胰腺疾病的磁共振成像诊断

磁共振成像(MRI)是20 世纪70年代后期发展起来的一项影像学检查技术,1984年起被尝试应用于胰腺疾病的诊断[1,2].随着MRI技术的不断发展,过去认为其显示胰腺较差的观念已改变.MRI能获得非常优良的胰腺图像,目前已成为诊断胰腺疾病的重要检查手段.     

增强磁共振成像对乏血供胰腺神经内分泌肿瘤及胰腺导管腺癌的鉴别诊断价值

目的： 探讨增强磁共振成像对乏血供胰腺神经内分泌肿瘤及胰腺导管腺癌的鉴别诊断价值。方法： 回顾性收集2015年1月至2020年12月复旦大学附属中山医院收治的术前行增强磁共振检查并经术后病理证实的39例乏血供胰腺神经内分泌肿瘤患者和2020年1月至2020年12月经手术病理或穿刺病理证实的37例胰腺导管腺癌患者临床资料，采用多因素回归分析影响鉴别诊断的影像学特征，结合临床特征及影像学特征绘制ROC曲线。结果： 乏血供胰腺神经内分泌肿瘤相对于胰腺导管腺癌患者发病年龄较小，边界清楚较多见（81.1%vs 43.6%，P=0.001），更少出现主胰管扩张（23.1%vs 70.3%，P<0.001）、淋巴结转移（25.6%vs 48.6%，P=0.038）及周围脂肪浸润（43.4%vs 89.2%，P<0.001），增强后三期强化率均高于胰腺导管腺癌组（P<0.001）。影像学特征中，主胰管扩张、周围脂肪浸润、强化方式是鉴别诊断的独立预测因子。联合临床特征及影像学特征的多因素鉴别诊断效能的AUC为0.93，诊断的灵敏度为91.7%，特异度为83.3%。结论： 乏血供胰腺神经内分泌肿瘤的边界、对比强化率、转移征象有助于其与胰腺导管腺癌的鉴别诊断。     

磁共振弹性成像评价主动脉壁硬度

目的 探讨磁共振弹性成像（MRE）评价主动脉壁硬度的可行性。方法 采用MRE技术观察5名健康志愿者的腹主动脉,将气动震动装置置于前腹壁,使其产生60 Hz低频率机械波,经腹部传播至腹主动脉,并在主动脉管腔内产生机械波传播;以梯度回波为基础的MRE序列对主动脉内传播的机械波进行成像。结果 机械波在腹主动脉管腔内沿腹其长轴传播良好;通过测量机械波波长,初步估算得出腹主动脉的硬度。结论 MRE技术对评价主动脉壁硬度具有一定可行性。     

基于磁共振弹性成像技术的肝纤维化分级方案

目的 探讨一种基于磁共振弹性成像技术的肝纤维化分级方案.方法 在介绍磁共振弹性成像原理和生物力学模型的基础上,讨论肝脏磁共振弹性成像需要考虑的关键技术和细节.结果 给出了具体可行的研究方案与实验步骤.结论 研究方案与实验步骤具有可操作性,动物体模预临床研究可弥补临床难以获取整个纤维化程度的缺陷.     

磁共振成像在胰腺疾病中的应用进展

胰腺疾病的发病率逐年升高,磁共振成像技术在胰腺疾病检查中的优势日趋明显.本文对不同胰腺疾病MRI表现、MRI在诊断和鉴别诊断中的作用及在胰腺疾病临床研究中的应用进展做一综述.     

胰腺分裂的磁共振胰胆管成像诊断

目的：总结磁共振胰胆管成像(MRCP)对胰腺分裂的诊断价值和影像表现。方法：回顾108例行MRCP病例，分析总结胰腺分裂MRCP的表现。结果：108例中12例(11．1％)诊断为胰腺分裂，包括5例不完全性胰腺分裂。其中1例因胰腺分裂合并有反复发作性腹痛，1例合并慢性胰腺炎胰管结石。结论：作为一种无创伤性检查，MRCP对胰腺分裂可作出明确诊断，对胰腺分裂合并不明原因反复发作性腹痛或急性胰腺炎反复发作病例的治疗有指导意义一     

胰腺磁共振扩散加权成像的临床应用进展

慢性胰腺炎(CP)和胰腺癌是临床常见病,发病率逐年增高.最近研究表明,胰腺DWI在CP早期诊断与外分泌功能评价、胰腺肿瘤性(样)病变的鉴别诊断具有重要的应用价值.本文对DWI的理论基础、胰腺DWI技术、特别是其在胰腺癌和CP诊断中的应用进展进行综述.     

磁共振弹性成像在肝细胞癌诊疗评估中的研究进展

肝细胞癌(hepatocellular carcinoma, HCC)是一种恶性程度高、转移性强、预后差的肿瘤,精准的影像评估有助于HCC患者的诊断及临床治疗决策制订。磁共振弹性成像(magnetic resonance elastography, MRE)为HCC的影像评估提供了一种全新的方式,其能够无创地量化组织力学特性、可重复性强、主观因素影响小、具有较好的临床适用性。MRE通过协助HCC疾病诊断及临床治疗决策制订,可提高患者生活质量及改善预后。本文对MRE在HCC的预测、诊断及鉴别诊断、疗效评估及预后生存预测的研究进展进行综述,分析现阶段MRE技术的优势与不足及未来发展方向,为HCC的诊疗提供有利参考,从而改善HCC患者的预后。     

胰腺癌磁共振功能成像的最新进展

胰腺癌发病隐匿,进展迅速,死亡率高,预后差。手术虽是主要治疗手段,但术后5年生存率小于5％l^[1]。另外,近85％的患者都是在晚期才得到诊断,丧失了手术机会,而传统的放化疗手段也不能明显改善患者的预后,且疗效不确切。副作用多121。由于极高的软组织对比度、多参数成像及无放射性,MR对于胰腺癌的筛查、诊断、分期及疗效评价起着不可或缺的作用。近年来,随着3．0TMR在临床上的应用推广,其对胰腺癌形态学的评价效果不仅可以与64排CT相媲美,另外在小胰腺癌的筛查诊断和转移灶的发现上甚至要优于64排CT^[1]”,而且MR功能成像可以评价CT所不能提供的肿瘤细胞恶性生物学特征及其微环境的生物信息,为进一步研究胰腺癌的诊断及其疗效评价提供了有效的成像方法,从而有助于提高胰腺癌患者的治疗效果和生存率。肿瘤的MR功能成像通常包括弥散加权成像（Diffusion weighted imaging,DWI）、灌注加权成像（Perfusion weighted imaging,PWI）和磁共振波谱分析（Magnetic resonance spectroscopy,MRS）。DWI是基于水分子布朗运动的不同对组织病理特征进行评价,主要通过显示肿瘤细胞密集程度及间质内纤维含量所导致的水分子受限程度来反映肿瘤组织的病理生物活性状态：PWI是一种无创性研究肿瘤组织的微血管分布及血流灌注情况的一类MR检查技术,反映肿瘤细胞微环境血液动力学方面的信息;MRS是一种无创性研究活体器官组织代谢、生化变化及化合物定量分析的方法,主要反映肿瘤组织内癌细胞及其赖以生存的周围微环境所发生的生物代谢变化。本文就近年来MRDWI、PWI及。^1H-MRS在胰腺癌中的应用作一综述。     

A microRNA meta-signature for pancreatic ductal adenocarcinoma

Evaluation of: Ma MZ, Kong X, Weng MZ et al. Candidate microRNA biomarkers of pancreatic ductal adenocarcinoma: meta-analysis, experimental validation and clinical significance. J. Exp. Clin. Cancer Res. 32(1), 71 (2013).

Due to its aggressive and late presentation, there is an urgent need for novel and reliable biomarkers for the diagnosis and prognostication of pancreatic ductal adenocarcinoma (PDAC). MiRNAs have been extensively profiled in PDAC tissues, biopsies, blood samples and other biofluids and their expression levels compared to normal and chronic pancreatitis (CP) specimens in order to identify the most relevant candidates. Consolidation of these activities has not been attempted until now. The evaluated meta-review by Ma et al. helps to define the use of miRNAs as biomarkers for detecting this tumor-type and predicting survival outcomes in PDAC. Based on frequency and consistency between microarray studies, they identified a miRNA meta-signature for recognising PDAC: upregulation of miR-21, 23a, 31, 100, 143, 155, and 221; with downregulation of miR-148a, 217 and 375. Furthermore, they validated high miR-21, high miR-31 and low miR-375 tumoural expression as independently prognostic for poor overall-survival (OS; n = 70).     

Tumor-stroma interactions in pancreatic ductal adenocarcinoma

The host stromal response to an invasive epithelial carcinoma is frequently called a desmoplastic reaction (DR) and is a universal feature of pancreatic ductal adenocarcinoma (PDA). This DR is characterized by a complex interplay between the normal host epithelial cells, invading tumor cells, stromal fibroblasts, inflammatory cells, proliferating endothelial cells, an altered extracellular matrix, and growth factors activating oncogenic signaling pathways by autocrine and paracrine mechanisms. Hence, the tumor microenvironment is a dynamic process promoting tumor growth and invasion through mechanisms likely to include anoikis resistance, genomic instability, and drug resistance. Cell coculture models, murine models (xenograft and genetic), and gene expression profiling studies on human PDA biopsies have identified several key molecules, such as collagen type I, fibronectin, laminin, matrix metalloproteinases (MMP) and their inhibitors (tissue inhibitors of MMP), growth factors (transforming growth factor beta, platelet-derived growth factor, connective tissue growth factor, and hepatocyte growth factor), chemokines, and integrins as constituents of the DR. Despite these findings, it is unclear which molecular-cellular events initiate and drive desmoplasia in PDA. Accumulating evidence indicates that pancreatic stellate cells when activated switch to a myofibroblast phenotype that produces components of the extracellular matrix, MMPs, and tissue inhibitors of MMPs by activating the mitogen-activated protein kinase (extracellular signal-regulated kinase 1/2) pathway. Based on current evidence, several therapeutic strategies are been evaluated on identified potential therapeutic targets. This review summarizes our current understanding of the mechanisms that potentially drive the DR in PDA and future possibilities for therapeutic targeting of this critical process.     

MR弹性成像评价梗阻型慢性胰腺炎

目的 探讨3.0T MR弹性成像（MRE）诊断梗阻型慢性胰腺炎的价值。方法 对32例疑诊梗阻型慢性胰腺炎且接受胰十二指肠切除术患者（病变组）及32名健康志愿者（正常对照组）行MRE检查,测量胰腺弹性值。评价2名医师间及重复测量胰腺弹性值的一致性;比较两组胰腺弹性值,绘制ROC曲线,评价以胰腺弹性值鉴别梗阻型慢性胰腺炎的诊断效能。结果 2名评估者间及重复测量胰腺弹性值一致性好（ICC均>0.9）;正常对照组及病变组胰腺体部弹性值分别为（1.21±0.11）kPa、（1.51±0.24）kPa,差异有统计学意义（t=-6.077,P<0.001）;MRE弹性值诊断有无、轻度与中重度、轻中度与重度慢性炎症的AUC分别为0.900、0.941和0.960（P均< 0.001）。结论 MRE可测量胰腺弹性值,有助于临床无创性客观评估慢性胰腺炎的严重程度。     

Screening for early pancreatic ductal adenocarcinoma in hereditary pancreatitis

Patients with hereditary pancreatitis have a 40% lifetime risk of developing pancreatic ductal adenocarcinoma. Existing methods of diagnosing pancreatic cancer such as tumor markers, endoscopy, and radiological imaging lack the sensitivity and specificity for early diagnosis, particularly in a background of chronic pancreatitis. Molecular based strategies offer new avenues of screening for pancreatic ductal adenocarcinoma in these high-risk patients, which may allow the development of highly sensitive and specific diagnostic tests for the early detection of cancer.     

MRI evaluation of pancreatic ductal adenocarcinoma: diagnosis,mimics, and staging

Abdominal Radiology - The radiologist’s role in the evaluation of pancreatic ductal adenocarcinoma remains critical in the management of this deadly disease. Imaging plays a vital role in the...     

PET/CT in brachytherapy early response evaluation of pancreatic ductal adenocarcinoma xenografts: comparison with apparent diffusion coefficient from diffusion-weighted MR imaging

Abdominal Radiology - To evaluate the feasibility of using PET/CT and diffusion-weighted magnetic resonance imaging (DW-MRI) to monitor the early response of pancreatic ductal adenocarcinoma (PDAC)...     

Role of epithelial-mesenchymal transition in chemoresistance in pancreatic ductal adenocarcinoma

Pancreatic cancer (PC) is the seventh leading cause of cancer death worldwide. The vast majority of patients who have PC develop metastases, resulting in poor treatment effects. Although great progress in therapeutic approaches has been achieved in recent decades, extensive drug resistance still persists, representing a major hurdle to effective anticancer therapy for pancreatic ductal adenocarcinoma (PDAC). Therefore, there is an urgent need to better understand the drug resistance mechanisms and develop novel treatment strategies to improve patient outcomes. Numerous studies suggest that chemoresistance is closely related to epithelial-mesenchymal transition (EMT) of PDAC cells. Thus, this article summarizes the impact of EMT on PDAC from the perspective of chemotherapy resistance and discusses the possible novel applications of EMT inhibition to develop more effective drugs against PDAC.