The functional neuroimaging techniques might help to understand cerebral neuronal activities,synaptic transmission,fiber connections and other associated diseases at the molecular level.Since neuroimaging datasets are large,it is important to find some easy and efficient analytical approaches to facilirate the diagnosis and to reveal the pathogenesis for many neurological diseases.Functional imaging techniques are expected to be novel modalities for assessing diagnosis,treatment response and prognosis for neurological diseases.The latest development of analytical approaches for functional neuroimaging based on nuclear medicine is reviewed in this article.

Objective To evaluate the parametric features of image textures on 18F-FDG PET/CT for the differentiation between malignant and benign pulmonary nodules and compare the diagnostic performance of these parameters with SUVmax.Methods 18F-FDG PET/CT images of 170 patients (102 males,68 females,age range:29-81 (mean 59)years) with pulmonary nodules were retrospectively evaluated.Eightynine pulmonary nodules (230 slices) were malignant and 81 (193 slices) were benign.The pulmonary nodules were contoured on CT images and mapped to the co-registered PET images.Thirteen parameters of textural features were extracted and SUVmax was measured.Logistic regression analysis was used to identify the significant texture parameters and create a regression model.The efficacy of the textural features and SUVmax to distinguish between malignant and benign pulmonary nodules was evaluated by ROC curve analysis.The textural features of squamous cell carcinoma and adenocarcinoma were compared via the Mann-Whitney u test.The sensitivity and specificity of the textural features and SUVmax for the differential diagnosis were compared with x2 test.Results Logistic regression model identified 4 textural features (skewness (β =1.7058),kurtosis (β =-1.0989),angular second moment (ASM,3 =-4.4140) and strength (β =0.5626) ; all P ＜ 0.05) to have significant correlation with the malignancy of lung nodules.The AUC of ROC curve was 0.775 (95％ CI0.732-0.819; P＜0.001) with the sensitivity of 89.6％ (206/230) and specificity of 50.8％ (98/193).ASM and strength had statistically significant differences between squamous cell carcinoma and adenocarcinoma [ASM:0.0303 (95％ CI 0.0392-0.0724) vs 0.0594 (95％ CI 0.0721-0.0947) ; strength:2.4714 (95％ CI 2.4632-4.1050) vs 1.5945 (95％ CI 1.9003-2.4652) ; u =3082.0 and 3115.0,both P＜0.01].The AUC of SUVmax-based diagnosis was 0.757 (95％ CI 0.711-0.802 ; P ＜ 0.001) with the sensitivity of 80.9 ％ (186/230) and specificity of 50.3 ％ (97/193) at a cut-off value of 2.5.The sensitivity of the textural features was superior to SUVmax in differentiating malignant from benign pulmonary nodules (x2 =6.903,P ＜ 0.01).Conclusions Image textural parametric features extracted from 18 F-FDG PET/CT are more sensitive to differentiate between malignant and benign pulmonary nodules compared to SUVmax.They might also be useful to discriminate between different pathological types of lung cancers.

Objective To demonstrate the manifestations on positron emission tomographycomputed tomography (PET-CT) at different stages in anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis.Methods PET-CT was performed in 10 patients with anti-NMDAR encephalitis at different clinical stages,and the images were analyzed to investigate the relation of metabolic patterns in the images with clinical presentations.Results Except for normal PET-CT images in 2 patients,images in 8 patients at early stage of the disease showed generally increased 2-[18F] fluoro-2-Deoxy-D-glucose(18F-FDG) uptake at frontal and temporal lobe,basal ganglion and cerebellum,indicating hyper-metabolism in these areas,while 2 of them also had mixture of hyper-and hypo-metabolism in parietal-occipital region.In longitudinal analysis of PET-CT images in these 8 cases,starting at basal ganglion,18 F-FDG uptake gradually decreased bilaterally,prominently at left dominant hemisphere and right cerebellum.Conclusions During the course of anti-NMDAR encephalitis,18F-FDG metabolism markedly increases at early stage and then gradually declines at late stage,at frontal,temporal,parietal and occipital lobes,basal ganglion and cerebellum,predominantly at left dominant hemisphere and right cerebellum.However,in relapsing anti-NMDAR encephalitis,18 F-FDG metabolism in brain does not show these characteristics.

In either type 1 or type 2 diabetes,there is significant loss of β cell mass.Understanding the changing of β cell mass in the course of diabetes would provide important information for diagnosis and treatment.Functional imaging like magnetic resonance imaging or positron emission tomography (PET) can provide safe and noninvasive detection of loss of β cell mass in the course of diabetes.Among them,radio-labelled imaging is the most sensitive imaging procedure of the β cell ; For dihydrotetrabenazine PET imaging aiming β cell mass,there has been some primary outcome.For the key factor causing type 2 diabetes,18 F-6-deoxy-6-fluoro-D-glucose (18F-6-FDG) PET imaging is an effective tracer to study the glucose transporting condition in vivo.Further development of functional imaging will be of great value in diagnosis and treatment of diabetes.

Objectives: By observing and evaluating the clinical curative effect systematically of electrical acupuncture (EA) on Tianshu (ST 25) on diarrhea-predominant irritable bowel syndrome (D-IBS), to make it benefit for the application and spread of EA on Tianshu (ST 25)on D-IBS. Methods: 103 D-IBS matched the involved standards were allocated into treatment group (EA on ST 25, n=53) and control group (EA on Daheng, SP 15, n=50) in randomized,controlled and single-blind ways. Curative effect differences were analyzed by Ridit analysis.Results: The incidence of diarrhea, abdominal pain, abdominal distention or abdominal discomfort, borborygmus, defecation urgency and defecation incompletion feeling were 100%,89.3%, 71.8%, 74.8%, 83.5% and 78.6% respectively in D-IBS. Generally, after treatment, 11cases got excellent results, 34 cases improved and 8 failed in treatment group, totally effective rate was 84.9%; while in control group, 4 cases got excellent effects, 26 improved and 20 failed,totally the effective rate was 60.0%. Conclusion: Compared with control group, EA on Tianshu (ST 25) has a better curative effect on D-IBS.

Objective To find the optimal scanning time window and then set up the normal binding potentials (BPs) of 2β-carbomethoxy-3β-(4-fluorophenyl)-(N-11C-methyl) tropane (11C-CFT) DAT PET/CT imaging.Methods Thirty-one healthy volunteers (20 males,11 females,average age:(55.7±2.3) years),who all gave written informed consent,were divided into three age and gender-matched groups according to block randomization.Each group underwent static PET/CT scan in different time windows from 40-60 min,60-80 min to 80-100 min after 11C-CFT injection.To determine the best scanning time window,the ratios of caudate and putamen of all volunteers were analyzed using automatic ROI method (caudate (putamen)/parieto-occipital cotex-1) and compared by one-way analysis of variance and the least significant difference (LSD) t test.The ratio of the same area between different age-groups and gender-groups was compared with independent two-sample t test.Results Ratios of left caudate (2.08±0.06,1.75±0.07and 1.77±0.12 respectively),right anterior putamen (2.33±0.06,1.95±0.09 and 2.08±0.12 respectively)and bilateral posterior putamen (left:1.88±0.66,1.55±0.88 and 1.72±0.09; right:1.98±0.07,1.61±0.09and 1.69±0.12) were all different in three time windows (F=3.588,3.345,4.479,3.557,all P＜0.05).There were significant differences in ratios of left caudate,right anterior and bilateral posterior putamen between 40-60 min and the 60-80 min (all P＜0.05),as well as the ratios of left caudate between 40-60 min and the 80-100 min group (P＜0.05).While no valid differences in ratios of those areas were shown between the groups of 60-80 min and 80-100 min scanning time window (all P＞0.05).DAT densities in right and left side of caudate,anterior and posterior putamen were significantly lower in the group over 60 years of age than those under 60 years (t=-3.260,-3.090,-3.270,-3.190,-2.270,-3.110,all P＜0.05),but were not different between gender-groups (t =0.367,0.522,0.144,0.524,0.166,0.004,all P＞0.05).Conclusions Sixty min after injection of 11C-CFT,the BPs achieve stable stage,so the best scanning time window of 11C-CFT DAT PET imaging was 60-80 min after injection.Identification of normal DAT distribution and understanding of normal BPs of 11C-CFF are necessary before its clinical application.

Objective: To investigate the electroencephalogram (EEG) characteristics, cerebral blood fl ow, glucose metabolism, and pathological characteristics in cats kindled by pentylenetetrazol (PTZ). Methods: Ten adult male cats received intramuscular injections of PTZ at a sub-convulsive dose of 25 mg/kg once daily. Cats were considered to be kindled when a class V or above seizure was observed. Subsequently, scalp EEG, 99mTc-ECD-single-photon emission computed tomography (SPECT), 18FDG-positron emission tomography (PET), and Cresyl violet staining were employed to evaluate brain activity, cerebral blood fl ow, glucose metabolism, and pathological characteristics representing epileptic foci during interictal stages. Results: The EEG data revealed bilateral dissymmetry paroxysmal activity in the form of δ and θ waves, as well as paroxysmal spikes and sharp waves instead of symmetric highamplitude rhythm of 8-12 Hz in cats kindled by PTZ compared to controls. In addition, low blood perfusion and low glucose metabolism unilaterally in the temporal lobe were observed in PTZ-kindled cats, in contrast to the bilateral symmetrical blood perfusion and high glucose metabolism observed in control cats. Pathological examinations showed a thickening of white matter in the ipsilateral temporal region and a thinning of gray matter in PTZ-kindled cats. Microscopically, we observed a structure disturbance of hippocampal CA3 area in PTZ-kindled cats. Conclusion: Epileptic foci of PTZ-kindled cats were localized to the unilateral temporal lobe, in a manner highly similar to the pathophysiology of human temporal lobe epilepsy.

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.

Objective To validate the reproducibility of abnormal cerebral metabolic characteristics in PD patients from different medical centers using 18F-FDG PET imaging.Methods A total of 108 subjects who were referred for resting-state brain 18 F-FDG PET imaging were retrospectively reviewed.Thirtythree PD patients (15 males,18 females,age:38-79 years) and 33 age-matched healthy controls (15 males,18 females,age:40-77 years) underwent evaluation at Shanghai Huashan Hospital Affiliated to Fudan University.Seventeen PD patients (10 males,7 females,age:44-74 years) and 17 age-matched healthy controls (6 males,11 females,age:42-67 years) underwent evaluation at the First Affiliated Hospital of Sun Yat-sen University.SPM was used to investigate the cerebral metabolic characteristics of the patients with two-sample t test.Statistically significant voxels were obtained by using familywise error rate (FWE;P＜0.05).Two sets of PD patients with abnormal glucose metabolism of brain regions were obtained and the cerebral metabolic characteristics were compared.Results Regarding the PD patients from Shanghai Huashan Hospital,the features of cerebral glucose metabolism by SPM analysis were demonstrated as follows:increased metabolism was found in the region of pons,cerebellum,thalamus,putamen and pallidum,while decreased metabolism was displayed in the region of parietal lobe and occipital lobe.The increased regions referred to 8 110 voxels and decreased regions referred to 2 810 voxels (P＜0.05).The similar metabolic pattern was found in PD patients from the First Affiliated Hospital of Sun Yat-sen University.The increased metabolism was shown in the regions of pons,cerebellum,thalamus,putamen and pallidum,and referred to 15 573 voxels.The metabolism-decreased regions included parietal lobe,occipital lobe and frontal lobe,and referred to 3 945 voxels (P＜0.05).Conclusions 18F-FDG PET/CT imaging results demonstrate similar metabolic pattern in PD patients from different medical centers,in whom the metabolism-increased regions are found in the pons,cerebellum,thalamus and pallidum and decreased regions were demonstrated in the parietal lobe and occipital lobe.The reproducibility from 18F-FDG PET/CT imaging provides reliable evidence for the multi-center study in the differential diagnosis of PD.