Interpretation of presynaptic dopaminergic PET imaging results / 中华核医学与分子影像杂志

Presynaptic dopaminergic PET imaging is a useful method for the diagnosis of parkinsonism. Based on the expert consensus on operation and clinical application of dopamine transporter brain PET imaging technology published in 2020, this paper further recommends the relevant elements of result interpretation of presynaptic dopaminergic PET imaging.

Establishment and clinical verification of brain template for analyzing 11C-CFT PET imaging data / 中华核医学与分子影像杂志

Objective:To establish standard spatial brain template and ROIs template of 11C-methyl- N-2β-carbomethoxy-3β-(4-fluorophenyl)tropane (CFT) PET images for automated quantitative analysis of dopamine transporter (DAT) distribution. Methods:From May 2014 to December 2015, 11C-CFT PET and MRI T 1 brain images of 16 healthy volunteers (3 males, 13 females; age (63.3±6.9) years) from Huashan Hospital, Fudan University were co-registered and smoothed using statistical parametric mapping(SPM)5 software based on MATLAB to create a standard spatial brain template. The ROIs template was established by ScAnVp procedures. These templates were clinically verified by using 11C-CFT PET images of 37 healthy volunteers (23 males, 14 females; age (61.7±7.1) years), 32 Parkinson′s disease (PD) patients (20 males, 12 females; age (61.1±5.4) years), 10 multiple system atrophy with predominant parkinsonism (MSA-P) patients (7 males, 3 females; age (60.8±7.1) years) and 10 progressive supranuclear palsy (PSP) patients (5 males, 5 females; age (58.4±6.1) years) from Huashan Hospital, Fudan University between January 2014 and March 2019. One-way analysis of variance was used to analyze data. Results:Based on the 11C-CFT PET images and MRI T 1 images of healthy volunteers, a standard spatial brain template for normalization of 11C-CFT PET images was created. The ROIs template was established including seven regions: bilateral caudate, anterior putamen, posterior putamen (along the long axis) and the occipital cortex. The ROIs template was accurately aligned in each verification group. The normal reference values of semi-quantitative DAT distribution in caudate, anterior putamen and posterior putamen were obtained (1.84±0.13, 2.18±0.16, 1.77±0.11). The semi-quantitative values of 11C-CFT uptake in each ROI in patients were significantly lower than those in healthy volunteers ( F values: 49.79-283.83, all P<0.05). Conclusion:The established brain templates with accurate spatial alignment for 11C-CFT image analysis can provide foundational tools for the application of 11C-CFT PET imaging in clinical practice and scientific research.

Distinguish mild cognitive impairment and normal cognitive change by β-amyloid PET imaging / 中华核医学与分子影像杂志

Objective:To explore the association of the impaired cognition and the deposition of β-amyloid (Aβ) in normal cognitive (NC) and mild cognitive impairment (MCI).Methods:From December 2018 to January 2021, 305 subjects (113 males, 192 females; age (64.0±7.7) years) who completed neuropsychological tests and MRI in Shanghai Sixth People′s Hospital, Shanghai Jiao Tong University and 18F-florbetapir (AV45) PET imaging in Huashan Hospital, Fudan University were retrospectively analyzed. The subjects were divided into MCI group and NC group based on neuropsychological tests, and each group was further divided into Aβ-positive and Aβ-negative based on PET imaging results. Independent-sample t test, Mann-Whitney U test and χ2 test were used to analyze the data. Results:There were 118 subjects in MCI group and 187 subjects in NC group. The Aβ-positive rate in MCI group (37.3%, 44/118) was higher than that in NC group (26.2%, 49/187; χ2=4.19, P=0.041). The assessment performances of MCI group in general cognitive function, memory function, language function and executive function were inferior to those of NC group ( t values: from -10.63 to -6.31, z values: from -11.01 to -6.03, all P<0.001). The Auditory Verbal Learning Test-Long Delay Recall (AVLT-LDR) score of Aβ-positive subjects was lower than that of Aβ-negative subjects in MCI group (1.00(0.00, 3.00) and 3.00(1.00, 4.00); z=-2.49, P=0.013). The Montreal Cognitive Assessment Basic (MoCA-B) score of Aβ-positive subjects was lower than that of Aβ-negative subjects in NC group (25.29±2.67 and 26.36±2.42; t=-2.61, P=0.010). Conclusion:Compared to Aβ-negative subjects, MCI patients with Aβ-positive perform worse on memory tests, and NC subjects with Aβ-positive perform worse on general cognitive function.

Imaging study of β-amyloid deposits in preclinical Alzheimer′s disease patients in communities of Shanghai / 中华核医学与分子影像杂志

Objective:To explore the β-amyloid (Aβ) deposition pattern of subjects with the preclinical Alzheimer′s disease (AD), community-derived amnestic mild cognitive impairment (aMCI) and normal cognition (NC) from communities of Shanghai.Methods:According to the inclusion and exclusion criteria, 273 subjects (104 males, 169 females; age (64.2±7.6) years) were recruited from Shanghai community and memory clinics from December 2018 to July 2020. All subjects underwent MRI, 18F-AV45 PET imaging and neuropsychological scale tests and were grouped into AD, aMCI and NC groups based on clinical diagnosis. Differences in demographic information, the neuropsychological scale tests′ scores and positive rate of Aβ deposition among each group were analyzed by one-way analysis of variance or χ2 test. Aβ deposition patterns of AD and MCI groups were analyzed at voxel level, and the differences of Aβ deposition among different groups were compared. Results:Among 273 patients, the positive rates of Aβ deposition in AD, aMCI and NC groups were 84.4%(38/45), 36.4%(20/55) and 23.1%(40/173), respectively ( χ2=58.37, P<0.001). Among AD, aMCI, NC and NC (Aβ-) groups ( n=132), the education years of AD group was the lowest ((9.7±4.6) years; F=8.86, P<0.001). In addition, there were significant differences in the scores of several neuropsychological scale tests among AD, aMCI, NC groups and NC (Aβ-) group ( F values: 27.68-235.50, all P<0.001). Compared with subjects in NC(Aβ-) group, the Aβ depositions in the aMCI and AD groups were widely distributed in the whole cerebral cortex; and AD group had higher Aβ deposition in bilateral frontal, parietal, temporal, occipital lobe, cingulate gyrus and precuneus than aMCI group. Conclusions:The positive rate of Aβ deposition in the preclinical AD population from the Shanghai community is obtained. There are significant different Aβ deposition patterns in subjects at different stages of AD.

Study of altered brain metabolism and connectivity in temporal lobe epilepsy / 中华核医学与分子影像杂志

Objective:To explore the abnormal brain metabolic pattern and connectivity in temporal lobe epilepsy (TLE) patients.Methods:18F-FDG PET images of 75 patients diagnosed as drug resistant unilateral TLE from January 2014 to December 2016 in Huashan Hospital of Fudan University were collected retrospectively, including 41 (22 males, 19 females, age (28.4±8.7) years) left TLE (LTLE) and 34 (13 males, 21 females, age (28.5±8.8) years) right TLE (RTLE). Forty-four healthy controls (24 males, 20 females, age (31.2±6.2) years) were also enrolled. The cerebral glucose metabolism in TLE patients and the controls were analyzed with statistical parametric mapping (SPM) 12. The brain connectivity based on glucose metabolism were analyzed with bilateral hippocampus and amygdala as seeds. Permutation test with 1 000 permutations was used to analyze data. Results:Compared to control group, in both LTLE and RTLE groups, hypometabolism was found in affected hippocampus, amygdala, insula and temporal gyrus and hypermetabolism was observed in health hippocampus, parahippocampal gyrus, amygdala, lenticular nucleus and thalamus. In addition, hypometabolism was also found in affected superior/middle frontal gyrus and hypermetabolism was also found in bilateral frontal-orbital gyrus, bilateral cerebellum, affected lenticular nucleus and thalamus in LTLE group. In both TLE groups, affected seeds exhibited increased connectivity with affected superior frontal gyrus, lingual gyrus, fusiform gyrus, superior/middle temporal gyrus and temporal pole (all P<0.05); affected seeds exhibited increased connectivity with health superior frontal gyrus ( P=0.005), lingual gyrus ( P=0.018) and transverse temporal gyrus ( P=0.016) in RTLE group in addition. Besides, affected seeds exhibited decreased connectivity with bilateral default mode network (DMN) (all P<0.05), affected caudate nucleus ( P=0.015) and health thalamus ( P=0.008), in a uniform distribution pattern in LTLE group, and with bilateral cerebral cortex in an irregular distribution pattern in RTLE group (all P<0.05). In LTLE group, health seeds exhibited more increased connections with superior ( P=0.005)/middle frontal gyrus ( P=0.042), health hippocampus ( P=0.038), parahippocampal gyrus ( P=0.019), amygdala ( P=0.038), posterior cingulate gyrus ( P=0.004), and bilateral fusiform gyrusand ( P=0.048) compared with RTLE group; while, in RTLE group, health seeds exhibited more decreased connections with health superior ( P=0.047), inferior frontal gyrus ( P<0.001), orbital frontal gyrus ( P<0.001) and rectus gyrus ( P=0.016) compared with LTLE group. Conclusion:Altered brain glucose metabolism and connectivity pattern are found and will elucidate the underlying metabolic pattern of TLE.

Guidance for operation and reading of 18F-FDG PET brain imaging in dementia / 中华核医学与分子影像杂志

Due to the availability of 18F-FDG in PET centers, this article aims to advocate and promote the standardization of 18F-FDG PET brain imaging in dementia in order to improve the reliability, repeatability and comparison of the imaging process and results. It is also provided to guide the PET imaging operation standard and to give suggestions on image interpretation.

Quality control of the multi-centre clinical trial on PET/CT brain imaging / 中华核医学与分子影像杂志

Multi-centre clinical trials on PET/CT brain imaging are complex to organize and require careful co-ordination and management. This article describes considerations, which are necessary when designing and starting a multi-centre clinical trial on PET/CT brain imaging, based on guidelines and multi-center clinical brain imaging studies, providing references for further studies.

Characteristics of brain glucose metabolism in patients with anti- N-methyl- D-aspartate receptor encephalitis underlying different inducing factors / 中华核医学与分子影像杂志

Objective:To investigate characteristics and differences of cerebral glucose metabolism in patients with anti- N-methyl- D-aspartate receptor (NMDAR) encephalitis from the perspective of different trigger factors of antibodies. Methods:A total of 15 patients (8 males, 7 females, age (30.5±17.7) years) with anti-NMDAR encephalitis between January 2016 and January 2019 in Huashan Hospital, Fudan University were recruited retrospectively. All patients underwent resting state cerebral 18F-FDG PET imaging. The characteristics of brain glucose metabolism were analyzed, and the SUV ratio (SUVR) was semi-quantitatively compared with that in 12 healthy subjects (HS; 7 males, 5 females, age (51.5±9.6) years). Independent-sample t test was used to analyze the data. Results:Among 15 patients, 5 patients were viral encephalitis-related anti-NMDAR encephalitis, showing focal decreased metabolism in unilateral temporal lobe or basal ganglia (SUVR: patients: 0.659±0.219; HS: 1.754±0.203; t=-9.58, P<0.001), with increased metabolism in contralateral temporal lobe or basal ganglia (SUVR: patients: 2.275±0.244; HS: 1.960±0.227; t=2.55, P=0.022) in 18F-FDG PET imaging. Six patients were cryptogenic anti-NMDAR encephalitis, showing asymmetric increased metabolism in frontal, temporal, parietal and basal ganglia (SUVR: patients: 2.482±0.395; HS: 1.754±0.203; t=5.23, P<0.001), with decreased metabolism in bilateral occipital lobes. The remaining 4 cases were paraneoplastic origin accompanied by teratoma, showing increased metabolism in bilateral temporal and basal ganglia (SUVR: patient: 2.359±0.181; HS: 1.960±0.227; t=3.16, P=0.007), with mild decreased metabolism in bilateral occipital lobe. Conclusions:The abnormal changes of cerebral glucose metabolism in patients with anti-NMDAR encephalitis can be divided into at least three patterns according to different trigger factors. A comprehensive understanding of these characteristic metabolic changes is helpful for detecting disease, and may provide potential value in indicating different causes.

Establishment and validation of 18F-FET PET radiomic features-based model in predicting IDH1 genotype in gliomas / 中华核医学与分子影像杂志

Objective:To establish O-(2-[ 18F]fluoroethyl)- L-tyrosine( 18F-FET) PET radiomics features-based model and investigate its predictive efficacy for isocitrate dehydrogenase type 1 (IDH1) genotyping in untreated gliomas. Methods:From November 2017 to February 2019, 58 pathologically confirmed glioma patients (36 males, 22 females; age (41.8±15.1) years) with preoperative 18F-FET PET/CT imaging in Huashan Hospital, Fudan University were retrospectively enrolled. PyRadiomics software package was used to extract 105 radiomics features. Least absolute shrinkage and selection operator (LASSO) algorithm with 5-fold cross-validation was used to build the logistic regression model. And radiomic scores (RS) of each lesion were calculated according to their weighted coefficients. The area under the receiver operating characteristic (ROC) curve was used for evaluating the predictive efficacy for IDH1 prediction. The predictive efficacies of radiomics model and traditional semi-quantitative parameters including tumor-to-background ratio (TBR; maximum TBR (TBR max), mean TBR (TBR mean), peak TBR (TBR peak)), metabolic tumor volume (MTV) and total lesion tracer uptake (TLU), were compared by Delong test. Results:Seven radiomics features including maximum 2-dimensional (2D) diameter slice, first order_maximum, first order_range, gray level co-occurrence matrix (GLCM)_joint energy, GLCM_inverse variance, gray level dependence matrix (GLDM)_dependence entropy and GLDM_large dependence low gray level emphasis were selected for the LASSO regression model building and RS calculation. ROC analysis results showed that the predictive accuracy of RS for IDH1 genotyping (mutation, n=20; wild-type, n=38) was 81.0%(47/58), with sensitivity of 65.0%(13/20), specificity of 89.5%(34/38), and area under curve (AUC) of 0.842, respectively. The traditional 18F-FET semi-quantitative parameter TLU ranked the second regarding the diagnostic performance, with accuracy of 60.3%(35/58), sensitivity of 85.0%(17/20), specificity of 47.4%(18/38), and AUC of 0.661( z=3.426, P<0.01). Conclusion:Radiomics analysis based on 18F-FET PET images can improve the predictive efficacy for IDH1 genotyping in untreated adult glioma patients.

Study on tau brain network and asymmetry of Alzheimer′s disease based on 18F-APN-1607 PET imaging / 中华核医学与分子影像杂志

Objective:To reveal the abnormal topology of brain network in Alzheimer′s disease (AD), and evaluate the laterality of tau protein deposition in brains of AD patients based on 18F-APN-1607 PET brain imaging combined with graph theory. Methods:From November 2018 to January 2020, 23 clinically diagnosed AD patients (9 males, 14 females; age (61.3±10.7) years) and 13 normal controls (NC) (9 males, 4 females; age (61.6±4.5) years) who underwent 18F-APN-1607 PET imaging in Huashan Hospital, Fudan University were analyzed in this cross-sectional study. The brain network analysis method based on graph theory was used to construct the tau network of the NC group and the AD group, the network attributes (clustering coefficient, shortest path length, local efficiency, and small-worldness) were calculated, and the asymmetry index (AI) of each group to evaluate the laterality of tau protein deposition was obtained. Permutation test (1 000 times) was used to analyze the differences in brain network parameters between the NC group and the AD group. Results:The tau network of the AD group had obvious topological disorder, and the connections in the olfactory cortex and temporal lobe were weakened, while in the posterior cingulate gyrus, anterior wedge, and parietal occipital lobe, the connections were enhanced. Compared with NC group, clustering coefficient ( t values: 2.28-2.69), local efficiency ( t values: 2.34-3.06) and small-worldness ( t values: 2.26-3.32) were significantly decreased in AD group (all P<0.05) with the sparsity of 20%-50%, while the shortest path length was significantly increased ( t values: 2.13-2.85; all P<0.05). There was significant tau laterality in the posterior cingulate gyrus, superior parietal gyrus, paracentral lobule, superior temporal gyrus and middle temporal gyrus (AI: 10.5%(8.1%, 13.9%), 14.1%(7.6%, 20.3%), -12.4%(-15.7%, -7.8%), -10.8%(-15.3%, -2.1%) , -12.1%(-17.9%, -6.6%), respectively). Conclusion:The tau network analysis based on 18F-APN-1607 may be used to reveal abnormal topological changes of AD patients, and the tau deposition in the posterior cingulate gyrus, superior parietal gyrus, paracentral lobule, superior temporal gyrus and middle temporal gyrus has obvious laterality in AD patients.

Study on tau related disease pattern of Alzheimer′s disease based on 18F-APN-1607 PET imaging / 中华核医学与分子影像杂志

Objective:Exploring tau related disease pattern (tauRDP) in the brain of Alzheimer′s disease (AD) patients based on 18F-APN-1607 PET scan. Methods:18F-APN-1607 PET images were collected from 17 AD patients (6 males and 11 females, age: (61.7±12.3) years, Mini-Mental State Examination (MMSE) score: 17.6±7.9) and 10 normal controls (NC; 6 males and 4 females, age: (61.2±4.7) years) from Huashan Hospital of Fudan University. The scaled subprofile model (SSM) based on principal component analysis (PCA) technique was used to construct the tauRDP. Then the expression value of tauRDP in each sample was calculated. The differences on tauRDP expression values between AD patients and NC were compared by independent-sample t test. Pearson correlation analysis was used to analyze the correlation between tauRDP expression values and MMSE values in AD patients. Results:The tauRDP area mainly included: precentral gyrus, dorsolateral superior frontal gyrus, middle frontal gyrus, inferior frontal gyrus of opercular part, inferior frontal gyrus of triangular part, supplementary motor area, medial superior frontal gyrus, left median cingulate and paracingulate gyri, right cuneus, superior occipital gyrus, middle occipital gyrus, postcentral gyrus, superior parietal gyrus inferior parietal, but supramarginal and angular gyri, supramarginal gyrus, angular gyrus, precuneus and middle temporal gyrus. There were significant differences ( t=4.395, P<0.001) between AD group (12.6±8.0) and NC group (0.0±1.0) in tauRDP expression values. The tauRDP expression values were correlated with MMSE values in AD group significantly ( r=-0.566, P=0.018). Conclusions:TauRDP established basing on SSM/PCA method can be used to quantitatively express the abnormal spatial distributions of tau deposition. Expression value of tauRDP has the potential to initially assess the severity of AD.

Application of 18F-AV45 PET imaging in subtle cognitive decline and mild cognitive impairment patients / 中华核医学与分子影像杂志

Objective:To investigate the correlations between cerebral β-amyloid (Aβ) deposition assessed by 18F-florbetapir (AV45) PET imaging and clinical cognitive symptoms in patients with subtle cognitive decline (SCD) and mild cognitive impairment (MCI). Methods:Data of twenty-four patients (11 males, 13 females, age: (63.2±7.6) years) diagnosed as SCD ( n=15) or MCI ( n=9) from December 2018 to March 2019 in Shanghai Jiao Tong University Affiliated Sixth People′s Hospital were collected prospectively. All patients underwent 18F-AV45 PET imaging, brain MRI T 1 scan and Mini-Mental State Examination (MMSE) within two weeks. 18F-AV45 PET images were analyzed visually (positive, mild positive, negative). After being pretreated according to the MRI, 18F-AV45 PET images were analyzed semi-quantitatively by calculating the standardized uptake value ratio (SUVR) of Aβ deposition in 8 regions of interest (ROIs; frontal lobe, lateral parietal lobe, lateral temporal lobe, medial temporal lobe, occipital lobe, basal ganglia, posterior cingulate and precuneus), with cerebellar gray matter as the reference. Partial correlation coefficients between regional SUVRs and MMSE score were calculated. Results:18F-AV45 PET imaging showed that 16 patients with positive results and 8 patients with mild positive results. MMSE score of 24 patients was 28.2±2.0, and the SUVR was 0.93-1.87. Correlation analysis revealed that Aβ deposition in frontal cortex ( r=-0.432), posterior cingulate lobe ( r=-0.434) and precuneus ( r=-0.418) was negatively correlated with MMSE score (all P<0.05); and no significant correlations between SUVR and MMSE in other brain regions were found ( r values: from -0.412 to -0.110, all P>0.05). Conclusion:18F-AV45 PET imaging can noninvasively detect brain Aβ deposition in patients, and can effectively reflect the clinical cognitive status of patients with SCD and MCI to a certain extent.

Preoperative 11C-methionine PET imaging in glioma grading efficacy and its predictive value for IDH1 gene mutation status / 中华核医学与分子影像杂志

Objective:To assess the preoperative 11C-methionine ( 11C-MET) PET imaging in glioma grading efficacy and its predictive value for isocitrate dehydrogenase enzyme 1 (IDH1) gene mutation status. Methods:A total of 118 glioma cases (70 males, 48 females; median age 45 years, age range: 10-71 years; Ⅱ grade 65 cases, Ⅲ grade 34 cases, Ⅳ grade 19 cases) received 11C-MET PET imaging in PET Center of Huashan Hospital from February 2012 to November 2017 were retrospectively analyzed. Lesion-based semi-quantitative analysis was conducted on the 11C-MET imaging. Maximum standardized uptake value (SUV max), peak standardized uptake value (SUV peak), tumor-to-background ratio (TBR; SUV max in lesion/mean standardized uptake value (SUV mean) in normal contralateral cortex) were calculated. Independent-sample t test and one-way analysis of variance were applied to assess the differentiating efficacy of 11C-MET PET imaging for different glioma groups. Based on IDH1 immunohistochemical staining results, predictive efficacy of 11C-MET PET diagnostic parameters on IDH1 mutation status in glioma patients was further analyzed with receiver operating characteristic (ROC) curve analysis. Results:Low-grade glioma (LGG; grade Ⅱ) group showed significant differences from high-grade glioma (HGG; grade Ⅲ-Ⅳ) group in SUV max(2.458±1.100 vs 3.828±1.540; t=5.624, P<0.01), SUV peak (2.160±0.991 vs 3.261±1.319; t=5.175, P<0.01) and TBR (2.283±0.942 vs 3.434±1.395; t=5.328, P<0.01). SUV max (2.458±1.100, 3.591±1.611 and 4.251±1.343; F=17.67, P<0.01), SUV peak(2.160±0.991, 3.040±1.335 and 3.656±1.225; F=15.48, P<0.01) and TBR (2.283±0.942, 3.010±1.242 and 4.192±1.358; F=22.73, P<0.01) were different in grade Ⅱ, Ⅲ and Ⅳ glioma subgroups. SUV max, SUV peak and TBR all showed significant differences between grade Ⅱ and grade Ⅲ gliomas, grade Ⅱ and grade Ⅳ gliomas, and there were also statistical differences between grade Ⅲ and grade Ⅳ glioma with TBR (all P<0.01). SUV max indicated the best single-parameter prediction performance (area under curve (AUC) =0.808, z=7.193, P<0.01), while the SUV max + SUV peak showed the best performance (AUC=0.852, z=9.115, P<0.01). In the subgroup of grade Ⅱ ( n=55), TBR of patients with IDH1 gene mutation ( n=41) was lower than that of patients with IDH1 wild-types ( n=14; 2.152±0.759 vs 2.793±1.208; t=2.326, P=0.02), while TBR of those with oligodendrogenic components ( n=26) was higher than that of patients with IDH1 gene mutation only ( n=18; 2.383±0.825 vs 1.854±0.478; t=2.447, P=0.02). Conclusions:Preoperative semi-quantitative parameters (SUV max, SUV peak, TBR) of 11C-MET brain PET imaging have satisfactory grading discrimination performance for glioma patients. SUV max is the best predictor for IDH1 mutation as a single parameter, while SUV max + SUV peak showed the most optimized predictive ability. The oligodendrogenic components in glioma can increase the uptake of 11C-MET, which may affect the effectiveness of 11C-MET in determining glioma grade to some extent.

Brain glucose metabolism network and connectivity in patients with somatoform disorders / 中华核医学与分子影像杂志

Objective To observe the alteration of brain glucose metabolic network in patients with somatoform disorders (SFD).Methods 18F-fluorodeoxyglucose (FDG) PET images of 18 SFD patients (10 males 8 females;age:(39.5±12.0) years;illness duration:(3.67±3.20) years) and 21 matched healthy controls (13 males,8 females;age:(43.9±8.4) years) in Huashan Hospital of Fudan University from October 2011 to December 2012 were enrolled to construct the brain glucose metabolic networks for 2 groups (SFD group,control group) respectively.Then the global network properties (normalized clustering coefficient,normalized shortest path length,small-worldness and global efficiency) and local parameters (clustering coefficient and betweenness centrality of the node) were calculated using the graph theory.Differences between 2 groups were compared by permutation test with 1000 permutations.The top 20％ (18/90) were classified as Hub nodes based on the results of clustering coefficient and betweenness centrality of the node.Results Small-worldness of SFD patients was similar to that of healthy controls (σ＞ 1).There were decreased tendency in normalized clustering coefficient and global efficiency,and increased tendency in normalized shortest path length in SFD patients,but without significant differences (P＞0.05).Compared to healthy controls,the betweenness centrality of left pallidum,left amygdala,left precuneus and right angular gyrus increased (permutation test,P＜0.05);the betweenness centrality of left middle temporal gyrus,right superior occipital gyrus decreased (permutation test,P＜0.05);the clustering coefficients of bilateral pallidum,bilateral thalamus,and left amygdala decreased (permutation test,P ＜ 0.05).Most changed Hub nodes (16/24) belonged to limbic system.Conclusion The changes of topological properties of brain glucose metabolic network in SFD patients including the decreased tendency of small-worldness and global efficiency,as well as the altered Hub nodes,may provide valid imaging evidences for brain dysfunction of somatization symptoms.

Brain glucose metabolism network and connectivity in patients with somatoform disorders / 中华核医学与分子影像杂志

Objective@#To observe the alteration of brain glucose metabolic network in patients with somatoform disorders (SFD).@*Methods@#18F-fluorodeoxyglucose (FDG) PET images of 18 SFD patients (10 males, 8 females; age: (39.5±12.0) years; illness duration: (3.67±3.20) years) and 21 matched healthy controls (13 males, 8 females; age: (43.9±8.4) years) in Huashan Hospital of Fudan University from October 2011 to December 2012 were enrolled to construct the brain glucose metabolic networks for 2 groups (SFD group, control group) respectively. Then the global network properties (normalized clustering coefficient, normalized shortest path length, small-worldness and global efficiency) and local parameters (clustering coefficient and betweenness centrality of the node) were calculated using the graph theory. Differences between 2 groups were compared by permutation test with 1 000 permutations. The top 20% (18/90) were classified as Hub nodes based on the results of clustering coefficient and betweenness centrality of the node.@*Results@#Small-worldness of SFD patients was similar to that of healthy controls (σ>1). There were decreased tendency in normalized clustering coefficient and global efficiency, and increased tendency in normalized shortest path length in SFD patients, but without significant differences (P>0.05). Compared to healthy controls, the betweenness centrality of left pallidum, left amygdala, left precuneus and right angular gyrus increased (permutation test, P<0.05); the betweenness centrality of left middle temporal gyrus, right superior occipital gyrus decreased (permutation test, P<0.05); the clustering coefficients of bilateral pallidum, bilateral thalamus, and left amygdala decreased (permutation test, P<0.05). Most changed Hub nodes (16/24) belonged to limbic system.@*Conclusion@#The changes of topological properties of brain glucose metabolic network in SFD patients including the decreased tendency of small-worldness and global efficiency, as well as the altered Hub nodes, may provide valid imaging evidences for brain dysfunction of somatization symptoms.

Combination of Magnetic Resonance Spectroscopy and ¹¹C-Methionine Positron Emission Tomography for the Accurate Diagnosis of Non-Enhancing Supratentorial Glioma

OBJECTIVE: To evaluate whether the combination of magnetic resonance spectroscopy (MRS) and 11C-methionine positron emission tomography (11C-MET PET) could increase accurate diagnostic sensitivity for non-enhancing supratentorial gliomas. MATERIALS AND METHODS: Between February 2012 and December 2017, 109 patients with non-enhanced supratentorial lesions on contrast-enhanced MRI were enrolled. Each patient underwent MRS and 11C-MET PET before treatment. A lesion was considered to be a glioma when either the MRS or 11C-MET PET results reached the diagnostic threshold. The radiological diagnosis was compared with the pathological diagnosis or medical diagnostic criteria. RESULTS: The sensitivity and specificity were 60.0% and 50.0% for MRS and 75.8% and 50.0% for 11C-MET PET, respectively. Upon combining the two modalities, the sensitivity and specificity of the imaging-based diagnosis prior to surgery reached 89.5% and 42.9%, respectively. Statistically significant differences in the sensitivities were observed between the combined and individual approaches (MRS alone, 89.5% vs. 60.0%, p < 0.001; 11C-MET PET alone, 89.5% vs. 75.8%, p = 0.001). However, no significant differences in specificity were observed between the combined and individual modalities. CONCLUSION: The combination of MRS and 11C-MET PET findings significantly increases accurate diagnostic sensitivity for non-enhancing supratentorial gliomas without significantly lowering the specificity. This finding suggests the potential of the combined MRS and 11C-MET PET approach in clinical applications.

Differential diagnosis value of single-case statistical parametric mapping analysis with 18F-FDG PET imaging for Parkinsonism / 中华核医学与分子影像杂志

Objective@#To investigate the value of statistical parametric mapping (SPM) analysis of 18F-fluorodeoxyglucose (FDG) PET imaging in the differential diagnosis of Parkinsonism in single-case level.@*Methods@#SPM software was used to retrospectively analyze the 18F-FDG PET images of 160 patients (104 males, 56 females, age: 30-82 years) who were suspected with Parkinsonism at baseline and were clinical confirmed by follow-up from April 2010 to December 2017. 18F-FDG PET images of patients was compared with those of age-matched healthy controls in single-case level using two-sample t test in SPM software to obtain the imaging diagnosis. By comparing imaging diagnosis with the final clinical diagnosis, the diagnostic accuracy of SPM in the overall cohort as well as the early subcohort (duration of disease less than 2 years (56 males, 22 females, age: 50-82 years)) were calculated respectively.@*Results@#Among 160 patients with Parkinsonism, 146(91.2%) had the same 18F-FDG PET diagnosis as their final clinical diagnosis. The diagnostic sensitivity for Parkinson′s disease (PD), multiple system atrophy (MSA), progressive supranuclear palsy (PSP) and cortical basal ganglia degeneration (CBD) were 93.5%(86/92), 92.3%(24/26), 84.0%(21/25) and 15/17, respectively. The specificity were 95.6%(65/68), 95.5%(128/134), 96.3%(130/135) and 100%(143/143), respectively. In the early subcohort, the analysis also achieved similar differential diagnosis effectiveness(92.3%).@*Conclusion@#The single-case 18F-FDG PET imaging SPM analysis can be helpful in the early differential diagnosis of Parkinsonism effectively.

Effects of short-term deep brain stimulation in subthalamic nucleus on glucose metabolism in Parkinson′s disease / 中华核医学与分子影像杂志

Objective@#To study the effect of short-term treatment of subthalamic nucleus (STN) deep brain stimulation (DBS) on cerebral glucose metabolism in patients with Parkinson′s disease (PD) and its relationship with the change of brain motor-related nerve pathways.@*Methods@#Five patients (2 males, 3 females; age: (63.6±11.8) years) with PD who underwent STN DBS between January 2014 and December 2018 were enrolled in this study. All patients underwent 18F-fluorodeoxyglucose (FDG) PET in " DBS-off" state before and 3 months after operation. Quantitative expression of PD-related metabolic pattern (PDRP) were calculated by scaled subprofile model/principal component analysis (SSM/PCA) on PET images. Brain regions with changes of glucose metabolism after DBS were located by statistical parametric mapping (SPM) paired t test.@*Results@#Compared with pre-operation, PDRP expression (5.1±1.3 vs 2.9±1.8) and unified Parkinson′s disease rating scale (UPDRS) motor score (50.2±8.2 vs 28.0±5.4) of PD patients were significantly decreased 3 months after STN DBS (t values: 6.17 and 3.88, both P<0.05). After DBS, the glucose metabolism of bilateral globus pallidus/putamen, caudate nucleus, thalamus, insula, pons and cerebellum decreased, while the glucose metabolism of bilateral prefrontal motor area and parietooccipital lobe increased (t=3.75, P<0.01).@*Conclusions@#Short-term STN DBS therapy can inhibit the cortico-striatum-pallidum-hypothalamus-cortex motor loop, which is abnormally excitable in the brain of PD. PDRP, as an imaging characterization of the regulation of this loop, is expected to become an imaging marker for monitoring the treatment of PD.

Quantification ofβcell mass using18 F-FP-(+)-DTBZ, a vesicular monoamine transporter type 2 radiotracer:A longitudinal study in type 1 diabetic rats / 中华内分泌代谢杂志

Objective The aim of this study was to investigate the possibility of type 2 vesicular monoamine transporter molecular probe,18 F-FP-(+)-DTBZ, in the monitoring of total islet β cell mass in animal models. Methods Two groups of Wistar rats were included in this study. In the type 1 diabetes group ( n = 6 ) , the streptozotocin ( STZ) was intraperitoneally injected at a dose of 65 mg/kg, and the control group ( n= 6 ) was likewisely injected with an equal volume of saline, Micro- positron emission tomography ( PET )/ computed tomography ( CT) imaging was performed at these rats post injection of18 F-FP-(+)-DTBZ at 0. 5, 1, 4, 6, and 12 months after STZ or saline injection, bodyweight and glucose level were also measured. Results The average standardized uptake values ( SUV) in the pancreas in the type 1 diabetes rats were decreased significantly than that of the control group at 0.5, 1, and, 4 months ( P<0.05) , and there was no significant difference at 6th and 12th months ( P>0.05) post injection of STZ and saline. Fasting blood glucose positively correlated with pancreatic SUV in the two groups at 0.5, 1, and 4 months (P<0.05) post injection of STZ and saline. Conclusion 18F-FP-(+)-DTBZ PET imaging is a promising method for dynamic monitoringβcell mass in type 1 diabetic rats.

Effects of short-term deep brain stimulation in subthalamic nucleus on glucose metabolism in Parkinson's disease / 中华核医学与分子影像杂志

Objective To study the effect of short-term treatment of subthalamic nucleus ( STN ) deep brain stimulation (DBS) on cerebral glucose metabolism in patients with Parkinson's disease (PD) and its relationship with the change of brain motor-related nerve pathways. Methods Five patients ( 2 males, 3 females;age:(63.6±11.8) years) with PD who underwent STN DBS between January 2014 and December 2018 were enrolled in this study. All patients underwent 18F-fluorodeoxyglucose (FDG) PET in "DBS-off"state before and 3 months after operation. Quantitative expression of PD-related metabolic pattern (PDRP) were calculated by scaled subprofile model/principal component analysis ( SSM/PCA) on PET images. Brain regions with changes of glucose metabolism after DBS were located by statistical parametric mapping (SPM) paired t test. Results Compared with pre-operation, PDRP expression (5.1±1.3 vs 2.9±1.8) and unified Parkinson's disease rating scale (UPDRS) motor score (50.2±8.2 vs 28.0±5.4) of PD patients were significantly decreased 3 months after STN DBS (t values:6.17 and 3.88, both P<0.05). After DBS, the glucose metabolism of bilateral globus pallidus/putamen, caudate nucleus, thalamus, insula, pons and cer-ebellum decreased, while the glucose metabolism of bilateral prefrontal motor area and parietooccipital lobe increased ( t=3.75, P<0.01) . Conclusions Short-term STN DBS therapy can inhibit the cortico-striatum-pallidum-hypothalamus-cortex motor loop, which is abnormally excitable in the brain of PD. PDRP, as an imaging characterization of the regulation of this loop, is expected to become an imaging marker for monito-ring the treatment of PD.