Benign focal liver lesions: The role of magnetic resonance imaging

Liver lesions are common findings in radiologists’ daily routine. They are a complex category of pathology that range from solitary benign lesions to primary liver cancer and liver metastases. Benign focal liver lesions can arise from different liver cell types: Epithelial (hepatocytes and biliary cells) and nonepithelial (mesenchymal cells). Liver magnetic resonance imaging (MRI) is a fundamental radiological method in these patients as it allows with its multiparametric approach optimal non-invasive tissue characterization. Furthermore, advanced liver MRI techniques such as diffusion-weighted imaging and hepatobiliary contrast agents have improved the detection of focal liver lesions and can be highly effective in differentiating pseudotumor from tumors, as well as benign from malignant lesions, and can also be used for differential diagnosis. Although histological examination can be useful in making a definitive diagnosis, MRI is an important modality in the diagnosis of liver lesions with a significant impact on patient care. This aim of this review is to provide a comprehensive overview of benign liver lesions on MRI.     

Influence of Liver Fibrosis on Hepatic Artery Doppler Resistance Index in Chronic Hepatitis of Viral Origin

Background: Hepatic arterial Doppler sonography is increasingly being used in liver diagnostics. The determinants of the elevation of hepatic artery impedance indexes in chronic liver disease, however, have still not been fully clarified. The aim of the present study was to investigate the relationship between histological alterations and liver circulation in chronic hepatitis. Methods: Hepatic artery resistance index and portal flow velocity were measured using Doppler sonography in 47 patients with chronic hepatitis of viral origin diagnosed at histopathology. The patients were divided into two groups, those with mild and those with severe alterations, in accordance with the various histological parameters of the Knodell scoring system. Results:     

多普勒超声监测肝硬化患者肾动脉阻力指数的临床意义

背景:肝硬化患者易发生肾脏血流灌注减少,导致肾功能损害。早期发现肾血流动力学的变化将有利于肝肾综合征的防治。目的:探讨不同阶段肝硬化患者肾血流动力学的变化,评价肾动脉阻力指数(RI)用于判断肝硬化患者早期肾功能损害的价值。方法:应用多普勒超声监测40例肝硬化患者和15名健康对照者的各级肾动脉RI。结果:肝硬化患者的各级肾动脉RI均较对照组显著增高(P<0.05),而血清肌酐、尿素氮水平与对照组相比无显著差异。大量腹水组肝硬化患者肾动脉主干、段动脉和皮质肾动脉的RI较少量腹水组和无腹水组显著增高(P<0.05),肾动脉RI由肾门至肾皮质依次降低的规律消失。结论:多普勒超声可在肝硬化患者血清肌酐、尿素氮水平增高前定量观察到肾血流动力学的变化。肾动脉RI可作为判断肝硬化患者早期肾功能损害较敏感的指标。     

Perfusion CT findings in liver of patients with tumor during chemotherapy

AIM: To investigate the microcirculation changes in liver of patients with tumor during chemotherapy by perfusion computed tomography (CT). METHODS: Sixty patients with tumor and 20 controls were enrolled in this study. Perfusion CT parameters of patients and controls were compared, including hepatic perfusion index (HPI), mean transit time (MTT), and permeability-surface area product (PS). Correlation between perfusion CT parameters, treatment cycle and alanine aminotransferase (ALT) level was studied. RES...     

Doppler ultrasonography in living donor liver transplantation recipients: Intra- and post-operative vascular complications

Living-donor liver transplantation has provided a solution to the severe lack of cadaver grafts for the replacement of liver afflicted with end-stage cirrhosis, fulminant disease, or inborn errors of metabolism. Vascular complications remain the most serious complications and a common cause for graft failure after hepatic transplantation. Doppler ultrasound remains the primary radiological imaging modality for the diagnosis of such complications. This article presents a brief review of intra- and post-operative living donor liver transplantation anatomy and a synopsis of the role of ultrasonography and color Doppler in evaluating the graft vascular haemodynamics both during surgery and post-operatively in accurately defining the early vascular complications. Intra-operative ultrasonography of the liver graft provides the surgeon with useful real-time diagnostic and staging information that may result in an alteration in the planned surgical approach and corrections of surgical complications during the procedure of vascular anastomoses. The relevant intraoperative anatomy and the spectrum of normal and abnormal findings are described. Ultrasonography and color Doppler also provides the clinicians and surgeons early post-operative potential developmental complications that may occur during hospital stay. Early detection and thus early problem solving can make the difference between graft survival and failure.     

Use of second generation contrast-enhanced ultrasound in the assessment of focal liver lesions

Ultrasound （US） is often the first imaging modality employed in patients with suspected focal liver lesions. The role of US in the characterisation of focal liver lesions has been transformed with the introduction of specific contrast media and the development of specialized imaging techniques. Ultrasound now can fully characterise the enhancement pattern of hepatic lesions, similar to that achieved with contrast enhanced multiphasic computed tomography （CT） and magnetic resonance imaging （MRI）. US contrast agents are safe, well-tolerated and have very few contraindications. Furthermore, real-time evaluation of the vascularity of focal liver lesions has become possible with the use of the newer microbubble contrast agents. This article reviews the enhancement pattern of the most frequent liver lesions seen, using the second generation US contrast media. The common pitfalls for each type of lesion are discussed. The recent developments in US contrast media and specific imaging techniques have been a major advance and this technique, in view of the intrinsic advantages of US, will undoubtedly gain popularity in the years to come.     

Phase inversion harmonic imaging versus contrast-enhanced power Doppler sonography for the characterization of focal liver lesions

BACKGROUND AND AIMS: We compared contrast-enhanced power Doppler sonography (CEPD) and phase-inversion harmonic imaging (PIHI) in the assessment of liver lesion vascularity and characterization of focal liver lesions. MATERIALS AND METHODS: We examined 101 focal liver lesions by CEPD and PIHI using Optison as echo-enhancing agent. Amount and architecture of lesion vascularity and the kinetics of contrast enhancement in the lesions were analyzed. A tumor diagnosis was assessed after each examination. RESULTS: Analysis of tumor vascularity was not possible in 30 liver lesions (30%) due to motion or blooming artifacts by CEPD. Vascularity was detected in 61% of liver lesions by CEPD and in 95% by PIHI. PIHI identified significantly more tumor vascularity pattern (93%) than CEPD (57%). Specific lesion diagnosis based on PIHI led to correct results in 92% compared to 59% by CEPD. CONCLUSION: PIHI is highly efficient in detecting tumor vascularity and is superior to CEPD in characterizing focal liver lesions.     

彩色多普勒超声在结节性甲状腺肿中的诊断价值

目的探讨彩色多普勒超声在结节性甲状腺肿(简称结甲)诊断中的价值。方法回顾88例结节性甲状腺肿的声像图与手术病理诊断对照分析。结果88例经手术病理证实的结甲,术前超声诊断的79例(诊断符合率90%),误诊为甲状腺腺瘤6例、甲状腺癌2例、亚急性甲状腺炎1例。结论结甲声像图表现复杂多样,超声检查虽具有一定特征性,但应注意鉴别诊断,以提高诊断符合率。     

Changes of duplex parameters and splenic size in liver transplant recipients during a long period of observation

AIM: To assess the changes of portal and arterial velocities, resistance index, spleen and liver size during a long observation period (13.7 years) after orthotopic liver transplantation (OLT). METHODS: Two hundred and sixty patients were recruited retrospectively for this study and divided into groups with defined time intervals after OLT. The cross-sectional changes of portal and arterial velocities, resistance index, spleen and liver size between the defined time intervals were studied. The complications detected by ultrasound were compared to gold standard methods. RESULTS: The mean values for liver size were all within the normal range. The splenic size decreased between the time intervals 100 and 1 000 d after OLT (t; P＜0.01). While portal and arterial flow velocities decreased up to 5.5 years (t; portal velocity P＜0.01, maximal systolic velocity P=0.05, maximal end diastolic velocity P＜0.01), RI increased during this interval (t: P＜0.01). Higher RI values were found in older patients (r = 0.24, P＜0.001). CONCLUSION: The arterial and portal velocities show adaptation processes continuing over the course of many years after OLT and are reported for the first time. The vascular complications detected by ultrasound occur mostly up to 100 d after OLT.     

多普勒无创血管检查在诊断肢体缺血中的应用

目的 :探讨多普勒无创血管检查在诊断缺血肢体的血管闭塞部位与程度中的正确性。方法 :对 2 0 0 0年 3月至 2 0 0 0年 12月的 38例肢体缺血患者 ,5 4例患肢进行多普勒血管超声与造影结果对比。结果 :多普勒超声对 5 4例缺血患肢诊断的正确率为 87% ,与血管造影结论无显著性差异。结论 :多普勒无创血管检查方便实用 ,正确率高 ,可用于治疗前后病情变化的对比与门诊患者的动态观察     

彩色多普勒超声检查诊断肝移植术后胆道并发症价值分析*

目的 探讨采用彩色多普勒超声检查诊断肝移植术后胆道并发症的应用价值,为提高移植肝的存活率提供保障。方法 2014年5月~2018年9月在我院行肝移植术的54例患者,采用胆道造影和彩色多普勒超声检查胆道情况。结果 经胆道造影检查,发现14例发生了肝移植术后胆道并发症,其中胆道狭窄9例,胆管内胆泥或胆石形成5例;有并发症患者肝内胆管内径和总胆管内径分别为（4.7±2.1） mm和（7.5±3.6） mm,显著大于40例无并发症患者的（1.2±0.5） mm和（4.3±1.6） mm（P<0.05）,有并发症患者肝内胆管壁厚和总胆管壁厚分别为（2.3±0.4） mm和（4.7±1.5） mm,显著大于无并发症患者的（0.8±0.2） mm和（2.1±0.9） mm（P<0.05）;以总胆管内径>6 mm、胆管壁回声增强和总胆管壁厚度>3.5 mm作为诊断标准,彩色多普勒超声检查诊断肝移植术后胆道并发症的敏感度为57.1%,特异度为80.0%。结论 使用彩色多普勒超声检查诊断肝移植术后胆道并发症的发生具有无创、方便和可重复进行的优点,具有很大的临床应用价值。     

钆塞酸二钠增强MR与增强CT诊断肝脏局灶性病变效能对比研究*

目的 探讨应用钆塞酸二钠增强 MR检查对肝脏局灶性病变的诊断效能。方法 2015年6月~2017年6月我院诊治的肝脏局灶性病变患者47例,行无肝胆期和有肝胆期钆塞酸二钠增强 MR和增强 CT检查,行肝穿刺活组织病理学检查,以此为金标准,计算各检查方法的诊断效能。结果 在47例肝脏局灶性病变患者中,病变大小为0.7~6.2 cm （2.1±0.8） cm。经病理学检查诊断为胆管细胞癌15例,胆管囊腺癌1例,结肠癌肝转移8例,直肠癌肝转移3例和肝血管瘤5例,局灶性结节性增生8例,肝硬化结节4例,脂肪瘤2例,腺瘤1例;有肝胆期钆塞酸二钠增强 MRI诊断的敏感度为88.9%,特异度为80.0%,准确度为85.1%,显著高于无肝胆期钆塞酸二钠增强 MRI的60.0%、61.7%和63.0%或增强 CT检查的45.0%、48.9%和51.9%,差异有统计学意义（P<0.05）。结论 有肝胆期钆塞酸二钠增强 MRI检查有利于提高对肝脏局灶性病变的临床定性诊断,值得进一步验证。     

Focal liver lesions detection and characterization: The advantages of gadoxetic acid-enhanced liver MRI

Since its clinical introduction, several studies in literature have investigated gadolinium ethoxybenzhyl diethylenetriaminepentaacetic acid or gadoxetic acid(Gd-EOB-DTPA) properties. Following contrast injection, it provides dynamic vascular phases(arterial, portal and equilibrium phases) and hepatobiliary phase, the latter due to its uptake by functional hepatocytes. The main advantages of Gd-EOB-DTPA of focal liver lesion detection and characterization are discussed in this paper. Namely, we focus on the possibility of distinguishing focal nodular hyperplasia(FNH) from hepatic adenoma(HA), the identification of early hepatocellular carcinoma(HCC) and the pre-operative assessment of metastasis in liver parenchyma. Regarding the differentiation between FNH and HA, adenoma typically appears hypointense in hepatobiliary phase, whereas FNH is isointense or hyperintense to the surrounding hepatic parenchyma. As for the identification of early HCCs, many papers recently published in literature have emphasized the contribution of hepatobiliary phase in the characterization of nodules without a typical hallmark of HCC. Atypical nodules(no hypervascularizaton observed on arterial phase and/or no hypovascular appearance on portal phase) with low signal intensity in the hepatobiliary phase, have a high probability of malignancy. Finally, regarding the evaluation of focal hepatic metastases, magnetic resonance pre-operative assessment using gadoxetic acid allows for more accurate diagnosis.     

Hemodynamic analysis of esophageal varices in patients with liver cirrhosis using color Doppler ultrasound

AIM: To study the portal hemodynamics and their relationship with the size of esophageal varices seen at endoscopy and to evaluate whether these Doppler ultrasound parameters might predict variceal bleeding in patients with liver cirrhosis and portal hypertension. METHODS: One hundred and twenty cirrhotic patients with esophageal varices but without any previous bleeding were enrolled in the prospective study. During a 2-year observation period, 52 patients who had at least one episode of acute esophageal variceal hemorrhage constituted the bleeding group, and the remaining 68 patients without any previous hemorrhage constituted the non-bleeding group. All patients underwent endoscopy before or after color Doppler-ultrasonic examination, and images were interpreted independently by two endoscopists. The control group consisted of 30 healthy subjects, matched to the patient group in age and gender. Measurements of diameter, flow direction and flow velocity in the left gastric vein (LGV) and the portal vein (PV) were done in all patients and controls using color Doppler unit. After baseline measurements, 30 min after oral administration of 75 g glucose in 225 mL, changes of the diameter, flow velocity and direction in the PV and LGV were examined in 60 patients with esophageal varices and 15 healthy controls. RESULTS: The PV and LGV were detected successfully in 115 (96%) and 105 (88%) of 120 cirrhotic patients, respectively, and in 27 (90%) and 21 (70%) of 30 healthy controls, respectively. Among the 120 cirrhotic patients, 37 had F1, 59 had F2, and 24 had F3 grade varices. Compared with the healthy controls, cirrhotic group had a significantly lower velocity in the PV, a significantly greater diameter of the PV and LGV, and a higher velocity in the LGV. In the cirrhotic group, no difference in portal flow velocity and diameter were observed between patients with or without esophageal variceal bleeding (EVB). However, the diameter and blood flow velocity of the LGV were significantly higher for EVB (+) group compared with EVB (-) group (P < 0.01). Diameter of the LGV increased with enlarged size of varices. There were differences between F1 and F2, F1 and F3 varices, but no differences between F2 and F3 varices (P = 0.125). However, variceal bleeding was more frequent in patients with a diameter of LGV >6 mm. The flow velocity in the LGV of healthy controls was 8.70+/-1.91 cm/s (n = 21). In patients with liver cirrhosis, it was 10.3+/-2.1 cm/s (n = 12) when the flow was hepatopetal and 13.5+/-2.3 cm/s (n = 87) when it was hepatofugal. As the size of varices enlarged, hepatofugal flow velocity increased (P < 0.01) and was significantly different between patients with F1 and F2 varices and between patients with F2 and F3 varices. Variceal bleeding was more frequent in patients with a hepatofugal flow velocity >15 cm/s (32 of 52 patients, 61.5%). Within the bleeding group, the mean LGV blood flow velocity was 16.6+/-2.62 cm/s. No correlation was observed between the portal blood flow velocity and EVB. In all healthy controls, the flow direction in the LGV was hepatopetal, toward the PV. In patients with F1 varices, flow direction was hepatopetal in 10 patients, to-and-fro state in 3 patients, and hepatofugal in the remaining 18. The flow was hepatofugal in 91% patients with F2 and all F3 varices. Changes in diameter of the PV and LGV were not significant before and after ingestion of glucose (PV: 1.41+/-1.5 cm before and 1.46+/-1.6 cm after; LGV: 0.57+/-1.7 cm before and 0.60+/-1.5 cm after). Flow direction in the LGV was hepatopetal and to-and-fro in 16 patients and hepatofugal in 44 patients before ingestion of glucose. Flow direction changed to hepatofugal in 9 of 16 patients with hepatopetal and to-and-fro blood flow after ingestion of glucose. In 44 patients with hepatofugal blood flow in the LGV, a significant increase in hepatofugal flow velocity was observed in 38 of 44 patients (86%) with esophageal varices. There was a relationship between the percentage changes in flow velocity and the size of varices. Patients who responded excessively to food ingestion might have a high risk for bleeding. The changes of blood flow velocity in the LGV were greater than those in the PV (LGV: 28.3+/-26.1%, PV: 7.2+/-13.2%, P < 0.01), whereas no significant changes in the LGV occurred before and after ingestion of glucose in the control subjects. CONCLUSION: Hemodynamics of the PV is unrelated to the degree of endoscopic abnormalities in patients with liver cirrhosis. The most important combinations are endoscopic findings followed by the LGV hemodynamics. Duplex-Doppler ultrasonography has no value in the identification of patients with cirrhosis at risk of variceal bleeding. Hemodynamics of the LGV appears to be superior to those of the PV in predicting bleeding.     

Nested stromal-epithelial tumour of the liver:An unusual liver entity

Nested stromal-epithelial tumours(NSETs)of the liver have been reported to be extremely unusual primary hepatic neoplasms.To date,few cases have been described in the literature.NSETs have been defined as non-hepatocytic and non-biliary tumours of the liver consisting of nests of epithelial and spindled cells,myofibroblastic stroma and variable intralesional calcification and ossification.Here,we report a case of a young female who underwent liver resection for a large hepatic lesion that proved to be a calcifying NSET on pathological examination.Details about the clinical and histopathological features of the tumour are reported.     

Differentiation of focal liver lesions using three-dimensional ultrasonography: Retrospective and prospective studies

AIM: To differentiate focal liver lesions based on enhancement patterns using three-dimensional ultrasonography (3D US) with perflubutane-based contrast agent.METHODS: Two hundred and eighty two patients with focal liver lesions,including 168 hepatocellular carcinomas (HCCs),63 metastases,40 hemangiomas and 11 focal nodular hyperplasias (FNHs),were examined by 3D US with perflubutane-based contrast agent.Tomographic ultrasound images and sonographic angiograms were reconstructed.Among 282 lesions,enhancemen...     

肝干细胞在肝病治疗中的应用

肝病是危害我国人民健康的严重疾病，如何治疗肝病是广大研究人员最为关注的课题。近年来，全球掀起了有关干细胞的研究热潮，为疾病的治疗提供崭新思路。其中造血干细胞移植治疗血液系统疾病较为成熟，并且自体骨髓干细胞冶疗心肌梗死，间充质干细胞治疗造血功能低下、帕金森氏病，以及构建组织工程骨，这些临床应用都收到了良好效果。这为肝干细胞在肝病治疗中的应用提供了新的契机。     

Perivascular epithelioid cell tumour of the liver

Perivascular epithelioid cell tumour is not uncommon in the liver but seldom malignant.     

Value of duplex Doppler ultrasonography in non-invasive assessment of children with chronic liver disease

AIM:To investigate the value of duplex Doppler ultrasonography (US) in the assessment of the hemodynamics of the portal and hepatic veins in a cohort of children with chronic liver disease (CLD) and to detect any relationship between the US changes,etiology and severity (or stage) of CLD. METHODS:We prospectively enrolled 25 children with biopsy-proven CLD. Thirteen had cirrhosis (aged 8.9 ± 2.0 years) and 12 had chronic hepatitis (aged 9.3 ± 2.3 years). Gray scale and color-coded duplex Doppler US were performed for all,as well as 30 healthy age and sex-matched controls. Findings were correlated with clinical,laboratory and histopathological characteristics. RESULTS:Prominent caudate lobe was detected in 100% of cirrhotics,but none of the chronic hepatitis or controls. Thickened lesser omentum and loss of the triphasic waveform of the hepatic vein were present in 69.2% and 53.8% of cirrhotics vs 33.3% and 8.3% of chronic hepatitis respectively. Portal vein flow velocity was significantly lower (P < 0.0001) and the congestion index was significantly higher (P < 0.005) in both patient groups compared to controls. Child-Pugh’s staging showed a positive correlation with both abnormal hepatic vein waveform and direction of portal blood flow; and a negative correlation with both hepatic and portal vein flow velocities. No correlation with the etiology of CLD could be detected. CONCLUSION:Duplex Doppler added to grayscale US can detect significant morphologic and portal hemodynamic changes that correlate with the severity (stage) of CLD,but not with etiology.