阿尔茨海默病的~(18)F-FDDNP脑断层扫描显像

目的探讨标记物18F-FDDNP在脑断层扫描(PET)显像中诊断阿尔茨海默病(AD)的价值。方法分别对7例AD患者(AD组)、6例血管性痴呆(VaD)患者(VaD组)及6例智能正常老年对照者(NC,NC组)进行18F-FDDNP脑PET显像,受试者分别在药物注射后5 min2、5 min和45 min采集图像。结果AD患者3个时段放射性清除情况与其他2组图像有明显的不同。药物注射45 min后脑内放射性清除率较VaD组、NC组明显减低。结论18F-FDDNP脑PET显像是诊断AD的一个有效的影像学指标。     

~(18)F氟脱氧葡萄糖正电子发射断层显像鉴别阿尔茨海默病和额颞叶痴呆的价值

目的探讨~(18)F-氟脱氧葡萄糖(~(18)F-FDG)正电子发射断层显像(positron emission tomography,PET)/CT对阿尔茨海默病(AD)和额颞叶痴呆(FTD)的鉴别诊断价值。方法回顾性分析临床诊断为AD 20例和FTD 10例的~(18)F-FDG PET/CT脑代谢显像资料,采用脑代谢影像进行视觉分析,测量相应部位的标准摄取值(standard up take value,SUV),以小脑为参考脑区,以放射性摄取减低脑区的SUV与小脑SUV的比值(SUVr)表示。采用NeuroQ脑分析软件进行定量分析其代谢模式特点。结果 20例AD患者视觉分析显示,16例(80.0%)伴有双侧顶叶代谢减低,8例(40.0%)伴有双侧颞叶代谢减低,5例(25.0%)伴有单侧额叶代谢减低,2例(10.0%)伴有单侧颞叶代谢减低;定量分析显示,全部患者(100.0%)均伴有双侧顶叶代谢减低,18例(90.0%)伴有后扣带回代谢减低,17例(85.0%)伴有双侧颞叶代谢减低,7例(35.0%)伴有单侧额叶代谢减低。10例FTD患者视觉分析显示,8例(80.0%)患者伴有颞叶代谢减低,6例(60.0%)患者伴有额叶代谢减低,3例(30.0%)伴有双侧顶叶代谢减低;定量分析显示,10例患者(100.0%)均伴有额叶代谢减低,8例(80.0%)伴有颞叶代谢减低,4例(40.0%)伴有双侧顶叶代谢减低,4例(40.0%)伴有基底节代谢减低,3例(30.0%)伴有后扣带回代谢减低。AD患者和FTD患者额叶、顶叶和颞叶SUVr比较,差异有统计学意义(1.08±0.13 vs 0.75±0.09,0.78±0.14 vs 1.06±0.05,0.81±0.14 vs 0.95±0.12,P<0.01)。结论 ~(18)F-FDG PET/CT脑显像显示的AD和FTD患者不同的代谢减低模式,有助于临床进行鉴别诊断。     

18F-脱氧葡萄糖单光子发射计算机断层显像鉴别阿尔茨海默病及额颞叶痴呆的临床研究

目的 探讨阿尔茨海默病(Alzheimers disease,AD)及额颞叶痴呆(Frontotemporal dementia,FTD)患者18 F-脱氧葡萄糖(18F-deoxyglucose,18F-FDG)单光子发射计算机断层显像(SPECT)的特点。方法 选择2014年12月~2015年10月在首都医科大学宣武医院核医学科就诊并诊断为AD和FTD的患者29例,按诊断分为AD组19例,其中男性8例,女性11例,平均年龄(61.57±7.46)岁;FTD组10例,其中男性6例,女性4例,平均年龄(62.80±7.53)岁。同期选健康老年人9例为对照组,其中男性4例,女性5例,平均年龄(60.11±10.79)岁。所有研究对象行18F-FDG的SPECT检查。结果 对照组双侧大脑皮质、丘脑和基底节区未见异常放射性浓聚、稀疏或缺损。AD组和FTD组患者与对照组相比,18F-FDG的SPECT检查均表现为皮质代谢减低。AD组15例双侧大脑皮质对称性减低,其中40.00%顶、颞叶皮质代谢对称性明显减低;33.3%双侧顶叶皮质代谢对称性明显减低;13.33%伴有双侧额叶皮质代谢对称性减低。FTD组8例对称性减低,其中50%双侧额叶皮质代谢对称性明显减低。Fisher确切概率法检验显示,AD组和FTD组患者的SPECT脑代谢表现具有显著统计学差异(P0.05)。结论18F-FDG的SPECT能够为临床鉴别诊断AD和FTD提供客观的影像学依据。     

18F-FDG PET/CT纳入肝细胞癌肝移植标准的趋势与价值

肝移植是治疗肝细胞癌(HCC)的有效方法,为降低HCC肝移植术后可能出现较高肿瘤复发率,有学者率先提出著名的Milan标准。但该标准过于严格,部分患者因其肿瘤病变较大或多个结节,虽其生物行为相对“温良”,也被排除在等待肝移植名单之外,随之世界各地出现了众多的“扩大Milan版标准”。HCC组织病理学的微血管侵犯(MVI)、肿瘤组织低分化与HCC肝移植术后较高复发率有显著相关性。复习总结了近年来国内外18氟-脱氧葡萄糖(18F-FDG)PET/CT在HCC肝移植方面的应用文献,发现18F-FDG在HCC病变部位不同的摄取程度,反映了肿瘤组织生物学行为特征即侵袭性的差异;18F-FDG高摄取与HCC病变的MVI、低分化呈正相关;18F-FDG还能敏感、准确地发现HCC肝外转移灶。认为术前18F-FDG PET/CT结果对HCC肝移植预后评估有巨大价值,将其结果纳入HCC肝移植标准是趋势所归,也有望统一“扩大Milan版标准”。建议新的肝移植标准可定义为,原则上遵循Milan标准;对超出Milan标准者,满足HCC病变18F-FDG PET/CT阴性,且排除大血管侵犯和肝外转移。     

The value of positron emission tomography in the clinical evaluation of dementia

Positron emission tomography (PET) has been promoted as a means of improving the diagnosis of Alzheimer's disease (AD), but the evidence to support its incremental value is unclear. To assess the evidence regarding the use of PET in the clinical evaluation of AD, a systematic review of the English-language literature indexed in MEDLINE (1975-January 2001), the Cochrane Library (issue 4, 2000), and health technology assessment (HTA) reports was conducted. Articles identified by this review process were graded for methodological and reporting quality using a standardized grading scheme. Sixteen original articles and seven HTA reports were identified. In general, the articles addressed: using PET to differentiate AD from normal aging or non-Alzheimer's dementias, PET imaging compared with single positron emission computed tomography imaging, using PET to predict the progression of dementia, and agreement and reliability in the interpretation of PET images. Serious problems with study design and methodology in all articles were identified. Previous HTA reports have generally recommended that PET not be used in the clinical evaluation of dementia. In conclusion, there is little evidence to support the addition of PET to the routine clinical evaluation of patients with suspected or established dementia. Suggestions for future research in this area are offered.     

Positron emission tomography imaging of adenoviral-mediated transgene expression in liver cancer patients

BACKGROUND & AIMS: In gene-therapy protocols, imaging of gene expression is needed to evaluate the transduction efficiency of the vector, its tissue distribution, and the duration of transgene expression and to assess the feasibility of repeated vector administration. METHODS: We have used positron emission tomography with a fluorine-18-labeled penciclovir analogue to monitor thymidine kinase gene expression after intratumoral injection of a first-generation recombinant adenovirus in patients with hepatocellular carcinoma. Patients were enrolled in a pilot clinical trial and treated with escalating doses of the vector. Two days after adenovirus inoculation, transgene expression was evaluated during the first hours after administration of the radiotracer both on the treated lesion and on a whole-body basis. RESULTS: Transgene expression in the tumor was dependent on the injected dose of the adenovirus and was detectable in all patients who received > or = 10(12) viral particles. However, when the study was repeated 9 days after vector injection, no expression could be observed. It is interesting to note that no specific expression of the transgene could be detected in distant organs or in the surrounding cirrhotic tissue in any of the cases studied. CONCLUSIONS: Our findings show the real possibility of imaging transgene expression in humans by using viral vectors. We show that hepatocarcinoma is a permissive tumor for adenoviral infection and that the nontumoral cirrhotic liver is spared from transduction when the vector is administered by intratumoral injection. These results show that positron emission tomography imaging may help in the design of gene-therapy strategies and in the clinical assessment of new-generation vectors.     

18FDG positron emission tomography versus 67Ga scintigraphy as prognostic test during chemotherapy for non-Hodgkin's lymphoma

A prospective study was performed, comparing gallium scintigraphy (67Ga) and positron emission tomography (PET) using fluorine-18 fluorodeoxyglucose (18FDG), to monitor the response of aggressive non-Hodgkin's lymphoma during treatment. 67Ga and 18FDG scans were performed in 26 patients after two cycles of CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) therapy. The scans were reviewed independently by four experienced nuclear physicians, who were blinded for the alternative scan technique and follow-up. Eleven out of 26 patients remained free from progression with a mean follow up of 25 +/- 5 months, whereas 14 patients relapsed, and one died of lung cancer. Interobserver variation was significantly greater for 67Ga than for 18FDG PET. Some 64% of patients who had a negative early restaging 18FDG PET remained free from progression versus 50% of patients with negative 67Ga scans. Only 25% of patients with a positive PET remained disease free versus 42% of 67Ga-positive patients. Time to progression was associated with 18FDG PET results, but not with those by 67Ga. 18FDG PET had better test characteristics than 67Ga for the evaluation of early response in aggressive non-Hodgkin's lymphoma patients.     

Prognostic value of positron emission tomography in the evaluation of post-treatment residual mass in patients with Hodgkin's disease and non-Hodgkin's lymphoma

The prognostic value of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in the assessment of post-treatment residual masses in patients with Hodgkin's disease (HD) or non-Hodgkin's lymphomas (NHL) was evaluated. We prospectively studied 58 patients with HD (n = 43) or NHL (n = 15) who had post-therapeutic complete remission with residual masses (CRu) indicated by computerized tomography. Analysis of 62 residual locations by FDG-PET was performed separately for HD and NHL. Patients with a PET-positive residual mass [standardized uptake value (SUV) > 3] had a recurrence rate of 62.5% (5/8 patients), whereas patients with PET-negative residual mass (SUV < or =3.0) showed a recurrence rate of 4% (2/50 patients, P = 0.004). A positive FDG-PET study correlated with a significantly poorer progression-free survival (P < 0.00001). No recurrence occurred in any of the 39 HD patients with a negative PET scan (negative predictive value, 100%). Four out of four NHL patients with a positive PET study relapsed (positive predictive value, 100%). In conclusion, FDG-PET is a suitable non-invasive method with a high degree of accuracy in the prediction of early recurrence in lymphoma patients with CRu.     

Impact of positron emission tomography on strategy in liver resection for primary and secondary liver tumors

Purpose Outcome of patients with metastatic disease mainly depends on accurate preoperative tumor staging. ¹⁸[F]fluorodeoxyglucose positron emission tomography (18F-PET) has been proven to be a valuable diagnostic tool in a number of different tumors but its direct influence on liver surgery has not been thoroughly investigated.Materials and methods Between July 1999 and March 2000, 50 consecutive patients with 174 suspected liver lesions were admitted to the University Hospital Jena. All 50 patients underwent abdominal ultrasound, CT-scan, and 18-FDG positron emission tomography scanning. In 23 patients the diagnostic work-up was completed by MRI scan.Results Altogether there were a total of 174 histologically proven intrahepatic lesions, nine of which were benign. The sensitivity, specificity, and positive predictive value of PET for all hepatic lesions was 82%, 25%, and 96% compared with 63%, 50%, and 96% for abdominal ultrasound, 71%, 50%, and 97% for CT-scan, and 83%, 57%, and 97% for MRI-scan. In 23 of 50 patients 24 extrahepatic lesions were identified. In these patients the sensitivity and specificity of PET—compared to abdominal ultrasound, CT-scan, and MRI-scan for all extrahepatic lesions—was 63% and 60%, 29% and 25%, 47% and 50% and 40% and 50%, respectively. The findings on PET scan had a direct impact on operative management in nine patients (18%).Conclusions Our series demonstrates good sensitivity and specificity for the detection of primary and secondary liver lesions which is superior to ultrasound and CT scan but not to MRI scan. The main value of PET scan consists in the detection of extrahepatic tumor (64%). Due to better detection of extrahepatic tumor, FDG-PET is a very useful addition to the currently used anatomically-based images in all cases of advanced tumor spread with high risk of extrahepatic tumor.     

[18F]fluorodeoxyglucose positron emission tomography is a useful tool to diagnose the early stage of Takayasu's arteritis and to evaluate the activity of the disease

Takayasu's arteritis (TA) is a rare disease that can be difficult to diagnose in its early stage. A young woman with a fever and neck pain was thought to have TA, although computed tomographic angiography did not show any specific changes of the arteries. [¹⁸F]fluorodeoxyglucose positron emission tomography ([¹⁸F]FDG-PET) was performed to detect the source of the inflammation. Specific accumulation of [¹⁸F]FDG-6-phosphate in the thoracic aorta and its direct branches was observed, leading to a diagnosis of TA. [¹⁸F]FDG-PET is therefore considered to be useful for the diagnosis of early-stage TA.     

[18F]fluorodeoxyglucose positron emission tomography is a useful tool to diagnose the early stage of Takayasu's arteritis and to evaluate the activity of the disease

Abstract

Takayasu's arteritis (TA) is a rare disease that can be difficult to diagnose in its early stage. A young woman with a fever and neck pain was thought to have TA, although computed tomographic angiography did not show any specific changes of the arteries. [¹⁸F]fluorodeoxyglucose positron emission tomography ([¹⁸F]FDG-PET) was performed to detect the source of the inflammation. Specific accumulation of [¹⁸F]FDG-6-phosphate in the thoracic aorta and its direct branches was observed, leading to a diagnosis of TA. [¹⁸F]FDG-PET is therefore considered to be useful for the diagnosis of early-stage TA.     

Quantification of liver glucose metabolism by positron emission tomography: validation study in pigs

BACKGROUND & AIMS: The liver is inaccessible to organ balance measurements in humans. To validate [(18)F]fluorodeoxyglucose ([(18)F]FDG) positron emission tomography (PET) in the quantification of hepatic glucose uptake (HGU), we determined [(18)F]FDG modeling parameters, lumped constant (LC), and input functions (single arterial versus dual). METHODS: Anesthetized pigs were studied during fasting (n = 6), physiologic (n = 4), and supraphysiologic (n = 4) hyperinsulinemia. PET was performed with C(15)O (blood pool) and [(18)F]FDG (glucose uptake). 6,6-Deuterated glucose ([(2)H]G) was coinjected with [(18)F]FDG and blood collected from the carotid artery and portal and hepatic veins to compute LC as ratio between tracers fractional extraction. HGU was estimated from PET images and ex vivo from high-performance liquid chromatography measurements of liver [(18)F]FDG versus [(18)F]FDG-6-phosphate and [(18)F]-glycogen. Endogenous glucose production was measured with [(2)H]G and hepatic blood flow by flowmeters. RESULTS: HGU was increased in hyperinsulinemia versus fasting (P < .05). Fractional extraction of [(18)F]FDG and [(2)H]G was similar (not significant), intercorrelated (r = 0.98, P < .0001), and equally higher during hyperinsulinemia than fasting (P 0.95, P < .0001), with a modest underestimation of HGU by the former. CONCLUSIONS: [(18)F]FDG-PET-derived parameters provide accurate quantification of HGU and estimates of liver perfusion and glucose production. In the liver, LC of [(18)F]FDG is nearly unitary. Using a single arterial input introduces only a small error in estimation of HGU.