Objective:To explore the value of 18F-FDG PET brain imaging in the auxiliary diagnosis of autoimmune encephalitis (AE) before treatment, and to analyze the regional and course-related characteristics of brain metabolic changes. Methods:The 18F-FDG PET brain imaging data of 49 AE patients (26 males, 23 females, age 48.0(29.0, 61.0) years) who did not receive first-line immunotherapy were retrospectively analyzed. Patients were collected from Renji Hospital, Shanghai Jiao Tong University School of Medicine, between July 2015 and December 2023. Forty-nine age- and gender-matched healthy subjects who underwent routine physical examination at the same time period were selected as the healthy controls (HC). The statistical parametric mapping (SPM) 8 two-sample t test ( P<0.001, k=50) was used to compare the imaging results of AE patients with those of HC. The screening results were adjusted by the cluster-level family-wise error rate (FWER) for P<0.05. Metabolic abnormalities associated with AE were identified, and differences in metabolic patterns at different stages of the disease course (short: ≤1 month; medium: >1 month and ≤3 month; long: >3 month) were compared by subgroup analysis. Mann-Whitney U test was used to analyze the data. Results:In the included AE patients, regions with elevated metabolism were mainly located in the limbic lobe, insula, putamen, and amygdala ( t values: 3.18-5.07, Z values: 3.17-4.76), while local metabolic reduction was observed in the frontal, parietal, and occipital lobes ( t values: 3.18-5.43, Z values: 3.23-5.06), with most of these regions passing FWER correction. In patients with anti- N-methyl- D-aspartate receptor (NMDAR) encephalitis, local metabolism increased in the right superior temporal gyrus ( t values: 3.55-4.79, Z values: 3.67-3.86) and decreased in the left middle temporal gyrus and inferior frontal gyrus ( t values: 3.55-5.43, Z values: 3.45-4.21), but the results did not pass the FWER correction. Subgroup analysis showed that in patients with short disease course ( n=17), regions with locally elevated metabolism included the brainstem, limbic lobe, and cerebellum ( t values: 3.37-5.27, Z values: 3.52-4.44), while regions with reduced metabolism were mainly located in the frontal, parietal, and occipital lobes ( t values: 3.37-6.77, Z values: 3.34-5.30), and these abnormal results all passed FWER correction. In patients with medium ( n=7) to long ( n=25) disease course, the regions with metabolic abnormalities were significantly reduced and did not pass FWER correction. Conclusions:18F-FDG PET can accurately identify brain metabolic abnormalities in AE patients, demonstrating significant regional and course-related characteristics. Metabolic abnormalities are more pronounced in patients with short disease course, while they are relatively less obvious in patients with medium to long disease course.

Objective:To explore the value of 18F-FDG PET brain imaging in the auxiliary diagnosis of autoimmune encephalitis (AE) before treatment, and to analyze the regional and course-related characteristics of brain metabolic changes. Methods:The 18F-FDG PET brain imaging data of 49 AE patients (26 males, 23 females, age 48.0(29.0, 61.0) years) who did not receive first-line immunotherapy were retrospectively analyzed. Patients were collected from Renji Hospital, Shanghai Jiao Tong University School of Medicine, between July 2015 and December 2023. Forty-nine age- and gender-matched healthy subjects who underwent routine physical examination at the same time period were selected as the healthy controls (HC). The statistical parametric mapping (SPM) 8 two-sample t test ( P<0.001, k=50) was used to compare the imaging results of AE patients with those of HC. The screening results were adjusted by the cluster-level family-wise error rate (FWER) for P<0.05. Metabolic abnormalities associated with AE were identified, and differences in metabolic patterns at different stages of the disease course (short: ≤1 month; medium: >1 month and ≤3 month; long: >3 month) were compared by subgroup analysis. Mann-Whitney U test was used to analyze the data. Results:In the included AE patients, regions with elevated metabolism were mainly located in the limbic lobe, insula, putamen, and amygdala ( t values: 3.18-5.07, Z values: 3.17-4.76), while local metabolic reduction was observed in the frontal, parietal, and occipital lobes ( t values: 3.18-5.43, Z values: 3.23-5.06), with most of these regions passing FWER correction. In patients with anti- N-methyl- D-aspartate receptor (NMDAR) encephalitis, local metabolism increased in the right superior temporal gyrus ( t values: 3.55-4.79, Z values: 3.67-3.86) and decreased in the left middle temporal gyrus and inferior frontal gyrus ( t values: 3.55-5.43, Z values: 3.45-4.21), but the results did not pass the FWER correction. Subgroup analysis showed that in patients with short disease course ( n=17), regions with locally elevated metabolism included the brainstem, limbic lobe, and cerebellum ( t values: 3.37-5.27, Z values: 3.52-4.44), while regions with reduced metabolism were mainly located in the frontal, parietal, and occipital lobes ( t values: 3.37-6.77, Z values: 3.34-5.30), and these abnormal results all passed FWER correction. In patients with medium ( n=7) to long ( n=25) disease course, the regions with metabolic abnormalities were significantly reduced and did not pass FWER correction. Conclusions:18F-FDG PET can accurately identify brain metabolic abnormalities in AE patients, demonstrating significant regional and course-related characteristics. Metabolic abnormalities are more pronounced in patients with short disease course, while they are relatively less obvious in patients with medium to long disease course.

Objective:To evaluate the values of 18F-PI-2620 PET/CT brain imaging with SUV ratio (SUVR) in the assessment of tau protein deposition in the brain of patients with different cognitive disorders and its correlation with cognition. Methods:This was a cross-sectional study. From December 2019 to November 2022, a total of 67 subjects including 54 patients with Alzheimer′s disease (AD; 21 males, 33 females, age (68.6±7.8) years), 7 patients with mild cognitive impairment (MCI; 1 male, 6 females, age (63.1±11.2) years) and 6 healthy controls (HC; 4 males, 2 females, age (69.0±5.8) years) were enrolled retrospectively in Renji Hospital. All participants were examined by 18F-PI-2620 PET/CT. SUVRs of brain regions were obtained, including frontal lobe, temporal lobe, occipital lobe, parietal lobe, insular lobe, whole brain, as well as 10 independent brain ROIs (amygdala, orbitofrontal cortex, cingulate gyrus, superior occipital gyrus, superior parietal gyrus, inferior angular gyrus, precuneus, inferior temporal gyrus, entorhinal cortex and parahippocampal gyrus), with inferior cerebellum cortex as the reference region. All participants were estimated by cognitive scales(mini-mental state examination (MMSE) and Montreal cognitive assessment (MoCA)). One-way analysis of variance and the least significant difference t test were used to compare the differences of SUVR in each brain region among HC, MCI and AD groups. ROC curve analysis was used to determine the optimal cut-off values of SUVR in each brain region for the differential diagnosis of AD-MCI and AD-HC. Pearson correlation analysis was employed to examine the correlations of SUVR with cognitive scale scores. Results:The SUVR of whole brain was 1.40±0.31 in AD group, 1.08±0.19 in MCI group, and 1.01±0.12 in HC group. SUVR analysis in the whole brain and each brain region could distinguish AD from HC, AD from MCI ( F values: 1.76-10.09, t values: 2.98-7.47, all P<0.05), but could not distinguish HC from MCI ( t values: 0.17-1.53, all P>0.05). ROC curve analysis showed that the best cut-off value of SUVR was 1.18 for whole brain (AUC=0.89), 1.13 for amygdala (AUC=0.94) and 1.26 for parahippocampal gyrus (AUC=0.94) for differential diagnosis of AD and HC, which was 1.06 for whole brain (AUC=0.82), 1.18 for amygdala (AUC=0.88) and 1.28 (AUC=0.88) for infratemporal gyrus to differential diagnosis of AD and MCI. SUVRs of the whole brain, frontal, occipital, parietal, temporal and insula were significantly negatively correlated with MMSE and MoCA cognitive scale scores ( r values: from -0.64 to -0.40, all P<0.05). Conclusions:SUVR quantitative analysis in 18F-PI-2620 PET imaging can assist the differential diagnosis of AD and HC, AD and MCI. The SUVRs of whole brain and five lobes show negative correlations with MMSE and MoCA scores.

Objective:To assess the diagnostic efficiency of 18F-FDG PET for Alzheimer′s disease (AD) in patients with memory impairment. Methods:A retrospective analysis was conducted on 96 patients (40 males, 56 females, age: 69.0(62.8, 74.0) years) initially diagnosed with memory impairment in Renji Hospital, School of Medicine, Shanghai Jiao Tong University between August 2019 and September 2023. The amyloid-tau-neurodegeneration (ATN) criteria, based on 18F-AV45+ 18F-PI-2620 PET/CT+ MRI imaging results, were used as the diagnostic standard for AD. Visual analysis (temporoparietal or posterior cingulate cortex (PCC) hypometabolism) and semi-quantitative analysis methods (PET-SCORE and NeuroQ software analysis (SUV ratio, SUVR)) were applied to evaluate the diagnostic efficiency of 18F-FDG PET imaging for AD. Diagnostic efficiencies of visual assessment and semi-quantitative parameters were compared by χ2 test. Additionally, Pearson correlation analysis was performed to examine the relationship between results of PET-SCORE and cognitive scales. Results:Of the 96 patients initially diagnosed with memory impairment, 61 were clinically diagnosed with AD, while 35 were non-AD patients. Visual assessment of temporoparietal hypometabolism showed the highest sensitivity (91.80%, 56/61), which was significantly different from the sensitivities of PET-SCORE (40.98%(25/61); χ2=29.03, P<0.001) and visual assessment of PCC hypometabolism (77.05%(47/61); χ2=5.82, P=0.016). While semi-quantitative assessment using PET-SCORE demonstrated the highest specificity (100%, 35/35), which was significantly different from the specificities of visual assessment methods (temporoparietal hypometabolism: 17.14%(6/35), χ2=27.03, P<0.001; PCC hypometabolism: 54.29%(19/35), χ2=14.06, P<0.001). PET-SCORE exhibited statistically significant correlations with Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and Activities of Daily Living (ADL) scores ( r values: -0.38, -0.36, 0.31, all P<0.01). Conclusions:Among patients initially diagnosed with memory impairment, visual assessment in 18F-FDG PET imaging analysis demonstrates higher sensitivity, while semi-quantitative analysis using PET-SCORE exhibits higher specificity. PET-SCORE shows statistically significant correlation with the severity of cognitive decline.

Objective:To investigate the clinical significance of seminal plasma polymorphonuclear neutrophil elastase(PMNE) concentration and semen quality in male infertility.Methods:Semen samples of 941 patients admitted to the andrology department from June 2017 to December 2018 in Dalian Municipal Women and Children′s Medical Center were selected. According to the World Health Organization (WHO) fifth edition standards, the positive group had a leukocyte content ≥ 1 × 10 9/L, and the negative group had a leukocyte content < 1 × 10 9/L; the samples were divided into the inflammatory group and the non-inflammatory group with the PMNE concentration of 600 μg/L as the cut-off point, and the relationship between the PMNE, semen parameters and mycoplasma positive rate was analyzed; the samples were divided into sterile group and normal group according to WHO standard, and the relationships among semen routine parameters, PMNE concentration and mycoplasma positive rate were analyzed. Results:PMNE in the positive group was significantly higher than that in the negative group [(1823.29 ± 557.64) × 10 9/L vs. (480.60 ± 195.36) × 10 9/L], and PMNE concentration was positively correlated with leukocyte content ( P<0.05); the semen quality of the inflammatory group decreased, and the positive rate of mycoplasma was higher than that of the non-inflammatory group [(23.7%(71/299) vs. 11.5%(74/642)] ( P<0.05). The semen quality of the sterile group decreased, and the PMNE and mycoplasma positive rate were both higher than that in the normal group [(1 230.89 ± 489.09) × 10 9/L) vs. (596.78 ± 159.25) × 10 9/L, 34.7%(90/259) vs. 8.1%(55/682)]( P<0.05). Conclusions:There is a good correlation between the concentration of PMNE and the leukocyte content, which can be used as an index to evaluate the male reproductive system infection. The concentration of PMNE is closely related to semen quality, which has clinical value in the diagnosis of male infertility.