小动物PET及PET-CT及其在分子影像学中的应用

阐述小动物PET及PET-CT技术特点及在分子影像学中的应用。小动物PET及PET-CT采用多项新技术,分辨率明显提高,结合小动物CT实现了图像融合。小动物PET及PET-CT实现了在活体上非侵入性分子水平显像,是研究分子影像的尖端设备。     

18F-FECNT的生物分布特性及小动物PET显像研究

Objective 2β-carbomethoxy-3β-(4-corophenyl)-8-(2-18F-fluoroethyl) nortropane (18F-FECNT) is a recently developed dopamine transporter (DAT) imaging agent. The aim of this study was to evaluate its brain biedistribution and to assess its usefulness in quantitation of DAT density in normal and hemiparkinsonian rats. Methods Six groups of mice (5 mice each group) received 18F-FECNT were sacri-ficed at indicated time post injection. Different brain regions (cortex, hippocampus, striatum, cerebellum) were removed, weighed, and countered. DAT blocking effect was investigated in mice pretreated with 2β-Carbomethoxy-3β-(4-fluorpbenyl)tropane (β-CFT) at before 18F-FECNT injection. MicroPET scans were performed in beth normal and unilaterally 6-hydroxydopamine-lesioned rats. Results The brain uptake of 18F-FECNT was 2.22, 1.20, 1.02, 0.78, 0.71, and 0.67 percent injection dose (%ID) at 5, 15, 30, 60, 120, and 180 min post injection. Radioactivity concentration of the striatum, the target region, was the highest in the brain regions and decreased quickly from 5 to 60 min and reached to background at 120 min of post injection. The striatum/cerebellum ratio was 2.56, 3.47, 2.78, 1.63, 0.97, and 0.88 at 5, 15, 30, 60, 120, and 180 min, respectively, post injection. The selective striatum uptake of 18F-FECNT decreased dramatically to the background when the DAT was blocked with β-CFT. The striatum of normal rats in micro-PET exhibited symmetrical (left/right = 1.00±0.05) and the highest uptake of radioactivity (striatum/cere-helium =2.18±0. 16 at 5- 125 min, n =3). As for the hemiparkinsonian rats, nonsymmetrical [unlesioned striatum/cerebellum vs lesioned striatum/cerebellum = 2.01 ± 0.23 (n = 3) vs 1.04 ± 0. 05] and the high-est uptake of radioactivity were also noted. Conclusions The results suggest that 18F-FECNT rapidly pas-ses through blood-brain barrier and locates in stiatal region with high affinity and selectivity to DAT. It is a potential radiotracer to assess the in vivo DAT density in Parkinson's disease.     

18F-FECNT的生物分布特性及小动物PET显像研究

Objective 2β-carbomethoxy-3β-(4-corophenyl)-8-(2-18F-fluoroethyl) nortropane (18F-FECNT) is a recently developed dopamine transporter (DAT) imaging agent. The aim of this study was to evaluate its brain biedistribution and to assess its usefulness in quantitation of DAT density in normal and hemiparkinsonian rats. Methods Six groups of mice (5 mice each group) received 18F-FECNT were sacri-ficed at indicated time post injection. Different brain regions (cortex, hippocampus, striatum, cerebellum) were removed, weighed, and countered. DAT blocking effect was investigated in mice pretreated with 2β-Carbomethoxy-3β-(4-fluorpbenyl)tropane (β-CFT) at before 18F-FECNT injection. MicroPET scans were performed in beth normal and unilaterally 6-hydroxydopamine-lesioned rats. Results The brain uptake of 18F-FECNT was 2.22, 1.20, 1.02, 0.78, 0.71, and 0.67 percent injection dose (%ID) at 5, 15, 30, 60, 120, and 180 min post injection. Radioactivity concentration of the striatum, the target region, was the highest in the brain regions and decreased quickly from 5 to 60 min and reached to background at 120 min of post injection. The striatum/cerebellum ratio was 2.56, 3.47, 2.78, 1.63, 0.97, and 0.88 at 5, 15, 30, 60, 120, and 180 min, respectively, post injection. The selective striatum uptake of 18F-FECNT decreased dramatically to the background when the DAT was blocked with β-CFT. The striatum of normal rats in micro-PET exhibited symmetrical (left/right = 1.00±0.05) and the highest uptake of radioactivity (striatum/cere-helium =2.18±0. 16 at 5- 125 min, n =3). As for the hemiparkinsonian rats, nonsymmetrical [unlesioned striatum/cerebellum vs lesioned striatum/cerebellum = 2.01 ± 0.23 (n = 3) vs 1.04 ± 0. 05] and the high-est uptake of radioactivity were also noted. Conclusions The results suggest that 18F-FECNT rapidly pas-ses through blood-brain barrier and locates in stiatal region with high affinity and selectivity to DAT. It is a potential radiotracer to assess the in vivo DAT density in Parkinson's disease.     

18F-FECNT的生物分布特性及小动物PET显像研究

Objective 2β-carbomethoxy-3β-(4-corophenyl)-8-(2-18F-fluoroethyl) nortropane (18F-FECNT) is a recently developed dopamine transporter (DAT) imaging agent. The aim of this study was to evaluate its brain biedistribution and to assess its usefulness in quantitation of DAT density in normal and hemiparkinsonian rats. Methods Six groups of mice (5 mice each group) received 18F-FECNT were sacri-ficed at indicated time post injection. Different brain regions (cortex, hippocampus, striatum, cerebellum) were removed, weighed, and countered. DAT blocking effect was investigated in mice pretreated with 2β-Carbomethoxy-3β-(4-fluorpbenyl)tropane (β-CFT) at before 18F-FECNT injection. MicroPET scans were performed in beth normal and unilaterally 6-hydroxydopamine-lesioned rats. Results The brain uptake of 18F-FECNT was 2.22, 1.20, 1.02, 0.78, 0.71, and 0.67 percent injection dose (%ID) at 5, 15, 30, 60, 120, and 180 min post injection. Radioactivity concentration of the striatum, the target region, was the highest in the brain regions and decreased quickly from 5 to 60 min and reached to background at 120 min of post injection. The striatum/cerebellum ratio was 2.56, 3.47, 2.78, 1.63, 0.97, and 0.88 at 5, 15, 30, 60, 120, and 180 min, respectively, post injection. The selective striatum uptake of 18F-FECNT decreased dramatically to the background when the DAT was blocked with β-CFT. The striatum of normal rats in micro-PET exhibited symmetrical (left/right = 1.00±0.05) and the highest uptake of radioactivity (striatum/cere-helium =2.18±0. 16 at 5- 125 min, n =3). As for the hemiparkinsonian rats, nonsymmetrical [unlesioned striatum/cerebellum vs lesioned striatum/cerebellum = 2.01 ± 0.23 (n = 3) vs 1.04 ± 0. 05] and the high-est uptake of radioactivity were also noted. Conclusions The results suggest that 18F-FECNT rapidly pas-ses through blood-brain barrier and locates in stiatal region with high affinity and selectivity to DAT. It is a potential radiotracer to assess the in vivo DAT density in Parkinson's disease.     

18F-FECNT的生物分布特性及小动物PET显像研究

Objective 2β-carbomethoxy-3β-(4-corophenyl)-8-(2-18F-fluoroethyl) nortropane (18F-FECNT) is a recently developed dopamine transporter (DAT) imaging agent. The aim of this study was to evaluate its brain biedistribution and to assess its usefulness in quantitation of DAT density in normal and hemiparkinsonian rats. Methods Six groups of mice (5 mice each group) received 18F-FECNT were sacri-ficed at indicated time post injection. Different brain regions (cortex, hippocampus, striatum, cerebellum) were removed, weighed, and countered. DAT blocking effect was investigated in mice pretreated with 2β-Carbomethoxy-3β-(4-fluorpbenyl)tropane (β-CFT) at before 18F-FECNT injection. MicroPET scans were performed in beth normal and unilaterally 6-hydroxydopamine-lesioned rats. Results The brain uptake of 18F-FECNT was 2.22, 1.20, 1.02, 0.78, 0.71, and 0.67 percent injection dose (%ID) at 5, 15, 30, 60, 120, and 180 min post injection. Radioactivity concentration of the striatum, the target region, was the highest in the brain regions and decreased quickly from 5 to 60 min and reached to background at 120 min of post injection. The striatum/cerebellum ratio was 2.56, 3.47, 2.78, 1.63, 0.97, and 0.88 at 5, 15, 30, 60, 120, and 180 min, respectively, post injection. The selective striatum uptake of 18F-FECNT decreased dramatically to the background when the DAT was blocked with β-CFT. The striatum of normal rats in micro-PET exhibited symmetrical (left/right = 1.00±0.05) and the highest uptake of radioactivity (striatum/cere-helium =2.18±0. 16 at 5- 125 min, n =3). As for the hemiparkinsonian rats, nonsymmetrical [unlesioned striatum/cerebellum vs lesioned striatum/cerebellum = 2.01 ± 0.23 (n = 3) vs 1.04 ± 0. 05] and the high-est uptake of radioactivity were also noted. Conclusions The results suggest that 18F-FECNT rapidly pas-ses through blood-brain barrier and locates in stiatal region with high affinity and selectivity to DAT. It is a potential radiotracer to assess the in vivo DAT density in Parkinson's disease.     

18F-FECNT的生物分布特性及小动物PET显像研究

Objective 2β-carbomethoxy-3β-(4-corophenyl)-8-(2-18F-fluoroethyl) nortropane (18F-FECNT) is a recently developed dopamine transporter (DAT) imaging agent. The aim of this study was to evaluate its brain biedistribution and to assess its usefulness in quantitation of DAT density in normal and hemiparkinsonian rats. Methods Six groups of mice (5 mice each group) received 18F-FECNT were sacri-ficed at indicated time post injection. Different brain regions (cortex, hippocampus, striatum, cerebellum) were removed, weighed, and countered. DAT blocking effect was investigated in mice pretreated with 2β-Carbomethoxy-3β-(4-fluorpbenyl)tropane (β-CFT) at before 18F-FECNT injection. MicroPET scans were performed in beth normal and unilaterally 6-hydroxydopamine-lesioned rats. Results The brain uptake of 18F-FECNT was 2.22, 1.20, 1.02, 0.78, 0.71, and 0.67 percent injection dose (%ID) at 5, 15, 30, 60, 120, and 180 min post injection. Radioactivity concentration of the striatum, the target region, was the highest in the brain regions and decreased quickly from 5 to 60 min and reached to background at 120 min of post injection. The striatum/cerebellum ratio was 2.56, 3.47, 2.78, 1.63, 0.97, and 0.88 at 5, 15, 30, 60, 120, and 180 min, respectively, post injection. The selective striatum uptake of 18F-FECNT decreased dramatically to the background when the DAT was blocked with β-CFT. The striatum of normal rats in micro-PET exhibited symmetrical (left/right = 1.00±0.05) and the highest uptake of radioactivity (striatum/cere-helium =2.18±0. 16 at 5- 125 min, n =3). As for the hemiparkinsonian rats, nonsymmetrical [unlesioned striatum/cerebellum vs lesioned striatum/cerebellum = 2.01 ± 0.23 (n = 3) vs 1.04 ± 0. 05] and the high-est uptake of radioactivity were also noted. Conclusions The results suggest that 18F-FECNT rapidly pas-ses through blood-brain barrier and locates in stiatal region with high affinity and selectivity to DAT. It is a potential radiotracer to assess the in vivo DAT density in Parkinson's disease.     

18F-FECNT的生物分布特性及小动物PET显像研究

Objective 2β-carbomethoxy-3β-(4-corophenyl)-8-(2-18F-fluoroethyl) nortropane (18F-FECNT) is a recently developed dopamine transporter (DAT) imaging agent. The aim of this study was to evaluate its brain biedistribution and to assess its usefulness in quantitation of DAT density in normal and hemiparkinsonian rats. Methods Six groups of mice (5 mice each group) received 18F-FECNT were sacri-ficed at indicated time post injection. Different brain regions (cortex, hippocampus, striatum, cerebellum) were removed, weighed, and countered. DAT blocking effect was investigated in mice pretreated with 2β-Carbomethoxy-3β-(4-fluorpbenyl)tropane (β-CFT) at before 18F-FECNT injection. MicroPET scans were performed in beth normal and unilaterally 6-hydroxydopamine-lesioned rats. Results The brain uptake of 18F-FECNT was 2.22, 1.20, 1.02, 0.78, 0.71, and 0.67 percent injection dose (%ID) at 5, 15, 30, 60, 120, and 180 min post injection. Radioactivity concentration of the striatum, the target region, was the highest in the brain regions and decreased quickly from 5 to 60 min and reached to background at 120 min of post injection. The striatum/cerebellum ratio was 2.56, 3.47, 2.78, 1.63, 0.97, and 0.88 at 5, 15, 30, 60, 120, and 180 min, respectively, post injection. The selective striatum uptake of 18F-FECNT decreased dramatically to the background when the DAT was blocked with β-CFT. The striatum of normal rats in micro-PET exhibited symmetrical (left/right = 1.00±0.05) and the highest uptake of radioactivity (striatum/cere-helium =2.18±0. 16 at 5- 125 min, n =3). As for the hemiparkinsonian rats, nonsymmetrical [unlesioned striatum/cerebellum vs lesioned striatum/cerebellum = 2.01 ± 0.23 (n = 3) vs 1.04 ± 0. 05] and the high-est uptake of radioactivity were also noted. Conclusions The results suggest that 18F-FECNT rapidly pas-ses through blood-brain barrier and locates in stiatal region with high affinity and selectivity to DAT. It is a potential radiotracer to assess the in vivo DAT density in Parkinson's disease.     

18F-FECNT的生物分布特性及小动物PET显像研究

Objective 2β-carbomethoxy-3β-(4-corophenyl)-8-(2-18F-fluoroethyl) nortropane (18F-FECNT) is a recently developed dopamine transporter (DAT) imaging agent. The aim of this study was to evaluate its brain biedistribution and to assess its usefulness in quantitation of DAT density in normal and hemiparkinsonian rats. Methods Six groups of mice (5 mice each group) received 18F-FECNT were sacri-ficed at indicated time post injection. Different brain regions (cortex, hippocampus, striatum, cerebellum) were removed, weighed, and countered. DAT blocking effect was investigated in mice pretreated with 2β-Carbomethoxy-3β-(4-fluorpbenyl)tropane (β-CFT) at before 18F-FECNT injection. MicroPET scans were performed in beth normal and unilaterally 6-hydroxydopamine-lesioned rats. Results The brain uptake of 18F-FECNT was 2.22, 1.20, 1.02, 0.78, 0.71, and 0.67 percent injection dose (%ID) at 5, 15, 30, 60, 120, and 180 min post injection. Radioactivity concentration of the striatum, the target region, was the highest in the brain regions and decreased quickly from 5 to 60 min and reached to background at 120 min of post injection. The striatum/cerebellum ratio was 2.56, 3.47, 2.78, 1.63, 0.97, and 0.88 at 5, 15, 30, 60, 120, and 180 min, respectively, post injection. The selective striatum uptake of 18F-FECNT decreased dramatically to the background when the DAT was blocked with β-CFT. The striatum of normal rats in micro-PET exhibited symmetrical (left/right = 1.00±0.05) and the highest uptake of radioactivity (striatum/cere-helium =2.18±0. 16 at 5- 125 min, n =3). As for the hemiparkinsonian rats, nonsymmetrical [unlesioned striatum/cerebellum vs lesioned striatum/cerebellum = 2.01 ± 0.23 (n = 3) vs 1.04 ± 0. 05] and the high-est uptake of radioactivity were also noted. Conclusions The results suggest that 18F-FECNT rapidly pas-ses through blood-brain barrier and locates in stiatal region with high affinity and selectivity to DAT. It is a potential radiotracer to assess the in vivo DAT density in Parkinson's disease.     

18F-FECNT的生物分布特性及小动物PET显像研究

Objective 2β-carbomethoxy-3β-(4-corophenyl)-8-(2-18F-fluoroethyl) nortropane (18F-FECNT) is a recently developed dopamine transporter (DAT) imaging agent. The aim of this study was to evaluate its brain biedistribution and to assess its usefulness in quantitation of DAT density in normal and hemiparkinsonian rats. Methods Six groups of mice (5 mice each group) received 18F-FECNT were sacri-ficed at indicated time post injection. Different brain regions (cortex, hippocampus, striatum, cerebellum) were removed, weighed, and countered. DAT blocking effect was investigated in mice pretreated with 2β-Carbomethoxy-3β-(4-fluorpbenyl)tropane (β-CFT) at before 18F-FECNT injection. MicroPET scans were performed in beth normal and unilaterally 6-hydroxydopamine-lesioned rats. Results The brain uptake of 18F-FECNT was 2.22, 1.20, 1.02, 0.78, 0.71, and 0.67 percent injection dose (%ID) at 5, 15, 30, 60, 120, and 180 min post injection. Radioactivity concentration of the striatum, the target region, was the highest in the brain regions and decreased quickly from 5 to 60 min and reached to background at 120 min of post injection. The striatum/cerebellum ratio was 2.56, 3.47, 2.78, 1.63, 0.97, and 0.88 at 5, 15, 30, 60, 120, and 180 min, respectively, post injection. The selective striatum uptake of 18F-FECNT decreased dramatically to the background when the DAT was blocked with β-CFT. The striatum of normal rats in micro-PET exhibited symmetrical (left/right = 1.00±0.05) and the highest uptake of radioactivity (striatum/cere-helium =2.18±0. 16 at 5- 125 min, n =3). As for the hemiparkinsonian rats, nonsymmetrical [unlesioned striatum/cerebellum vs lesioned striatum/cerebellum = 2.01 ± 0.23 (n = 3) vs 1.04 ± 0. 05] and the high-est uptake of radioactivity were also noted. Conclusions The results suggest that 18F-FECNT rapidly pas-ses through blood-brain barrier and locates in stiatal region with high affinity and selectivity to DAT. It is a potential radiotracer to assess the in vivo DAT density in Parkinson's disease.     

18F-FECNT的生物分布特性及小动物PET显像研究

Objective 2β-carbomethoxy-3β-(4-corophenyl)-8-(2-18F-fluoroethyl) nortropane (18F-FECNT) is a recently developed dopamine transporter (DAT) imaging agent. The aim of this study was to evaluate its brain biedistribution and to assess its usefulness in quantitation of DAT density in normal and hemiparkinsonian rats. Methods Six groups of mice (5 mice each group) received 18F-FECNT were sacri-ficed at indicated time post injection. Different brain regions (cortex, hippocampus, striatum, cerebellum) were removed, weighed, and countered. DAT blocking effect was investigated in mice pretreated with 2β-Carbomethoxy-3β-(4-fluorpbenyl)tropane (β-CFT) at before 18F-FECNT injection. MicroPET scans were performed in beth normal and unilaterally 6-hydroxydopamine-lesioned rats. Results The brain uptake of 18F-FECNT was 2.22, 1.20, 1.02, 0.78, 0.71, and 0.67 percent injection dose (%ID) at 5, 15, 30, 60, 120, and 180 min post injection. Radioactivity concentration of the striatum, the target region, was the highest in the brain regions and decreased quickly from 5 to 60 min and reached to background at 120 min of post injection. The striatum/cerebellum ratio was 2.56, 3.47, 2.78, 1.63, 0.97, and 0.88 at 5, 15, 30, 60, 120, and 180 min, respectively, post injection. The selective striatum uptake of 18F-FECNT decreased dramatically to the background when the DAT was blocked with β-CFT. The striatum of normal rats in micro-PET exhibited symmetrical (left/right = 1.00±0.05) and the highest uptake of radioactivity (striatum/cere-helium =2.18±0. 16 at 5- 125 min, n =3). As for the hemiparkinsonian rats, nonsymmetrical [unlesioned striatum/cerebellum vs lesioned striatum/cerebellum = 2.01 ± 0.23 (n = 3) vs 1.04 ± 0. 05] and the high-est uptake of radioactivity were also noted. Conclusions The results suggest that 18F-FECNT rapidly pas-ses through blood-brain barrier and locates in stiatal region with high affinity and selectivity to DAT. It is a potential radiotracer to assess the in vivo DAT density in Parkinson's disease.     

S-11C-甲基-L-半胱氨酸在荷Hepa 1-6肝癌小鼠体内的分布及PET显像研究

目的 研究S-11C-甲基-L-半胱氨酸(11C-MCYS)在荷Hepa 1-6肝癌小鼠体内的生物学分布及其在肿瘤PET显像中的价值.方法 (1)荷Hepa 1-6肝癌小鼠25只,经尾静脉注射11C-MCYS注射液1.48 MBq,分别在注药后5、10、20、30和60 min5个时间点测量肿瘤组织及各器官的放射性,计算％ID/g.荷瘤小鼠10只,经尾静脉注射11C-MCYS 1.48 MBq,分别于5、10、20、30和60 min行全身PET/CT扫描,观察全身放射性分布及代谢情况.(2)荷瘤小鼠及炎性反应小鼠模型各20只,经尾静脉注射11C-MCYS 1.48 MBq,1h后行全身PET/CT扫描.通过ROI获得肿瘤和炎性反应组织的SUVmax,并计算肿瘤/肌肉、炎性反应组织/肌肉放射性比值.采用t检验进行统计分析.结果 (1)11C-MCYS在体内吸收迅速,给药后5 min放射性分布即可达到高峰,5 min时肝和肾放射性分布分别为(1.97±0.12)和(1.02±0.09) ％ID/g,60 min时肝和肾放射性摄取降为(0.53±0.14)和(0.29±0.05)％ID/g,而脑、肺、胃及肌肉等组织放射性摄取均小于(0.23±0.05)％ID/g,肿瘤组织放射性摄取为(0.48±0.05)％ID/g.荷瘤小鼠不同时间点PET显像示小鼠各脏器的放射性摄取与各相应时间点小鼠体内放射性分布一致.(2)肿瘤组织摄取11C-MCYS较高,SUVmax为4.58±0.65,而炎性反应组织摄取11C-MCYS较低,SUVmax为1.02±0.18,肿瘤/肌肉及炎性反应组织/肌肉的放射性比值分别为7.27和1.62,差异有统计学意义(t=2.906,P＜0.01).结论 11C-MCYS是一种有前景的新型氨基酸类PET显像剂,有望用于肿瘤与无菌性炎性反应的鉴别.     

缺血心肌动物模型PET和SPECT显像及组织学对比研究

目的评估^201TI SPECT及^18F-脱氧葡萄糖（FDG）PET显像对模型猪心肌活力的鉴别。方法健康家猪12头，其中10头于冠状动脉左旋支起始处放置Ameriod环，饲养28d形成慢性心肌缺血动物模型（另2头作正常对照），行^201TI SPECT心肌灌注显像和^18F—FDG PET心肌代谢显像并与HE染色病理学改变进行比较。结果81个心肌节段中，^18F—FDG心肌显像示心肌有活力的节段为73个（90．1％），明显高于^201TI心肌显像所示的62个（76．5％），差异有显著性（P〈0．05）。HE染色结果示有心肌活力的节段为74个（91．3％），与^18F—FDG心肌显像所示结果差异无显著性（P〉0．05）。结论^18F—FDGPET心肌显像检测心肌活力的准确性明显高于^201TI SPECT心肌显像。     

18F-FLT PET显像预测肿瘤放射敏感性的实验研究

目的 探讨18 F-FLT PET显像能否预测肿瘤放射敏感性.方法 对乳腺癌MDA-MB-231细胞和脑胶质瘤LN229细胞以6 MVX线照射0、8和16Gy后分别行克隆形成细胞存活率实验和18 F-FLT细胞摄取实验,各剂量组2种细胞的数据差异行t检验,同种细胞放疗前(0 Gy)与放疗后数据差异行单因素方差分析.将MDA-MB-237和LN229细胞分别接种至雌性BALB/c nu/nu裸鼠右后肢外侧皮下,待肿瘤直径长至10 mm时,将2种荷瘤鼠均按0、8和16 Gy分组(随机数字表法),每组20只.各组按相应剂量放疗后分别行18F-FLT PET显像和免疫组织化学检测,计算肿瘤与肌肉的SUV比值(T/M)和TK1标记指数(LITK1),并行相关性分析.结果 8Gy辐照后MDA-MB-231细胞和LN229细胞生存分数分别为(59.73±4.3)％和(93.41±3.75)％(t=-13.20,P＜0.001),16 Gy时两者生存分数分别为(43.57±4.06)％和(81.77±4.42)％(t=-14.24,P＜0.001).8Gy辐照后1 h MDA-MB-231细胞18F-FLT摄取降至(18.32±1.38) kBq/105细胞[0Gy时为(128.22±8.24) kBq/105细胞,F=266.41,P＜0.01],72h内保持在较低水平;LN229细胞辐照后1h摄取降至(9.87±1.30) kBq/105细胞[0 Gy时为(134.88±6.59) kBq/105细胞,F=346.06,P＜0.01],后逐渐增加,72 h时升至(127.17±9.08) kBq/105细胞(F =346.06,P＞0.05);16 Gy时2种细胞摄取变化基本同8Gy组.8 Gy放疗后裸鼠MDA-MB-231移植瘤18 F-FLT摄取在第1天T/M比值下降至0.78±0.39(放疗前为2.84±0.29,F=39.78,P＜0.01),后缓慢升高,在第7天时仍低于放疗前水平(F=39.78,P＜0.01);16 Gy时变化基本同8Gy组.LN229移植瘤8 Gy放疗在第1天T/M比值升高至2.41±0.47(放疗前为1.58±0.29,F=34.01,P＜0.05),后逐渐降低,到第7天降至0.66±0.32(F=34.01,P＜0.05);16 Gy放疗后18 F-FLT摄取值持续下降,至第7天降到0.44±0.22 (F=41.85,P＜0.01).2组细胞移植瘤8Gy和16 Gy放疗后18F-FLT摄取与TK1表达相关(8 Gy:r =0.67,0.73; 16 Gy:r =0.73,0.69,均P＜0.01).结论 实验结果示18F-FLT PET显像能够预测肿瘤放射敏感性,能否应用于临床需进一步研究.     

基于18F-FDG PET显像建立帕金森病脑代谢网络模式

目的 在PD患者中建立疾病相关脑代谢网络模式(PDRP),为PD早期诊断和鉴别诊断奠定基础.方法 对32例不同严重程度的PD患者和32名年龄、性别匹配的健康对照者分别行静息状态下18F-FDG PET脑显像,将2组的PET图像进行主成分分析(PCA)以获得PDRP.观察PDRP表达值与疾病严重程度[PD综合评分量表(UPDRS)运动功能评分和Hoehn&Yahr评分]之间的相关性.统计学比较采用两样本t检验和Pearson相关分析.结果 PDRP的特征表现为脑内壳核、苍白球、丘脑、脑桥、小脑和初级运动皮质的葡萄糖代谢增高,而运动前区和后顶叶的代谢相对减低.PD组的PDRP表达值明显高于对照组(1.605±0.655与0.000±0.523;t=10.829,P＜0.001),且与UPDRS运动功能评分呈明显正相关(r=0.760,P＜0.001).PDRP表达值与Hoehn&Yahr评分之间亦存在明显正相关(r=0.736,P＜0.001).结论 基于18F-FDG PET显像得到的PDRP可以有效区分PD患者和健康对照者,并反映病情的严重程度.     

肿瘤血管生成的PET检测

肿瘤血管生成作为肿瘤的主要特征,在肿瘤生长和转移中起着重要作用,为肿瘤治疗提供了新策略.通过标记血管生成相关的受体、多肽、激酶或细胞外基质蛋白,形成高亲和力的分子探针,与肿瘤血管生成过程中产生的特异性靶分子结合,从而显示包括整合素、VEGF/VEGFR、基质金属蛋白酶(MMPs)等与血管生成关系密切的特征性血管生成因子,可从分子水平对肿瘤新生血管及血管靶向治疗疗效进行无创性检测.笔者就肿瘤血管生成PET影像学检测研究进展及未来发展作一综述.     

肿瘤PET代谢显像剂及其特点

随着肿瘤PET代谢显像技术的不断发展,其在肿瘤的诊断、治疗及评价等方面的应用也越来越广泛,同时对各种代谢显像剂的研究也日趋深入。综述了各种PET代谢显像剂的基本特性和临床应用,并重点对反映糖代谢、氨基酸代谢和胆碱代谢的显像剂进行评价和比较。     

PET／CT对多发性骨髓瘤的诊断价值

目的探讨多发性骨髓瘤的PET／CT影像学特点,评价其在多发性骨髓瘤诊断中的价值。方法15例按2001年WHO诊断标准确诊为多发性骨髓瘤患者,均在治疗前行PET／CT显像。15例患者经骨髓穿刺和（或）手术病理检查测浆细胞,实验室检查显示有9例患者血清IgG明显升高（〉35g／L）,有8例24h尿本周蛋白增高（〉1g）,15例患者均有溶骨性病变。结果CT所示骨质破坏区域及PET示代谢变化骨髓瘤病灶137个。多发性骨髓瘤病变部位以颅骨37．2％（51／137）、肋骨26．3％（36／137）、椎体12．4％（17／137）为多发,其次为髂骨7．3％（10／137）、骶骨5．8％（8／137）、四肢骨4．4％（6／137）、锁骨3．6％（5／137）、肩胛骨2．9％（4／137）。在137个病灶中,有71个病灶PET显示放射性摄取增高,阳性率为51．8％;有66个病灶表现为放射性摄取稀疏及缺损。而CT主要表现为多发性穿凿样或虫蚀样骨质破坏。结论PET／CT显像对多发性骨髓瘤的临床诊断有较高的价值。     

图像法获取犬18F-FDG PET/CT显像的输入函数

目的 比较^18F-FDG PET图像法和动脉采血法获取输入函数的差别，寻求图像法获取输入函数的最佳部位。方法 5条犬均进行股动脉连续采血和心腔及大血管^18F-FDG PET动态显像，获得动脉血浆输入函数和心腔及大血管区域显像的输入函数，比较不同输入函数计算的曲线下面积（AUC）及通过Patlak方法计算犬心肌的抑制指数（Ki）。结果 心腔和大血管^18F-FDG PET图像获得的输入函数与动脉采血法计算的AUC有很好的相关性（r≥0．97），其中采用主动脉弓（AC）和降主动脉（DA）区域的输入函数获得的心肌FDG代谢Ki与动脉采血法获得的值一致（两者比值分别为1．0±0．1和1．1±0．1）。结论 采用AC和DA区域获得输入函数较适合进行无创的定量分析。     

新生儿脑18F-FDG PET显像初步研究

目的 观察部分新生儿肺炎患儿和早产儿的脑^18F-脱氧葡萄糖（FDG）PET显像图,从代谢角度分析其脑功能.方法 对9例新生儿肺炎患儿及7例早产儿行脑^18F-FDG PET检查.结果 新生儿正常脑^18F-FDG PET影像与成人及儿童明显不同,整个脑的结构不清晰,其葡萄糖代谢活性区主要集中在丘脑、小脑、感觉运动皮质、基底节等脑组织,其中丘脑摄取^18F-FDG最多,大脑皮质摄取^18F-FDG的量较低.分别用1、2、3 min的透射采集作衰减校正,所得图像质量无明显差异.结论 脑^18F-FDG PET显像可作为研究新生儿脑功能代谢行之有效的方法之一.对新生儿行脑^18F-FDGPET显像应尽量减少透射采集时间.