Contrast-enhanced ultrasound in diagnosis and characterization of focal hepatic lesions

The extensive use of imaging techniques in differential diagnosis of abdominal conditions and screening of hepatocellular carcinoma in patients with chronic hepatic diseases, has led to an important increase in identification of focal liver lesions. The development of contrast-enhanced ultrasound (CEUS) opens a new window in the diagnosis and follow-up of these lesions. This technique offers obvious advantages over the computed tomography and magnetic resonance, without a decrease in its sensitivity and specificity. The new second generation contrast agents, due to their intravascular distribution, allow a continuous evaluation of the enhancement pattern, which is crucial in characterization of liver lesions. The dual blood supply in the liver shows three different phases, namely arterial, portal and late phases. The enhancement during portal and late phases can give important information about the lesion's behavior. Each liver lesion has a different enhancement pattern that makes possible an accurate approach to their diagnosis. The role of emerging techniques as a contrast-enhanced three-dimensional US is also discussed. In this article, the advantages, indications and technique employed during CEUS and the different enhancement patterns of most benign and malignant focal liver lesions are discussed.     

Contrast-enhanced ultrasound in evaluation of adrenal lesions with CT/MRI correlation

Most of the adrenal masses are incidentally detected. Multiphasic CT forms the mainstay for diagnosis and characterization of adrenal masses. MRI can further be used if the masses are indeterminate on CT scan. But as these investigations are expensive with risk of radiation exposure, contrast-enhanced ultrasound (CEUS) is currently under evaluation to assess its utility to act as a screening modality to differentiate benign vs malignant adrenal masses This investigative modality is relatively safe and can be used in patients having renal dysfunction or allergy to CT contrast. We, hereby, present a pictorial review of imaging appearance of various adrenal lesions on CEUS with CT and MRI correlation.     

肝血管瘤超声造影表现

目的:探讨肝血管瘤超声造影(contrast enhanced ultrasound,CEUS)的表现。方法:应用对比剂Sonovue及对比脉冲序列成像(contrast pulse sequenuce sound,CPS)技术对25例28个肝血管瘤进行超声造影检查,观察对比剂在动脉期、门脉期及延迟期的增强表现。结果:26个(92.9%)病灶动脉期呈环状增强伴附壁结节或球状突起,门脉期呈缓慢向心性充填,21个病灶呈完全充填,5个病灶呈不完全充填,延迟期与周围肝实质期比呈相对高增强;另2个(7.1%)病灶动脉期、门脉期及延迟期均无增强。结论:超声造影肝血管瘤的典型增强表现为动脉期环状增强,门脉期缓慢向心性充填,延迟期呈高增强。     

Evaluation of shearwave elastography for the characterisation of focal liver lesions on ultrasound

Objectives

To determine the elasticity characteristics of focal liver lesions (FLLs) by shearwave elastography (SWE).

Methods

We used SWE in 108 patients with 161 FLLs and in the adjacent liver for quantitative and qualitative FLLs stiffness assessment. The Mann–Whitney test was used to assess the difference between the groups of lesions where a P value less than 0.05 was considered significant.

Results

SWE acquisitions failed in 22 nodules (14 %) in 13 patients. For the 139 lesions successfully evaluated, SWE values were (in kPa), for the 3 focal fatty sparings (FFS) 6.6?±?0.3, for the 10 adenomas 9.4?±?4.3, for the 22 haemangiomas 13.8?±??5.5, for the 16 focal nodular hyperplasias (FNHs) 33?±??14.7, for the 2 scars 53.7?±?4.7, for the 26 HCCs 14.86?±?10, for the 53 metastasis 28.8?±?16, and for the 7 cholangiocarcinomas 56.9?±?25.6. FNHs had significant differences in stiffness compared with adenomas (P?=?0.0002). Fifty percent of the FNHs had a radial pattern of elevated elasticity. A significant difference was also found between HCCs and cholangiocarcinomas elasticity (P?=?0.0004).

Conclusions

SWE could be useful in differentiating FNHs and adenomas, or HCCs and cholangiocarcinomas by ultrasound.

Key Points

? Elastography is becoming quite widely used as an adjunct to conventional ultrasound ? Shearwave elastography (SWE) could help differentiate adenomas from fibrous nodular hyperplasia ? SWE could also be helpful in distinguishing between hepatocellular carcinomas and cholangiocarcinomas ? SWE could improve the identify hepatocellular carcinomas in cirrhotic livers     

Contrast-enhanced ultrasound for assessing carotid atherosclerotic plaque lesions

OBJECTIVE: Contrast-enhanced ultrasound that is used to assess atherosclerotic carotid plaques improves visualization of vessel wall irregularities and provides direct visualization of intraplaque neovascularization. This article illustrates the use of contrast-enhanced ultrasound in the assessment of carotid atherosclerotic lesions. CONCLUSION: Contrast-enhanced ultrasound is a new, noninvasive, and safe procedure for imaging carotid atherosclerotic lesions. It is a valuable tool for evaluating the vulnerable plaque at risk for rupture and for evaluating both the development and severity of systemic atherosclerotic disease.     

CT检查中窗技术的合理应用对提高肝内病灶检出率的意义

目的评价在传统软组织窗基础上加用肝组织窗对提高肝内病灶检出率的意义。方法接受腹部CT增强扫描的859例患者的895张顺序编号的CT片是由两位有经验的放射学医师评价的。所有的肝脏成像均采用两种窗技术进行，即起初软组织窗和随后肝组织窗。逐例记录了两种技术检出的病灶数与符合率。确定了利用肝组织窗有新增病灶的患者比例。对两种窗技术在检出病灶数方面的差异进行了统计学分析。结果在859例中，205例（24％）患者在软组织窗和肝组织窗上有肝脏病灶，其中，40例（14．6％）患者随着肝组织窗的加用，检出的病灶数亦增多。这40例中的14例患者具有在软组织窗上看不见的新增病灶。两种窗技术的病灶检出率有统计学差异（P〈0．05）。结论 单一的软组织窗不足以全部发现肝内病灶，因此，有些病灶容易漏诊，而肝组织窗的加用，可有效提高肝脏病灶的检出率与诊断准确性。     

Contrast-enhanced ultrasound for diagnosis of prostate cancer and kidney lesions

PURPOSE OF REVIEW: Conventional ultrasonography of both, kidney and prostate, is limited due to the poor contrast of B-mode imaging for parenchymal disease and limited sensitivity of colour Doppler for the detection of capillaries and deep pedicular vessels. Contrast-enhanced ultrasound (CEUS) overcomes these limitations. RECENT FINDINGS: CEUS investigates the blood flow of the prostate, allows for prostate cancer visualization and for targeted biopsies. Comparisons between systematic and CEUS-targeted biopsies have shown that the targeted approach detects more cancers with a lower number of biopsy cores and with higher Gleason scores compared with the systematic approach. Also the kidney offers promising applications as CEUS improves the detection of abnormal microvascular and macrovascular disorders. SUMMARY: In recent literature CEUS has shown its value for diagnosis of both, prostate cancer and kidney lesions. This paper describes recent improvements and future perspectives of CEUS.     

慢性肝病患者发生肝性脑病的危险因素

 目的 探讨慢性肝病患者发生肝性脑病(hepatic encephalopathy, HE)的危险因素。方法 以2014—2019年医院收治的64例HE患者为研究对象。以HE患者首次明确诊断为肝炎或肝硬化的时间为研究起点,首次发作HE作为研究终点,通过单因素和多因素分析,探讨引发HE可能的独立危险因素。结果 单因素和多因素分析表明,年龄(OR:1.066,P<0.0001)、肝硬化(7.979,P<0.0001)、乙肝病毒(HBV)感染及治疗(5.838,P<0.0001)、脾脏肿大(2.722,P=0.003)、食管胃底静脉曲张(EGV, 1.986,P=0.024)和ALT水平高低(2.940,P<0.0001)是影响HE 发病的独立危险因素。肝病患者HE 1年、3年、5年、10年的发病率分别是14.06%、34.38%、42.19%和85.94%。结论 年龄、肝硬化、HBV感染及治疗、脾大、EGV和血清ALT水平是潜在预判肝病患者HE发作的临床指标。     

超声造影与CT增强扫描对肝占位性病变的诊断价值比较

目的 :对比超声造影与CT增强扫描在肝占位性病变中的诊断价值,为临床诊断肝占位性病变提供参考依据。方法 :回顾性分析71例肝占位性病变患者的临床资料,比较超声造影与CT增强扫描的诊断阳性率,对比2种检查方法的诊断价值。结果:超声造影对肝癌、肝血管瘤及肝局灶性结节增生的诊断阳性率分别为83.33%、88.00%及82.14%,而CT增强扫描分别为88.89%、92.00%及85.71%,2种检查方法的诊断阳性率比较差异无统计学意义(P0.05)。此外,2种检查方法对肝癌、肝血管瘤及肝局灶性结节增生均具有较高的诊断效能(P0.05)。结论:超声造影与CT增强扫描对肝占位性病变的诊断价值相当。     

Percentage of signal intensity loss for characterisation of focal liver lesions in patients with chronic liver disease using ferucarbotran-enhanced MRI

The purpose of this study was to determine the percentage of signal intensity loss (PSIL) threshold for the characterisation of focal liver lesions among patients with chronic liver disease. 55 nodules in 49 patients with chronic liver disease who underwent ferucarbotran-enhanced MR studies were included. Among the 49 patients, 40 had liver cirrhosis and 9 had chronic hepatitis. 8 haemangiomas, 3 focal nodular hyperplasia, 9 dysplastic nodules and 12 well, 19 moderately and 4 poorly differentiated hepatocellular carcinomas (HCCs) were revealed. The PSIL, signal-to-noise ratio and contrast-to-noise ratio of each lesion type were calculated. The diagnostic performance of PSIL on ferucarbotran-enhanced T₂ weighted images (PSIL_T2WI) and T₂ weighted fat-suppression images (PSIL_FS-T2WI) that characterised hepatic tumours was compared with receiver operating characteristic (ROC) analysis. Using ROC analysis, the diagnostic performance of PSIL_FS-T2WI was superior to that of PSIL_T2WI (p = 0.01). The mean PSIL_FS-T2WI of the benign lesions was significantly higher than that of HCC (p<0.001), and the mean PSIL_FS-T2WI of well-differentiated HCC was significantly higher than that of moderately/poorly differentiated HCCs (p = 0.001). With a PSIL_FS-T2WI threshold of 40% in lesions characterising ferucarbotran-enhanced FS-T2WI, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value were 88.6%, 95%, 90.9%, 96.9% and 82.6%, respectively. In conclusion, with ferucarbotran-enhanced FS-T2WI, a PSIL_FS-T2WI threshold of 40% for characterising focal liver nodules among patients with chronic liver disease is recommended. It is useful for distinguishing HCC from benign nodules.Nodular lesions against a background of cirrhosis are diagnostically challenging in daily practice. Hepatocellular carcinoma (HCC) develops by means of a multistep dedifferentiation process that progresses from regenerative nodule to dysplastic nodule and then to HCC [1]. Early detection of HCC is important in improving patient outcome and decision making in therapeutic strategies. Asahina et al [2] reported that the assessment of Kupffer cells by ferumoxide-enhanced MRI is beneficial for accurately diagnosing HCCs that are characterised as borderline or early-stage HCCs based on their haemodynamic profile.Ferucarbotran (Resovist, Schering, Germany), a superparamagnetic iron oxide (SPIO), is a liver-specific particulate MRI contrast agent that is primarily taken up by the Kupffer cells of the liver. The uptake-clustered particles can produce a susceptibility effect and cause loss of the signal intensity on post-contrast T₂ weighted images (T2WI) [3]. Imai et al [4] reported that SPIO-enhanced MRI might reflect Kupffer cell numbers in HCCs and was useful for estimation of histological grading in HCCs. However, it is difficult to detect borderline lesions and early-stage HCCs such as dysplastic nodules and well-differentiated HCCs (wHCCs) using SPIO-enhanced MRI because of SPIO uptake by the retained Kupffer cell activity in the nodules [5, 6].Namkung et al [7] have reported that a percentage of signal intensity loss (PSIL) threshold of 25% is effective for the differentiation of benign and malignant hepatic lesions. HCC tends to occur in patients with chronic liver disease such as chronic hepatitis, liver cirrhosis and alcoholism [8]. Could the threshold also be effective in detection of HCC and lesion characterisation for these patients? To our knowledge, the value of PSIL threshold in characterisation of focal liver lesions among high-risk patients has not been elucidated properly. The purpose of our study was to determine the PSIL threshold for differentiation between benign and malignant lesions in patients with chronic liver disease.     

Detecting hepatic lesions: the added utility of CT liver window settings

PURPOSE: To prospectively evaluate the utility of adding computed tomographic (CT) liver windows to conventional soft-tissue windows for the detection of hepatic disease. MATERIALS AND METHODS: One of four radiologists experienced in abdominal imaging interpreted 1,175 consecutive abdominal CT scans from one institution. Hepatic images were first interpreted by using standard soft-tissue windows. The number of lesions and confidence in lesion detection were recorded. The liver-window images were then interpreted in conjunction with the soft-tissue-window images, and the number of lesions and confidence in detection were recorded again. The proportion of patients in whom additional lesions were found by using liver windows was determined. RESULTS: On soft-tissue-window and liver-window scans interpreted together, 869 (74%) patients had no hepatic lesions. Thirty-six (3.1%) patients had new lesions seen with the addition of liver windows. Twelve of these 36 patients had no lesions seen on soft-tissue-window scans. Twenty-six of the 36 patients with additional lesions seen had a history of neoplasm. There was a change in diagnosis in 1.7% of the patients with the addition of liver windows and a change in recommendation for follow-up in 0.85%. CONCLUSION: Routine interpretation of liver-window scans for all abdominal CT scans has limited added utility in detecting hepatic disease.     

小转移性肝癌的超声造影表现及其应用价值

目的：观察小于3cm的恶性肿瘤肝转移病灶的超声造影表现并探讨其临床应用价值。方法：对77例已确诊为恶性肿瘤肝转移的患者进行Sono Vue超声造影检查,记录并分析不同大小病灶的造影后各时相增强的特征。结果：大小〈1.0cm的4例病灶,动脉相均表现为整体团状增强;大小为〉1.0cm～≤2.0cm的39例病灶中,动脉相整体团状增强18例,环状增强17例,不均匀整体增强2例,无增强2例;大小为〉2.0cm～≤3.0cm的34例病灶中,动脉相整体团状增强6例,环状增强24例,不均匀整体增强3例,等增强1例。病灶大小与增强模式之间比较有统计学意义（P〈0.01）。结论：在小转移性肝癌中,病灶的增强模式与大小有关;超声造影对恶性肿瘤临床分期及治疗方案的选择有重要的应用价值。     

Simulation of liver lesions for pediatric CT

PURPOSE: To develop and validate a technique based on characteristics of real lesions for simulating realistic small liver lesions on pediatric computed tomographic (CT) images. MATERIALS AND METHODS: The institutional review board provided exempt status for this study, determined that it was not subject to HIPAA compliance, and did not require informed consent. Patient identification information was removed from clinical images from contrast material-enhanced multi-detector row CT examinations performed in 10 children. Patients were infants or children up to 18 years old. Information about sex was not available. Children had one or more liver lesions of 2-6 mm in maximum transverse diameter. Images with more than one lesion were rendered multiple times, and each time, all but one of the lesions were digitally removed in sequence. This process provided images (n = 19) with a single real lesion. For consistency, the same image backgrounds (images with all real lesions removed) were used to create an identical number of images (n = 19), each with a single simulated lesion. Subsequently, three radiologists independently assessed images of real and simulated lesions that were presented in random order with a score on a continuous scale of 0 (definitely simulated) to 100 (definitely real). Mixed-model analysis of variance was used to test the null hypothesis that the difference in population mean scores between the two lesion types was zero. RESULTS: The observer study did not reveal a significant difference in the ability of any radiologist to discriminate between real and simulated lesions (P > .31). The differences in mean scores for discrimination between real and simulated lesions for the three observers were -6, 9, and -7, respectively. The estimated overall difference was -1. CONCLUSION: Mathematic simulation of liver lesions is a feasible technique for creating realistic lesions for image quality or dose reduction studies in pediatric CT.     

肾乳头状细胞癌的超声造影特征分析并与增强CT对照研究

目的 探讨超声造影与增强CT在肾乳头状细胞癌诊断中的应用价值.方法 分析12例肾乳头状细胞癌的超声造影及增强CT的增强特征,并比较两者敏感性、假包膜显示率、坏死区显示率.结果 肾乳头状细胞癌超声造影模式主要为“慢进”、增强程度为低增强;增强CT主要表现为轻度强化或不强化;两者的敏感性及假包膜显示率无统计学差异,超声造影坏死区显示率高于增强CT.结论 超声造影结合增强CT有助于肾乳头状细胞癌的诊断与鉴别诊断.     

肝脏疾病的螺旋CT扫描技术

随着螺旋CT成像技术的不断发展，螺旋CT扫描对腹部及腹膜后等疾病的显示，特别是对肝脏等实质部分的显示，是传统X线摄影所不及的。肝脏螺旋CT检查技术已经日益成为肝癌等肝脏占位性病变的常规检查方法，如何提高螺旋CT扫描的图像质量以满足临床诊断是需要进一步解决的问题。笔者通过实践，对如何合理地优化扫描参数，得到高质量的图像有一些经验体会，现总结如下。     

Multidetector helical CT plus superparamagnetic iron oxide-enhanced MR imaging for focal hepatic lesions in cirrhotic liver: a comparison with multi-phase CT during hepatic arteriography

The aim of this study was to evaluate multidetector helical computed tomography (MDCT), superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging, and CT arterial portography (CTAP) and CT during hepatic arteriography (CTHA) for the detection and diagnosis of hepatocellular carcinomas (HCC). This included visual correlations of MDCT and SPIO-MR imaging in the detection of HCC using receiver operating characteristic (ROC) analysis. Twenty-five patients with 57 nodular HCCs were retrospectively analyzed. A total of 200 segments, including 49 segments with 57 HCCs, were reviewed independently by three observers. Each observer read four sets of images (set 1, MDCT; set 2, unenhanced and SPIO-enhanced MR images; set 3, combined MDCT and SPIO-enhanced MR images; set 4, combined CTAP and CTHA). The mean Az values representing the diagnostic accuracy for HCCs of sets 1, 2, 3, and 4 were 0.777, 0.814, 0.849, and 0.911, respectively, and there was no significant difference between sets 3 and 4. The sensitivity of set 4 was significantly higher than those of set 3 for all the lesions and for lesions 10 mm or smaller (p<0.05); however, for lesions larger than 10mm, the sensitivities of the two sets were similar. No significant difference in positive predictive value and specificity was observed between set 3 and set 4. Combined MDCT and SPIO-enhanced MR imaging may obviate the need for more invasive CTAP and CTHA for the pre-therapeutic evaluation of patients with HCC more than 10mm.     

Contrast-enhanced ultrasound is helpful in the differentiation of malignant and benign breast lesions

Objective

To evaluate the significance of contrast-enhanced ultrasound (CEUS) examination in differential diagnosis of malignant and benign breast lesions.

Methods

Seventy-one patients with seventy-six breast tumors are selected randomly. CEUS examinations were performed before and after bolus injection of the contrast agent SonoVue (Bracco, Milan, Italy). Specific sonographic quantification software, Qontrast, was adopted to determine the morphology of vessels. Wash-in and wash-out parameters of each lesion were assessed for both procedures.

Results

The final histopathological findings distinguished 45 malignant and 31 benign from all of the lesions. Following SonoVue administration different perfusion phases could be identified: early (0-1 min), mid (1-4 min) and late (4-6 min) phases. In the early phase, CEUS identified 91.1% of malignant tumors characterized by a claw-shaped enhancement, while 83.9% of benign tumors had a homogeneous enhancement, with a statistically significant difference between the two enhancement patterns (χ² = 43.16, P < 0.01). Moreover, contrast medium persistence in the late phase was helpful in the identification of benign and malignant tumors (χ² = 46.88, P < 0.01): contrast medium was present in 88.9% of malignant tumors, while in only 9.7% of the benign tumors. The study showed that various parametric imaging color maps for peak intensity and time to peak were mostly suggestive of malignancy, while quite uniform peak intensity and time to peak of color maps were the characteristic of benign tumors. The study also found that malignant lesions presented with a higher maximum intensity signal than benign ones (P < 0.05) on the time-intensity curves.

Conclusions

CEUS cooperating with conventional US shows improved accuracy in differentiating between malignant and benign breast tumors. It could be a reliable diagnostic method of breast lesions.     

Contrast-enhanced ultrasound study of primary hepatic angiosarcoma: a pitfall of non-enhancement

Objective

To investigate the contrast-enhanced ultrasound (CEUS) characteristics of primary hepatic angiosarcoma (PHA).

Methods

The sonographic findings and CEUS images of PHA in three patients were retrospectively analyzed.

Results

In our study, 3 cases of PHA (2 multiple nodules and 1 solitary mass) showed similar enhancement pattern on CEUS, characterized by remarkable central non-enhancement and peripheral irregular enhancement in the arterial and portal phase, and complete wash-out in the late phase. Furthermore, we unexpectedly found that abundant neoplastic tissues were present in the central area of non-enhancement on pathological evaluation. Based on literature review, we supposed that the unusual finding may be associated with the very low velocity of blood flow in the central region of tumors.

Conclusion

CEUS could well depict PHA with some common features, which may provide valuable clues in diagnosis of this rare disease. And non-necrotic tumor tissue of PHA could also demonstrate non-enhancement on CEUS, which warrant further investigations.     

Contrast-enhanced ultrasound imaging of active bleeding associated with hepatic and splenic trauma

Purpose

The aim of this study was to evaluate contrast-enhanced ultrasound (CEUS) imaging of active bleeding from hepatic and splenic trauma.

Materials and methods

Three hundred and ninety-two patients with liver or/and spleen trauma (179 liver and 217 spleen injuries), who underwent CEUS examinations following contrast-enhanced computed tomography (CT), were enrolled in this retrospective study over a period of >4 years. CEUS detected contrast medium extravasation or pooling in 16% (63/396) of liver or spleen lesions in 61 patients, which was confirmed by contrast-enhanced CT. Special attention was paid to observing the presence, location, and characteristics of the extravasated or pooled contrast medium.

Results

The CEUS detection rate for active bleeding was not different from that of contrast-enhanced CT (p=0.333). Information from surgery, minimally invasive treatment and conservative treatment was used as reference standard, and the sensitivities of the two techniques were not different (p=0.122). Of 63 lesions in 61 patients, CEUS showed that 74.6% (47/63) (21 liver lesions and 26 spleen lesions) presented contrast medium extravasation or pooling, both in the organ and out the capsule, in 14.3% (9/63) and only outside the capsule in 11.1% (7/63). CEUS imaging of active bleeding from hepatic and splenic trauma presented various characteristics, and the sizes and shapes of the active bleeding due to contrast medium extravasation or pooling were variable.

Conclusions

CEUS can show the active bleeding associated with hepatic and splenic trauma with various imaging characteristics, thus making it possible to diagnose active bleeding using CEUS.