Positron emission tomography (PET) now plays an important role in the research and development (R&D) of central nervous system (CNS) drugs. PET could characterize the biodistribution, pharmacokinetics, and receptor binding of CNS drugs quantitatively. The present review summarized the quantitative methods of PET used in the pharmacokinetics and receptor occupancy analysis of CNS drugs. Moreover, the present review listed various applications of PET supporting R&D of CNS drugs, which could provide a new direction for the R&D of CNS drugs.

Objective:To investigate the clinical efficacy and safety of ferric derisomaltose injection versus iron sucrose injection in the treatment of iron deficiency anemia (IDA) .Methods:A total of 120 patients with iron deficiency anemia admitted from June 2021 to March 2023 were given intravenous iron supplementation with ferric derisomaltose to assess the efficacy and safety of hemoglobin (HGB) elevation before and after treatment. Simultaneously, the clinical effects of iron supplementation with iron sucrose were compared to those of inpatient patients during the same period.Results:Baseline values were comparable in both groups. Within 12 weeks of treatment, the elevated HGB level in the ferric derisomaltose group was higher than that of the iron sucrose group, with a statistical difference at all time points, and the proportion of HGB increased over 20 g/L in the patients treated for 4 weeks was higher (98.7%, 75.9% ). During the treatment with ferric derisomaltose and iron sucrose, the proportion of mild adverse reactions in the ferric derisomaltose group was slightly lower than that of the iron sucrose group, and neither group experienced any serious adverse reactions. The patients responded well to the infusion treatment, with no reports of pain or pigmentation at the injection site.Conclusion:The treatment of IDA patients with ferric derisomaltose has a satisfactory curative effect, with the advantages of rapidity, accuracy, and safety. Therefore, it is worthy of widespread clinical use.

Objective:To standardize the quantitation of 18F-Florbetapir PET SUV ratio (SUVR) to the Centiloid (CL) scale, and analyze the positive rate of β-amyloid (Aβ) in Chinese Preclinical Alzheimer′s Disease (AD) Study (C-PAS). Methods:11C-Pittsburgh compound B(PIB) and 18F-Florbetapir images from public databases " Standard PIB" and " Florbetapir Calibration" were preprocessed by statistical parametric mapping (SPM) 12, and the transformative formulas from SUVR to CL were derived. Then a total of 942 subjects (357 males, 585 females; age (66.4±8.1) years) from C-PAS who received 18F-Florbetapir PET at the Department of Nuclear Medicine & PET Center, Huashan Hospital, Fudan University from October 2018 to August 2023 were retrospectively included. CL values were calculated and the Aβ positive rates (CL value≤12, Aβ negative; 12< CL value<30, Aβ subtle pathology; CL value≥30, Aβ positive) of AD, mild cognitive impairment (MCI) and cognitive unimpaired (CU) groups were explored. Data were analyzed by using Kruskal-Wallis rank sum test, Dunn′s test (Bonferroni correction ) and χ2 test. Results:The formula for the 18F-Florbetapir SUVR converted to CL was CL=179.64×SUVR_Florbetapir-186.95. In the C-PAS cohort, the SUVR, CL value, Aβ positive rate (including subtle pathology) of patients with clinically diagnosed AD were 1.29±0.22, 43.97±39.23, 71.80%(140/195), which were 1.04(1.02, 1.14), 1.16(-4.04, 17.14), 28.50%(61/214) for patients with MCI, and 1.04(1.01, 1.08), 0.54(-5.29, 7.69), 15.38%(82/533) for CU subjects, respectively. SUVR, CL value and the ratio of negative, subtle and positive Aβ pathology of the above three groups exhibited statistical differences ( H=148.30, H=148.30, χ2=262.12, all P<0.001). Besides, mixed MCI group exhibited higher CL values ((2.45(-1.54, 46.32) vs -1.58(-6.33, 7.20); H=8.21, P=0.016; z=2.81, P=0.015) and Aβ positive rate (including subtle pathology) (41.18%(14/34) vs 14.64%(6/41); χ2 values: 12.71 and 10.63, both P<0.01), compared to non-amnestic MCI group. The CL values and Aβ positive rates were also increased with age in CU group. Conclusion:This study validates the feasibility of the CL formula with 18F-Florbetapir images and reveals Aβ deposition in C-PAS cohort, which can lay the foundation for multi-center Aβ PET studies in China.

Objective:To compare the effects of different reference brain regions on the semi-quantitative SUV ratio (SUVR) of 18F-Florzolotau PET images of Alzheimer′s disease (AD). Methods:The 18F-Florzolotau PET images of 28 (13 males, 15 females, age (57.3±9.5) years) normal controls (NC), 19 patients (4 males, 15 females, age (73.3±7.3) years) with β-amyloid (Aβ)-positive mild cognitive impairment (MCI) and 40 patients (19 males, 21 females, age (61.9±9.1) years) with AD were collected from Huashan Hospital, Fudan University between November 2018 and July 2020. Six semi-quantitative reference brain regions were defined, including whole cerebellum (WC), cerebellar gray matter (GM), cerebellar white matter (WM), parametric estimation of reference signal intensity (PERSI), WC after partial volume correction (WC_pvc), cerebellar GM after partial volume correction (GM_pvc). SUVR was calculated for 14 ROIs, which included the whole brain defined by the automated anatomical labeling (AAL) template, fusiform, inferior temporal, lingual, middle temporal, occipital, parahippocampal, parietal, posterior cingulate, precuneus defined by the AAL template, and Meta ROI composed of the above brain regions, and braak_Ⅰ-Ⅱ, braak_Ⅲ-Ⅳ, braak_Ⅴ-Ⅵ defined by the Desikan Killiany template. AUC was used to evaluate the classification ability of SUVR, and the correlation between SUVR and clinical scale scores were assessed by Spearman rank correlation analysis. Results:The SUVRs of most brain regions showed a steady upward trend in the AD disease spectrum. In the classification task of NC and MCI, the overall performance of SUVR based on WC_pvc was relatively optimal (AUCs: 0.975-1.000). In the classification task of NC and AD, SUVRs of 10 ROIs based on the WC_pvc method showed the relatively best performance (AUCs: 0.976-1.000). The correlation between SUVR of fusiform based on cerebellar WM and mini-mental state examination (MMSE) score was the strongest ( rs=-0.72, P<0.001), and the SUVR of precuneus based on WC_pvc showed the strongest correlation with clinical dementia rating (CDR) score ( rs=0.78, P<0.001). Conclusion:The SUVR based on WC_pvc method performs well in classification and correlation tasks, and is recommended to be used in semi-quantification of 18F-Florzolotau PET images of AD.

Objective:To investigate the application of (4R)-4-(3-[ 18F]fluoranyl-5-fluorophenyl)-1-((3-methylpyridin-4-yl)methyl)pyrrolidin-2-one( 18F-SynVesT-1), a synaptic vesicle glycoprotein 2A (SV2A) radioactive tracer, in patients with Alzheimer′s disease (AD). Methods:A total of 20 AD patients (2 males, 18 females, age (66.4±8.1) years) with positive β-amyloid (Aβ) deposition and 20 normal controls (NC; 9 males, 11 females, age (62.6±8.6) years ) without Aβ deposition were retrospectively recruited from Huashan Hospital, Fudan University between December 2021 and December 2022. All of them underwent 18F-SynVesT-1 PET/MR and 18F-Florbetapir (AV45) PET/CT scans. Preprocessing of brain 18F-SynVesT-1 PET images was carried out using statistical parametric mapping (SPM). The differences of the uptke of 18F-SynVesT-1 (synaptic density) between two groups based on ROI were compared by using either the independent-sample t test or Mann-Whitney U test. Spearman rank correlation analysis was performed to assess the relationship between synaptic density and cognitive performance. For voxelwise analysis, a general linear model was constructed to analyze differences in synaptic density between the two groups using the independent-sample t test. Furthermore, a multiple linear regression model was developed to explore the relationship between synaptic density and cognitive performance. Results:Compared to the NC group, the AD group exhibited significant widespread reduction in synaptic density across the cortical regions ( P<0.05, false discovery rate (FDR)-corrected), particularly in the medial temporal lobe (0.84±0.09 vs 1.04±0.09; t=-6.95, P<0.001), lateral temporal lobe (1.15±0.13 vs 1.31±0.08; t=-4.56, P<0.001), and lateral parietal lobe (1.24(1.04, 1.26) vs 1.32(1.23, 1.39); z=-3.25, P=0.001). Moreover, synaptic density in extensive cortical regions showed a positive correlation with mini-mental state examination (MMSE) and Montreal cognitive assessment-basic (MoCA-B) scores ( P<0.05, FDR-corrected). Notably, significant associations were observed between MMSE and MoCA-B scores and synaptic density in the lateral temporal lobe ( rs values: 0.71, 0.74, both P<0.001) and medial temporal lobe ( rs values: 0.71, 0.74, both P<0.001). Conclusions:18F-SynVesT-1 PET imaging is a valuable tool for evaluating synaptic density, specifically in the context of AD. The observed widespread reduction in synaptic density across cortical regions of patients with AD are closely related to cognitive decline.

Objective:To perform harmonization based on the ComBat method for PET brain imaging scanned by different types of scanners from the same manufacturer and explored its effect on center effect.Methods:The three-dimensional (3D) Hoffman brain model was scanned by two different PET/CT instruments (Siemens Biograph64 TruePoint and Biograph128 mCT). Fourteen healthy subjects (8 males, 6 females, age: (57.7±9.5) years) underwent 18F-FDG PET/CT on Siemens Biograph64 TruePoint and 12 healthy subjects (9 males, 3 females, age: (55.8±10.5) years) underwent 18F-FDG PET/CT on Siemens Biograph128 mCT (all from Huashan Hospital, Fudan University; from November 2020 to March 2023). The whole brain was divided into 116 brain regions based on the anatomical automatic labeling (AAL) brain template. The ComBat method was applied to harmonized the PET data from brain model and healthy subjects. Mann-Whitney U test was performed on the radioactive counts and SUV ratios (SUVR) before and after homogenization acquired by both PET/CT instruments. Voxel-based statistical parametric mapping (SPM) independent-sample t test was also performed on data of healthy subjects. Results:In 3D Hoffman brain model, radioactivity counts (5 590.33(4 961.67, 6 102.95) vs 6 116.03(5 420.97, 6 660.66); z=-9.35, P<0.001) and SUVR (1.35(1.19, 1.47) vs 1.37(1.21, 1.49); z=-3.63, P<0.001) were significantly different between the two PET/CT scanners before harmonization and not after harmonization (radioactivity counts: 5 845.95(5 192.68, 6 378.63) vs 5 859.17(5 193.84, 6 380.52); SUVR: 1.35(1.20, 1.48) vs 1.36(1.20, 1.49); both z=-0.68, both P=0.498). In the healthy subjects, radioactive counts in 19 brain regions (12 422.78(11 181.60, 13 424.28)-18 166.40(15 882.80, 18 666.27); z values: from -3.24 to -2.06, all P<0.05) and SUVR in 40 brain regions (1.46(1.41, 1.52)-2.28(2.16, 2.36); z values: from -3.65 to -1.70, all P<0.05) were significantly different between the two scanners before harmonization, while after homogenization there were no statistical differences for all 116 brain regions (radioactivity counts: 9 243.55(8 502.38, 9 854.87)-20 419.60(19 931.51, 21 179.43); z values: from -0.72 to 0, all P>0.05; SUVR: 1.04(1.01, 1.09)-2.32(2.24, 2.40); z values: from -0.82 to 0, all P>0.05). SPM showed that significant differences of glucose metabolism in the cerebral cortex, basal ganglia, midbrain and cerebellum were found in healthy subjects between the two PET/CT scanners before homogenization, and brain regions with obvious differences reduced after homogenization. Conclusion:ComBat harmonization method is efficient at removing the center effect among different types of PET/CT scanners from the same manufacturer and may provide a simple and easy-to-implement homogenization for multicenter brain imaging studies.

Objective:To compare the localization accuracy of interictal 18F-FDG and 18F-flumazenil (FMZ) PET/CT imaging for focal cortical dysplasia (FCD). Methods:A retrospective analysis was conducted on 22 patients (12 males, 10 females; age 8-36 years) with pathologically confirmed FCD who underwent surgical resection at Huashan Hospital, Fudan University from July 2021 to June 2023. All patients underwent 18F-FDG and 18F-FMZ PET/CT scans before surgery. Surgical pathological diagnosis was used as the gold standard. Visual scoring was used to analyze the images. The accuracy of the two imaging methods in the localization of FCD was compared, and subgroup analysis (FCD Ⅱa, FCD Ⅱb) of different pathological type was further performed. Paired- t test, χ2 test or Fisher′s exact test was used to analyze the data. Results:The visual score of 18F-FMZ PET/CT was higher than that of 18F-FDG (3.00±0.82 vs 2.27±0.92; t=4.17, P=0.020). The accuracy of interictal 18F-FMZ PET/CT was 77.27%(17/22), which was higher than that of 18F-FDG PET/CT (36.36%, 8/22; χ2=7.50, P=0.006). Subgroup analysis showed that within the cohort of patients diagnosed with FCD Ⅱa ( n=18), 18F-FMZ PET/CT outperformed 18F-FDG in terms of accuracy for localization (15/18 vs 6/18; P=0.006). Conclusion:Compared to 18F-FDG, 18F-FMZ PET/CT demonstrates clearer and more accurate identification of lesion borders, and exhibits higher precision, which provides valuable guidance for preoperative localization.

Objective:A voxel-level quantification method based on the tau IQ algorithm and Braak staging, excluding β-amyloid (Aβ) imaging, was developed to achieve specific tau quantification. Methods:This cross-sectional study included 92 subjects (35 males, 57 females; age (62.9±10.4) years) from the Nuclear Medicine/PET Center of Huashan Hospital, Fudan University between November 2018 and July 2020. The cohort comprised 28 cognitively normal (CN) individuals, 20 patients with mild cognitive impairment (MCI), and 44 patients with Alzheimer′s disease (AD). All participants underwent 18F-florzolotau PET imaging, Mini-Mental State Examination (MMSE), and Clinical Dementia Rating (CDR) scoring. A longitudinal tau dataset was constructed based on Braak staging. Voxel-level logistic regression fitting provided a baseline matrix, decomposed via least squares to yield the Tau load coefficient. One-way analysis of variance (with post hoc Tukey) was used to compare Tau load and SUV ratio (SUVR) among groups. ROC curve analysis was used to evaluate classification between CN, MCI and AD. Spearman rank correlation was used to assess the relationships between Tau load, SUVR, and MMSE scores or CDR scores. Results:The Tau load in the CN group was close to 0 and significantly lower than that in the MCI and AD groups ( F=55.03, P<0.001; post hoc tests all P<0.001). Significant differences were also observed in the SUVR across all ROIs ( F values: 36.46-55.38, all P<0.001). Compared to SUVR, Tau load demonstrated greater intergroup differences. In ROC curve analyses between each pair of CN, MCI, and AD groups, Tau load consistently achieved the highest AUC (0.754-1.000). Both Tau load and SUVR for each ROI were negatively correlated with MMSE scores ( rs values: from -0.698 to -0.583, all P<0.05) and positively correlated with CDR scores ( rs values: 0.648-0.783, all P<0.05), with Tau load showing the highest absolute correlation coefficients. Conclusion:Compared to the traditional semi-quantitative SUVR method, the Braak-tau IQ algorithm does not require a specific reference brain region to achieve specific tau quantification.

Atherosclerosis(As)is a chronic inflammatory disease caused by lipid deposition.Panvascular disea-ses,which are mainly caused by As,have gradually attracted the attention of many scholars,and their main pathological features are vascular lesions.Vitamin D plays an important role in anti-As in panvascular diseases.It is involved in the regulation of renin-angiotensin system(RAS),endothelial cell injury,immune response,neutrophil extracellular traps(NET)regulation,apoptosis and autophagy,and is a new target in panvascular diseases research.Traditional Chinese Medicine(TCM)has certain advantages in the prevention and treatment of panvascular diseases.Among them,single herbs,active ingredients and compound prescriptions can regulate vitamin D-related metabolism,and have unique scientific value for the prevention and treatment of As.This article mainly discusses the role of vitamin D in multiple pathological links of panvascular diseases and related Chinese medicine interventions,aiming to provide effective ideas for the prevention and treatment of panvascular diseases from the perspective of vitamin D.

Purpose To investigate the characteristics of 18F-Florbetaben(18F-FBB)β-amyloid(Aβ)PET imaging in different brain regions of Alzheimer's disease(AD)patients with different degrees of cognitive impairment,and to explore the correlation between Aβ deposition and cognitive dysfunction.Materials and Methods A total of eighteen patients with a clinical diagnosis of probable AD from August 2022 to October 2023 were retrospectively included in Huashan Hospital.All patients had Aβ abnormal deposition in the brain as confirmed by 18F-FBB PET imaging.According to the severity of symptoms,they were divided into the AD-induced mild cognitive impairment(MCI)group(8 cases)and the dementia group(10 cases).In addition,12 healthy controls were included.First,the standardized uptake value ratio of abnormal Aβ deposition in the frontal lobe,lateral parietal lobe,lateral temporal lobe,anterior and posterior cingulate gyrus,and compound cortex was semi-quantitatively calculated and compared among the three groups based on the subjects'brain MRI and automated anatomical labeling template.The correlation between the degree of Aβ deposition in the brains of AD patients and cognitive scale scores(mini-mental state examination,Montreal cognitive assessment)was then further analyzed.Results The standardized uptake value ratio values of Aβabnormal deposition in the frontal lobe,lateral temporal lobe,lateral parietal lobe,anterior and posterior cingulate cortex and compound cortex in the AD-induced MCI and dementia groups were significantly higher than those in the healthy controls(t=7.442-9.151,all P＜0.05).However,there was no significant difference in the standardized uptake value ratio values of Aβ abnormal deposition in the above brain regions between the MCI and dementia groups(t=0.312-0.996,all P＞0.05).In addition,there was no significant correlation between the degree of Aβ deposition in the brain and the cognitive scale scores(mini-mental state examination,Montreal cognitive assessment)in the AD-induced MCI and dementia groups(r=-0.049-0.050,all P＞0.05).Conclusion Aβ deposition in the brains of AD-induced MCI and dementia is significantly higher than in the healthy controls.However,Aβ deposition cannot identify AD patients with different degrees of cognitive impairment,reflecting that Aβ deposition has certain limitations in assessing the severity of clinical symptoms of AD.