201Tl定量门控心肌灌注体层显像与99mTc-红细胞门控心血池显像测定左心室射血分数的对比研究

目的 探讨201Tl定量门控心肌灌注体层显像与99mTc-红细胞门控心血池显像测量左心室射血分数(LVEF)的相关性.方法 72例受检者接受201Tl静息门控心肌灌注体层显像,用AUTOQUANT 4.21软件测量LVEF,并与24 h内的静息99mTc-红细胞平衡法门控心血池显像结果进行比较.结果 ①门控心肌灌注体层显像与门控心血池显像测量LVEF值的结果呈明显正相关(r=0.554,P=-0.000),两种方法无统计学差别(t=1.194,P＞0.05).②不同疾病组之间两种测量方法无统计学差异(P值均大于0.05).③门控心肌灌注体层显像及门控心血池显像测量的LVEF值分别为(64.68±10.77)%和(62.46±8.99)%,门控心肌灌注体层显像测量的LVEF值要比门控心血池显像高出3.55%.结论 201Tl门控心肌灌注体层显像与99mTc-红细胞门控心血池显像测量LVEF值的相关性好且结果准确,但门控心肌灌注体层显像的LVEF测量值要稍高于门控心血池显像.     

门控(99m)~Tc-MIBI心肌灌注显像分析

采用门控~(99)Tc-MIBI心肌灌注断层显像法对29例心肌疾病患者的舒张末期(ED)和收缩末期(ES)图像进行了定性和定量分析,并与非门控心肌断层图像进行了对比。结果发现前者的ED、ES图像在发现缺血和梗塞灶方面高于后者(P<0.001),尤其ED图像可发现微小的心内膜下缺血灶,显示了此法在分辨率上的优势。通过对左室收缩分数(LVCF)和室壁收缩厚度率(STR)的测定,认为LVCF在检测左室整体功能方面为临床心脏病患者提供了心室功能的可靠指标,而STR则可提供室壁局部收缩功能的定性定量信息。由于本法能同时提供心肌灌注的定性定位诊断和心功信息。从而使心肌灌注显像的临床应用得到了扩展。     

心肌灌注门控断层显像初步研究

用９９ｍＴｃ－甲酯异两基异腈（ＣＰＩ）对２３例行心肌灌注门电路触发断层显像研究，能清楚地显示心肌边缘、厚度和放射性分布．经与静息断层比较，门控断层可显著提高缺血心肌节段的诊断灵敏度，检出率提高１７．７％（Ｐ＜０．０１）．经计算机处理可获得左心室收缩分数，与核素平衡法门电路心血池显像（ｒ＝０．７０５４，Ｐ＜０．０１）和超声心动图法（ｒ＝０．６８１２，Ｐ＜０．０５）测得的左心室射血分数呈有意义的中度相关，可作为反映左心功能的指标．还可测定舒张状态心肌容积，反映心脏收缩过程中心肌形态和放射性分布变化，具有反映室壁运动的潜力．     

双核素显像评价PCI术后心肌代谢与血流灌注

目的: 探讨18F-FDG葡萄糖代谢显像结合99mTc-MIBI静息灌注显像评价急性心肌梗塞(AMI)患者经皮冠心病介入治疗(PCI)后的心肌代谢及血流灌注.材料和方法: 用符合线路ECT对25例AMI患者在PCI术后2周行18F-FDG及99mTc-MIBI显像,通过圆周剖面半定量分析,评价局部心肌灌注、代谢和超声心动图检测的室壁运动功能之间的关系.结果: 术后2周运动正常心肌节段99mTc-MIBI%与18F-FDG%摄取值分别为83.7±15.7、89.4±13.6,比运动减弱节段(68.5±17.3、71.2±18.6)和无运动节段(32.3±14.9、56.1±18.8)高,(P<0.01);3个月后运动恢复心肌节段(n=67) MIBI%、FDG%分别为43.6±14.6、71.1±17.9高于运动未恢复节段(n=49) 的31.5±13.4、48.0±14.3高(P<0.01).室壁运动评分指数(WMSI)与99mTc-MIBI缺损%成正相关(r=0.791).结论: 心肌血流灌注、代谢显像能预测室壁运动改善,可用于临床判断PCI术后疗效.     

核素显像识别存活心肌的临床应用进展

存活心肌的判断对冠心病患者治疗方案的选择及预后十分重要。201Tl再注射法、硝酸甘油介入的静息99Tcm-sestamibi法增强了心肌灌注核素体层显像对存活心肌的检测能力,门控SPECT技术能在评估心肌灌注的同时计算LVEF(左心室射血分数)、局部室壁运动和局部室壁增厚率,具有符合线路的SPECT可以进行心肌代谢显像及灌注显像,其对存活心肌的检测能力可能接近于PET,而检查费用可大大降低。     

核素显像识别存活心肌的临床应用进展

存活心肌的判断对冠心病患者治疗方案的选择及预后十分重要。^201Tl再注射法、硝酸甘油介入的静息^99Tc^m-sestamibi法增强了心肌灌注核素体层显像对存活心肌的检测能力，门控SPECT技术能在评估心肌灌注的同时计算LVEF(左心室射血分数)、局部室壁运动和局部室壁增厚率，具有符合线路的SPECT可以进行心肌代谢显像及灌注显像，其对存活心肌的检测能力可能接近于PET，而检查费用可大大降低。     

门控99Tcm-MIBI/18F-FDG双核素同时采集显像评价左心室功能

目的探讨门控99Tcm-甲氧基异丁基异腈(MIBI)/18F-脱氧葡萄糖(FDG)双核素同时采集(DISA)显像评价左心室功能的临床价值.方法 77例冠心病患者行门控DISA,其中53例行X线左心室造影(LVG),分别比较LVG心室射血分数(EF)值和DISA法门控99Tcm-MIBI和18F-FDG 同时显像所得EF值.局部室壁运动行Kappa值比较.结果门控99Tcm-MIBI和门控18F-FDG显像所得EF值间相关性高(r=0.90,P<0.001).两者与LVG EF值相关性均高(r分别为0.86和0.85,P均<0.001).门控99Tcm-MIBI和18F-FDG显像与LVG比较Kappa值分别为0.765和0.742.结论门控99Tcm-MIBI/18F-FDG DISA可同时了解左室心肌灌注、代谢及功能,提供左心室功能的重要信息,有重要的临床价值.     

定量门控心肌显像评价局部室壁运动

目的　探讨定量门控99Tcm 甲氧基异丁基异腈 (MIBI)、2 0 1 Tl和99Tcm tetrofosmin心肌显像评价局部室壁运动的可靠性。方法　对 30 1例左室功能受检者行门控99Tcm MIBI(n =15 8)、2 0 1 Tl(n =113)和99Tcm tetrofosmin(n=30 )心肌显像 ,采用QGSPECT程序评价左室总体和各区域局部室壁运动。并与二维超声心动图进行比较。结果　①左室总体局部室壁运动 :定量门控99Tcm MIBI心肌显像评价室壁运动与超声心动图的结果基本符合 (Kappa =0 6 3,P <0 0 1) ,定量门控2 0 1 Tl(Kappa =0 5 2 ,P <0 0 1)和99Tcm tetrofosmin(Kappa =0 5 4 ,P <0 0 1)心肌显像评价室壁运动与超声心动图的结果中等符合。②左室各区域局部室壁运动 :定量门控99Tcm MIBI和99Tcm tetrofosmin心肌显像能较准确评价左室前壁、前侧壁、后侧壁、下壁、前间壁、后间壁和后壁局部室壁运动 (Kappa =0 4 6～ 0 89,P <0 0 1) ;而定量门控2 0 1 Tl心肌显像只能较准确评价左室前壁、下壁和后壁局部室壁运动 (Kappa=0 6 5～ 0 72 ,P <0 0 1) ,其侧壁和间壁的可靠性低于前者 (Kappa =0 2 7～ 0 39)。结论　定量门控99Tcm MIBI、2 0 1 Tl和99Tcm tetro fosmin心肌显像能较准确评价局部室壁运动。     

定量门控99Tcm-tetrofosmin心肌显像测量左室功能

目的探讨定量门控(QG)99Tcm-tetrofosmin心肌显像测量左室功能的临床应用价值.方法74例受试者进行了门控99Tcm-tetrofosmin心肌显像,采用QGSPECT专用分析程序全自动测量左室功能.其中36例同时进行静息门控心室显像,以比较两种方法测量左室功能的相关性.结果①74例99Tcm-tetrofosminQGSPECT全自动定量测定左室功能均获成功.②QGSPECT全自动测量36例受试者的静息左室射血分数(LVEF)、舒张末期容积(EDV)、收缩末期容积(ESV)分别与静息门控心室显像计算结果显著正相关(r分别为0.859,0.914,0.950,P均<0.001),重复性好.③心肌缺血组(n=28)静息LVEF与对照组(n=23)比较差异无显著性,而心肌梗死组(n=9)静息LVEF明显低于对照组(t=6.33,P<0.001).结论定量门控心肌显像99Tcm-tetrofosmin能准确评价左室功能.     

门控心肌显像局部室壁运动异常对判断冠状动脉狭窄程度的价值

目的　探讨99Tcm 甲氧基异丁基异腈 (MIBI)门控心肌显像可逆性局部室壁运动异常(RWMA)对判断冠状动脉 (简称冠脉 )狭窄程度的价值。方法　 116例疑诊冠心病患者 ,在行运动 静息99Tcm MIBI门控心肌显像前后 2周内进行冠脉造影 (CAG)。运动显像于运动后 15～ 2 0min内进行图像采集 ;应用 2 0节段 5分制进行室壁运动及增厚率评分。结果　用心肌显像可逆性RWMA判断狭窄程度≥ 75 %冠脉狭窄的灵敏度为 6 5 % ,特异性为 97% ;用可逆性RWMA区别严重冠脉狭窄 (≥75 % )和不严重冠脉狭窄 (<75 % )有较高的阳性预测值 (98% )。多因素分析示负荷室壁运动总积分(SSSWM)、室壁运动差分值 (SDSWM)和运动显像灌注总积分 (SSS)是濒危冠脉积分的独立危险因子。结论　根据99Tcm MIBI门控心肌显像可逆性RWMA判断严重冠脉狭窄特异性和阳性预测值较高。运动后及可逆性RWMA可提高心肌灌注显像对冠脉狭窄程度的评估价值。     

Molecular imaging techniques in body imaging

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.     

Molecular imaging: integration of molecular imaging into the musculoskeletal imaging practice

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.     

Molecular imaging will replace myocardial perfusion imaging

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.     

用于肿瘤显像的三种显像剂

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。     

Optimizing joint imaging: MR imaging techniques

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.     

Magnetic resonance imaging: Review of imaging techniques and overview of liver imaging

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.     

Comparison of contrast-enhanced fundamental imaging, second-harmonic imaging, and pulse-inversion harmonic imaging

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.     

Undersampled projection-reconstruction imaging for time-resolved contrast-enhanced imaging.

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.