F-FDG PET/CT is an ideal auxiliary tool for early and accurate diagnosis of malignant tumors in children.This guideline aimed to standardize 18F-FDG PET/CT examination process for malignant tumors in children,hence providing references for nuclear medicine professionals.

Parkinson's disease(PD),the second most prevalent neurodegenerative disease,has shown an increasing incidence in recent years,significantly impacting the quality of life of elderly individuals and their families.The onset of cognitive impairment and Parkinson's disease dementia(PDD)are critical milestones in the progression of PD.Imaging examinations,serving as essential detection and evaluation tools for neurodegenerative diseases,have been increasingly applied to PD-related research.Different imaging techniques demonstrate distinct advantages and features in screening cognitive dysfunction in PD.Choosing a reliable imaging method not only maximizes the advantages of the examination,enhancing the sensitivity and specificity in identifying PD patients at risk of cognitive impairment,but also reduces the frequency of examinations and the radiation dose received by patients.This review summarizes the existing findings on imaging markers of cognitive impairment in PD from three aspects,structural imaging,functional imaging,and multimodal techniques.Furthermore,it explores future research directions,aiming to provide powerful imaging support for the clinical diagnosis and treatment of PD.

Parkinson's disease(PD),the second most prevalent neurodegenerative disease,has shown an increasing incidence in recent years,significantly impacting the quality of life of elderly individuals and their families.The onset of cognitive impairment and Parkinson's disease dementia(PDD)are critical milestones in the progression of PD.Imaging examinations,serving as essential detection and evaluation tools for neurodegenerative diseases,have been increasingly applied to PD-related research.Different imaging techniques demonstrate distinct advantages and features in screening cognitive dysfunction in PD.Choosing a reliable imaging method not only maximizes the advantages of the examination,enhancing the sensitivity and specificity in identifying PD patients at risk of cognitive impairment,but also reduces the frequency of examinations and the radiation dose received by patients.This review summarizes the existing findings on imaging markers of cognitive impairment in PD from three aspects,structural imaging,functional imaging,and multimodal techniques.Furthermore,it explores future research directions,aiming to provide powerful imaging support for the clinical diagnosis and treatment of PD.

F-FDG PET/CT is an ideal auxiliary tool for early and accurate diagnosis of malignant tumors in children.This guideline aimed to standardize 18F-FDG PET/CT examination process for malignant tumors in children,hence providing references for nuclear medicine professionals.

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.