心血管疾病基因治疗的分子影像学研究进展

近年来,利用基因治疗心血管疾病的实验与临床前期研究取得了较快的发展.分子影像学是在分子或细胞水平上研究活体生命或疾病过程的特定分子事件的新技术,为心血管疾病的基因治疗提供了一种实时、无创地检测方法,促进了这一治疗模式的发展和完善.本文主要综述分子影像学在心血管疾病基因治疗中的应用,包括分子探针、成像技术(包括核医学、MRI、超声、光学成像)的进展.     

Classification and basic properties of contrast agents for magnetic resonance imaging

A comprehensive classification of contrast agents currently used or under development for magnetic resonance imaging (MRI) is presented. Agents based on small chelates, macromolecular systems, iron oxides and other nanosystems, as well as responsive, chemical exchange saturation transfer (CEST) and hyperpolarization agents are covered in order to discuss the various possibilities of using MRI as a molecular imaging technique. The classification includes composition, magnetic properties, biodistribution and imaging applications. Chemical compositions of various classes of MRI contrast agents are tabulated, and their magnetic status including diamagnetic, paramagnetic and superparamagnetic are outlined. Classification according to biodistribution covers all types of MRI contrast agents including, among others, extracellular, blood pool, polymeric, particulate, responsive, oral, and organ specific (hepatobiliary, RES, lymph nodes, bone marrow and brain). Various targeting strategies of molecular, macromolecular and particulate carriers are also illustrated. Copyright © 2009 John Wiley & Sons, Ltd.     

Molecular MRI of atherosclerotic plaque with targeted contrast agents

Molecular MRI of atherosclerosis involves the use of novel contrast agents to image cellular and molecular processes within atherosclerotic plaque. Agents to image plaque lipid content, inflammation, angiogenesis, and thrombosis have been developed and studied extensively in animal models of atherosclerosis and vascular injury. Selected agents have also been studied in humans, with highly promising initial results. In this brief review, recent advances as well as opportunities and challenges in the field are discussed.     

Magnetic resonance imaging of the liver

Hepatic MRI has become a useful imaging modality in recent years. As with all diagnostic imaging, the scanning techniques available for hepatic MRI are manifold and complex. The article discusses these techniques and their practical applications. Contrast agents and the MR appearances of various pathologic hepatic entities are also reviewed.     

前列腺癌磁共振分子影像学研究进展

前列腺癌严重影响男性健康。MR分子影像学结合了MRI和分子影像学优势,为前列腺癌的早期诊断和靶向治疗提供了新的方法,具有良好的应用前景。本文将就前列腺癌的MR分子影像学研究进展进行综述。     

趋磁细菌磁小体及其相关MRI报告基因分子影像学研究

趋磁细菌受基因调控形成纳米Fe₃O₄颗粒——磁小体,自带天然脂性包膜,其独特结构与特性受到分子影像学研究的重视,特别是纯化磁小体在磁性粒子成像中的应用和磁小体相关调控基因在MRI报告基因的分子影像学中的应用。相关研究逐年增多,但有关MRI报告基因的研究尚处于初级阶段。本文对趋磁细菌磁小体及其相关基因在MRI报告基因的分子影像学研究进行综述。     

前列腺癌的分子影像学进展

前列腺癌是严重威胁男性健康的疾病。分子影像学的出现,从一个全新角度为前列腺癌的早期诊断与治疗提供了可能,新的前列腺癌标志物也不断出现。本文对当前分子影像学技术,包括核素显像、MRI、超声和光学技术在前列腺癌诊治中的应用进展进行回顾。     

Solid silica nanoparticles: applications in molecular imaging

Silica and silica‐based nanoparticles have been widely used for therapeutic and diagnostic applications in cancer mainly through delivery of drugs, genes and contrast agents. Development of synthesis methods has provided the possibility of fabricating silica nanoparticles with different sizes in nanometer ranges as well as silica‐based multimodal nanoparticles with many innovative properties and intriguing applications in biomedicine. The surface of silica particles facilitates different methods of surface modifications and allows conjugation of various biomolecules such as proteins and nucleic acids. In this review, different methods of fabrication of silica and silica‐based nanoparticles, their surface modification and the application of these nanoparticles in molecular imaging are discussed. Overall, the aim of this review is to address the development of silica and silica‐based multifunctional nanoparticles that are introduced mainly for molecular imaging applications using optical, magnetic (MRI), X‐ray (computed tomography) and multimodal imaging techniques. Copyright © 2014 John Wiley & Sons, Ltd.     

High-resolution MR imaging of the breast

Investigation into the use of MRI as a breast imaging tool is ongoing. Several studies have shown that MRI is a very accurate imaging method for the identification of implant failure in the symptomatic patient with augmented breasts. In this clinical setting, MRI may be the study of choice. Imaging techniques, and the MRI appearance of normal and abnormal implants, are described. The use of MRI for the detection of breast cancer is not as straightforward. Preliminary results suggest that this technique can be used as an adjunct to mammography for the detection and diagnosis of breast cancer. However, it is premature to draw firm conclusions regarding the role that MRI should play in the management of women with breast disease because of the wide variability of imaging techniques, protocols, and patient populations in the studies reported to date. In this overview, the current state of MR imaging of the breast is discussed. Technical requirements are described, and potential clinical applications—including the differentiation of benign from malignant lesions, breast cancer staging, detection of recurrence after breast conservation therapy, and detection of cancer in patients presenting with positive axillary lymph nodes with an unknown primary—are reviewed. Many of these potential clinical applications will require an accurate MR-guided biopsy system, and the implementation of such a system as well as its inherent limitations are discussed.     

Contrast-enhanced magnetic resonance body imaging 5

Many new techniques and applications in magnetic resonance imaging of the body have been introduced in the last decade and, at the same time, a wide variety of contrast media have become available for different imaging strategies. The aim of this article is to review the current use of contrast agents in body MRI. Extracellular and hepatobiliary gadolinium chelates, as well as iron oxide-based contrast media, are discussed and their use in different areas of the body highlighted. Topics to be covered include breast imaging, imaging of the thorax and the mediastinum, and imaging of the upper abdomen, kidneys, and pelvis. Established applications as well as new emerging indications are discussed, and the impact on improved detection and characterization of pathologies is demonstrated.     

Nuclear medicine techniques in breast imaging

Progress has been made in anatomic imaging with mammography, ultrasound, and MRI, but the noninvasive differentiation of malignant from benign breast masses is an unmet goal. Most breast biopsies still are performed in patients with benign disease. Improved nuclear medicine imaging devices, better radiopharmaceutical agents, and new methods of guiding biopsies and surgery are being developed, signaling a growing role for nuclear medicine techniques. The use of dual-photon positron emission tomography and single-photon imaging are discussed as a means of imaging both primary and regionally metastatic breast cancers.     

磁共振氨基质子转移成像的临床应用

磁共振氨基质子转移(amide proton transfer,APT)成像是一种基于化学交换饱和转移技术且可反映生物组织中内源性游离蛋白和肽类含量以及氨基质子交换速率的无创性分子磁共振成像方法。APT加权图像是通过对Z谱中水频率两侧±3.5 ppm处的非对称性磁化转移率进行计算得到的。近年来,APT磁共振成像(magnetic resonance imaging,MRI)已被越来越多地应用于疾病诊断中。本文针对目前APT MRI在临床应用和科学研究方面的进展予以综述。     

Design of ProCAs (Protein‐Based Gd3+ MRI Contrast Agents) with High Dose Efficiency and Capability for Molecular Imaging of Cancer Biomarkers

Magnetic resonance imaging (MRI) is the leading imaging technique for disease diagnostics, providing high resolution, three‐dimensional images noninvasively. MRI contrast agents are designed to improve the contrast and sensitivity of MRI. However, current clinically used MRI contrast agents have relaxivities far below the theoretical upper limit, which largely prevent advancing molecular imaging of biomarkers with desired sensitivity and specificity. This review describes current progress in the development of a new class of protein‐based MRI contrast agents (ProCAs) with high relaxivity using protein design to optimize the parameters that govern relaxivity. Further, engineering with targeting moiety allows these contrast agents to be applicable for molecular imaging of prostate cancer biomarkers by MRI. The developed protein‐based contrast agents also exhibit additional in vitro and in vivo advantages for molecular imaging of disease biomarkers, such as high metal‐binding stability and selectivity, reduced toxicity, proper blood circulation time, and higher permeability in tumor tissue in addition to improved relaxivities.     

冠状动脉粥样硬化斑块磁共振成像研究进展

当前直接显示冠状动脉管壁和粥样斑块为磁共振成像(MRI)研究的热点之一,这是因为不引起冠状动脉管腔50%以上狭窄程度的粥样硬化斑块常为具有破裂倾向的易损斑块,斑块破裂随后血栓形成是导致心肌梗死的主要原因。无创性、高分辨率MRI具有显示冠状动脉粥样硬化斑块、判定斑块成分的潜力。本综述总结冠脉斑块MR成像原理,描述现有MRI技术下斑块的信号特点,并讨论MR在斑块成像的新对比剂、靶向分子成像等方面的研究进展。     

Magnetic resonance imaging of liver malignancies

The histological structure of the liver is complex, consisting of hepatocytes, biliary epithelium, and mesenchymal cells. From this large variety of cells, a broad spectrum of benign and malignant liver lesions in originate. An accurate diagnosis of these lesions is mandatory for choosing an appropriate therapeutic approach. With the recent developments in hardware and software, magnetic resonance imaging (MRI) has emerged as the method of choice in the diagnostic workup of focal liver lesions, in particular in the pretherapeutic stage. The introduction of high-field MRI at 3.0 T in the routine workup and the selective use of liver-specific contrast agents, including hepatobiliary and reticuloendothelial agents, have also strengthened the role of MRI in liver imaging. In this overview article, we will review the recent developments in 3.0-T MRI and MRI contrast agents in the diagnostic workup of the most common malignant liver tumors.     

CT、MRI及与PET融合显像评价宫颈癌分期及淋巴结转移中的应用进展

传统影像学检查方法(CT、MRI)在宫颈癌分期及淋巴结转移的诊断方面应用较为广泛,对制定治疗方案、改善预后和降低死亡率有重要的作用。近年来,随着分子影像技术的发展,多模态分子影像技术(PET/CT及PET/MR)被逐渐应用于宫颈癌的诊断并指导治疗。本文对CT、MRI及与PET融合显像技术在宫颈癌分期及淋巴结转移评价中的临床应用进行综述。     

Molecular imaging of myocardial injury: A magnetofluorescent approach

The role of molecular imaging in enhancing the understanding of myocardial injury and repair is rapidly expanding. Moreover, in recent years magnetic resonance and fluorescence-based approaches have been added to the molecular imaging armamentarium and have been used to image selected molecular and cellular targets in the myocardium. Apoptosis, necrosis, macrophage infiltration, myeloperoxidase activity, cathepsin activity, and type 1 collagen have all been imaged in vivo with a magnetofluorescent (MRI and/or fluorescence) approach. This review highlights the potential of these and other magnetofluorescent agents, with particular focus on their role in ischemic heart disease.     

Molecular imaging; current status and future prospects in USA

The goal of this review is to introduce the definition, current status, and future prospects of the molecular imaging, which has recently been a hot topic in medicine and the biological science in USA. In vivo imaging methods to visualize the molecular events and functions in organs or animals/humans are overviewed and discussed especially in combinations of imaging modalities (machines) and contrast agents(chemicals) used in the molecular imaging. Next, the close relationship between the molecular imaging and the nanotechnology, an important part of nanomedicine, is stressed from the aspect of united multidisciplinary sciences such as physics, chemistry, biology, and medicine.     

Molecular imaging: challenges of bringing imaging of intracellular targets into common clinical use

Molecular imaging (MI) takes advantage of several new techniques to detect biomarkers or biochemical and cellular processes, with the goal of obtaining high sensitivity, specificity and signal‐to‐noise ratio imaging of disease. The imaging modalities bearing the most promise for MI are positron emission tomography (PET), single photon emission computer tomography (SPECT) and different optical imaging techniques with high sensitivity. Also magnetic resonance imaging (MRI) with contrast agents like ultra‐small superparamagnetic iron oxide particles (USPIO), magnetic resonance spectroscopy and ultrasound imaging with contrast agents may be useful approaches. MI techniques have been used in the clinic for many years, i.e. PET imaging using ¹⁸ F‐labeled fluorodeoxyglucose. Animal studies have during the last years revealed great potential for MI also with several other agents. The focus of the present article is the challenges of clinical imaging of intracellular targets following intravenous injection of the agents. Thus, the great challenge of getting enough contrast agent into the cytosol and at the same time obtaining a low signal from tissue just outside the diseased area is discussed. Copyright © 2012 John Wiley & Sons, Ltd.