Comparison of 18F-FLT PET and 18F-FDG PET in esophageal cancer.

18F-FDG PET has gained acceptance for staging of esophageal cancer. However, FDG is not tumor specific and false-positive results may occur by accumulation of FDG in benign tissue. The tracer 18F-fluoro-3'-deoxy-3'-L-fluorothymidine (18F-FLT) might not have these drawbacks. The aim of this study was to investigate the feasibility of 18F-FLT PET for the detection and staging of esophageal cancer and to compare 18F-FLT PET with 18F-FDG PET. Furthermore, the correlation between 18F-FLT and 18F-FDG uptake and proliferation of the tumor was investigated. METHODS: Ten patients with biopsy-proven cancer of the esophagus or gastroesophageal junction were staged with CT, endoscopic ultrasonography, and ultrasound of the neck. In addition, all patients underwent a whole-body 18F-FLT PET and 18F-FDG PET. Standardized uptake values were compared with proliferation expressed by Ki-67 positivity. RESULTS: 18F-FDG PET was able to detect all esophageal cancers, whereas 18F-FLT PET visualized the tumor in 8 of 10 patients. Both 18F-FDG PET and 18F-FLT PET detected lymph node metastases in 2 of 8 patients. 18F-FDG PET detected 1 cervical lymph node that was missed on 18F-FLT PET, whereas 18F-FDG PET showed uptake in benign lesions in 2 patients. The uptake of 18F-FDG (median standardized uptake value [SUV(mean)], 6.0) was significantly higher than 18F-FLT (median SUV(mean), 3.4). Neither 18F-FDG maximum SUV (SUV(max)) nor 18F-FLT SUV(max) correlated with Ki-67 expression in the linear regression analysis. CONCLUSION: In this study, uptake of 18F-FDG in esophageal cancer is significantly higher compared with 18F-FLT uptake. 18F-FLT scans show more false-negative findings and fewer false-positive findings than do 18F-FDG scans. Uptake of 18F-FDG or 18F-FLT did not correlate with proliferation.     

Correlation of hypoxic cell fraction and angiogenesis with glucose metabolic rate in gliomas using 18F-fluoromisonidazole, 18F-FDG PET, and immunohistochemical studies.

PET offers a noninvasive means to assess neoplasms, in view of its sensitivity and accuracy in staging tumors and potentially in monitoring treatment response. The aim of this study was to evaluate newly diagnosed primary brain tumors for the presence of hypoxia, as indicated by the uptake of 18F-fluoromisonidazole (18F-FMISO) and to examine the relationship of hypoxia to the uptake of 18F-FDG and molecular markers of hypoxia. METHODS: Seventeen patients with suspected primary glioma were enrolled prospectively in this study. Sixteen patients had histology, with 2 having metastatic disease. All patients had PET studies with 18F-FMISO and 18F-FDG and MRI studies. Immunohistochemistry was undertaken with tumor markers of angiogenesis and hypoxia. Patients were monitored for disease progression and statistical analysis of data was performed. RESULTS: Of the 14 patients with histology, 8 died with a median time of 16 mo (range, 2-30 mo) until death. Of those who died, 7 had positive and 1 had negative 18F-FMISO uptake. 18F-FMISO uptake was observed in all high-grade gliomas but not in low-grade gliomas. A significant relationship was found between 18F-FDG or 18F-FMISO uptake and expression of VEGF-R1 and Ki67 expression. Other immunohistochemical markers demonstrated a trend toward increased uptake but none was significant. CONCLUSION: 18F-FMISO PET provides a noninvasive assessment of hypoxia in glioma and was prognostic for treatment outcomes in the majority of patients. 18F-FMISO PET may have a role not only in directing patients toward targeted hypoxic therapies but also in monitoring response to such therapies.     

~(18)F-FDG和~(18)F-FLT PET显像SUV在肺结块诊断中的价值

目的:探讨18F-氟氏脱氧葡萄糖(18F-FDG)和18F-氟氏胸腺嘧啶(18F-FLT)PET显像诊断肺结块的影响因素,以提高PET/CT对肺结块的诊断价值。方法:选择肺结块患者55例为研究对象,其中28例为肺内孤立结块,其余为2～3个结块,结块大小0.6～11.0cm。所有患者均行肺部18 F-FDG和18 F-FLT PET/CT检查,检查结果按不同性别、年龄、结块大小及病理类型进行分组,以各组18F-FDG和18F-FLT显像标准摄取值(SUV)的均数为界定标准,分析SUV与肺结块患者的性别、年龄、结块大小及病理类型等相互关系。结果:55例肺结块患者,不同性别、年龄、结块大小患者的18 F-FDG和18F-FLT显像SUV差异均无统计学意义(P>0.05),不同病理类型患者的18 F-FDG显像SUV差异无统计学意义(P>0.05),而不同病理类型患者的18F-FLT显像SUV差异有统计学意义(P<0.05)。结论:肺结块患者结块的病理类型是影响18F-FLT显像SUV的重要因素,18F-FLT PET/CT显像SUV鉴别诊断肺结块良恶性具有重要的价值和意义。     

The value of SUV in 18F-FDG and 18F-FLT PET imaging for diagnosing pulmonary nodules

目的:探讨18F-氟氏脱氧葡萄糖(18F-FDG)和18F-氟氏胸腺嘧啶(18F-FLT)PET显像诊断肺结块的影响因素,以提高PET/CT对肺结块的诊断价值.方法:选择肺结块患者55例为研究对象,其中28例为肺内孤立结块,其余为2～3个结块,结块大小0.6～11.0 cm.所有患者均行肺部18F-FDG和18F-FLT PET/CT检查.检查结果按不同性别、年龄、结块大小及病理类型进行分组,以各组18F-FDG和18F-FLT显像标准摄取值(SUV)的均数为界定标准.分析SUV与肺结块患者的性别、年龄、结块大小及病理类型等相互关系.结果:55例肺结块患者,不同性别、年龄、结块大小患者的18F-FDG和18F-FLT显像SUV差异均无统计学意义(P>0.05),不同病理类型患者的18F-FDG显像SUV差异无统计学意义(P>0.05),而不同病理类型患者的18F-FLT显像SUV差异有统计学意义(P<0.05).结论:肺结块患者结块的病理类型是影响18F-FLT显像SUV的重要因素,18F-FLT PET/CT显像SUV鉴别诊断肺结块良恶性具有重要的价值和意义.     

Beads phantom for evaluating heterogeneity of SUV on 18F-FDG PET images

Annals of Nuclear Medicine - This study aimed to develop a dedicated phantom using acrylic beads for texture analysis and to represent heterogeneous 18F-fluorodeoxyglucose (FDG) distributions in...     

Lack of correlation of hypoxic cell fraction and angiogenesis with glucose metabolic rate in non-small cell lung cancer assessed by 18F-Fluoromisonidazole and 18F-FDG PET.

PET offers a noninvasive means to assess neoplasms, in view of its sensitivity and accuracy in staging tumors and potentially in monitoring treatment response. The aim of this study was to evaluate newly diagnosed non-small cell lung cancer (NSCLC) for the presence of hypoxia, as indicated by the uptake of (18)F-Fluoromisonidazole ((18)F-FMISO), and to examine the relationship of hypoxia to the uptake of (18)F-FDG, microvessel density, and other molecular markers of hypoxia. METHODS: Twenty-one patients with suspected or biopsy-proven NSCLC were enrolled prospectively in this study. All patients had PET studies with (18)F-FMISO and (18)F-FDG. Seventeen patients subsequently underwent surgery, with analysis performed for tumor markers of angiogenesis and hypoxia. RESULTS: In the 17 patients with resectable NSCLC (13 men, 4 women; age range, 51-77 y), the mean (18)F-FMISO uptake in tumor was significantly lower than that of (18)F-FDG uptake (P < 0.0001) and showed no correlation with (18)F-FDG uptake (r = 0.26). The mean (95% confidence interval [CI]) (18)F-FMISO SUV(max) (maximum standardized uptake value) was 1.20 [0.95-1.45] compared with the mean [95% CI] (18)F-FDG SUV(max) of 5.99 [4.62-7.35]. The correlation between (18)F-FMISO uptake, (18)F-FDG uptake, and tumor markers of hypoxia and angiogenesis was poor. A weakly positive correlation between (18)F-FMISO and (18)F-FDG uptake and Ki67 was found. CONCLUSION: The hypoxic cell fraction of primary NSCLC is consistently low, and there is no significant correlation in NSCLC between hypoxia and glucose metabolism in NSCLC assessed by (18)F-FDG. These findings have direct implications in understanding the role of angiogenesis and hypoxia in NSCLC biology.     

Regional cerebral glucose metabolic abnormality in Prader-Willi syndrome: A 18F-FDG PET study under sedation.

Prader-Willi syndrome (PWS) is a genetic disorder caused by the nonexpression of paternal genes in the PWS region of chromosome 15q11-13 and is the most common cause of human syndromic obesity. METHODS: We investigated regional brain metabolic impairment in children with PWS by 18F-FDG PET. Sixteen children with PWS (9 males, 7 females; mean age +/- SD, 4.2 +/- 1.1 y) and 7 healthy children (4 males, 3 females; mean age +/- SD, 4.0 +/- 1.7 y) underwent brain 18F-FDG PET in the resting state. The images of PWS children were compared using statistical parametric mapping analysis with those of healthy children in a voxelwise manner. RESULTS: Group comparison showed that children with PWS had decreased glucose metabolism in the right superior temporal gyrus and left cerebellar vermis, regions that are associated with taste perception/food reward and cognitive and emotional function, respectively. Metabolism was increased in the right orbitofrontal, bilateral middle frontal, right inferior frontal, left superior frontal, and bilateral anterior cingulate gyri, right temporal pole, and left uncus, regions that are involved in cognitive functions related to eating or obsessive-compulsive behavior. Interestingly, no significant metabolic abnormality was found in the hypothalamus, the brain region believed to be most involved in energy intake and expenditure. CONCLUSION: This study describes the neural substrate underlying the abnormal eating behavior and psychobehavioral problems of PWS.     

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。     

18F-FDG PET/CT显像正常腹部消化器官的标准摄取值分析

目的分析^18F-脱氧葡萄糖（FDG）PET/CT显像正常腹部消化器官标准摄取值（SUV）的变化范围.方法60例要求行PET/CT检查的健康人,按体重7.77 MBq/kg静脉注射^18F-FDG,PET采集为三维模式,每个床位3 min.对腹部肝、胆囊、脾、胰腺、胃、盲肠、结肠和直肠进行半定量分析,各器官的SUV由横断面测量,准确定位时参考同机CT.结果正常腹部消化器官^18F-FDG摄取有较大差异,其中摄取较高者SUV平均值（SUVavg）依次为直肠、肝、乙状结肠、回盲部和脾、升结肠,SUV最大值（SUVmax）依次为直肠、乙状结肠、肝、回盲部、升结肠、脾.结论PET/CT显像能较好地识别腹部消化器官;熟悉正常腹部消化器官^18F-FDG摄取的差异,对判读图像十分重要.     

氩氦刀冷冻消融术后PET/CT的标准化摄取值与肿瘤残存的相关性研究

目的 探讨肿瘤氩氦刀冷冻消融术后18F-FDG PET/CT显像的标准化摄取值(SUV)与肿瘤残存的相关性.方法 收集2008年3月至2015年12月40例肝、肺恶性肿瘤氩氦刀冷冻消融治疗患者的临床资料,治疗前后行18F-FDG PET/CT检查,记录每例患者的SUV值,并根据病理和临床随访进行数据分析.结果 40例患者共42个治疗灶,38个病灶术后发现放射性核素浓聚,经影像学随访和病理检查证实16个病灶有肿瘤残存,22个病灶为炎性反应.肿瘤残存病灶的SUV值明显高于炎性反应(6.13±1.21对2.64±0.96,P＜0.05),低SUV值组具有较低的复发率(P=0.020)和较高的生存率(P=0.039).低SUV值组的肿瘤残存率明显低于高SUV值组(x2=14.994,P=0.000 2).结论 18F-FDG PET/CT显像在冷冻消融术后边缘残余病灶的及时检出方面具有独特价值,为判断消融效果和进一步的临床治疗提供依据.     

Measurement of skeletal muscle glucose utilization by dynamic 18F-FDG PET without arterial blood sampling

OBJECTIVE: Skeletal muscle glucose utilization (SMGU) can be measured by 18F-FDG PET to characterize insulin resistance. The aim of this study was to determine whether femoral muscle SMGU can be measured without arterial blood sampling by sequential PET imaging of the thoracic and femoral regions. METHODS: Ten patients with possible insulin resistance underwent dynamic 18F-FDG PET of the femoral region during hyperinsulinaemic euglycaemic clamping (group A), and femoral muscle SMGU was calculated using PET data of various time periods and measured arterial input. SMGU was also calculated using venous plasma activity, instead of arterial activity, as input during the late phase. Another five patients underwent sequential PET of the thoracic and femoral regions after single tracer injection (group B). The input function was estimated from aorta activity on thoracic images during the early phase and from venous activity during the late phase, and SMGU with this estimated input was compared with that with measured arterial input. RESULTS: In group A, exclusion of early dynamic PET data from analysis had essentially no effect on the calculated SMGU, and partial substitution of venous activity for arterial activity only marginally changed the estimates. The difference between SMGUs with measured and estimated inputs was minimal in group B. CONCLUSION: Femoral muscle SMGU can be calculated without femoral imaging early after tracer injection, and the input function can be assessed using data of thoracic imaging and venous blood samples. These results support the validity of measuring femoral muscle SMGU without arterial sampling, simultaneously with measurement of myocardial glucose utilization.     

18F-FET与18F-FDG PET显像对照研究

目的探讨O（2-[^18F]氟代乙基）-L-酪氨酸（^18F—FET）对肿瘤的探测能力。方法2例脑瘤患者，用于了解^18F—FETPET显像的全身分布情况。经病理检查或手术证实的其他部位肿瘤患者12例（肺癌6例，胰腺癌、神经内分泌肿瘤各2例，肾上腺皮质癌、鼻咽癌各1例），均有近期CT检查，少数行MRI或全身骨显像检查，1周内分别行^18F—FET与^18F-脱氧萄萄糖（FDG）PET显像。结果①^18F—FET主要经泌尿及胆道系统排泄，骨骼、软组织及心、肝等仅轻度摄取，标准摄取值（SUV）0．38—1．64，肠道、胰腺基本不显影。②12例肿瘤患者^18F—FDGPET显像共检出110个病灶，^18F—FET仅检出15个，病灶的SUV也明显低于^18F—FDG。^18F—FET不仅对一些^18F—FDG代谢活性高的孤立病灶显示不清，对小病灶的检出率也明显低于^18F—FDG。结论^18F—FETPET显像对肺癌、胰腺癌、肾上腺皮质癌等的探测能力明显低于^18F—FDG。     

动态18F-FDG PET定量分析用于骨病变鉴别诊断

目的 评价^18F-脱氧葡萄糖（FDG）PET在骨骼病变中的诊断价值。谅研究对象为40例原发性骨骼病变患者。所有患者在注射示踪剂后立即开始动态PET采集，持续60min。对动态PET图像进行半定量分析，分别计算平均和最大标准摄取值（SUVaver和SUVmax)，病灶SUV／肌肉SUV比值（T／M），病灶60min SUV/30min SUV比值（SUVaver60/30min和SUVmax60/30min）等。采用Patlak作图分析法对动态图像数据进行拟合计算，得出摄入常数（Ki），计算FDG代谢率（MRFDG）。根据接受器工作特性曲线（ROC）确定各定量指标的诊断阈值，并比较其鉴别良恶性病变的灵敏度和特异性。结果 经病理检查证实恶性病变21例，良性病变19例。恶性病变的MRFDG和SUV值高于良性病变，但各种指标的数值分布均存在交叉重叠。SUVaver与MRFDG呈正相关（r=0.67)。以SUV值≥1.8作为阈值时，鉴别良恶性病变的灵敏度和特异性分别为85．0％和82．4％，以MRFDG（1．1）为阈值时的灵敏度（82．4％）与SUV相近，而特异性（92．9％）较高。同时采用SUV（1．8）和SUVaver60/30min(1.1)作为鉴别标准时，较之单独有用SUV特异性可改善为93．3％，灵敏度略有降低（81．3％）。结论 骨骼良恶性病变之间存在葡萄糖代谢率差异。单用静态FDG PET获取SUV值不能很好鉴别骨骼良恶性病变。动态显像定量分析可提供更有价值的信息。根据动态图像进行半定量分析获取可反映动态过程的摄取指标，可能是一种较简便和有价值的鉴别方法。     

Simple quantification of skeletal muscle glucose utilization by static 18F-FDG PET.

Skeletal muscle glucose utilization (SMGU) can be measured by dynamic PET imaging with (18)F-FDG to characterize insulin resistance. The aim of this study was to determine the validity of simple methods to quantify SMGU by static PET imaging. METHODS: Ten patients underwent dynamic (18)F-FDG PET of the femoral region during hyperinsulinemic euglycemic clamping. SMGU was determined by Patlak graphical analysis using data from dynamic imaging with frequent arterial blood sampling. Standardized uptake values (SUVs) were calculated at 45 and 55 min after tracer injection. Skeletal muscle-to-background ratio (SM/B ratio), tissue count divided by venous plasma activity, was also computed at 45 and 55 min. These simple indices were compared by linear regression with the SMGU measured as above, and an estimated SMGU was obtained using the regression equation thus generated, together with a simple index. RESULTS: SMGU was highly correlated with SUVs (r = 0.941 at 45 min, r = 0.951 at 55 min) and SM/B ratios (r = 0.968 at 45 min, r = 0.984 at 55 min). Although SMGU was almost proportional to SM/B ratios, the y-intercepts of the regression lines for SUVs significantly differed from zero. The residual in estimating SMGU using the regression equation was marginally smaller for SM/B ratios than for SUVs and for indices at 55 min than at 45 min, but these differences did not reach statistical significance. Correction for plasma glucose level slightly elevated the correlation coefficients between SMGU and these simple indices. CONCLUSION: It is proposed that the simple quantitative indices, SUV and the SM/B ratio, are reliable indicators of SMGU during hyperinsulinemic euglycemic clamping. Static imaging with or without a single venous blood sampling may therefore be able to replace dynamic imaging with frequent arterial blood sampling, offering substantially greater convenience in evaluating insulin resistance.     

A prospective analysis of 18F-FDG PET/CT in patients with uveal melanoma: comparison between metabolic rate of glucose (MRglu) and standardized uptake value (SUV) and correlations with histopathological features

Purpose

To evaluate whether standardized uptake value (SUV) and/or metabolic rate of glucose (MRglu) are different among epithelioid, mixed, and spindle cell uveal melanomas, as well as between low and high risk melanomas; to correlate ultrasonographic data and metabolic parameters with histopathological features; and to assess the role of ¹⁸F-FDG PET/CT for evaluating prognosis.

Methods

Of 34 eligible patients prospectively enrolled with clinical suspicion of medium/large uveal melanoma, 26 (15 men, mean age 62.8?±?11.8 years) were evaluated. All patients underwent metastatic work-up, 3-D dynamic brain and whole-body ¹⁸F-FDG PET/CT, and surgery.

Results

Of the 26 ocular lesions, 23 showed ¹⁸F-FDG uptake, with a sensitivity of 88 %. MRglu was significantly higher in the epithelioid cell melanomas than in the spindle cell melanomas, as well as in high-risk lesions than in low-risk lesions (p?=?0.01, p?=?0.02, respectively). SUV and MRglu were correlated with histopathological features while ultrasonographic data were not.

Conclusion

MRglu is useful for distinguishing the different cell types in uveal melanoma, as well as high-risk from low-risk lesions, while SUV is not. MRglu provides a more accurate evaluation of glucose consumption, whereas SUV provides only an estimation. In addition, the metabolic parameters correlate with histopathological features, well also reflecting cellular behaviour in ocular malignancy. A longer follow-up is needed to assess the role of ¹⁸F-FDG in evaluating prognosis.     

Parametric images of myocardial metabolic rate of glucose generated from dynamic cardiac PET and 2-[18F]fluoro-2-deoxy-d-glucose studies

We describe a method for generating parametric images of the myocardial metabolic rate of glucose (MMRGlc) with positron emission tomography (PET). The method employs serially acquired images of 2-[18F]fluoro-2-deoxy-D-glucose (FDG) uptake and a Patlak graphical analysis of the image data. The arterial input function is derived from images of the left ventricular blood pool calibrated with 18F-plasma measurements. The approach is computationally fast enough to be used in a clinical environment. The MMRGlc parametric images improve myocardial contrast relative to non-parametric images, especially in studies with poor myocardial uptake of FDG. In addition, MMRGlc parametric images consolidate the large amount of data in a dynamic PET study into a clinically usable image set.     

FDG肿瘤显像相关分子机制研究进展

18F-FDG(18F-氟代脱氧葡萄糖)PET显像是依靠不同组织对18F-FDG的吸收差异来完成的,18F-FDG在肿瘤中的摄取增高与肿瘤的代谢及增殖情况、病理分级、分化程度、细胞的增生活性、倍增时间等生物学特性密切相关。进一步研究FDG吸收机制,将有助于对肿瘤的生物学特性更深一步的了解。     

放射性核素标记胆碱与18F-FDG PET肿瘤显像的对比研究

18F-FDG PET是目前临床上许多恶性肿瘤分期和再分期的首选检查方法,可明显提高恶性肿瘤的诊断准确性,对患者的治疗方案的选择产生了很大影响,而且在恶性肿瘤的疗效监测中也有很大价值.胆碱是保持细胞膜结构和功能完整性的重要成分,恶性肿瘤的胆碱代谢增高.11C-/18F-胴碱PET在临床上已用于许多恶性肿瘤的诊断及转移瘤的检出.该文回顾了18F-FDG和11C-/18F-胆碱PET在肿瘤显像中的应用价值,并比较了其优势和限度.     

放射性核素标记胆碱与18F-FDG PET肿瘤显像的对比研究

18F-FDG PET是目前临床上许多恶性肿瘤分期和再分期的首选检查方法,可明显提高恶性肿瘤的诊断准确性,对患者的治疗方案的选择产生了很大影响,而且在恶性肿瘤的疗效监测中也有很大价值.胆碱是保持细胞膜结构和功能完整性的重要成分,恶性肿瘤的胆碱代谢增高.11C-/18F-胴碱PET在临床上已用于许多恶性肿瘤的诊断及转移瘤的检出.该文回顾了18F-FDG和11C-/18F-胆碱PET在肿瘤显像中的应用价值,并比较了其优势和限度.     

Different metabolic patterns analysis of Parkinsonism on the 18F-FDG PET

Idiopathic Parkinson's disease (IPD), progressive supranuclear palsy (PSP) and multiple system atrophy (MSA) are the most common movement disorders associated with neurodegenerative disease. A clinical differential diagnosis of IPD and atypical Parkinsonian disorders, such as MSA and PSP, is often complicated by the presence of symptoms common to both groups. Since Parkinsonism has a different pathophysiology in the cortical and subcortical brain structures, assessing the regional cerebral glucose metabolism may assist in making a differential diagnosis of Parkinsonism. The 18F-FDG PET images of IPD, MSA and PSP were assessed using statistical parametric mapping (SPM) in order to determine the useful metabolic patterns. Twenty-four patients with Parkinsonism: eight patients (mean age 67.9 +/- 10.7 years; M/F: 3/5) with IPD, nine patients (57.9 +/- 9.2 years; M/F: 4/5) with MSA and seven patients (67.6 +/- 4.8 years; M/F: 3/4) with PSP were enrolled in this study. All patients with Parkinsonism and 22 age-matched normal controls underwent 18F-FDG PET, (after 370 MBq 18F-FDG). The three groups and the individual IPD, MSA and PSP patients were compared with a normal control group using a two-sided t-test of SPM (uncorrected P < 0.01, extent threshold > 100 voxel). The IPD, MSA and PSP groups showed significant hypometabolism in the cerebral neocortex compared to the normal control group. The MSA group showed significant hypometabolism in the putamen, pons and cerebellum compared to the normal controls and IPD groups. In addition, PSP showed significant hypometabolism in the caudate nucleus, the thalamus, midbrain and the cingulate gyrus compared to the normal controls, the IPD and the MSA groups. In conclusion, an assessment of the 18F-FDG PET images using SPM may be a useful adjunct to a clinical examination when making a differential diagnosis of Parkinsonism.