assessed the value of the sinusoidal phase of CEUS with a second-generation contrast agent in the characterization of focal liver lesions to distinguish benign from malignant. Two hundred hepatic lesions with suspicious features at baseline ultrasound were prospectively studied with CEUS. Sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy of the sinusoidal phase in the characterization of benign versus malignant liver lesions were evaluated. Hypoechogenicity of the focal liver lesion, during the sinusoidal phase of CEUS, allowed the diagnosis of malignancy with a sensitivity of 85%, specificity of 88%, positive predictive value of 92%, negative predictive value of 77%, and diagnostic accuracy of 86%. The diagnostic confidence in the diagnosis of malignancy significantly increased, with receiver operating characteristic curve areas from 0.536 for baseline ultrasound to 0.902 for the sinusoidal phase of CEUS.     

Contrast enhanced ultrasound in diagnosing liver lesion that spontaneously disappeared: A case report

BACKGROUNDFocal liver lesions (FLLs) are abnormal masses that are distinguishable from the surrounding liver parenchyma, solid or cystic and may be benign or malignant. They are usually detected incidentally on abdominal examinations. The classification of FLLs is very important as it directly determines the diagnosis and treatment of patients.CASE SUMMARYA 46-year-old male patient was admitted into the hospital with tarry stool, during the investigation of this issue an incidental FLL was detected. Upon further investigation of this “incidentaloma” computerized tomography and magnetic resonance imaging reached contradictory conclusions. The lesion was then further investigated using contrast-enhanced ultrasound (CEUS) with an initial diagnosis of idiopathic FLL was acquired and observation of the FLL over time need for final diagnosis, however in the follow up the FLL disappeared spontaneously.CONCLUSIONCEUSs value for characterization of FLLs is undeniable, especially when other methods produce inconsistent results, is undeniable but with its limitations. Why and how the FLL disappeared is not known, and can be only hypothesized it was a pseudolesion.     

The current status of contrast-enhanced ultrasound in China

This review article provides an overview of the use of contrast-enhanced ultrasound (CEUS) in China. Currently, the only licensed contrast agent is SonoVue, a sulfur hexafluoride-filled microbubble contrast agent. In combination with a low mechanical index contrast-specific imaging mode, SonoVue-enhanced CEUS can be used to visualize the micro and macro-vasculature continuously. Since 2004, CEUS has been widely used in China in various clinical scenarios. The authors compared CEUS with baseline ultrasound or contrast-enhanced computed tomography with regard to characterization of focal liver lesions (FLLs). On CEUS, heterogeneous or homogeneous hyperenhancement during the arterial phase and washout in the portal/late phase are typical findings for hepatocellular carcinoma. The enhancement features of intrahepatic cholangiocarcinoma, infected FLLs, focal fatty infiltration, focal fatty sparing, complex cystic FLLs, and uncommon benign FLLs were carefully depicted. CEUS was also used for patient selection in ablation therapy and evaluation of response to ablation for liver cancer. The utility of three-dimensional CEUS of the liver was also explored. In non-liver use, CEUS in hilar cholangiocarcinoma, gallbladder, breast, and prostate was initially investigated. In addition, CEUS was used in interventional procedures such as CEUS-guided hemostatic injection, intraoperative CEUS in neurosurgery, and evaluation of response to high-intensity focused ultrasound ablation of uterine fibroids. The Chinese experience has resulted in increased use of CEUS.     

The role of contrast-enhanced ultrasound for focal liver lesion detection: an overview

The development of new ultrasound (US) contrast agents and sonographic techniques has considerably improved the possibilities of ultrasound in the assessment of liver tumors. An overview is given on diagnostic potential of contrast-enhanced US (CEUS) and real-time low mechanical index technique in the detection of various focal liver lesions compared with computed tomography, magnetic resonance imaging or intraoperative US. In two of our own studies that included 100 patients each we showed an increase of correct findings in CEUS compared with B-mode US from 64% to 87% and from 67% to 84% as confirmed by intraoperative evaluation of the liver. Especially after chemotherapy and in the case of small metastases, significantly more metastases were correctly detected by CEUS compared with B-mode US. These results and clinical study results in the literature show that CEUS allows tumor detection and direct visualization of the tumor vascularity and put contrast-enhanced sonography among recommended noninvasive imaging methods for focal liver lesions with improvements in diagnostic strategy.