正电子发射型计算机断层显像

ＰＥＴ(派特 )是继ＣＴ和磁共振 (ＭＲ1)之后应用于临床的一种新型影像技术 .ＰＥＴ的原理是将人体代谢所必需的物质如葡萄糖、蛋白质、核酸、脂肪酸等标记上超短半衰期的放射性核素 ,如11Ｃ、13 Ｎ、15 0、18Ｆ等制成显像制(如氟代脱氧葡萄糖 ,简ＦＤＧ) ,注入人体后进行扫描显像 ,由于人体不同组织的代谢状态不同 ,所以这些被标记了的物质在人体的不同组织中的分布也不同 .随着机体的生理、生化、病理等代谢活动 ,这些特点能通过计算机断层显像 ,显示出脑、心脏 ,全身器官的生理和病理活动及代谢状态 ,经过图像处理及重建 ,获得三维的人体…     

正电子发射断层图(PET)的原理与展望

1导言正电子发射断层图（positronemissiontomogfaphy,PET）是电子计算机图像处理、核医学、微量放射化学合成、生物物理学的示H踪动力学模型等多学科综合产生的医学成像新技术。目前在理论研究和临床诊断方面,已有广泛的应用l'－'l。PET是用示踪核素标记的化合物注入人...     

骨显像诊断恶性肿瘤骨转移临床价值的探讨

探讨骨显像在诊断恶性肿瘤骨转移中的临床应用价值。478例已确诊恶性肿瘤患者均行SPECT99mTc-MDP全身骨显像,结合CT、MRI检查结果,分析计算全身骨显像对恶性肿瘤骨转移的灵敏度、特异性、阳性预测值、阴性预测值、诊断准确率等,并统计恶性肿瘤骨转移的高发部位。获得数据采用χ2检验分析处理。结果显示：骨显像的灵敏度、特异性、阳性预测值、阴性预测值和诊断准确率分别为：91.9%、68.2%、90.6%、74.1%和79.3%。结论：骨显像对探测骨骼病理改变的灵敏度非常高,在早期诊断恶性肿瘤骨转移方面较MRI/CT敏感（χ2=3.99P〈0.05）。做为一种简便、安全、灵敏的显像技术,其性价比很高,值得临床大力推广。     

18F-FDG PET/CT盆部延迟显像在原发性膀胱癌诊断和局部分期中的临床价值

目的观察18F-FDG PET/CT盆部延迟显像在原发性膀胱癌的诊断和局部分期中的价值。方法 27例疑似膀胱癌患者,术前均行增强CT及18F-FDG PET/CT常规加盆部延迟显像进行诊断和分期,以手术病理结果作为金标准,观察盆部延迟显像在原发性膀胱癌诊断和局部分期上的价值,并与增强CT作比较。结果 27例患者中,增强CT、盆部延迟显像诊断原发肿瘤的灵敏度分别为77.27%、90.90%;特异度分别为60.00%、40.00%;准确度分别为74.07%、81.48%;盆部延迟显像和增强CT诊断准确度比较无统计学差异（P=0.263）。12例患者接受了膀胱癌根治术,其中10例有盆腔淋巴结或邻近组织转移,增强CT、盆部延迟显像局部分期准确度分别为33.33%、91.67%,盆部延迟显像优于增强CT（P=0.018）。结论18F-FDG PET/CT盆部延迟显像在原发性膀胱癌的诊断上与增强CT具有同等价值,局部分期准确度优于增强CT,具有更高的临床价值。     

18F-FDG PET/CT显像对可疑甲状腺原发病变的评估价值

目的 对18F-FDG PET/CT检查发现可疑甲状腺高代谢结节的发病率和良恶性进行回顾性分析.方法 回顾2010年11月至2013年5月间行18F-FDG PET/CT检查,发现甲状腺结节的2569例患者中,甲状腺呈高代谢灶的患者1219例,有病理证实及随访结果的67例.根据病变病理及随访结果,结合代谢情况、影像表现,对此67例甲状腺良恶性病变发病率进行分析.结果 甲状腺弥漫性病变恶性率与局灶性高代谢病变恶性率的差异有统计学意义（P＜0.01）.单发高代谢结节中,恶性结节及良性结节SUVmax值分别为6.63±4.49和3.07±1.42,两者之间差异有统计学意义（=2.436,P=0.035）.多发结节单发高代谢灶病变中,恶性及良性病变SUVmax值分别为5.72±2.47和3.37±0.74,两者之间差异无统计学意义.多发高代谢结节的良恶性SUVmax值差异无统计学意义（t=1.870,P=0.151）.结论 甲状腺高代谢结节有较高的恶性率,SUVmax值对单发高代谢结节的良恶性鉴别有意义.     

99Tcm-MIBI SPECT/CT同机融合显像在卵巢恶性肿瘤诊断中的应用价值

近几年来,在SPECT/CT同机融合显像技术的高速发展下,广泛应用于临床的亲肿瘤示踪显像剂99Tc^m-MIBI在卵巢恶性肿瘤的早期诊断方面展现了越来越大的应用价值。本文介绍了显像剂99Tc^m-MIBI的显像机制以及多模态影像学技术,并阐明了99Tc^m-MIBISPECT/CT同机融合显像技术在卵巢恶性肿瘤诊断中的临床应用价值。     

基于集成SVM的肺部肿瘤PET/CT三模态计算机辅助诊断方法

本研究提出基于集成SVM的肺部肿瘤PET/CT三模态计算机辅助诊断新方法.首先在临床采集肺部肿瘤患者PET、CT和PET/CT各2000例三模态图像数据上提取对同一病灶ROI区域;然后根据CT、PET和PET/CT的不同特点,从三模态图像的ROI区域中提取形状特征、灰度特征、Tamura纹理特征和GLCM特征等不同特征分别构成80、98、98维特征分量,并分别在不同特征空间里构造个体分类器,包括CT-SVM、PET-SVM、PET/CT-SVM;最后,基于相对多数投票原则,对CT-SVM、PET-SVM和PET/CT-SVM进行集成,识别对肺部肿瘤.实验结果表明,该方法能够有效提高肺部肿瘤的诊断正确率.     

正电子发射体层摄影示踪剂^11C-乙酸的合成改进及其生物分布

目的建立快速、有效合成正电子发射体层摄影（PET）示踪剂11C-乙酸的方法并研究其生物分布,满足临床PET的用药需要。方法以^11C-CO2为原料,与CH3MgBr反应后再用17%的H3PO4酸解,产物通过加热的方法蒸出,同时通过控制^11C-CO2的释放速度和适当延长^11C-CO2与CH3MgBr的反应时间,提高反应产率。小鼠给药后不同时间处死,分别取不同器官称重并测放射线计数。结果从加速器生产出^11C-CO2到产物^11C-乙酸的蒸出完毕,需15min,放化纯度大于98%,化学纯度大于99%,平均产率为34.6%（未经衰变校正）。注射^11C-乙酸后,放射线主要集中在肝脏及肾脏。结论改进反应条件后的合成方法具有快速、高效的特点,为PET日常耗材节省了成本,提高了用药的质量。     

正电子发射断层显像在乳腺癌诊治中的应用

乳腺癌是常见的恶性肿瘤之一,在过去25年中,其发病率增高了10%~15%。但随着临床诊断技术和治疗水平的提高,死亡率呈现下降趋势[1]。乳腺成像技术在临床上的广泛应用对乳腺癌的早期诊断与治疗起着重要作用,尤其是功能影像学技术的开展,可在早期甚至是亚临床期及时发现肿瘤。本文讨     

正电子发射体层摄影示踪剂11 C-乙酸的合成改进及其生物分布

目的 建立快速、有效合成正电子发射体层摄影(PET)示踪剂11C-乙酸的方法并研究其生物分布,满足临床PET的用药需要.方法 以11C-CO2为原料,与CH3 MgBr反应后再用17%的H3PO4酸解,产物通过加热的方法蒸出,同时通过控制11C-CO2的释放速度和适当延长11C-CO2与CH3MgBr的反应时间,提高反应产率.小鼠给药后不同时间处死,分别取不同器官称重并测放射线计数.结果 从加速器生产出11C-CO2到产物11C-乙酸的蒸出完毕,需15 min,放化纯度大于98%,化学纯度大于99%,平均产率为34.6%(未经衰变校正).注射11C-乙酸后,放射线主要集中在肝脏及肾脏.结论 改进反应条件后的合成方法具有快速、高效的特点,为PET日常耗材节省了成本,提高了用药的质量.     

18F-FDG PET/CT对心脏肿瘤的临床诊断价值

目的 评价18F-FDGPET/CT在心脏肿瘤诊断中的应用价值.方法 回顾性分析自2015年1月至2020年4月在我院行18F-FDG PET/CT常规显像的心脏肿瘤患者共82例,其中男50例,女32例,年龄24～91(56±17)岁.患者分组以手术病理结果或临床随访结果为依据,分析不同病理类型心脏肿瘤的位置、形态等影像学特征及病灶最大标准摄取值(maximum standardized uptake value,SUVmax)的差异,探究18 F-FDG PET/CT对心脏肿瘤良恶性的鉴别能力.结果 82例心脏肿瘤病变患者中,恶性肿瘤组71例,良性肿瘤组11例,良性组及恶性组的中位SUVmax为:1.50和6.62.Mann-Whitney U检验结果显示良性组与恶性组的中位SUVmax差异有统计学意义(Z=-4.796,P = 0.00).组1(淋巴组织肿瘤组)、组2(原发恶性组)、组3(继发恶性组)及组4(良性肿瘤组)的中位SUVmax为:6.42、8.00、6.41及1.50.Mann-Whitney U 检验结果显示组2的中位 SUVmax 均高于组 1、组3,(Z=-0.883,P = 0.037)、(Z =-1.010,P = 0.031),组1及组3之间差异无统计学意义(Z =-0.088,P = 1.930).采用ROC曲线分析确定的鉴别良恶性心脏肿瘤的最佳界值为:SUVmax=3.4,将SUVmax = 3.4作为恶性阈值18F-FDG PET/CT诊断心脏恶性肿瘤的灵敏度为87.3％,特异性为91.0％,准确性为87.3％.结论 常规18F-FDG PET/CT检查可为鉴别诊断心脏病变的良恶性提供帮助.     

Promising Role of 18-F-Fluoro-D-Deoxyglucose Positron Emission Tomography in Clinical Infectious Diseases

18-F-fluoro-D-deoxyglucose positron emission tomography (FDG PET) has become an established imaging tool in clinical oncology, cardiology and neurology and is now entering the field of clinical infectious diseases. The purpose of this article is to review the currently available, albeit limited, literature on FDG PET in the diagnosis of various infections and fever of unknown origin. Those indications for which FDG PET offers added value over more available techniques like labelled leucocyte scanning, gallium scanning and magnetic resonance imaging are especially highlighted. FDG PET seems to have an incremental value in the assessment of chronic osteomyelitis, especially in the axial skeleton, as well as in the diagnostic workup of fever of unknown origin and HIV complications. Cost-effectiveness studies are needed to define its place in the current diagnostic strategies of these pathologies. Electronic Publication     

18氟-氟代脱氧葡萄糖正电子发射计算机断层扫描在肺部结节诊断中的临床应用

目的 探讨18氟-氟代脱氧葡萄糖（18F-FDG）正电子发射计算机断层扫描（PET/CT）在肺部结节诊断中的应用价值。方法 回顾性分析2016年6月~2017年12月常熟市中医院呼吸科收治的21例肺部结节病例资料,计算PET/CT在该类疾病中的诊断特异度及敏感度,评价PET/CT对肺部结节的诊断价值。结果 PET/CT诊断肺癌的特异度、敏感度分别为50.00%、94.10%;与血清肿瘤标志物检测相比,该检查的敏感度更高,差异具有统计学意义（P＜0.05）。结论 PET/CT相对于血清肿瘤标志物检测在诊断早期肺癌方面,其诊断敏感度更高,对肺部结节的诊断有较高的价值。     

Prognostic Value of 18F-Fluorodeoxyglucose Positron Emission Tomography in Patients with Resectable Pancreatic Cancer

Purpose

We evaluated the prognostic value of ¹⁸F-2-fluoro-2-deoxyglucose positron emission tomography (FDG PET) in patients with resectable pancreatic cancer.

Materials and Methods

We retrospectively reviewed the medical records of pancreatic cancer patients who underwent curative resection, which included 64 consecutive patients who had preoperative FDG PET scans. For statistical analysis, the maximal standardized uptake value (SUVmax) of primary pancreatic cancer was measured. Survival time was estimated by the Kaplan-Meier method, and Cox''s proportional hazard model was used to determine whether SUVmax added new predictive information concerning survival together with known prognostic factors. p<0.05 indicated statistical significance.

Results

Overall survival (OS) and disease-free survival (DFS) were respectively 42.9 months (27.6-58.2; 95% CI) and 14.9 months (10.1-19.7; 95% CI). When subjects were divided into two groups according to SUVmax with a cutoff value of 3.5, the high SUVmax group (n=32; SUVmax >3.5) showed significantly shorter OS and DFS than the low SUVmax group. Multivariate analysis of OS and DFS showed that both high SUVmax and poor tumor differentiation were independent poor prognostic factors.

Conclusion

Our study showed that degree of FDG uptake was an independent prognostic factor in pancreatic cancer patients who underwent curative resection.     

Application of Silicon Photomultipliers to Positron Emission Tomography

Historically, positron emission tomography (PET) systems have been based on scintillation crystals coupled to photomultipliers tubes (PMTs). However, the limited quantum efficiency, bulkiness, and relatively high cost per unit surface area of PMTs, along with the growth of new applications for PET, offers opportunities for other photodetectors. Among these, small-animal scanners, hybrid PET/MRI systems, and incorporation of time-of-flight information are of particular interest and require low-cost, compact, fast, and magnetic field compatible photodetectors. With high quantum efficiency and compact structure, avalanche photodiodes (APDs) overcome several of the drawbacks of PMTs, but this is offset by degraded signal-to-noise and timing properties. Silicon photomultipliers (SiPMs) offer an alternative solution, combining many of the advantages of PMTs and APDs. They have high gain, excellent timing properties and are insensitive to magnetic fields. At the present time, SiPM technology is rapidly developing and therefore an investigation into optimal design and operating conditions is underway together with detailed characterization of SiPM-based PET detectors. Published data are extremely promising and show good energy and timing resolution, as well as the ability to decode small scintillator arrays. SiPMs clearly have the potential to be the photodetector of choice for some, or even perhaps most, PET systems.     

Positron Emission Tomography in the Study of Aging and Senile Dementia

¹⁸F-2-deoxy-2-fluoro-D-glucose (¹⁸FDG) is a positron emitting tracer for rate of glucose utilization in brain. When used in conjunction with positron emission tomography (PET), the PET-FDG technique permits in vivo quantitation of regional brain metabolism in man. We have applied this technique to the study of regional brain function in normal aging and senile dementia. Preliminary results for 7 patients with senile dementia of the Alzheimer's type (SDAT) and 3 elderly normal subjects indicated a large, statistically significant (p < 0.01) diminution in rate of glucose utilization in SDAT. Furthermore, the degree of diminution in metabolic activity in SDAT was highly correlated with objective measures of degree of cognitive impairment. These results demonstrate the feasibility and potential utility of the PET-FDG technique for studying regional brain function in normal aging and dementia.     

Positron Emission Tomography in the Study of Aging and Senile Dementia

¹⁸F-2-deoxy-2-fluoro-D-glucose (¹⁸FDG) is a positron emitting tracer for rate of glucose utilization in brain. When used in conjunction with positron emission tomography (PET), the PET-FDG technique permits in vivo quantitation of regional brain metabolism in man. We have applied this technique to the study of regional brain function in normal aging and senile dementia. Preliminary results for 7 patients with senile dementia of the Alzheimer's type (SDAT) and 3 elderly normal subjects indicated a large, statistically significant (p < 0.01) diminution in rate of glucose utilization in SDAT. Furthermore, the degree of diminution in metabolic activity in SDAT was highly correlated with objective measures of degree of cognitive impairment. These results demonstrate the feasibility and potential utility of the PET-FDG technique for studying regional brain function in normal aging and dementia.     

18F-FDG PET/CT在甲状腺结节中的诊断价值

目的 探讨18F-FDG PET/CT在甲状腺良恶性结节中的诊断价值.方法 回顾性分析了48例(男17例,女31例)于本院行18F-FDG PET/CT显像的甲状腺结节患者,所有结节均得到病理证实.利用ROC曲线选取PET/CT半定量指标最大标准摄取值(SUVmax)最佳诊断界值.根据病灶的视觉分级、摄取形态、SUVmax值、CT衰减程度、钙化、突出于甲状腺边界外及病灶边缘是否清晰等七项指标进行综合评分,比较这种综合评分方法与单纯利用SUVmax值判断良恶性的诊断效能,并比较良恶性两组间SUVmax值是否具有差异.最后利用Logistic回归分析七项指标与良恶性结节的相关性.结果 ①SUVmax诊断甲状腺结节的最佳界值为4.71,此时18F-FDG诊断甲状腺恶性病变的灵敏度为80.6％,特异度为75％;②将SUVmax与病理结果对照,发现恶性组SUVmax较良性组明显增高,但恶性组与良性组有重叠;③结合七项指标综合判断结节良恶性的诊断效能较单独利用SUVmax判断良恶性的诊断效能无明显差异(P=0.09);④七项评价指标中SUVmax及CT衰减程度与良恶性相关,对良恶性诊断具有一定价值.结论 ①SUVmax最佳诊断界值为4.71;②良恶性两组间SUVmax差异具有统计学意义;③联合PET及CT多项指标综合诊断不能提高诊断效能;④SUVmax大小及CT中表现为低密度与恶性结节相关,CT中表现为极低密度与良性结节相关,对于良恶性鉴别诊断有一定意义.