Objective:To investigate the value of 18F-FDG PET/CT imaging in the diagnosis of suspected autoimmune encephalitis (AE) in children with epilepsy and negative MRI. Methods:From May 2019 to August 2022, 94 suspected AE children (49 males, 45 females; age 1-15 years) with epilepsy and negative MRI who underwent brain 18F-FDG PET/CT imaging at Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine were retrospectively analyzed. All patients were divided into AE and non-AE groups based on clinical final diagnosis. The effectiveness of visual diagnosis was evaluated. The cortical lesion extent score (S), and SUV max, SUV mean and minimum of SUV (SUV min) of cortical lesions (L), basal ganglia (B) and thalamus (T) were measured and SUV ratios (SUVR) of L/B or L/T were obtained. Independent-sample t test or Mann-Whitney U test was used to analyze data. Binary logistic regression analysis was used to screen the diagnostic factors of AE, and a diagnostic model was established. The diagnostic efficiency was evaluated by ROC curve analysis and Delong test. Results:There were 53 cases in AE group and 41 cases in non-AE group. Based on visual analysis, the sensitivity, specificity and accuracy of 18F-FDG PET/CT for AE were 100%(53/53), 43.9%(18/41) and 75.5%(71/94), respectively. Differences of LSUV max, LSUV mean, LSUV min, L/BSUVR max, L/BSUVR mean, L/BSUVR min, L/TSUVR max, L/TSUVR mean, L/TSUVR min and S between AE and non-AE groups were statistically significant ( z=-6.74, t values: from -8.51 to -3.97, all P<0.001). ROC curve analysis showed that the AUC of L/BSUVR max was the highest (0.914) among visual analysis and semi-quantitative parameters. Logistic regression analysis showed that S (odds ratio ( OR)=11.40, 95% CI: 2.18-59.52, P=0.004), L/BSUVR max( OR=13.19, 95% CI: 2.11-82.51, P=0.006) and L/TSUVR max( OR=9.66, 95% CI: 1.57-59.55, P=0.015) were independent diagnostic factors for AE. Regression model was established: P=1/(1+ e - x), x=2.433×S+ 2.580×L/BSUVR max+ 2.267×L/TSUVR max-3.802. The AUC of this model was 0.948, with the sensitivity, specificity and accuracy of 98.1%(52/53), 90.2%(37/41) and 94.7%(89/94), respectively. The diagnostic efficacy of the optimized scoring system was consistent with the pre-optimization model, and were both superior to L/BSUVR max(both z=2.01, both P=0.040). Conclusion:The diagnostic model and scoring system based on the semi-quantitative analysis of 18F-FDG PET/CT have better diagnostic efficacy for AE and are superior to semi-quantitative parameters alone.

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.

The important role of TDP-43 proteinopathy in Alzheimer's disease (AD) has been gradually revealed. High proportion of AD patients have TDP-43 proteinopathy on their postmortem diagnosis. Patients with TDP-43 proteinopathy show more sever hippocampal atrophy and cognitive dysfunction, suggesting that TDP-43 proteinopathy can serve as an important target in AD diagnosis and treatment. Evaluation of TDP-43 proteinopathy in vivo would hold great promise in AD diagnosis, drug development and treatment. In this review, we describe the pathological characteristics of TDP-43 proteinopathy in AD, and summarize the recent progress of TDP-43 proteinopathy in the diagnosis and treatment of AD.

Objective:To investigate whether the presynaptic dopamine neuronal depletion in different striatal subregions predicts future development of wearing-off (WO) in Parkinson′s disease (PD) patients.Methods:A retrospective longitudinal study included 57 PD patients who were referred to the Department of Neurology of Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from January 2019 to September 2020, and completed 11C-2β-carbomethoxy-3β-(4-fluorophenyl) tropane dopamine transporter (DAT) positron emission tomography scans at the initial evaluation and received dopaminergic drugs for at least 12 months during follow-up. The time of starting dopaminergic drug treatment and the occurrence of WO were recorded. After adjusting for clinical related factors, the predictive value of DAT uptake and related parameters in striatal subregions for WO was evaluated by Cox proportional hazards model. Results:During a median follow-up period of 23 months, 10 patients (18.18%) developed WO. Patients with WO exhibited less DAT uptake in the caudate nucleus and anterior putamen nucleus (0.66±0.52 vs 1.08±0.42, t=2.76, P=0.008 and 0.66±0.20 vs 0.87±0.28, t=2.27, P=0.027 respectively), especially in these subregions contralateral to the less-affected side of the body, compared to those without WO. Cox proportional hazard models revealed that after adjusting for gender, age, course of disease, baseline Unified Parkinson′s Disease Rating Scale Ⅲ score and increment of levodopa equivalent dosage, the lower the DAT uptake of the caudate ipsilateral to the less-affected side of the body ( HR=0.20, 95% CI 0.07-0.63, P=0.006), as well as the lower the DAT uptake of the caudate nucleus and posterior putamen nucleus ( HR=0.28, 95% CI 0.11-0.69, P=0.006 and HR=0.08, 95% CI 0.01-0.64, P=0.018 respectively) and the higher the ratio of putamen/caudate contralateral to the less-affected side of the body ( HR=2.33, 95% CI 1.02-5.33, P=0.045), the higher the risk of WO. Conclusion:The presynaptic dopamine neuronal loss, particularly bilateral caudate nucleus dopaminergic depletion at the early stage, has predictive value of development of WO in PD.

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.

Objective To evaluate the predictive value of posttreatment whole body scan (RxWBS) for radiation damage to the salivary glands in patients with differentiated thyroid carcinoma (DTC).Methods From April 2015 to June 2015,24 patients (8 males,16 females;age:26-64 years) with DTC,who accepted 131I therapy only one time and underwent Rx-WBS 2-4 d after 131I treatment,were recruited from the First Hospital of China Medical University.All patients had normal salivary glands function on salivary gland scintigraphy (SGS) performed on the day before 131I treatment,and 21 patients underwent SGS again 3 months after 131I treatment.The SGS results and clinical manifestations were used to evaluate the function of salivary glands after 131I therapy.Rx-WBS was analyzed by visual analysis and quantitative analysis (salivary gland to background uptake ratios,SUR).The SUR was compared between patient groups with different function of salivary glands.Mann-Whitney u test was used.Receiver operating characteristic (ROC) curve analysis was used to calculate the sensitivity of SUR for predicting the salivary gland damage.Results The SUR in dysfunctional parotid glands (n =12) was significantly higher than that in other glands with normal function (n=30;3.60(2.55,4.33) vs 2.75(2.33,3.29);z=-2.005,P＜0.05).The SUR was not different between submandibular glands with lower function (n =15) and those with normal function (n=27;z=-0.144,P＞0.05).The SUR of parotid glands (n =32) in patients with parotitis was significantly higher than that in others (n=16;3.16(2.53,4.01) vs 2.49(206,2 81);z=-3.073,P＜0.05).The SUR of submandibular glands (n=28) in patients with sialadenitis was significantly higher than that in others (n=20;4.43(2.67,7.61) vs 2.93(1.92,4.65);z=-2.740,P＜0.05).When 2.97 and 3.66 were selected as cutoff values,the sensitivities of SUR for predicting parotitis and sialadenitis were 59％(19/32) and 64％ (18/ 28),respectively.Conclusion Rx-WBS may play a role in predicting radiation damage to the salivary glands.

Nicotinic acetylcholine receptors (nAChRs) play an important role in cognitive function.Vascular cognitive impairment (VCI) seriously affects the health and quality of life.Early diagnosis and timely effective intervention of VCI may delay or even prevent the occurrence of dementia.The development of nAChRs agents and molecular imaging,such as PET/CT or PET/MR,may promote research on the early diagnosis and treatment of VCI.This review summarizes the pathogenesis of VCI,the relationship between nAChRs and VCI,the progress on nAChRs receptor imaging,and the treatment of VCI.

Objective To compare the imaging features of 18F-FDG PET/CT in malignant pleural effusion (MPE) and tuberculosis pleural effusion (TPE).Methods From January 2012 to December 2014,93 patients (52 males,41 females,and average age (66.7±12.7) years) with unexplained pleural effusion who underwent 18F-FDG PET/CT were retrospectively studied.MPE and TPE were confirmed by histology,cytology or clinical follow-up.Lesion SUVmax and T/NT were calculated.Both lesion size and density (in Hounsfield units) of pleural abnormalities on CT images were measured.The difference of images between MPE and TPE was analyzed.Diagnostic efficiency of 18F-FDG PET/CT for detecting MPE and TPE were estimated.Two-sample t test and x2 test were used to analyze the data.Results The lesion SUVmax of 66 patients with MPE and 27 patients with TPE was higher than that in normal tissues (7.72±6.50,8.43±4.92;t=7.81 and 7.15,both P＜0.01),but there was no statistical difference between the TPE and MPE (t=0.56,P＞0.05).T/NT was not significantly different between MPE and TPE (5.40±4.29,5.20±2.73 respectively,t=-0.22,P＞0.05) either.The uptake features of 18F-FDG were different between MPE and TPE (x2=29.3,P＜0.01).When the nodular 18F-FDG uptake increase in pleura was taken as the malignancy,diffuse 18F-FDG uptake increase in pleura as tuberculosis,the sensitivity,specificity,positive predictive value,and negative predictive value of 18F-FDG PET/CT were 78.8％ (52/66),81.5％ (22/27),91.2％ (52/57),61.1％ (22/36),respectively,for differentiation of MPE from TPE.Primary cancers were found in 43 patients.When the nodular uptake increase in pleura,or primary cancer associated with increased pleural uptake found by PET was taken as the malignancy,the above mentioned parameters were95.5％(63/66),81.5％(22/27),92.6％(63/68),88.0％(22/25),respectively.Conclusions The 18FFDG uptake in MPE and TPE is higher than that in normal tissues.18F-FDG PET/CT is helpful in the search for the primary tumor of MPE.Qualitative method of 18F-FDG PET/CT has a good value in the differentiation of MPE from TPE.

Background and purpose:The proportion of incidental thyroid cancer in PET imaging was sig-niifcantly increased with the wide application of18F-FDG PET/CT. The correlation between the glucose metabolism of thyroid incidental thyroid cancer and pathological changes is unclear. The objective of this study is to analyze the relationship between the glucose metabolism by18F-FDG PET/CT and tumor differentiation or lymph node metastasis in patients with incidental thyroid cancer.Methods:A total of 195 patients with focal FDG-avid thyroid incidentaloma during cancer evaluation were enrolled. Fifty-three patients were diagnosed as having thyroid cancer by the pathology. The SUVmax of thyroid cancer foci, lesion size, lesion number, and SUVmax of normal thyroid tissue were quantiifed. The tumor pathological grades and lymph node metastasis were analyzed by the pathology. The patients were broken down into 4 groups (G1, G2, G3 and G4) according to the tumor pathological grades and lymph node metastasis (differentiated thyroid cancer, non-differentiated thyroid cancer, without lymph node metastasis and with lymph node metastasis). The differences of glucose metabolism between G1and G2groups, G3 and G4 groups were analyzed.Results:Fifty-three foci were found by PET imaging. Sixty-two foci were found by the pathology (37 papillary thyroid carcinoma, 4 follicular thyroid carcinoma, 9 medullary thyroid carcinoma, 3 poorly differentiated thyroid cancer). The SUVmax in the normal thyroid tissue, G1and G2were 1.51±0.30, 4.25±1.70 and 6.34±2.45, respectively. The SUVmax in the G1and G2were signiifcantly higher than in the normal thyroid tissue (t=11.0,t=7.10,P<0.01). The SUVmax of G3was 4.77±2.15, and the SUVmax of G4group was 4.67±2.02. The differences between G1and G2groups, G3 and G4groups were not statisti-cally signiifcant (t=3.61,P>0.05;t=0.33,P=0.56).Conclusion:The differentiated incidental thyroid carcinoma and non-differentiated incidental thyroid carcinoma had high glucose metabolism, and there was no signiifcant difference in the levels of glucose metabolism in different differentiation degree and metastasis ability cancer.

Neuronal nicotinic acetylcholine receptors (nAChRs) are involved in a spectrum of cognitive functions and related to some psychiatric and neurodegenerative disorders such as AD,PD,autosomal dominant nocturnal frontal lobe epilepsy and schizophrenia.Nuclear medicine imaging of neuronal nAChRs in living human is a relatively new field.Halogenated analogs of 3 (2 (S)-2-azetidinylmethoxy) pyridine (A-85380) are the most widely used brain imaging radiotracers.In this review,the progress on the latest research on SPECT and PET using the analogs of A-85380 is summarized.