共查询到20条相似文献,搜索用时 15 毫秒
1.
Molecular imaging techniques in body imaging 总被引:6,自引:0,他引:6
Molecular imaging of the body involves new techniques to image cellular biochemical processes, which results in studies with high sensitivity, specificity, and signal-to-background. The most prevalently used molecular imaging technique in body imaging is currently fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET). FDG PET has become the method of choice for the staging and restaging of many of the most common cancers, including lymphoma, lung cancer, breast cancer, and colorectal cancer. FDG PET has also become extremely valuable in monitoring the response to therapeutic drugs in many cancers. New PET agents, such as fluorothymidine and acetate, have also shown promise in the evaluation of response to therapy and in the staging of prostate cancer. Magnetic resonance (MR) spectroscopy has shown promise in the evaluation of prostate cancer. Breast cancer evaluation benefits from advances in spectroscopic imaging and contrast-enhanced kinetic evaluation of vascular permeability, which is altered in neoplastic processes because of release of angiogenic factors. Superparamagnetic iron oxide (SPIO) particles represent the first of an expanding line of MR contrast agents that target specific cellular processes. SPIO particles have also been used in the evaluation of the cirrhotic liver and at MR lymphangiography. 相似文献
2.
Molecular imaging: integration of molecular imaging into the musculoskeletal imaging practice 总被引:3,自引:0,他引:3
Chronic musculoskeletal diseases such as arthritis, malignancy, and chronic injury and/or inflammation, all of which may produce chronic musculoskeletal pain, often pose challenges for current clinical imaging methods. The ability to distinguish an acute flare from chronic changes in rheumatoid arthritis, to survey early articular cartilage breakdown, to distinguish sarcomatous recurrence from posttherapeutic inflammation, and to directly identify generators of chronic pain are a few examples of current diagnostic limitations. There is hope that a growing field known as molecular imaging will provide solutions to these diagnostic puzzles. These techniques aim to depict, noninvasively, specific abnormal cellular, molecular, and physiologic events associated with these and other diseases. For example, the presence and mobilization of specific cell populations can be monitored with molecular imaging. Cellular metabolism, stress, and apoptosis can also be followed. Furthermore, disease-specific molecules can be targeted, and particular gene-related events can be assayed in living subjects. Relatively recent molecular and cellular imaging protocols confirm important advances in imaging technology, engineering, chemistry, molecular biology, and genetics that have coalesced into a multidisciplinary and multimodality effort. Molecular probes are currently being developed not only for radionuclide-based techniques but also for magnetic resonance (MR) imaging, MR spectroscopy, ultrasonography, and the emerging field of optical imaging. Furthermore, molecular imaging is facilitating the development of molecular therapies and gene therapy, because molecular imaging makes it possible to noninvasively track and monitor targeted molecular therapies. Implementation of molecular imaging procedures will be essential to a clinical imaging practice. With this in mind, the goal of the following discussion is to promote a better understanding of how such procedures may help address specific musculoskeletal issues, both now and in the years ahead. 相似文献
3.
Robert J. Gropler MD 《Journal of nuclear cardiology》2008,15(3):429-434
Conclusion
“The order is rapidly fadin’. And the first one now will later be last ...”
In 2008 myocardial perfusion imaging is the main-stay of nuclear cardiology. However, the lyrics of Dylan from the 1960s are
applicable today, as we are in rapidly changing times in medicine. We are seeing a paradigm shift in disease detection and
treatment from a focus on cardiovascular morphology, function, and pathophysiology to genetic and molecular events. Cardiovascular
molecular imaging will be the vanguard of noninvasive imaging in this era. Nuclear cardiology is uniquely positioned to play
a central role in both the clinical and research applications of cardiovascular molecular imaging. The question should not
be whether myocardial perfusion imaging will remain the dominant clinical application but how does nuclear cardiology transition
to embrace and foster cardiovascular molecular imaging. If we do not do this, there are several other imaging specialties
that will be more than willing to fill this void. 相似文献
4.
5.
张海三 《国际放射医学核医学杂志》2006,30(2):99-102
肿瘤阳性显像具有较高的敏感性和特异性,易于对肿瘤的原发、复发以及转移做出定性、定位诊断。201Tl、99mTc-甲氧基异丁基异腈已经用于鉴别诊断良恶性病灶、寻找转移灶、评价治疗效果和判断预后,99mTc-氮-二(N-乙基-N-乙氧基二硫代氨基甲酸盐)在肿瘤中的应用则尚在探讨中。 相似文献
6.
7.
For optimizing MR of the joints, a sophisticated knowledge of MR system hard-and software condition, and coil technologies, sequence and contrast preparation techniques, and the use of paramagnetic contrast agents is necessary. This review article discusses the basic principles of the appropriate use of surfacecoilsas well as the different conventional and fast imagingsequences, including three-dimensional (3D)MR imaging. In addition, the applications of contrast agents as well as the most important contrast prepaation techniques are reviewed. 相似文献
8.
Magnetic resonance imaging (MRI) of the liver is slowly transitioning from a problem solving imaging modality to a first line imaging modality for many diseases of the liver. The well established advantages of MRI over other cross sectional imaging modalities may be the basis for this transition. Technological advancements in MRI that focus on producing high quality images and fast imaging, increasing diagnostic accuracy and developing newer function-specific contrast agents are essential in ensuring that MRI succeeds as a first line imaging modality. Newer imaging techniques, such as parallel imaging, are widely utilized to shorten scanning time. Diffusion weighted echo planar imaging, an adaptation from neuroimaging, is fast becoming a routine part of the MRI liver protocol to improve lesion detection and characterization of focal liver lesions. Contrast enhanced dynamic T1 weighted imaging is crucial in complete evaluation of diseases and the merit of this dynamic imaging relies heavily on the appropriate timing of the contrast injection. Newer techniques that include fluoro-triggered contrast enhanced MRI, an adaptation from 3D MRA imaging, are utilized to achieve good bolus timing that will allow for optimum scanning. For accurate interpretation of liver diseases, good understanding of the newer imaging techniques and familiarity with typical imaging features of liver diseases are essential. In this review, MR sequences for a time efficient liver MRI protocol utilizing newer imaging techniques are discussed and an overview of imaging features of selected common focal and diffuse liver diseases are presented. 相似文献
9.
Comparison of contrast-enhanced fundamental imaging, second-harmonic imaging, and pulse-inversion harmonic imaging 总被引:7,自引:0,他引:7
RATIONALE AND OBJECTIVES: To investigate the feasibility of recent contrast-specific ultrasound techniques in depicting vascular flow and the effects of changing the output power of the transducer and insonation mode on contrast enhancement, the authors performed an experimental study with a flow phantom. METHODS: While changing the mechanical index and the sound insonation mode (continuous and intermittent), images were obtained with three contrast-enhanced ultrasound techniques: fundamental, second-harmonic, and pulse-inversion harmonic imaging (PIHI) after a bolus injection of microbubble contrast agent. The images were compared on a time-intensity curve. RESULTS: In assessing fixed flow (10 cm/s), PIHI showed the best depiction of flow signal. In intermittent scanning, increases in the mechanical index caused stronger flow signals and longer enhancement duration in all techniques. However, continuous scanning revealed poor depiction of flow signal regardless of the technique or changes in the mechanical index because of significant bubble destruction. CONCLUSIONS: Microbubble-enhanced PIHI with intermittent scanning at a high mechanical index can depict vascular flow highly effectively without shortening the duration of enhancement. 相似文献
10.
K K Vigen D C Peters T M Grist W F Block C A Mistretta 《Magnetic resonance in medicine》2000,43(2):170-176
In time-resolved contrast-enhanced 3D MR angiography, spatial resolution is traded for high temporal resolution. A hybrid method is presented that attempts to reduce this tradeoff in two of the spatial dimensions. It combines an undersampled projection acquisition in two dimensions with variable rate k-space sampling in the third. Spatial resolution in the projection plane is determined by readout resolution and is limited primarily by signal-to-noise ratio. Oversampling the center of k-space combined with temporal k-space interpolation provides time frames with minimal venous contamination. Results demonstrating improved resolution in phantoms and volunteers are presented using angular undersampling factors up to eight with acceptable projection reconstruction artifacts. 相似文献
11.
12.
MR imaging of the heart: functional imaging 总被引:1,自引:0,他引:1
To date, most applications of cardiovascular MRI relate to the evaluation of major vessels rather than the heart itself.
However, MRI plays a major role in the evaluation of specific types of cardiovascular pathology, namely intracardiac and paracardiac
masses, pericardial disease, and congenital heart disease. In addition, because the visualization of cardiovascular anatomy
with MR is non-invasive and permits three-dimensional analysis but also allows functional assessment of the cardiac pump,
it is clear that MRI will have a growing and significant impact over the next years. We review some of the technical aspect
of cardiac MRI and describe the current and potential clinical and investigative applications of this new methodology. 相似文献
13.
Combined magnetic resonance imaging and spectroscopic imaging approach to molecular imaging of prostate cancer 总被引:18,自引:0,他引:18
Kurhanewicz J Swanson MG Nelson SJ Vigneron DB 《Journal of magnetic resonance imaging : JMRI》2002,16(4):451-463
Magnetic resonance spectroscopic imaging (MRSI) provides a noninvasive method of detecting small molecular markers (historically the metabolites choline and citrate) within the cytosol and extracellular spaces of the prostate, and is performed in conjunction with high-resolution anatomic imaging. Recent studies in pre-prostatectomy patients have indicated that the metabolic information provided by MRSI combined with the anatomical information provided by MRI can significantly improve the assessment of cancer location and extent within the prostate, extracapsular spread, and cancer aggressiveness. Additionally, pre- and post-therapy studies have demonstrated the potential of MRI/MRSI to provide a direct measure of the presence and spatial extent of prostate cancer after therapy, a measure of the time course of response, and information concerning the mechanism of therapeutic response. In addition to detecting metabolic biomarkers of disease behavior and therapeutic response, MRI/MRSI guidance can improve tissue selection for ex vivo analysis. High-resolution magic angle spinning ((1)H HR-MAS) spectroscopy provides a full chemical analysis of MRI/MRSI-targeted tissues prior to pathologic and immunohistochemical analyses of the same tissue. Preliminary (1)H HR-MAS spectroscopy studies have already identified unique spectral patterns for healthy glandular and stromal tissues and prostate cancer, determined the composition of the composite in vivo choline peak, and identified the polyamine spermine as a new metabolic marker of prostate cancer. The addition of imaging sequences that provide other functional information within the same exam (dynamic contrast uptake imaging and diffusion-weighted imaging) have also demonstrated the potential to further increase the accuracy of prostate cancer detection and characterization. 相似文献
14.
15.
16.
17.
Parametric imaging 总被引:2,自引:0,他引:2
The analysis of circulatory dynamics by functional data extraction from radiologic image sequences constitutes the latest development of digital imaging techniques in angiography. In this article, the methodologic approach of angiographic parameter extraction and the interpretation of functional information are outlined. Applications of parametric imaging in arterial blood flow, arterial flow distribution, parenchymal perfusion, and coronary and myocardial perfusion are discussed. 相似文献
18.
Classic symptoms of appendicitis include right lower quadrant pain on palpation, loss of appetite, nausea and vomiting. However, only about half of patients present with these characteristic symptoms. The remainder of patients must undergo some type of diagnostic study to verify or rule out appendicitis. This article describes the types of medical imaging that are used to evaluate possible appendicitis, including conventional abdominal radiography, ultrasound, computed tomography and nuclear medicine imaging. 相似文献
19.
Osteoporosis imaging 总被引:4,自引:0,他引:4
Because osteoporotic fractures may be prevented, diagnostic techniques are essential in the assessment of osteoporosis. Conventional radiographs of the spine are not suited for diagnosing early osteoporosis, but they show fractures that may have no clinical symptoms. The radiologist should be aware of the enormous significance of these fractures for future osteoporotic fractures. Bone mass measurements are standard techniques in the diagnosis of osteoporosis, which are the basis of the WHO definition of osteoporosis. In this article the authors presented these standard techniques and newer diagnostic techniques that provide insights in the structure of trabecular bone. 相似文献
20.