ABSTRACT
Objective:To explore values and differences of multi-modality image registration and normalization methods in 18F-AV45 PET quantitative analysis of Alzheimer′s disease (AD). Methods:Twenty AD patients (10 males, 10 females; age (77.0±5.8) years) and 20 normal controls (NC; 8 males, 12 females; age (75.2±4.8) years) from the AD neuroimaging initiative (ADNI) open database of the National Institute on Aging were analyzed. β-amyloid (Aβ) deposition (positive/negative) was assessed by visual analysis. The SUV ratio (SUVr) in each brain region and individual average SUVr were calculated using template normalization method (M1), normalization after registration with 18F-FDG PET or MRI image (M2 or M3) respectively with the cerebellum as the reference area. The intra-class correlation coefficient (ICC) was used to complete the reliability between methods, and independent-sample t test and one-way repeated measures analysis of variance were used to compare the differences of quantitative indexes between different groups and different methods. ROC curve analysis was used to compare the diagnostic efficacy in distinguishing AD and NC, Aβ positive and negative cases. Results:There were 15 and 6 patients with positive Aβ deposition in AD group and in NC group respectively by visual analysis. The SUVrs of three methods were with good consistency (ICC=0.82, P<0.001), and the differences among individual average SUVrs (1.29±0.17, 1.36±0.23, 1.45±0.24) were significant ( F=68.78, P<0.001). There were significant differences between AD group (1.39±0.17, 1.48±0.24, 1.58±0.25) and NC group (1.20±0.10, 1.24±0.15, 1.33±0.16; t values: 3.55-4.33, all P<0.05), Aβ positive group (1.39±0.16, 1.50±0.21, 1.59±0.23) and negative group (1.19±0.11, 1.21±0.14, 1.31±0.15; t values: 4.58, 5.11, 4.41, all P<0.001), and the individual average SUVr of M3 was higher (both P<0.001). The AUCs of distinguishing Aβ positive and negative deposition of M1-M3 were 0.86, 0.88, 0.84 and the thresholds of SUVrs were 1.29, 1.37, 1.52, respectively. Conclusion:The three multi-modality registration and normalization methods are reliable methods for quantitation of 18F-AV45 PET imaging with certain differences, and should be selected carefully based on data conditions in practice.
ABSTRACT
Objective To establish a local human brain 18F-fluorodeoxyglucose positron emission tomography (PET) database with NeuroQ software, and to test its practical value. Methods With NeuroQ software, the PET images of 93 selected subjects were analyzed, and the results were used to create a local normal human database. The metabolism characteristics of the local population were obtained by comparing the original data of the local database with those of the built-in software database, and the difference in case analysis was compared between the two databases. Results Compared with the built-in database, the local database showed the region with high metabolic rate concentrated in the frontal lobe (right superior frontal gyrus: 4.61%, right middle frontal gyrus: 4.49%, left superior frontal gyrus: 3.77%, and left middle frontal gyrus: 3.11%), right posterior cingulate gyrus (6.28%), right inferior parietal lobule (2.46%), left inferior parietal lobule (2.66%), the region with reduced metabolism mainly in the right cerebellum (−3.57%), left cerebellum (−5.27%), and pons (−3.59%). For case analysis, the local database generated results were better consistent with the clinical assessment results of cases. Conclusion Establishment of a local database would eliminate the differences in regions and acquisition conditions, which is of great value to improve the accuracy of diagnosis.
ABSTRACT
Objective To evaluate the clinical value of 18F-FDG PET/CT for detecting tumor on physical examination people with unexplained elevated serum carcinoembryonic antigen (CEA). Methods A total of 100 physical examination people with unexplained elevated serum levels of CEA in our hospital from June 2010 to December 2014 were involved in the study. All the people were detected with 18F-FDG PET/CT. The pathology, clinical follow ups and conventional medical imaging results were combined to evaluate the value of 18F-FDG PET/CT in diagnosing tumor. The doubling time (DT) of CEA was calculated in the patients who were received more than twice of serum CEA detection. The relationships between serum CEA levels, CEA DT and 18F-FDG PET/CT imaging were analyzed. The receiver operating characteristic (ROC) curve was used to assess the diagnostic efficiency of serum CEA. Results Twenty-seven patients were confirmed with malignant tumor, and the rest of 73 cases were excluded. The 18F-FDG PET/CT reported one false positive and one false negative respectively. The sensitivity, specificity, accuracy, positive and negative predictive values of 18F-FDG PET/CT in diagnosing malignant tumors were 96.3%, 98.6%, 98.0%, 96.3% and 98.6% respectively. The median serum CEA levels were significantly higher in the positive 18F-FDG PET/CT patients than those in the negative patients (Z=5.796, P180 d and DT180 d and patients with DT0.05). The area under the curve (AUC) of serum CEA was 0.894, the optimal diagnostic cutoff value was 14.24μg/L. Conclusion 18F-FDG PET/CT is a useful image modality for detecting malignant tumors in patients with unexplained elevated serum CEA, especially for patients with CEA≥14.24μg/L and increase progressively.
ABSTRACT
Objective To investigate the characteristics of cerebral glucose metabolism (CGM) in PD patients with cognitive impairment (PD-CI) using 18F-FDG PET/CT,and to analyze the correlation between the progress of PD-CI and CGM changes.Methods A total of 31 idiopathic PD patients (14 males,17 females,aged 37-77 years) from May 2013 to February 2014 were divided into 3 groups based on Montreal cognitive assessment (MOCA):none CI in PD (PD-NC) group (MOCA＞26 scores),mild CI in PD (PD-MCI) group (MOCA 21-26 scores),PD with dementia (PDD) group (MOCA＜21 scores).The normal controls (NC) group included 12 age-and gender-matched healthy adults (7 males,5 females,aged 40-76 years).All subjects underwent PET/CT imaging after intravenous injection of 18F-FDG(5.55 MBq/kg).MIMneuro software was used to analyze the data.The correlation between the CGM and cognitive function was analyzed using Pearson or Spearman correlation analysis.Results (1) Compared with NC group,PDD group presented a widespread cortical metabolism decrease in frontal,parietal,temporal,occipital 19bes and the limbic lobe;PD-MCI group showed hypometabolic areas in the parietal and occipital lobes,and with less extent in the frontal and temporal lobes;PD-NC group showed no significant cerebral hypometabolism.(2) Compared with PD-NC group,PDD group showed widespread cortical metabolism decrease in occipital lobe,temporal lobe,partial parietal cortex and the posterior cingulated cortex.Compared with PD-MCI group,PDD group had lower metabolism,mainly in posterior brain areas (parietal,occipital and temporal lobes).Compared with PD-NC group,PD-MCI group showed hypometabolism in right supramarginal gyrus and the left parahippocampal gyrus.(3) There were positive correlations between visuospatiaL/executive function and visual cortex metabolism,angular gyrus metabolism or superior parietal lobule metabolism (r =0.535,0.443,0.395;all P＜0.05).A positive correlation was also found between delayed memory and heschl's gyrus metabolism (r=0.337,P＜0.05).Conclusions The cerebral glucose metabolism detected with 18F-FDG PET/CT is well correlated with MOCA assessments.Thus it may be helpful in evaluation of the progress of cognitive impairments in PD.
ABSTRACT
Objective To investigate the change of the cerebral glucose metabolism in Parkinson's disease(PD) with cognitive impairment.Methods Fifty patients with PD and twenty normal controls were enrolled in this study.Based on MMSE score,the PD patients were divided into PD-NC(n=25) and the PDD(n=25) group.Twenty age-and sex-matched physical health examinationer were colleted as control group.Using the SPM to analyze the characteristics of the metabolism in different cognitive level io PD patients.Results (1) Compared with control group,P D-NC group showed significant hypermetabolism in occipital (-24,-92,10),parietal (-48,12,-16) and temporal lobe(52,8,-32).(2)Compared with control group,the glucose metabolism of PDD group decreased in most cerebral cortex and subcortex.(3)Compared with PD-NC group,the metabolism of parietal lobe (-42,-48,40),occipital lobe (-22,-96,-6) and tetnporal lobe (-42,-58,16) reduced in PDD group.Conclusion Cortical brain metabolism decreases in PD-NC group.The degree and scope of glucose metabolism of PDD group will increase with the progress of cognitive dysfunction.These features could help with the diagnosis and differential diagnosis of cognitive dysfunction in Parkinson's disease.