显像时间与活性对PET/CT图像质量的影响

目的探讨显像时的活性水平与显像时间对PET/CT图像质量的影响.方法分别在Jaszczak模型内高活性短采集时间、推荐活性和采集时间以及低活性长采集时间下,以全身显像方式采集发射数据;采用X线CT作衰减校正(CTAC)和全身显像方式进行图像重建.相同患者按5.18 MBq/kg给药,分别于给药50 min和90 min后采集数据,采用CTAC和全身显像方式进行图像重建.以152.026 MBq、每床位采集3 min 30 s对1例74 kg女性志愿者进行显像.结果三种显像条件所得图像都可清晰分辨模型中直径为6.4 mm的冷、热区,且均匀区域未见伪影.给药50 min后开始采集所得患者图像清晰,但有时病灶难以与正常组织区分;给药90 min后开始采集所得患者图像清晰,对比度良好,能进一步明确病灶轮廓与数量.低活性较长采集时间也能获得较好的图像质量.结论通过对活性和显像时间的平衡,明显降低了二者对PET/CT图像质量的影响.给药与开始采集数据的时间间隔最好在90 min以上.     

125I-USPIO-bevacizumab用于肝细胞肝癌的SPECT/CT/MRI多模态显像研究

目的：探讨125I标记的超小超顺磁性氧化铁颗粒（ultrasmall superparamagnetie iron oxide,USPIO）偶联的贝伐珠单抗（bevacizumab）用于HepG2肝细胞肝癌模型鼠多模态显像的可行性.方法：用125I标记bevacizumab,将其经尾静脉注射入HepG2肝细胞癌肝模型鼠,注射后2h和24 h分别进行小动物活体SPECT/CT显像.然后,用直径小于20 nm的USPIO偶联bevacizumab,合成USPIO-bevacizumab;用125I标记USPIO-bevacizumab形成125I-USPIO-bevacizumab,将其经尾静脉注射入HepG2肝细胞癌模型鼠;注射后2h和24 h分别行小动物SPECT/CT显像.显像结束后,处死模型鼠,采用免疫组化实验验证放射性标记的纳米颗粒的靶向性.为了验证USPIO-bevacizumab用于MRI显像的效果,将未用125I标记的USPIO-bevacizurnab从尾静脉注射到到1只HepG2肝细胞癌模型鼠,分别于注射前后行活体MRI T2WI加权显像.结果：”5I-bevacizumab注射后,HepG2肝细胞癌模型鼠的Nano SPECT/CT显像及感兴趣区（ROI）定量分析显示,肿瘤的放射性吸收在2h及24h分别为2.3％和2.5％,放射标志物集中在肿瘤边缘;而125I-USPIO-bevacizumab注射后,模型鼠肿瘤的放射性吸收在2 h及24 h分别为0.54％和1.04％,放射标志物在实体瘤呈均匀分布.肝细胞癌模型鼠MRI T2WI加权MRI成像显示,注射显像剂后,肝脏及肿瘤部位信号均较注射前轻微减弱.免疫组化显示,HepG2肿瘤组织中有血管内皮生长因子（VEGF）的阳性表达及新生血管形成.结论：125I-USPIO-bevacizumab对HepG2肝细胞肝癌组织具有较好的生物靶向性,可作为新型双模态分子影像探针应用于肝细胞肝癌的SPECT/MRI显像研究.     

99Tcm-TRODAT-1多巴胺转运蛋白SPECT脑显像在亚临床期和临床期帕金森病模型猴诊断中的研究

目的探讨99Tcm-TRODAT-1多巴胺转运蛋白SPECT脑显像在帕金森病亚临床期诊断中的价值.方法对4只食蟹猴静脉注射多巴胺转运蛋白显像剂99Tcm-TRODAT-1,观察99Tcm-TRODAT-1在不同时间点正常猴体内分布并进行纹状体DAT功能分析.用MPTP分别制备无症状亚临床期和临床期PD猴模型,利用计算机感兴趣区(ROI)技术进行纹状体DAT功能半定量分析.结果99Tcm-TRODAT-1最佳SPECT脑显像时间为注射99Tcm-TRODAT-1后3～4 h.PD猴毁损侧(右侧)纹状体在亚临床期就已存在DAT功能的降低,并随着损伤的加重毁损侧纹状体DAT功能进一步降低,对侧纹状体的DAT也受损.结论99Tcm-TRODAT-1 SPECT脑显像可用于PD的亚临床期诊断和病情监测.     

新型心肌灌注显像剂^99mTc—tetrofosmin诊断冠心病的价值

目的：探讨新型心肌灌注显像剂^99mTc-tetrofosmin诊断冠心病的临床价值。材料与方法：对59例确诊或疑诊并已行冠状动脉造影的患者进行运动。静息心肌灌注断层显像,分别在运动高峰及静息状态静脉注射^99mTc-tetrofosmin740MBq后30－60min按常规方法做SPECT断层采集。结果：在注射^99mTc-tetrofosmin的后无任何不适反应,并获得良好心肌断层图像,以冠状动脉造影结果为金标准,^99mTc-tetrofosmin诊断冠心病的灵敏度、特异性及准确度分别为89．1％,84．6％及88．1％。结论：^99mTc-tetrofosmin具有标记简便,给药后无需脂餐促排、显像时间短、图像质量清晰及诊断准确度较高等特点,有着良好的临床应用前景。     

比较两种SPECT/CT动态采集方法对消化道出血点核素显像的影响

目的探讨不同的单光子发射计算机断层成像术/电子计算机X射线断层扫描技术（single-photon emission computed tomography/electronic computer X-ray tomography technique,SPECT/CT）采集方法对消化道出血的出血点核素显像的影响。方法对拟诊为消化道出血的45例患者,采用99m锝（99mTc）体内标记红细胞法,分两组使用不同的采集参数行全腹动态显像。结果动态采集过程中,每帧图像采集时间长的一组阳性率明显高于采集时间短的一组。结论动态采集中适当延长每帧图像采集时间可以更容易发现出血点位置,具有较高的应用价值,应为首选。     

SPECT门控心肌灌注显像定量分析的诊断价值

目的:探讨SPECT门控心肌灌注显像定量分析在提高诊断准确性方面的应用价值。方法:回顾分析112例具有完整的~(99m)Tc-MIBI门控静息/负荷心肌灌注显像资料和冠状动脉造影结果的患者资料。由3名有经验的核医学医师首先对SPECT心肌灌注显像的断层图像进行了分析并做出诊断,然后应用定量分析软件对门控图像进行定量分析获得左心室射血分数(LVEF)等功能指标并动态显示室壁运动情况,结合断层图像再次进行图像分析。以冠状动脉动脉造影的结果为标准,对比分析是否应用定量分析软件时诊断的敏感性、特异性和准确性。分析除LVEF外的其他功能性指标对诊断是否具有帮助。结果:112例患者冠状造影结果显示共计有147支冠状动脉管腔狭窄>50%。单纯SPECT心肌灌注显像断层图像目测分析诊断的敏感性、特异性和准确性分别为91.8%、86.8%和90.0%。综合分析断层图像与定量分析指标,诊断的敏感性、特异性和准确性分别为95. 9%、94.2%和94.9%。除LVEF外,其他定量分析指标被认为对诊断具有帮助的占59.8%(67/112),认为不确定者23.2%(26/ 112),认为没有价值者占17.0%(19/112)。结论:借助于定量分析软件可以明显的提高SPECT心肌灌注显像诊断的准确性。     

PET/CT骨骼显像方法学探讨

目的：利用PET/CT检查设备，对Na18F断层骨显像进行方法学研究。资料和方法：PET/CT、小型回旋加速器均采用美国通用电气公司生产的设备，型号分别为Discovery LS和Minitrace；骨显像剂为Na18F（放化纯为95.3％）。采用不同断层骨显像方法对比分析，探讨人体Na18F摄取速度、显像采集速度及显像时间对断层骨显像的影响。结果：适宜的骨显像方法能提高Na18F断层骨显像的质量。结论：PET/CT检查骨肿瘤较SPECT平面骨显像具有更好的灵敏性和图像质量。     

列表模式采集在18F-FDG PET/CT采集时长优化中的初步应用

目的:探讨应用列表采集模式优化18F-FDG PET/CT采集时长的可行性.方法:共22例常规接受PET/CT检查患者入选本研究.患者按照7.4 MBq/kg的标准注射显像剂,显像仪器为西门子Biograph 64 PET/CT.选择肝脏作为靶器官,先行CT扫描,然后行180 s列表模式PET采集.通过设置不同的采集时间长度参数对原始数据重建静态图像,获得40～180 s间8个时长条件下的PET图像.选择肝脏最大层面、无病灶区域勾画直径为4 cm的感兴趣区,测量感兴趣区的SUVmax及SUVmean.所有统计分析使用SPSS16完成.结果:SUVmax与SUVmean均呈现出随采集时间增加而降低的变化趋势,在采集时长≥80 s的情况下,各组间SUVmax与SUVmean均无显著差异,与常规PET/CT采集获得图像亦无显著差异.结论:优化的采集时长在保证图像质量基础上显著提高了检查效率.列表模式采集能够动态反映采集时长与图像质量间的关系,可以作为确定18F-FDGPET/CT最优采集时长的有效方法.     

门控心肌显像评价肝细胞生长因子转染小型猪心肌梗死的实验研究

目的：探讨99mTc-MIBI门控静息心肌显像在评价转染携带人肝细胞生长因子的腺病毒（Ad5-HGF）治疗心肌梗死的价值。方法：25只小型猪随机分成对照组、模型组和3个治疗组（Ad5-HGF低、中、高剂量组），均在手术前及观察期结束时分别接受门控心肌显像和冠状动脉造影，并行组织学检查。结果：①治疗前模型组及各治疗组心肌灌注和Rentrop计分均明显低于对照组（P<0.01）；低剂量组治疗前、后心肌灌注和Rentrop计分差值与模型组比较没有明显差别（P＞0.05）；中、高剂量组治疗前、后差值明显高于模型组（P<0.01）。②治疗前模型组及各治疗组左室射血分数均明显低于对照组（P<0.01）；低剂量组治疗前、后左室射血分数差值与模型组比较没有明显差别（P＞0.05）；中、高剂量组治疗前、后差值明显高于模型组（P<0.05）。③模型组血管数量和低剂量组比较没有差别（P＞0.05），但明显少于对照组和中、大剂量组（P<0.01）。结论：可以利用99mTc-MIBI门控静息心肌显像来评价Ad5-HGF治疗猪心肌梗死的疗效。     

口服乙酰唑胺脑负荷试验的观察与护理

口服乙酰唑胺脑负荷试验SPECT（单光子反射型计算机断层照相机，简称SPECT）显像检查可了解短暂性脑缺血发作患者的脑血流（rCBF）情况，提高缺血性脑血管疾病（TIA）的阳性诊断率，正确评价脑血管的储备功能。作者观察15例TIA患者口服乙酰唑胺后均无严重不良反应，经rCBF静息与负荷显像同一部位图像比较分析，结果认为其扩张脑血管效果满意，可通过正常与病变部位图像确定rCBF差异的对比度而发现病灶．其方法简便，经济实用，药物反应轻微，患者容易接受。护理要点包括心理疏导以保持患者心态平静，维持脑血管的稳定性，掌握显像剂注射时间，观察病情及药物反应，注意安全，防止发生意外事故。     

不稳定型心绞痛患者全球急性冠状动脉事件注册评分与心肌灌注显像危险分层的相关研究

目的：研究不稳定型心绞痛患者^99mTc-甲氧基异丁基异腈（MIBI）负荷／静息门控心肌灌注显像危险度分层与全球急性冠状动脉事件注册（GRACE）评分的相关性。方法：2006年6月--2007年11月确诊为不稳定型心绞痛的住院患者37例。首先依据GRACE评分方法进行评分；然后行^99mTc-MIBI运动或腺苷负荷门控心肌灌注显像和静息心肌灌注显像，依据负荷／静息门控心肌灌注显像所测定的可逆性心肌缺血计分值（SDS）和负荷后左室射血分数（LVEF）将患者分为低危组和中危组。分析^99mTc-MIBI负荷／静息门控心肌灌注显像危险分层与GRACE评分的相关性。结果：37例患者均顺利完成^99mTc-MIBI运动或腺苷负荷门控心肌灌注显像和静息心肌灌注显像。低危组和中危组之间的GRACE评分有显著差异（P〈0．01）。GRACE评分与负荷状态下心肌缺血计分值（SSS）呈正相关（r=0．561，P〈0．01），与SDS呈正相关（r=0．623，P〈0．01），与静息状态下心肌缺血计分值（SRS）无关（r=0．175，P〉0．05）。结论：GRACE评分对不稳定型心绞痛患者的核素心肌灌注显像危险度分层有一定的预测价值。     

经皮冠状动脉介入治疗急性心肌梗死的护理效果

目的:探讨急诊经皮冠状动脉介入治疗(PCI)急性心肌梗死(AMI)的护理效果。方法:选取我院2012年1~10月收治的100例AMI患者,并对这些患者在15 h内进行直接PCI治疗及护理,共置入支架104枚,观察患者梗死相关动脉的再通率、住院病死率、心功能恢复等情况。结果:本组患者入院至梗死相关动脉开通平均时间为(41.8±13.6)min,进入导管室至梗死相关动脉开通时间为(17.7±2.1)min,梗死相关动脉达TIMIⅢ级血流为88%,术后患者胸痛及心电图相关导联ST段良好率达88%,心功能恢复良好率达95%。本组有3例发生并发症,其中1例患者因广泛前壁心肌梗死出现心脏破裂在入院后第3天死亡,2例术中出现恶性心律失常经及时治疗明显缓解。结论:PCI治疗与全程护理AMI具有及时、有效疏通血管,保证良好心肌供血的作用,并且能够最大程度地降低AMI病死率,值得在临床治疗及护理上推广应用。     

心房颤动患者的低剂量、大螺距双源CT冠状动脉成像的可行性研究(英文)

Objective The objective was to attempt to rule out whether high-pitch spiral acquisition dual-source computed tomography coronary angiography(CTCA)can be performed in patients with atrial fibrillation at low dose.Methods Ten patients with atrial fibrillation who were admitted for a first diagnostic coronary angiogram were screened for participation.All patients underwent dual-source CT.Patients were performed CTCA using the prospectively ECG-gated high-pitch mode and retrospective ECG gating spiral acquisition respectively with their permissions.The start phase for image acquisition of the most cranial slice was selected at 20%-30% of the R-R interval in all patients.Results Image qualities of prospectively ECG-gated high-pitch mode were rated as being excellent in 7 cases of all the patients and only 3 cases′ image qualities were graded score 2.By using retrospective ECG gating spiral acquisition mode,non-diagnostic image quality (score 3) occurred in 4 patients which were observed in RCA and 1 patient in LCX.The estimated radiation dose ranges from 0.68 to 1.887 mSv in flash mode and the radiation dose of spiral mode were very high ranging from 14.92 to 29.308 mSv.Conclusions Our case series suggest that patients with atrial fibrillation rhythm can be performed CTCA with high-pitch spiral acquisition mode.20%-30% of the RR interval window for data acquisition for high-pitch dual-source CTCA may probably obtain good image quality with low doses.     

急性ST抬高心肌梗死心电图心肌缺血分级的临床意义

目的 通过对急性ST段抬高心肌梗死患者入院时心电图QRS波群变化进行缺血分级,探讨缺血分级的临床意义.方法 STEMI患者105例,根据入院时心电图QRS波群变化进行缺血分级:2级缺血组(56例);3级缺血组(49倒).所有患者于梗死后2周行99m锝-甲氧基异丁基异腈(99mTc-MIBI)心肌灌注断层显像(SPECT)和99m锝-红细胞(99mTc-RBC)心血池显像,测定心肌梗死面积和心功能;住院期间观察并发症的发生率.结果 入院时心电图,3级缺血组ST段抬高的幅度(∑ST)显著大于2级缺血组(0.75±0.56)mV vs (0.50±0.32) mV,肌酸激酶同工酶(338±112) U/L vs(178±92)U/L和肌钙蛋白峰值(21.4±11.0)μg/L vs(9.2±5.4)μg/L显著高于2级缺血组(P＜0.05),心肌梗死面积大于2级缺血组(18.82±8.76)％vs(14.75±6.24)％(P＜0.05),而左心室射血分数低于2级缺血组(P＜0.05);在住院并发症包括心律失常发生率、心力衰竭或心源性休克的发生率、住院病死率、室壁瘤发生率方面,3级缺血组均显著高于2级缺血组(P＜0.05);而再梗死发生率,3级缺血与2级缺血组间差异无统计学意义(P＞0.05).结论 入院时心电图呈3级缺血的急性STEMI患者心肌梗死面积大,心功能和预后差,需要采取更加积极的治疗措施.     

New Software Solutions for Cardiac SPECT Imaging

Recent advances in myocardial perfusion single photon emission computed tomography (SPECT) processing software, incorporating iterative reconstruction, resolution recovery, and noise compensation, now provide the ability to acquire high quality scans despite reduced administered activity, shortened acquisition time, or both. These methods have thereby provided imaging protocol flexibility and facilitated patient-centered imaging. Other software methods allow for improved image quality by prescribing an image acquisition time that will yield optimal SPECT image count density. On some new solid state cameras list mode acquisition is now available, whereby suboptimal acquisition stops such as those with patient motion can be eliminated prior to SPECT reconstruction. Still other methods, incorporating phase analysis of gated perfusion SPECT, provide a quantitative analysis of left ventricular dyssynchrony, aiding in the selection of patients for whom cardiac resynchronization therapy is most beneficial.     

State and Recent Progress of Nuclear Cardiology in China

In this review, we focus mainly on the clinical applications of myocardial perfusion imaging (MPI) with single-photon emission CT (SPECT) and metabolic imaging in clinical practice. Important advances have been made in the clinical applications of MPI, including its role in stratifying risk and guiding management decisions. The impact of incomplete and complete myocardial ischemia correction on long-term outcomes was analyzed and compared with complete and incomplete diseased vessel intervention. Importantly, a new pharmacologic stress testing agent—higenamine—was developed and has completed phase III clinical trials. Ventricular synchrony was assessed by phase analysis of gated MPI in healthy Chinese subjects and in patients with or without left ventricular (LV) dysfunction. Finally, the clinical value of technetium (^99mTc) sestamibi SPECT and fludeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) in patients with LV aneurysms was deeply investigated. Viability of LV aneurysm in patients with ischemic cardiomyopathy was a negative independent predictor of survival. The diagnostic accuracy of LV parameters analyzed by both gated SPECT and gated PET was investigated in patients with LV aneurysm, who revealed severe perfusion defects and LV remodeling. Additionally, end-systolic volume measured by gated PET was the only independent predictor of cardiac death among all the LV functional parameters evaluated by gated SPECT, gated PET, cardiac magnetic resonance imaging, and echocardiography.     

Single-point cardiac troponin T at coronary care unit discharge after myocardial infarction correlates with infarct size and ejection fraction

BACKGROUND: One of the major concerns in replacing creatine kinase MB (CK-MB) with cardiac troponins is the lack of evidence of the ability of troponins to estimate the size of acute myocardial infarction (AMI). We investigated the ability of a single measurement of cardiac troponin T (cTnT) at coronary care unit (CCU) discharge to estimate infarct size and assess left ventricular (LV) function in AMI patients. METHODS: We studied 65 AMI patients in whom infarct size was estimated by CK-MB peak concentrations and gated single-photon emission computed tomography (SPECT) myocardial perfusion using technetium-99m sestamibi and LV function by SPECT imaging. Measurements of cTnT and SPECT were performed 72 h (median) after admission (range, 40-160 h). SPECT was also repeated 3 months later. RESULTS: We found a significant correlation between cTnT and both the peak CK-MB concentrations (r = 0.76; P <0.001) and the perfusion defect size at SPECT (r = 0.62; P <0.001). cTnT was inversely related to LV ejection fraction (LVEF) assessed both early (r = -0.56; P <0.001) and 3 months after AMI (r = -0.70; P <0.001). cTnT >2.98 micro g/L predicted a LVEF <40% at 3 months with a sensitivity of 86.7%, specificity of 81.4%, and a likelihood ratio for a positive test of 4.7 (95% confidence interval, 4.0-5.4). CONCLUSIONS: A single cTnT measurement at CCU discharge after AMI is useful as a noninvasive estimate of infarct size and for the assessment of LV function in routine clinical setting.     

B型脑钠肽在初发急性心肌梗死患者危险分层和短期临床预后中的作用

目的 分析初发急性心肌梗死(AMI)患者血浆B型脑钠肽(BNP)水平与梗死面积及住院期间和随访3个月的主要不良心脏事件(MACE)之间的关系,评价BNP在AMI患者的危险分层和短期预后中的意义.方法 选取非心力衰竭初发AMI患者82例,按照心电图分为ST段抬高型心肌梗死(STEMI)组和非ST段抬高型心肌梗死(NSTEMI)组,比较各组BNP水平;并按照BNP水平分为BNP＜100 ng/L组,BNP≥100～200 ng/L组和BNP≥200ng/L组,比较各组MACE的发生率.结果 STEMI组血浆BNP水平显著高于NSTEMI组,(208.4±180.2)ng/L vs(93.6±76.8)ng/L (P＜0.01).BNP≥200 ng/L组MACE发生率高于BNP≥100～200 ng/L组和BNP＜100ng/L组(分别为46.2％,8.33％,3.12％;P＜0.01).BNP与住院期间和短期MACE发生相关(HR＝0.985,95％可信区间CI=0.973～0.996;P＜0.01).结论 AMI患者的BNP水平越高,梗死面积越大,近期MACE发生率越高,高BNP水平是与住院期间和短期MACE发生率相关的危险因素.BNP测定有助于AMI患者的危险分层及预后判断.     

心肌损伤标志物联合检测在急性心肌梗死诊断中的价值

目的评价心肌损伤标志物肌钙蛋白T/I(cTnT/I)、肌红蛋白(Myo)、肌酸激酶同工酶(CK-MB)在急性心肌梗死(AMI)中的诊断价值。方法对150例AMI患者进行心肌标志物和心肌酶谱比较。结果心肌标志物在AMI发病早期升高的幅度较心肌酶谱升高显著,差异有统计学意义(P0.01)。结论心肌损伤标志物cT-nT/I、Myo、CK-MB在AMI早期诊断中具有重要的临床价值。     

Co-registration of cardiac MRI and rest gated SPECT in the assessment of myocardial perfusion, function and viability.

PURPOSE: Myocardial perfusion is routinely measured by SPECT--this technique has a rather low spatial resolution but covers the whole myocardium and is equipped with efficient image analysis software. Cardiac MRI has higher spatial resolution than SPECT and excellent sequences for myocardial function and viability detection but the lack of easy-to-use methods of acquisition and post-processing of perfusion images prevents this method from being used for perfusion evaluation in clinical practice. The aim of the study was to explore whether the 3-D co-registration of "cine" MRI (cine MRI), delayed enhancement MRI (DE MRI) and gated SPECT (GSPECT) images might be used for differentiating all reversible and irreversible effects of ischemia in anatomically matched myocardial regions. METHODS: We analyzed 685 segments of the heart (6 segments in each short axis slice)-obtained as a result of MRI and GSPECT studies performed in 18 patients. In each segment, myocardial function, perfusion and viability were analyzed. Myocardial wall function was evaluated using the matched images of diastolic and systolic phases of cine MRI. Perfusion as MIBI uptake per volume (MIV) (counts/mm3) in each myocardial segment was evaluated by co-registration of diastolic phases of cine MRI and GSPECT. Transmural extent of infarction was determined by co-registration of DE MRI and diastolic phase of cine MRI. RESULTS: We have found a close correlation between regional perfusion and function at rest in matched MRI and SPECT images: dysfunctional segments had significantly less MIV (MIV = 4.63 SD 1.58) than normal segments (MIV = 8.86 SD 2.77) (p < .05). There was no significant difference in MIV between viable and non-viable dysfunctional segments defined by DE MR due to a small number of nonviable segments in our study (18/685). CONCLUSION: Matching rest perfusion and function in anatomically co-registered myocardial segments in our study confirms that 3-D image co-registration of cine MRI, DE MRI and gated SPECT could be a precise method of integrated visualization of perfusion, function and viability helping in differentiating all forms of reversible and irreversible effects of myocardial ischemia.