MR LAVA技术在肝脏良、恶性病变诊断中的应用

目的 探讨1.5 T MR肝脏三维容积快速扫描(LAVA)技术在肝脏良、恶性病变中的应用价值.资料与方法 对78例肝脏病变患者分别进行平扫和LAVA扫描,观察LAVA各期的影像表现,分析病灶的强化规律及血供关系.结果 78例中53例拟诊为恶性肿瘤,与手术、穿刺病理结果及实验室检查比较,诊断符合率为96.2%(51/53);25例良性患者诊断符合率为92%(23/25).结论 LAVA技术能够清晰地显示肝脏病变的各期动态变化及血供,结合平扫,对肝脏良、恶性病变的定性诊断以及治疗有重要指导意义.     

探讨血供在鉴别乳腺良恶性病变中的价值

目的 研究动态增强磁共振成像(DCE-MRI)中同侧血供增加在鉴别乳腺良恶性病变中的价值.资料与方法前瞻性研究21例乳腺摄影、超声或临床体检有乳腺病变患者的:MRI资料.在最大强度投影(MIP)图像上,记录患侧乳腺血管的数目、直径、长度和可见性.根据Sardanelli血供评分,分为四个等级,即0～3分,分别代表乳腺乏血供或低血供(0分)、低血供(1分)、中等血供(2分)及高血供(3分);2～3分均被认为乳腺血供增加,与同侧乳腺癌相关.以病理结果作为参考标准,比较乳腺良恶性病变侧乳腺的血供差异.结果 21例患者MRI发现22个病灶,病理提示8个良性病变,14个恶性病变.良、恶性病变侧乳腺的血管平均数目±标准差分别为2.5±1.6、4.1±1.8(P＜0.05);良、恶性病变侧乳腺的血供评分±标准差分别为2.0±0.8、2.5±0.5(P＞0.05).结论 良、恶性病变侧乳腺的血管平均数目的 差别有统计学意义,但是血供评分间的差别无统计学意义,因此Sar-danelli血供评分在鉴别乳腺良恶性病变中的价值尚需进一步探讨和验证.     

肝脏炎性病变与肝脏乏血供肿瘤的CT和磁共振成像诊断及鉴别诊断

目的 探讨肝脏炎性病变与乏血供肿瘤的CT和磁共振成像(MRI)诊断及鉴别诊断,为临床诊断及治疗提供影像参考.方法 回顾性分析2016年1月至2020年4月的20例肝脏炎性病变及20例乏血供肿瘤患者的CT和MRI的平扫及增强后动脉期、静脉期及延迟扫描的影像表现.结果 肝脓肿10例,呈双环征;不典型肝脓肿5例,多发单环强化...     

Gd-EOB-DTPA的特性及其在肝细胞肝癌诊断中的应用现状

肝细胞肝癌(HCC)是世界上第5大最常见恶性肿瘤,愈后很差,未经任何治疗的5年生存率小于5%。HCC的早期诊断非常关键,但早期HCC放射学表现不典型,诊断敏感性及特异性较低。Gd-EOB-DTPA是一种新型肝细胞特异性钆对比剂,通过肝胆特异性期获得病变正常肝细胞含量情况,对肝脏病变的诊断和鉴别诊断提供更多的信息。目前,多数文献表明钆塞酸二钠(Gd-EOB-DTPA)MR增强检查对HCC的诊断优于常规MRI及CT增强检查,综述Gd-EOB-DTPA的特性及其在肝细胞肝癌诊断中的应用现状。     

肝脏血管平滑肌脂肪瘤的钆塞酸二钠增强MRI表现及文献复习

目的分析混合型肝脏血管平滑肌脂肪瘤的钆塞酸二钠(Gd-EOB-DTPA)增强MRI表现及诊断要点。方法 1例因偶然发现肝脏结节性占位病变的60岁老年女性病人进行了肝脏MRI平扫和Gd-EOB-DTPA增强MRI检查,经外科手术切除肝脏病变后,病理诊断为血管平滑肌脂肪瘤。回顾性分析病人的临床资料、MRI表现及病理所见,复习相关文献。结果 MRI检查见肝Ⅷ段一类圆形异常信号影,大小2.0 cm×1.7 cm,边界清楚。病灶在化学位移双回波T_1WI同相位影像呈稍低信号,同层面反相位影像病灶信号强度不均匀减低,快速反转快速自旋回波(FRFSE)脂肪抑制T_2WI呈不均匀高信号,DWI呈稍高信号。静脉注射Gd-EOB-DTPA后动态增强扫描时,病灶在动脉早期因明显不均匀强化呈显著高信号,其内下方见一条迂曲增粗的异常血管连接门静脉分支;在动脉晚期和门静脉期,病灶信号强度略低于周围的肝实质;在平衡期及延迟期,病灶呈不均匀低信号;在20 min及50 min肝胆期,病灶呈明显的低信号。结论混合型肝脏血管平滑肌脂肪瘤的Gd-EOB-DTPA增强MRI表现与富血供肝细胞癌有一定重叠,鉴别诊断需结合临床资料、超声检查及平扫MRI信号特点综合分析。     

钆塞酸二钠增强MRI检查在小肝癌临床诊断中的应用价值

目的 评价Gd-EOB-DTPA MRI检查中肝胆管期对定期复查肝硬化患者检出小肝癌的临床诊断价值.方法 33例肝硬化患者分别进行超声增强检查、Gd-EOB-DTPA增强MRI检查和64排螺旋CT检查共检测出48枚肝脏小结节(直径为10～30 mm),全程使用盲法,以2005年美国肝脏病研究协会标准为诊断标准.结果 48枚肝脏小结节中,38枚(79.2％)被诊断为肝细胞癌,MRI检查中30枚(78.9％)符合典型血管强化征象(快进快出),CT检查有22枚(57.9％),增强超声检查有17枚(44.7％).所有38枚肝细胞癌和3枚良性结节在肝胆管期显示低信号(敏感性100％,特异性70％,阳性预测值93％,阴性预测值100％,阳性似然比3.33,阴性似然比0).38枚肝细胞癌结节中,有7枚在各影像学检查中均不显示典型血管强化征象,有8枚(21.1％)显示为门静脉期廓清,MR肝胆管期低信号征象,此征象未见于良性病变中.结论 Gd-EOB-DTPA MRI检查能提高定期复查的肝硬化患者小肝癌检出的敏感性.门静脉期/静脉期低信号,肝胆管期低信号可以作为MRI最新诊断征象,特别是对乏血供肝细胞癌的检出.     

肝脏特异性对比剂在肝脏肿瘤中的临床应用价值

【摘要】钆塞酸二钠（Gd-EOB-DTPA）是目前常用的肝脏特异性对比剂，其应用使肝脏MRI在肝脏肿瘤评估方面取得了重大进展。Gd-EOB-DTPA增强MRI（EOB-MRI）在肝脏肿瘤的检测与定性、治疗决策、肝脏及胆系的结构及功能评估方面具有重要价值，其正在与新的诊断工具（如生物标志物、影像组学、影像基因组学和人工智能等）相结合，以开发新的影像标志物，应用前景愈加广阔。本文介绍了EOB-MRI的成像原理和技术，并就其在肝脏肿瘤临床应用现状和进展及其作为影像标志物在新兴领域中的应用进行综述。     

三维彩色多普勒超声在乳腺良恶性肿物血管分布方面的研究

目的:应用三维彩色多普勒超声研究乳腺良恶性肿物的血管分布情况,探讨其在乳腺良恶性肿物诊断中的价值。方法:对94例由手术及病理证实的乳腺肿物患者进行三维彩色多普勒超声检查,探查乳腺供血动脉对乳腺肿物的供血情况,分析乳腺肿物的整体血管分布特征。结果:乳腺供血动脉对乳腺良恶性肿物的供血方式不同。乳腺良性肿物的血管分布形态以"球状"、"星条状"和"树枝状"三种多见,以其作为乳腺良性肿物的诊断标准,敏感性87.8%,特异性82.2%,Youden指数0.70;乳腺恶性肿物的血管分布形态以"荆棘状"、"珊瑚状"和"花环状"三种多见,以其作为乳腺恶性肿物的诊断标准,敏感性73.3%,特异性89.8%,Youden指数0.63。结论:在三维彩色多普勒成像中,乳腺良恶性肿物的血管分布形态是不同的,且有一定规律可循的。     

2种磁共振对比剂动态增强扫描对肝内结节的鉴别诊断价值

目的：探讨钆喷酸葡胺(Gd-DTPA)及钆塞酸二钠(Gd-EOB-DTPA)的磁共振动态增强扫描对肝脏结节的鉴别诊断价值。方法回顾性分析60例经 Gd-DTPA 及 Gd-EOB-DTPA 增强的肝内结节磁共振平扫、多时相动态增强扫描图像。结果所有入组病例经 Gd-DTPA 动态增强扫描后,19例患者诊断为原发性肝细胞癌,并经病理证实;8例确诊为肝转移瘤;18例诊断为肝内良性结节,随访3~6个月结节大小无明显变化。15例鉴别诊断困难的患者行 Gd-EOB-DTPA 多时相动态增强扫描,4例动脉期明显强化,门脉期强化程度迅速下降,平衡期轻度强化,肝特异性期与正常肝实质比较呈等信号,后证实为肝腺瘤;7例动脉期轻到中度强化,门脉期强化程度下降,平衡期强化不明显,肝特异性期与正常肝实质比较呈低信号,经随访或病理确诊为肝细胞癌;3例动脉期表现为轻度强化,门脉期及平衡期略强化,肝特异性期与正常肝实质比较呈低信号,根据其病史诊断为转移瘤;1例动脉期病变周边明显强化,门脉期强化程度迅速下降,平衡期轻度强化,肝特异性期与正常肝实质比较呈等信号,病变中心始终呈低信号,经复查诊断为肝良性病变。结论Gd-DTPA 动态增强 MRI 扫描对诊断肝内结节性病灶具有重要作用,Gd-EOB-DTPA 在鉴别结节的良恶性方面具有较大优势。     

Gd-EOB-DTPA在肝脏局部结节性病变诊断中的应用

目的 研究肝细胞特异性对比剂Gd-EOB-DTPA在肝脏结节性病变定性诊断中的应用价值.方法 收集经CT或MR(Gd-DTPA)增强检查证实肝内有结节性病变的患者30例,再进行肝细胞特异性对比剂Gd-EOB-DTPA MR增强扫描,采集T1WI、T2WI、DWI、LAVA动态增强扫描,在注射对比剂后15～20 min采集肝胆特异摄取期图像.结果 30例入组患者,共发现36个病灶.其中中低分化肝细胞癌14个,高分化肝细胞癌8个,再生结节或不良性再生结节9个,局灶性再生结节5个.注射肝细胞特异性对比剂Gd-EOB-DTPA后,病灶在动静脉期强化方式与非特异性钆基对比剂Gd-DTPA相同;在对比剂Gd-EOB-DTPA被肝细胞摄取的特异期内观察,不同分化程度的肝细胞癌均表现为境界清晰的低信号,而不同阶段的肝硬化结节信号强度出现分化,肝局灶性结节均表现为等或稍高信号.结论 Gd-EOB-DTPA在肝脏结节性病变的定性诊断中有重要价值.     

Magnetic resonance imaging of the liver: consensus statement from the 1st International Primovist User Meeting

The role of contrastenhanced liver MRI using the hepatocyte-specific agent gadoliniumethoxybenzyl-diethylene triamine penta-acetic acid (Gd-EOB-DTPA, Primovist, Bayer Schering Pharma, Berlin, Germany) is considered, based on the discussion at the Forum of Liver MRI: The 1st International Primovist User Meeting. Current clinical evidence supports Gd-EOB-DTPA’s use in non-invasive diagnosis of benign and malignant liver lesions and staging of focal and diffuse liver disease. The information thus gained assists in the provision of cost-effective patient management. The pharmacological properties of Gd-EOB-DTPA facilitate the imaging of both the vascular and hepatobiliary phases in the cirrhotic and non-cirrhotic liver and may provide an opportunity for one-stop diagnosis of liver lesions, such as focal nodular hyperplasia, adenomas, haemangiomas, hepatocellular carcinoma and metastases. The currently recommended protocols using Gd-EOB-DTPA are appropriate for the majority of patients, but imaging time points may require modification in specific patient groups. Further experience in routine clinical practice, as opposed to that gained from rigidly designed clinical studies, may provide greater understanding of the potential of Gd-EOB-DTPA for the evaluation of the cirrhotic and non-cirrhotic liver. Additional studies may substantiate the potential of Gd-EOB-DTPA in the imaging of other abdominal organs and in the evaluation of liver function and fibrosis.     

Accuracy and confidence of Gd-EOB-DTPA enhanced MRI and diffusion-weighted imaging alone and in combination for the diagnosis of liver metastases

Purpose

To evaluate the accuracy and confidence in diagnosing liver metastases using combined gadolinium-EOB-DTPA (Gd-EOB-DTPA) enhanced magnetic resonance imaging (MRI)/diffusion-weighted imaging (DWI) in comparison to Gd-EOB-DTPA enhanced MRI and DWI alone.

Materials and methods

Forty-three patients (age, 58 ± 13 years) with 89 liver lesions (28 benign, 61 malignant) underwent liver MRI for suspected liver metastases. Three image sets (DWI, Gd-EOB-DTPA and combined Gd-EOB-DTPA/DWI) in combination with unenhanced T1- and T2-weighted images were reviewed by three readers. Detection rates of focal liver lesions were assessed and diagnostic accuracy was evaluated by calculating the areas under the receiver-operating-characteristics curve (AUC). Confidence in diagnosis was evaluated on a 3-point scale. Histopathology and imaging follow-up served as the standard of reference.

Results

Detection of liver lesions and confidence in final diagnosis for all readers were significantly higher for the combined Gd-EOB-DTPA/DWI dataset than for DWI. The combination of DWI and Gd-EOB-DTPA rendered a significantly higher confidence in final diagnosis (2.44 vs. 2.50) than Gd-EOB-DTPA alone for one reader. For two readers, accuracy in diagnosis of liver metastases was significantly higher for Gd-EOB-DTPA/DWI (AUCs of 0.84 and 0.83) than for DWI datasets (AUCs of 0.73 and 0.72). Adding DWI to Gd-EOB-DTPA did not significantly increase diagnostic accuracy as compared to Gd-EOB-DTPA imaging alone.

Conclusion

Addition of DWI sequences to Gd-EOB-DTPA enhanced MRI did not significantly increase diagnostic accuracy as compared to Gd-EOB-DTPA enhanced MRI alone in the diagnosis of liver metastases. However, the increase in diagnostic confidence might justify acquisition of DWI sequences in a dedicated MRI protocol.     

Diffusion weighted imaging of liver lesions suspect for metastases: Apparent diffusion coefficient (ADC) values and lesion contrast are independent from Gd-EOB-DTPA administration

Purpose

Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) enhanced liver MRI is widely used for detection and differentiation of focal liver lesions. Diffusion weighted imaging (DWI) including apparent diffusion coefficient (ADC) measurements is increasingly utilised as a fast and, with limitations, quantitative method for liver lesion detection and characterisation. Herein we investigate whether the administration of Gd-EOB-DTPA affects DWI.

Materials and methods

31 consecutive patients referred to standardised liver MRI (1.5 T, Gd-EOB-DTPA, 0.025 mmol/kg) were retrospectively reviewed. All underwent a breathhold DWI sequence before and after contrast agent administration (EPI-DWI, TR/TE (effective): 2100/62 ms, b-values: 0 and 800 s/mm²). Patients with previously treated liver lesions were excluded. Signal intensity of lesion, parenchyma and noise on DWI images as well as the ADC value were measured after identification by two observers in consensus using manually placed regions of interest. The reference standard was imaging follow-up determined separately by two radiologists. Data analysis included signal-to-noise (SNR) ratio and contrast-to-noise ratio (CNR) calculations, comparisons were drawn by employing multiple Bonferroni corrected Wilcoxon signed-rank tests.

Results

50 malignant and 39 benign lesions were identified. Neither SNR, CNR nor ADC values showed significant differences between pre- and postcontrast DWI. Both pre- and postcontrast ADC values differed significantly between benign and malignant lesions (P < 0.001).

Conclusion

We did not identify a significant influence of Gd-EOB-DTPA on DWI of liver lesions. This allows for individual tailoring of imaging protocols according to clinical needs.     

Diffusion-weighted MR imaging findings in a growing problem: Hepatic alveolar echinococcosis

Hepatic alveolar echinococcosis (AE) is a rare parasitic disease which simulates slow growing malignant processes. Cross-sectional imaging techniques play important role in differentiating between AE lesions and malignant processes such as cholangiocellular carcinoma (CCC) and hepatocellular carcinoma (HCC). Diffusion-weighted (DW) MRI is a non-invasive technique, which can be used for liver lesion detection and characterisation as benign or malignant in recent years. Both conventional MRI and non-contrast enhanced CT images may be insufficient the differential diagnosis in hepatic AE lesions particularly in solid components. In our study, we have performed to differentiate hepatic AE lesions from HCC and CCC lesions of the liver by using DW MRI and tried to define ADC value of hepatic AE lesions for differentiation from malignant hepatic lesions.     

MR imaging in patients with suspected liver metastases: value of liver-specific contrast agent Gd-EOB-DTPA.

The appropriate staging of malignant tumors is increasingly important as new therapeutic strategies develop. Because metastatic involvement of the liver in extrahepatic malignant disease may significantly change therapeutic approach, it is important to rule out such involvement with high confidence. Moreover, the differentiation between incidental benign lesions, such as hemangioma, focal nodular hyperplasia (FNH), or adenoma, is of high interest. Magnetic resonance (MR) imaging has proved reliable for diagnostic work-up of the liver. Liver-specific contrast agents have been especially helpful in detecting and precisely characterizing focal liver lesions, but the use of these agents has been limited because it has not been possible to perform both proper vascular phase and liver-specific phase within a reasonable time frame and in a single examination after a single injection of contrast agent. However, the hepatobiliary contrast agent gadolinium-ethoxybenzyl (Gd-EOB)-DTPA now allows combined dynamic imaging and hepatocyte-specific imaging in one examination. Gd-EOB-DTPA can be injected as a bolus and shows the enhancement characteristics and vascularity of liver lesions. In the delayed phase, which is acquired most appropriately 20 min after injection, Gd-EOB-DTPA is taken up selectively by functioning hepatocytes. Thus, malignant liver lesions, e.g. metastases, are spared from contrast uptake of the surrounding liver parenchyma. These lesions are hypointense in contrast to the surrounding bright liver. We review the current literature and present a practical approach to Gd-EOB-enhanced MR imaging using imaging examples of patients with liver metastases.     

Potential for differential diagnosis with gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging in experimental hepatic tumors

RATIONALE AND OBJECTIVES: To investigate whether dynamic and delayed magnetic resonance imaging (MRI) with gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA), a hepatobiliary MRI contrast agent, has potential for the differential diagnosis of experimental hepatic tumors. METHODS: Twelve male rats received N-nitrosomorpholine solution as drinking water to induce hepatic tumors. After injection of Gd-EOB-DTPA, rats were subjected to dynamic and delayed MRI. The relative enhancement (RE) was calculated, and the time of the maximum RE (Tmax) was evaluated. After MRI, liver was histologically analyzed. RESULTS: One hundred sixty-three hepatic tumors 3-12 mm in diameter were induced after 18 weeks of treatment with 0.01 wt/vol% of N-nitrosomorpholine, and 81 of them were evaluated. The RE in hyperplastic nodules (HPNs) was significantly higher than that in moderately or poorly differentiated hepatocellular carcinomas (HCCs) in the late phase, whereas there was no significant difference in RE between well-differentiated HCCs and HPNs. The average Tmax in HPNs was about 13 minutes, whereas that of each differentiated HCCs was about 1 minute. CONCLUSIONS: It was possible to differentiate benign HPNs and malignant HCCs (especially well-differentiated HCCs) by evaluating the change of RE or comparison of Tmax with Gd-EOB-DTPA-enhanced MRI.     

How to detect hepatocellular carcinoma in cirrhosis

Cirrhosis predisposes to hepatocellular carcinoma (HCC) which develops by sequential steps of de-differentiation of hepatocytes from regenerative nodules via borderline (dysplastic) nodules to frankly malignant HCC. Effective treatment depends on early recognition of HCC, so the key tasks for imaging are firstly recognising the presence of a suspicious lesion, and secondly differentiating between benign, borderline and malignant nodules. Screening of high-risk cirrhotic patients with sonography and measurement of alpha fetoprotein (AFP) is helpful but will not reliably differentiate small HCC from benign or dysplastic nodules. Large HCCs can usually be recognised by their characteristic morphology on imaging, but the appearances of smaller benign and malignant nodules show considerable overlap on unenhanced sonography, CT and MRI. Increasing degrees of histological malignancy are associated with increasing arterialisation and loss of portal blood supply, so the recognition of HCC requires the use of dynamic imaging with contrast-enhanced CT or T1-weighted MRI with gadolinium enhancement. Sonography with microbubble contrast media now offers another method for detecting arterialised nodules; however, some non-malignant nodules show arterial hypervascularity and a minority of HCCs are hypovascular, so the assessment of perfusion does not conclusively distinguish benign from malignant lesions. Kupffer cell function is another attribute of liver tissue which can be explored using MRI with superparamagnetic iron oxide particles (SPIO). Experience thus far suggests that uptake of SPIO is an effective discriminator between benign and malignant nodules. The combination of SPIO with gadolinium-enhanced MRI offers the opportunity for imaging characterisation of cirrhotic nodules by cellular function as well as by blood supply, and this approach is now proposed as the examination of choice for detecting HCC in cirrhosis.     

Focal nodular hyperplasia: typical and atypical MRI findings with emphasis on the use of contrast media

Focal nodular hyperplasia is a benign hypervascular hepatic tumour, frequently detected in asymptomatic patients undergoing imaging studies for unrelated reasons. Magnetic resonance imaging (MRI) generally allows a confident differential diagnosis with other hypervascular liver lesions, either benign or malignant. In addition, due to the recent development of hepatospecific MRI contrast agents, MRI concomitantly enables functional and morphological information to be obtained, thus providing important clues for the detection and characterization of focal nodular hyperplasia lesions.     

Hepatic adenomatosis may mimic metastatic lesions of liver with 18F-FDG PET/CT

Hepatic adenomatosis is an uncommon benign neoplasm, with the presence of multiple adenomas (generally more than 4) within the liver. A 52-year-old woman presented with multiple (>10) solid liver lesions detected with abdominal ultrasonography and verified with magnetic resonance imaging (MRI). Subsequently, F-18 FDG PET/CT demonstrated increased uptake in these lesions. Histology revealed hepatic adenomatosis. F-18 FDG PET/CT cannot reliably differentiate hepatic adenomas from malignant processes on the basis of uptake.     

Focal liver lesion detection and characterization with GD-EOB-DTPA

Superior soft-tissue contrast affords magnetic resonance imaging (MRI) some advantages compared to computed tomography (CT) in both detection and characterization of focal liver lesions. Because of its relatively recently introduction into clinical practice, a growing number of articles in the literature have demonstrated the usefulness of the hepatobiliary-specific MRI contrast agent gadoxetic acid disodium (Gd-EOB-DTPA) in liver imaging. The purpose of this review is to demonstrate the typical enhancement patterns of the most common liver lesions using Gd-EOB-DTPA in daily clinical scenarios and briefly describe its mechanism of action. Radiologists interpreting liver MRI studies with this agent must be familiar with the appearance of focal lesions in the hepatocyte phase to avoid misinterpretation.