PET-CT显像仪的临床应用

目前,PET-CT设备发展迅速,在临床应用中发挥着十分重要的作用。PET显像仪共有三种类型:专用型PET(dedicated PET)、混合型PET(hybrid PET)和组合型PET(combined PET)。PET与CT组合即PET-CT,不仅能反映人体解剖结构改变,更重要的是可以提供人体器官及组织结构的功能代谢信息,从分子水平揭示疾病发病机理和治疗效应,是临床诊断心脑疾病和肿瘤的重要手段。PET-CT临床应用十分广泛,尤其是在肿瘤、神经系统、心血管系统等病变的临床应用方面具有其独特的功能和作用。

PET-CT显像对卵巢恶性肿瘤淋巴结转移的诊断作用研究

目的:研究PET-CT显像对卵巢恶性肿瘤淋巴结转移的诊断作用。方法:选择2013年2月至2015年3月我院收治的48例卵巢恶性肿瘤患者作为研究对象,48例患者术前均给予PET-CT显像检测腹膜后淋巴结的转移情况,其中有35例为初治者,13例为复发者。35例初治者应用细胞减灭术治疗再实施腹膜后淋巴结清扫术治疗,13例复发者应用病灶淋巴结清扫术,对比48例患者术前淋巴结检测和术后淋巴结病理检验的结果,分析PET-CT显像对卵巢恶性肿瘤淋巴结检测的敏感性、特异性及准确性、预测值等。结果:对比结果表明,PET-CT显像对卵巢恶性肿瘤淋巴结转移的敏感性、特异性、准确性及预测值等诊断更为准确。结论:应用PET-CT显像对卵巢恶性肿瘤淋巴结转移的诊断价值高,值得推广应用。

Clinical usefulness of ^(18) F-FDG PET/CT in the restaging of esophageal cancer after surgical resection and radiotherapy

AIM： To evaluate the clinical usefulness of lSF-fluorodeoxyglucose positron emission and computed tomography QSF-FDG PET/CT） in restaging of esophageal cancer after surgical resection and radiotherapy. METHODS： Between January 2007 and Aug 2008, twenty histopathologically diagnosed esophageal cancer patients underwent 25 PET/CT scans （three patients had two scans and one patient had three scans） for restaging after surgical resection and radiotherapy. The standard reference for tumor recurrence was histopathologic confirmation or clinical follow-up for at least ten months after ^18F-FDG PET/CT examinations. RESULTS： Tumor recurrence was confirmed histopathologically in seven of the 20 patients （35%） and by clinical and radiological follow-up in 13 （65%）. ^18F-FDG PET/CT was positive in 14 patients （68.4%） and negative in six （31.6%）. ^18F-FDG PET/CT was true positive in 11 patients, false positive in three and true negative in six. Overall, the accuracy of ^18F-FDG PET/CT was 85%, negative predictive value （NPV） was 100%, and positive predictive value （PPV） was 78.6%.The three false positive PET/CT findings comprised chronic inflammation of mediastinal lymph nodes （n = 2） and anastomosis inflammation （n = 1）. PET/ CT demonstrated distant metastasis in 10 patients. ^18F-FDG PET/CT imaging-guided salvage treatment in nine patients was performed. Treatment regimens were changed in 12 （60%） patients after introducing ^18F-FDG PET/CT into their conventional post-treatment follow-up program. CONCLUSION： Whole body ^18F-FDG PET/CT is effective in detecting relapse of esophageal cancer after surgical resection and radiotherapy. It could also have important clinical impact on the management of esophageal cancer, influencing both clinical restaging and salvage treatment of patients.

Role of F-18 FDG PET/CT imaging in the diagnosis of paraneoplastic neurological syndromes

Paraneoplastic neurological syndromes(PNS) is a series of rare neurologic disorders which happen with an underlying malignancy. It has various clinical symptoms proceding to the diagnosis of tumors. Although the abnormality of anti-neuronal antibodies is suggestive of PNS and tumors, there exist many false positive and false negative cases. The diagnosis of PNS is usually a challenge in clinic. Positron emission tomography/computed tomography(PET/CT) imaging is an anatomical and functional fusion imaging method, which provides the whole-body information by single scan. Fluorodeoxyglucose(FDG) PET/CT imaging can not only detect potential malignant lesions in the whole body, but also assess functional abnormality in the brain. In this review, the mechanism, clinical manifestation, diagnostic procedure and the recent progress of the utility of FDG PET/CT in PNS are introduced respectively.

^(18)F-FETNIM PET/CT hypoxia imaging in non-small cell lung cancer:preliminary clinical observation

Objective:The aims of this study were to evaluate potential side effects of 18F-fluoroerythronitroimidazole (18F-FETNIM) as a new-type hypoxia-imaging agent and to investigate the feasibility of 18F-FETNIM PET imaging in advanced non-small cell lung cancer (NSCLC) patients and the correlations of hypoxia extent with tumor volume or pathological type. Methods: Twenty-six NSCLC patients were prospectively included in the study. PET/CT scans were performed 2 h after intravenous injection of 18F-FETNIM in all 26 patients. A pixel-by-pixel calculation of tumor to blood (T/B) activity ratio for all image planes was calculated. The number of pixels in the tumor volume with a T/B ratio≥ 1.5,indicating significant hypoxia,was determined and converted to mL units to measure the hypoxia volume (HV). Results: The images were clearly identified after 2 h post-injection of 18F-FETNIM. The tumors in 4 cases were not distinguished from background,while the remaining 22 displayed local 18F-FETNIM uptake in thoracic lesions moderately to markedly higher than background. There was no correlation between 18F-FETNIM uptake with pathological type. There were significant correlations of HV and also the T/B ratio with tumor volume. Conclusion:18F-FETNIM is a promising hypoxia-imaging agent which clinical use is safe and satisfactory. The preliminary study provides valuable methods and experience to its further research.

HSV1-tk乳腺癌移植瘤裸鼠模型PET-CT报告基因显像

目的对^18F-FHBG体外摄取、体内分布及荷瘤裸鼠PET—CT显像等方面进行研究。方法利用吖井型计数器测定体外肿瘤细胞T47D和T47D—tk对^18F-FHBG的摄取、正常昆明小鼠和移植瘤裸鼠^18F-FHBG体内分布；并进行荷皮下移植瘤裸鼠^18F-FHBGPET-CT显像。结果体外肿瘤细胞摄取实验显示T47D-tk细胞摄取^18F-FHBG的程度明显高于正常的T47D细胞，120min时T47D—tk细胞对^18F-FHBG的摄取为T47D细胞的64倍（P〈0．001）。正常小鼠注射^18F-FHBG后，主要分布于肝脏、肠道、肾脏和膀胱，而脑部未见明显放射性分布。荷皮下移植瘤裸鼠PET—CT显像显示，T47D．tk肿瘤浓聚^18F-FHBG的程度明显高于T47D肿瘤，且2h显像效果较好。结论体外T47D—tk细胞摄取^18F-FHBG的程度明显高于正常的T47D细胞；在小鼠体内^18F-FHBG主要经肠道和泌尿系统排泄。^18F-FHBG报告基因探针可以有效的定位于HSV1-tk基因表达的部位且与移植瘤裸鼠体内分布研究结果一致。这可为进一步开展^18F-FHBG报告基因显像与肿瘤基因治疗的监测提供有效手段和科学依据。

以正电子发射型计算机断层显像技术研究针刺作用机制试验过程的质量控制

正电子发射型计算机断层显像(PET-CT)融合了功能代谢显像和解剖结构显像,代表了当前核医学影像技术的最高水平,已被越来越广泛地运用于针灸作用机制的研究中。但由于脑功能的复杂性和脑代谢变化的灵敏性,脑功能成像的研究结果往往重复性低,甚至截然相反,究其原因,往往与实验方法学密切相关。本文拟从研究对象的筛选、PET-CT扫描检查前中后受试者的准备、扫描参数的设定、机器和显影剂的选择、数据的分析处理、针刺操作的规范、针刺时机和扫描时机的设计方面,探讨以PET-CT技术研究针刺作用机制试验过程的质量控制,以期为今后的研究提供参考。