分子核医学的发展和应用前景

分子核医学是分子影像学的重要组成部分,主要包括PET和SPECT技术.目前,CT、MRI、超声、光学成像等影像技术与分子核医学影像技术的融合,以及多模式放射性药物探针的研究及应用成为核医学的主要发展方向.分子核医学在疾病的生物治疗疗效评估研究,基因治疗及其监测,干细胞生长、繁殖、迁移监测,以及新药的开发和筛选等生命科学研究方面将有越来越广泛的应用.     

切伦科夫光学成像研究进展

分子影像技术在疾病的诊断、治疗和疗效评估中发挥着重要作用,多模式分子影像能集多种不同显像设备的特点,提供更多的信息.切伦科夫核素光学成像为新兴的分子影像学方法,其利用放射性核素发射的带电粒子在介质中运行速度大于光速时产生的荧光进行成像,信号强度与放射性活度有关,并与SPECT或PET显像信号具有良好的线性相关性.以此可使用一种分子探针进行SPECT或PET显像及切伦科夫光学成像.     

RSNA2015分子影像学

RSNA2015报道的分子影像学研究进展主要包括以下几个方面:①靶向特异性分子探针及复合分子探针的研发和应用:如靶向特异性超顺磁氧化铁纳米探针,放射性核素示踪剂免疫,复合超声微泡对比剂及光学对比剂等,应用于肿瘤血管靶向显像,肿瘤诊断、治疗疗效评估及肿瘤淋巴结转移等.③新型的放射学分子成像方法:如磁性粒子成像,磁共振波谱成像及化学交换饱和转移成像等.③多模态或多参数分子显像:MRI、PET、SPECT、超声及光学分子成像技术中两种或多种技术的结合.④干细胞追踪及显像.     

分子影像探针:揭示生命活动本质的钥匙

分子影像能从细胞和分子水平显示活体内的生物学过程,为疾病的早期无创性诊断和疗效监测提供分子水平的信息.分子影像自20世纪90年代提出[1]以来,一直受到生命科学界的广泛关注,其基础研究和临床应用均快速发展,使医学影像学正从宏观的解剖影像时代进入微观的分子影像时代.这种从非特异性的物理学成像到相对特异性的分子成像的转变是现代分子生物学与先进的影像学技术相互融合的结晶,是当今影像技术发展的主要趋势.     

乳腺癌分子成像的应用价值

乳腺癌是女性最常见的恶性肿瘤之一,早期诊断及正确评估其侵袭性是影响乳腺癌病人预后的重要因素。多种分子成像技术(包括超声、磁共振成像、放射性核素显像及光学分子成像)对乳腺癌的诊断、临床亚型判断、治疗方式选择及预后评估均有重要价值。其中,超声靶向微泡治疗和光学分子成像指导乳腺癌手术治疗等技术的发展有望成为乳腺癌治疗的新方式。就多种分子成像技术在乳腺癌中的应用价值予以综述。     

分子核医学的发展和应用前景

分子核医学是分子影像学的重要组成部分,主要包括PET和SPECT技术。目前,CT、MRI、超声、光学成像等影像技术与分子核医学影像技术的融合,以及多模式放射性药物探针的研究及应用成为核医学的主要发展方向。分子核医学在疾病的生物治疗疗效评估研究,基因治疗及其监测,干细胞生长、繁殖、迁移监测,以及新药的开发和筛选等生命科学研究方面将有越来越广泛的应用。     

介入分子影像学研究进展

近年来分子影像学迅速发展,为分子生物学、临床靶向治疗学等相关领域研究提供了有力的活体内监测手段.但目前多种分子影像技术在临床应用均存在一定的局限性,其对大动物乃至人的研究工作受到极大限制,使得分子影像学仍处于小动物基础成像或临床前研究阶段.介入分子影像学的出现,为解决这一系列问题提供了新思路,通过优化分子探针导入方式、改良现有分子成像技术装置等,使分子影像学从小动物基础研究发展为大动物研究和临床应用研究成为可能,并最终成为临床转化的重要桥梁.同时,介入分子影像学融合了分子影像诊断学与临床靶向治疗学,这无疑将成为推动临床靶向治疗及个体化治疗的重要力量,对未来临床诊治工作产生又一革命性影响,也是未来介入放射学发展的重要方向.     

RSNA2012分子影像学进展

RSNA2012报道的分子影像学研究进展主要包括以下几个方面:①靶向特异性分子探针及多功能分子探针的研发:如靶向特异性磁性纳米对比剂、超声微泡对比剂及放射性示踪剂等,应用于肿瘤靶向显像、动脉粥样硬化斑块易损性评价、老年痴呆Aβ斑块显像及感染分期和预后评估等。②多模态分子显像技术的发展:包括MRI、PET、光学成像及超声分子成像。③干细胞示踪及成像。     

MR靶向分子成像在胰腺癌早期诊断中的研究进展

胰腺癌起病隐匿、侵袭性强,早期诊断是提高胰腺癌总体生存率及改善预后的关键。分子成像可以发现疾病发展过程中分子或细胞水平的早期异常变化,能够早期诊断胰腺癌病灶。就MR靶向分子成像技术原理、胰腺癌早期诊断相关受体和蛋白抗原标志物分子靶点选择以及以钆和磁性纳米颗粒为基础的MR靶向分子成像在胰腺癌早期诊断研究中的应用和进展予以综述。     

乳腺疾病的MRI研究进展

MRI具有极佳的软组织分辨率,近年来,该技术越来越广泛的应用于乳腺疾病的诊断.乳腺动态增强成像和灌注加权成像可从不同角度反映乳腺组织及病灶的血供灌注情况,弥散加权成像和磁共振波谱分析则从分子水平提供乳腺病变组织信息,磁共振乳腺导管成像为导管内病变提供了新的影像诊断方法.随着MRI技术的成熟、软硬件的迅速发展,MRI在乳腺疾病的检出和诊断方面显示出其独到的优势.     

分子影像报告基因系统的研究进展

分子影像报告基因系统的应用使基因治疗从实验阶段逐渐走向了临床应用,为无创性监测治疗基因的表达及进行定量分析提供了方法学技术.目前研究最多、最成熟的仍是放射性核素报告基因系统,近年来磁共振报告基因系统和光学报告基因系统的兴起和发展,极大地丰富和完善了分子影像报告基因系统的内容,并且在与应用化学和分子生物学等多学科交叉合作的基础上,涌现出了很多新型的修饰或改良的报告基因和分子探针.该文主要概述各类报告基因系统的优缺点和发展趋势.     

在体光学分子影像技术在乳腺癌基础及临床研究中的应用

在体光学分子影像作为一种快速发展的生物医学影像技术,以其实时、定量及非侵入性等特点,已被广泛应用于各学科的研究中.光学分子影像技术在监测乳腺癌的远处转移、检测肿瘤细胞的凋亡、细胞周期、细胞乏氧与肿瘤血管生成、观察ER介导的分子路径、观察乳腺癌干细胞等基础研究领域及在乳腺癌早期诊断、引导前哨淋巴结活组织检查、药物疗效评价、检测乳腺癌原癌基因人类表皮生长因子受体2 (HER-2)表达等基础研究及临床应用中有着良好的前景.     

Advances in musculoskeletal MRI: Technical considerations

The technology of musculoskeletal magnetic resonance imaging (MRI) is advancing at a dramatic rate. MRI is now done at medium and higher field strengths with more specialized surface coils and with more variable pulse sequences and postprocessing techniques than ever before. These innumerable technical advances are advantageous as they lead to an increased signal‐to‐noise ratio and increased variety of soft‐tissue contrast options. However, at the same time they potentially produce more imaging artifacts when compared with past techniques. Substantial technical advances have considerable clinical challenges in musculoskeletal radiology such as postoperative patient imaging, cartilage mapping, and molecular imaging. In this review we consider technical advances in hardware and software of musculoskeletal MRI along with their clinical applications. J. Magn. Reson. Imaging 2012;36:775–787. © 2012 Wiley Periodicals, Inc.     

Magnetic resonance imaging of atherosclerosis

Abundant data now link composition of the vascular wall, rather than the degree of luminal narrowing, with the risk for acute ischemic syndromes in the coronary, central nervous system, and peripheral arterial beds. Over the past few years, magnetic resonance angiography has evolved as a well-established method to determine the location and severity of advanced, lumen-encroaching atherosclerotic lesions. In addition, more recent studies have shown that high spatial resolution, multisequence MRI is also a promising tool for noninvasive, serial imaging of the aortic and carotid vessel wall, which potentially can be applied in the clinical setting. Because of the limited spatial resolution of current MRI techniques, characterization of coronary vessel wall atherosclerosis, however, is not yet possible and remains the holy grail of plaque imaging. Recent technical developments in MRI technology such as dedicated surface coils, the introduction of 3.0-T high-field systems and parallel imaging, as well as developments in the field of molecular imaging such as contrast agents targeted to specific plaque constituents, are likely to lead to the necessary improvements in signal to noise ratio, imaging speed, and specificity. These improvements will ultimately lead to more widespread application of this technology in clinical practice. In the present review, the current status and future role of MRI for plaque detection and characterization are summarized.     

Nuclear Molecular Imaging for Vulnerable Atherosclerotic Plaques

Atherosclerosis is an inflammatory disease as well as a lipid disorder. Atherosclerotic plaque formed in vessel walls may cause ischemia, and the rupture of vulnerable plaque may result in fatal events, like myocardial infarction or stroke. Because morphological imaging has limitations in diagnosing vulnerable plaque, molecular imaging has been developed, in particular, the use of nuclear imaging probes. Molecular imaging targets various aspects of vulnerable plaque, such as inflammatory cell accumulation, endothelial activation, proteolysis, neoangiogenesis, hypoxia, apoptosis, and calcification. Many preclinical and clinical studies have been conducted with various imaging probes and some of them have exhibited promising results. Despite some limitations in imaging technology, molecular imaging is expected to be used both in the research and clinical fields as imaging instruments become more advanced.     

分子水平的影像医学

现代分子生物学和分子病理学对疾病的认识已从细胞和大体组织水平深入到分子水平，基因诊断和基因治疗更体现了疾病诊治的标志性进展。依托电子学和计算机等高新技术的飞速发展，影像医学与临床诊治已密不可分。因而，将影像医学与基因诊断和治疗相结合，不仅能促进影像医学向分子水平发展；同时能够为临床诊断、治疗方案选择、疗效判断和预后评估提供更深入、精确和全面的信息。     

Medical imaging in pharmaceutical clinical trials: what radiologists should know

The role of medical imaging in pharmaceutical clinical trials includes identification of likely responders; detection and diagnosis of lesions and evaluation of their severity; and therapy monitoring and follow-up. Nuclear imaging techniques such as PET can be used to monitor drug pharmacokinetics and distribution and study specific molecular endpoints. In assessing drug efficacy, imaging biomarkers and imaging surrogate endpoints can not only be more objective and faster to measure than clinical outcomes, but also allow small group sizes, quick results and good statistical power. In this article some basic principles of drug clinical development are explained. Study design, image reading and quantitative image processing in clinical trials with imaging components are discussed.     

肿瘤MR分子影像学研究进展

MR分子影像学以分子生物学为基础,借助MRI技术在活体状态下从分子、基因水平对肿瘤进行更早期、更特异性诊断与监测治疗效果。目前关于MR分子影像研究多集中于MR特异性分子探针的制备、肿瘤血管形成显像、报告基因显像、波谱显像等方面,由于MR具有精确的空间定位及功能成像等优势,因此在肿瘤分子影像研究中具有极大的发展潜力,将在21世纪肿瘤的诊断与治疗中发挥重要作用。MR分子影像学以分子生物学为基础,借助MRI技术在活体状态下从分子、基因水平对肿瘤进行更早期、更特异性诊断与监测治疗效果。目前关于MR分子影像研究多集中于MR特异性分子探针的制备、肿瘤血管形成显像、报告基因显像、波谱显像等方面,由于MR具有精确的空间定位及功能成像等优势,因此在肿瘤分子影像研究中具有极大的发展潜力,将在21世纪肿瘤的诊断与治疗中发挥重要作用。     

Reduction of truncation artifacts in rapid 3D articular cartilage imaging

PURPOSE: To reduce Gibbs ringing artifact in three-dimensional (3D) articular knee cartilage imaging with linear prediction (LP). MATERIALS AND METHODS: A reconstruction method using LP in 3D was applied to truncated data sets of six healthy knees. The technique first linearizes the data before applying the prediction algorithm. Three radiologists blindly reviewed and ranked images of the full, truncated, and predicted data sets. Statistical analysis of the radiologists' reviews was performed for image quality, clinical acceptability of the images, and equivalence with the gold standard. RESULTS: LP applied to 3D knee cartilage imaging allows for 40% decreased scan time while providing image quality with statistical equivalence to a full data set. CONCLUSION: 3D spoiled gradient echo imaging (SPGR) knee cartilage imaging requires significant scan time. This 40% reduction in scan time will allow such scans to be more feasible without sacrificing clinical acceptability.     

Invited. Ultrafast MR imaging of the abdomen: Echo planar imaging and diffusion-weighted imaging

Ultrafast MRI technique has become available with the introduction of new generation MR scanners for abdominal imaging. However, there is no consensus about the optimal imaging acquisition at the present time. Because single shot echo planar imaging (EPI) technique is based on high technology and had just applied in clinical imaging, further clinical investigation will be needed. Currently, the hypersensitivity to magnetic inhomogeneity and local magnetic susceptibility and the low spatial resolution may limit the widespread application of EPI technique. In addition to providing information for morphologic diagnosis, EPI will be more widely used for functional and qualitative diagnosis. Diffusion-weighted imaging can be used for differentiation of solid tumors according to their different cellular construction, evaluation of cystic lesions based on the different viscosity of their contents, and assessment of diffused pathologic changes in the parenchyma of solid organs. In addition to the previous parameters such as proton density and T1 and T2 values, diffusion factors may provide important information for the qualitative and dynamic evaluation of abdominal pathologic changes. Even though there are many difficulties that must be solved for diffusion-weighted imaging, a more wide application of this technique is expected through technologic improvement.