Benign liver masses: imaging with microbubble contrast agents

Benign focal liver lesions are frequently encountered in routine ultrasound (US) scanning as well as in staging US examination for the patients with known malignancy. Noninvasive characterization of benign liver masses by imaging features has been a challenge for the radiologist. Some benign liver masses show typical findings on US; however, these findings are not highly specific. Contrast-enhanced ultrasound (CEUS) is useful to make an instant, confident diagnosis of benign liver masses. Contrast-enhanced multiphasic computed tomography (CT) is an excellent imaging technique to detect and characterize focal liver masses. But there are a considerable number of indeterminate focal liver lesions, which require further evaluation. CEUS provides the evaluation of perfusion and hemodynamics of nodular liver lesions as well as real-time morphologic evaluation of lesion vascularity. Most benign liver masses show characteristic features on CEUS, allowing an accurate diagnosis. This review article describes typical enhancement features of common benign liver masses.     

灰阶超声影像组学与超声造影鉴别诊断肝脏局灶性病变良恶性的对比研究

目的 对比分析灰阶超声影像组学与超声造影对肝脏局灶性病变（FLLs）良恶性的鉴别诊断价值。方法 选取我院经手术病理证实的162例FLLs患者,其中恶性86例,良性76例,均行灰阶超声及超声造影检查,比较两者声像图表现的差异。162例FLLs患者随机按照7∶3比例分为训练组113例和验证组49例,比较两组灰阶超声影像组学参数,包括形态学特征、直方图特征、灰度区域大小矩阵特征、Haralick特征、灰度共生矩阵特征、灰度游程矩阵特征,筛选有意义的非冗余特征,选择最优特征子集构建灰阶超声影像组学模型,绘制受试者工作特征曲线分析其鉴别诊断FLLs良恶性的效能。结果 恶性病灶超声造影多表现为动脉相病灶呈高增强,门脉相病灶呈低增强,且两者间存在明显分界（67例）;良性病灶超声造影均表现为动脉相病灶呈等增强或稍高增强,造影剂从病灶周边缓慢向中心灌注,门脉相及延迟相病灶均呈等增强或高增强,未见明显的造影剂消退现象。训练组和验证组良恶性病灶直方图特征、灰度共生矩阵特征、灰度游程矩阵特征比较差异均有统计学意义（均P<0.05）;最终纳入1个直方图特征、1个灰度共生矩阵特征、1个灰阶游程矩阵特征构建灰...     

31例肝局灶性结节状增生的影像学检查结果对比分析

【目的】分析肝局灶性结节状增生超声、CT、核磁共振影像学结果,明确各种检查的诊断价值,提高肝局灶性结节状增生诊断的准确率,避免不必要的手术治疗。【方法】回顾性分析31例（33个病灶）经病理证实的肝局灶性结节状增生患者的超声、CT、核磁共振影像检查的结果。【结果】31例患者（33个病灶）中,二维灰阶超声诊断为良性病变18个病灶,彩色多普勒超声诊断为良性病变26仓病灶,22个病灶CT诊断为良性病变．共有26个病灶MRI诊断为肝局灶性结节状增生;其中行超声造影者9例,8例均诊断为肝局灶性结节状增生。【结论】彩色多普勒超声与MRI对肝局灶性结节状增生的良恶性诊断大体一致,但是MRI对肝局灶性结节状增生的定性诊断明显高于彩超;而超声造影是所有影像定性诊断中最准确的方法。     

Characterization of benign hepatic tumors arising in fatty liver with SonoVue and pulse inversion US

Background We describe the spectrum of contrast-enhancement patterns of benign hepatic tumors arising in fatty liver on contrast-enhanced ultrasound (US). Methods Sixteen patients (12 women and four men) with 27 benign hepatic tumors (17 hemangiomas, eight focal nodular hyperplasias, and two hepatocellular adenomas) arising in fatty liver underwent baseline and pulse inversion US after administration of SonoVue. Two experienced radiologists evaluated baseline echogenicity and dynamic enhancement pattern of each lesion in comparison with adjacent liver parenchyma. Results After administration of SonoVue, in the arterial phase 13 of 17 hemangiomas showed peripheral globular enhancement and one showed a rim of peripheral enhancement, followed by progressive centripetal fill-in, which was complete in 10 of 14 cases and incomplete in four. Three of 18 hemangiomas showed rapid and complete fill-in in the arterial phase. Eight of eight focal nodular hyperplasias became hyperechoic in comparison with adjacent liver parenchyma in the arterial phase and slightly hyperechoic or isoechoic in the portal venous and delayed phases. Both adenomas showed strong arterial contrast enhancement that became less intense in the portal venous and delayed phases. Conclusion Contrast-enhanced US after administration of SonoVue enables depiction of typical contrast-enhancement patterns in most benign hepatic tumors arising in fatty liver, thus providing useful clues for characterization.     

肝脏实质性占位病灶的超声造影检测

目的评价低机械指数超声造影技术对肝脏占位性病变的检测和定性诊断能力。方法对363例共389个肝占位性病变(256个原发性肝癌、53个转移性肝癌、49个血管瘤、19个局灶性结节增生、7个肝脓肿和5个炎性假瘤)行超声造影检查,分析造影表现并与临床病理结果进行比较。结果超声造影显示原发性肝癌表现为动脉相整体完全增强或斑片状增强、门脉期减退(敏感性93.7%,特异性69.9%);转移性肝癌动脉相呈整体完全增强和环状增强、门脉期低回声(敏感性41.5%,特异性96.7%);肝血管瘤的常见特征是周边向中央逐渐或快速填充增强(敏感性95.9%,特异性99.1%);肝局灶性结节增生的表现是动脉相快速离心性整体完全增强,并持续高或等回声至延迟期(敏感性84.2%,特异性98.9%),中央疤痕的出现率低;肝脓肿的特异表现是整个时相呈蜂窝状增强(敏感性71.4%,特异性100%);炎性假瘤则始终未见增强。结论低机械指数超声造影能无创地鉴别诊断肝脏占位性病变,可作为首选的影像诊断技术应用于临床。     

Imaging of focal liver lesions: low-mechanical-index real-time ultrasonography with SonoVue.

OBJECTIVE: The purpose of this study was to evaluate the usefulness of a contrast-enhanced contrast-specific ultrasonographic technique with a low mechanical index for characterization of focal liver lesions. METHODS: Contrast-specific ultrasonography was used to assess 144 patients with 147 focal liver lesions: 87 primary liver carcinomas, 27 hemangiomas, 16 focal nodular hyperplasias, 5 hepatic abscesses, 3 inflammatory pseudotumors of the liver, and 9 metastases. A sulfur hexafluoride gas-based contrast agent was used with a mechanical index of 0.08 to 0.11. RESULTS: On contrast-enhanced ultrasonography, the typical hemodynamic pattern of primary liver carcinoma was the whole-lesion enhancement or mosaic enhancement in the arterial phase with an enhancement defect in the late phase (sensitivity, 92.0%; specificity, 86.7%). The most common enhancement pattern of hemangioma was that enhancement appeared in the periphery first and progressively filled into the lesion center (sensitivity, 96.3%; specificity, 97.5%). The enhancement pattern of focal nodular hyperplasia was that the whole lesion enhanced early and rapidly in the arterial phase with a centrifugal radiating configuration and appeared isoechoic or hyperechoic until the late phase (sensitivity, 87.6%; specificity, 94.5%). The central scar was detected in 31.3% of cases in the late phase. The specific enhancement of a hepatic abscess was the honeycomblike enhancement in all phases (sensitivity, 80.0%; specificity, 100%). No enhancement of a lesion in all phases was specific for an inflammatory pseudotumor of the liver. CONCLUSIONS: Contrast-enhanced real-time ultrasonography is a promising approach in the noninvasive characterization of focal liver lesions and can be useful as a first-line imaging technique clinically when a focal liver lesion is detectable on ultrasonography.     

超声造影结合血清甲胎蛋白、磷脂酰肌醇蛋白聚糖3对早期肝硬化结节状小肝癌的诊断价值研究

目的：探讨超声造影(CEUS)结合血清甲胎蛋白(AFP)、磷脂酰肌醇蛋白聚糖3(GPC3)对早期肝硬化结节状小肝癌的诊断价值研究。方法：回顾性分析本院收治的78例早期发现肝硬化合并小结节样病灶患者的临床资料,根据病理结果分为小肝癌组(46例)和良性病变组(32例)。所有患者术前均行超声造影、血清AFP、GPC3水平检测,并比较两组之间各参数的差异,分析三者单独或联合诊断小肝癌的价值。结果：小肝癌组的超声造影特征与良性病变组显著不同(P<0.05),小肝癌组大多呈“快进快出”表现,而良性病变组大多呈“慢进慢出”表现。小肝癌组患者血清AFP、GPC3水平显著高于良性病变组(P<0.05)。超声造影结合血清AFP、GPC3水平联合诊断HCC的准确性、敏感度、特异度、阳性预测值、阴性预测值最高(P<0.05)。结论：超声造影结合血清AFP、GPC3有助于提高对早期肝硬化结节状小肝癌的鉴别诊断价值,对临床治疗方案的选择有一定指导意义。     

SonoVue超声造影在肝良性占位病变诊断中的应用

目的探讨超声造影在肝良性占位病变诊断中的应用。方法30例肝良性占位病变患者经肘部静脉团注SonoVue。采用超声造影二次谐波成像技术,实时观察注射造影剂后病灶增强特征。结果经超声造影后,23个肝血管瘤动脉相均呈高回声增强,20个(87%)表现为周边向心型,2个(8.7%)为中央扩散型,1个(4.3%)为整体型增强特征,20个病灶在门脉相和延迟相仍为高回声增强,2个病灶渐变为等回声增强,1个病灶渐变为低回声增强。2个肝局灶性结节增生病灶在动脉相均呈中央扩散型增强,表现为轮辐状,门脉相及延迟相呈等回声增强。3个肝局部脂肪缺失病灶均显示动脉相无增强,门脉相及延迟相呈等回声。2个肝脓肿病灶动脉相周边无增强,延迟相病灶内呈低回声增强及无增强。结论SonoVue超声造影二次谐波成像技术能动态显示病灶增强特征,有助于肝良性占位病变的诊断及鉴别诊断。     

超声造影对肝局灶性病变病灶类型诊断的应用价值

目的探讨超声造影对肝局灶性病变病灶类型判断的能力。方法比较研究常规超声及低机械指数超声造影对238例298个肝局灶性病变鉴别诊断的效能。结果298个肝局灶性病变常规超声正确诊断病变类型159个(53.4%),超声造影正确诊断病变类型279个(93.6%),两者比较有统计学差异(P<0.01)。结论超声造影提高了超声正确诊断肝局灶性病变病灶类型的能力。     

Analysis of different contrast enhancement patterns after microbubble-based contrast agent injection in liver hemangiomas with atypical appearance on baseline scan

Background We describe different possible enhancement patterns in liver hemangiomas with atypical appearance on baseline ultrasound after microbubble-based contrast agent injection. Methods From a series of 253 consecutive lesions that were indeterminate on baseline ultrasound and then scanned after injection of air-filled microbubble contrast agent, 65 focal liver lesions were retrospectively selected on the basis of a diagnosis of liver hemangioma on multiphase contrast-enhanced computed tomography (n = 23), magnetic resonance imaging (n = 27), or histology (n = 15). Each lesion was scanned during arterial phase (30 s after microbubble injection) and late phase (5 min after injection). On-site sonologists performed retrospective assessment of contrast-enhancement patterns by consensus. Results Centripetal fill-in preceded (n = 50) or not preceded (n = 3) by peripheral nodular/rim-like enhancement was the prevalently observed contrast-enhancement pattern, equivalent to the typical enhancement pattern of liver hemangiomas on contrast-enhanced computed tomography or magnetic resonance imaging. In the remaining lesions, additional enhancement patterns (diffuse contrast enhancement with rapid fill-in and a late hyper-isoechoic appearance, n = 6; peripheral nodular enhancement with a late hypoechoic appearance, n = 3; or persistent heterogeneous and hyperechoic appearance, n = 3) were observed. Conclusion Different contrast-enhancement patterns are possible in atypical liver hemangiomas after microbubble injection. Typical centripetal fill-in is the prevalent pattern and its evidence allows diagnosis.     

实时超声造影鉴别诊断肝脏良、恶性病变

目的 探讨实时超声造影在肝脏病变良恶性鉴别诊断中的应用价值.方法 应用新型超声对比剂SonoVue与低机械指数实时脉冲反向谐波超声造影技术,对103例肝脏局灶性和弥漫性病变患者进行常规超声与超声造影比较研究,其中经穿刺活检、手术或临床确诊的79例作为本文研究对象.结果 79例肝脏病变患者具有不同的超声造影增强时相和增强类型,与病理结果对照,常规超声与实时超声造影对肝脏病变的诊断准确性分别为34.2%(27/79)和88.6%(70/79),两者差异有显著性.结论 实时超声造影技术在肝脏局灶性病变的良恶性诊断和鉴别诊断中具有重要的临床应用价值.     

肝脏局灶性病变MR动态增强扫描的临床应用

目的：探讨肝脏局灶性疾病ＭＲ动态增强扫描的方法和临床应用。方法：回顾性分析６８例肝脏局灶性病变：包括原发性肝细胞癌２４例,周围型肝管细胞癌２例,转移瘤１６例,海绵状血管瘤２４例,局灶性结节增生２例。     

超声造影对肝脏肿瘤良恶性鉴别诊断的临床应用

目的探讨应用SonoVue进行超声造影对比常规超声在提高肝脏肿瘤良恶性鉴别诊断的应用价值。方法回顾分析78例常规超声检出肝脏局灶性病变（FLL）,根据二维及彩色多普勒特点,结合病史给出初步良恶性判断后,进一步采用超声造影,对病灶造影剂灌注过程进行分析,得出修正判断;最后以病理结果为金标准,进行统计学分析。结果78个病灶中病理结果示良性病灶32例,恶性病灶46例。超声造影在良恶性鉴别诊断的敏感性为92.8%,特异性为91.7%,准确性92.3%,明显优于常规超声。结论应用静脉团注SonoVue法进行实时灰阶超声造影有助于肝局灶性病变良恶性的鉴别诊断。     

超声造影对肝脏局灶性病变的诊断价值

目的评价超声造影对肝脏局灶性病变的诊断与鉴别诊断价值。方法对103个肝脏局灶性病变的常规超声及超声造影特征进行前瞻性研究,采用5分评分法进行良、恶性诊断及ROC曲线分析,比较超声造影前后肝脏局灶性病变的鉴别诊断价值。结果98.2%恶性病灶(56/57)超声造影动脉相表现为弥漫或环状增强,诊断敏感性98.2%,特异性82.6%;延迟相,82.5%(47/57)恶性病灶增强信号廓清,诊断敏感性82.5%,特异性84.8%。良性病灶中17.4%(8/46)动脉相弥漫增强;84.8%(39/46)延迟相持续增强。血管瘤呈向心性增强,诊断敏感性81.8%,特异性100%。局灶性结节性增生动脉相放射状增强,诊断敏感性66.7%,特异性99.0%。根据诊断评分,超声造影诊断肝脏良恶性病变的敏感性为98.2%,特异性为91.3%,高于常规超声诊断;其ROC曲线下面积(0.948)大于常规超声诊断者(0.811,P=0.000)。结论超声造影肝局灶性良恶性病变具有特征性表现,其诊断应用价值高于常规超声。     

Hepatic Angiomyolipomas: Ultrasonic Characteristics of 25 Patients from a Single Center

Twenty-five pathologically proven hepatic angiomyolipomas (AMLs) were included in the study. Ultrasonic features of hepatic AMLs were reviewed. Three types of echogenicity were observed on ultrasound examination: (i) strong hyper-echogenicity, (ii) moderate hyper-echogenicity and (iii) hypo-echogenicity. Vascular signals within tumors could be detected in 22 (88.00%) tumors as multiple punctiform, filiform or dendriform signals by color Doppler flow imaging. Based on the enhancement patterns in the arterial, portal and late phases, the features of hepatic AMLs on contrast-enhanced ultrasound were divided into four subtypes: (i) “fast in slow out” (68.00%, n = 17); (ii) “fast in same out” (16%, n = 4); (iii) “fast in fast out” (12.00%, n = 3); and (iv) “fast in uneven out” (4.00%, n = 1). Contrast-enhanced ultrasound diagnosed 22 (88.00%) tumors as benign tumors and 13 (52.00%) as hepatic AMLs. Four cases were misdiagnosed as hepatic hemangioma, five cases as focal nodular hyperplasia (total = 36.00%). The rate of correct diagnosis of hepatic AMLs increased significantly from 24.00% for ultrasound alone to 52.00% for contrast-enhanced ultrasound. Therefore, information obtained from ultrasound, color Doppler flow imaging and contrast-enhanced ultrasound should be combined to improve diagnosis.     

Evaluation of hepatic focal nodular hyperplasia with contrast-enhanced gray scale harmonic sonography: initial experience.

OBJECTIVE: To assess the potential of contrast-enhanced gray scale harmonic sonography in the evaluation of the typical vascular and enhancement patterns of hepatic focal nodular hyperplasia. METHODS: Thirteen patients with 13 lesions of hepatic focal nodular hyperplasia underwent contrast-enhanced gray scale harmonic sonography. After the injection of a microbubble contrast agent (SH U 508A), gray scale harmonic sonographic studies using a Coded Harmonic Angio technique were performed with a combination of a period of continuous scanning to assess the vascular pattern (vascular imaging) and interval delay scanning to determine the sequential enhancement pattern (acoustic emission imaging). Each imaging pattern was categorized and analyzed by consensus of 2 experienced radiologists. RESULTS: In 12 (92%) of 13 lesions, vascular imaging during the arterial phase showed central arteries of a spoked wheel pattern, whereas the remaining lesion had stippled vascularity. On acoustic emission imaging, 11 (85%) of 13 lesions were hyperechoic during the early phase, and the remaining 2 (15%) were isoechoic compared with surrounding parenchyma. Ten (77%) of 13 lesions remained either hyperechoic (5 of 13) or isoechoic (5 of 13) during the delay phase, whereas the remaining 3 lesions (23%) were hypoechoic. CONCLUSIONS: Contrast-enhanced gray scale harmonic sonography showed the typical vascularity of a spoked wheel pattern during the vascular phase and persistent enhancement on serial acoustic emission imaging in most cases of hepatic focal nodular hyperplasia, and thereby it can be a promising technique in noninvasive diagnosis of this entity.     

A Model-Based Prediction of the Probability of Hepatocellular Adenoma and Focal Nodular Hyperplasia Based on Characteristics on Contrast-Enhanced Ultrasound

Contrast-enhanced ultrasound (CEUS) is an emerging imaging technique that is increasingly used to diagnose liver lesions. It is of the utmost importance to differentiate between the two most common solid focal liver lesions (i.e., hepatocellular adenoma [HCA] and focal nodular hyperplasia [FNH]), because their management and follow-up differ greatly. The main objective of this study was to determine how frequently the specific CEUS features of HCA and FNH are visible on CEUS and to define their predictive value for discrimination between HCA and FNH. We included 324 CEUS examinations performed on patients with FNH (n = 181) or HCA (n = 143). Patients with HCA and FNH significantly differed with respect to age and CEUS features of steatosis, echogenicity, homogeneity, the presence of a central scar, central artery, arterial enhancement pattern, necrosis or thrombus and enhancement in the late venous phase.     

高帧频超声造影在肝富血供占位性病变动脉期中的成像优势与临床价值

目的探讨高帧频超声造影（H-CEUS）在肝富血供结节动脉期成像的优势及其潜在的临床价值。 方法选取2018年5月至2019年12月在解放军总医院第一医学中心因肝局灶性病变而行超声造影（CEUS）检查患者88例。根据病理及增强磁共振结果分为恶性组和良性组。研究对象分别行超声、CEUS和H-CEUS检查并记录动态图像。2位医师分别对超声、CEUS和H-CEUS图像进行独立分析并记录结果,统计分析CEUS和H-CEUS图像特征。采用t检验比较良性组和恶性组患者年龄和结节最大径的差异,采用χ²检验比较良性组和恶性组患者性别、结节数量和结节血流的差异、2种超声造影模式特征（开始增强时间、增强程度、均匀性、方向和血管形态）的差异以及2种造影模式下不同大小恶性结节血管形态的差异。 结果良性组与恶性组间患者年龄（t=3.428,P=0.001）、结节最大径（t=3.039,P=0.003）及结节血流比较（χ²=8.159,P=0.004）差异均有统计学意义。开始增强时间、增强程度与均匀性在CEUS和H-CEUS技术间比较,差异均无统计学意义（P均>0.05）。造影增强方向及血管形态在2种造影技术间比较,差异均有统计学意义（χ²=54.795、11.510,P均<0.05）。结节最大径≤3.0 cm的恶性组中2种造影技术在显示血管形态方面,差异有统计学意义（χ²=12.983,P<0.001）,结节最大径>3.0 cm的恶性组中2种造影技术在显示血管形态方面,差异无统计学意义（P>0.05）。 结论通过提高超声图像帧频有助于准确地显示动脉期的增强特征和血管形态,尤其是对于最大直径≤3.0 cm的富血供结节H-CEUS可以弥补CEUS在这方面的局限性。     

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.     

肝局灶性病变超声造影与增强CT和MRI表现的比较

目的 比较肝局灶性病变CEUS与增强CT(CECT)、增强MRI(CEMRI)表现的异同,并分析差异原因。方法 回顾性分析我院70例肝局灶性病变患者的影像资料,共75个病灶,包括肝细胞癌39个,转移性肝癌6个,胆管细胞癌6个,局灶性结节性增生6个,肝硬化结节5个,肝血管瘤4个,坏死结节4个,其他5个。阅片医师对各时相增强水平、增强类型、有无新发病灶等进行评价。采用Kappa检验评估CEUS与CECT/CEMRI表现及医师阅片结果间的一致性,并分析不一致的影像表现。结果 CEUS与CECT/CEMRI在病灶是否存在确切无增强的坏死或瘢痕区域方面一致性最高(Kappa=0.68);在门静脉期病灶相对于周围肝实质的主要增强水平方面一致性最低(Kappa=0.48)。44.23%(23/52)的恶性病灶及21.74%(5/23)良性病灶的CEUS与CECT/CEMRI表现不完全一致。结论 CEUS与CECT/CEMRI各时相表现一致性较好,差异性表现多集中于恶性病变。病灶影像表现存在差异的原因可能与对比剂不同及病理组织特征等有关。