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.

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.

Objective:To establish standard spatial brain template and ROIs template of 11C-methyl- N-2β-carbomethoxy-3β-(4-fluorophenyl)tropane (CFT) PET images for automated quantitative analysis of dopamine transporter (DAT) distribution. Methods:From May 2014 to December 2015, 11C-CFT PET and MRI T 1 brain images of 16 healthy volunteers (3 males, 13 females; age (63.3±6.9) years) from Huashan Hospital, Fudan University were co-registered and smoothed using statistical parametric mapping(SPM)5 software based on MATLAB to create a standard spatial brain template. The ROIs template was established by ScAnVp procedures. These templates were clinically verified by using 11C-CFT PET images of 37 healthy volunteers (23 males, 14 females; age (61.7±7.1) years), 32 Parkinson′s disease (PD) patients (20 males, 12 females; age (61.1±5.4) years), 10 multiple system atrophy with predominant parkinsonism (MSA-P) patients (7 males, 3 females; age (60.8±7.1) years) and 10 progressive supranuclear palsy (PSP) patients (5 males, 5 females; age (58.4±6.1) years) from Huashan Hospital, Fudan University between January 2014 and March 2019. One-way analysis of variance was used to analyze data. Results:Based on the 11C-CFT PET images and MRI T 1 images of healthy volunteers, a standard spatial brain template for normalization of 11C-CFT PET images was created. The ROIs template was established including seven regions: bilateral caudate, anterior putamen, posterior putamen (along the long axis) and the occipital cortex. The ROIs template was accurately aligned in each verification group. The normal reference values of semi-quantitative DAT distribution in caudate, anterior putamen and posterior putamen were obtained (1.84±0.13, 2.18±0.16, 1.77±0.11). The semi-quantitative values of 11C-CFT uptake in each ROI in patients were significantly lower than those in healthy volunteers ( F values: 49.79-283.83, all P<0.05). Conclusion:The established brain templates with accurate spatial alignment for 11C-CFT image analysis can provide foundational tools for the application of 11C-CFT PET imaging in clinical practice and scientific research.

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.

Objective:To investigate the clinical, neuropsychological, and neuroimage characteristics in patients with corticobasal syndrome (CBS), and to elucidate the exact diagnosis of CBS patients.Methods:Twelve CBS cases admitted to the Department of Neurology, Huashan Hosiptal,Fudan University from April 2019 to July 2021 were retrospectively enrolled in this study. Those data, including clinical features (demographic data and clinical characteristics of cortical dysfunction and movement disorder), neuropsychological assessment [Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) scales score], brain magnetic resonance imaging (MRI) and multi-mode positron emission tomography (PET)/CT, were collected and carefully reviewed. Exact diagnosis of these patients was given according to the disease diagnosis criteria.Results:Cortical dysfunction and asymmetrical movement disorders were found in all cases, with poor response to levodopa. Patients suffered from cognitive impairment (MMSE score 16.16±9.82, MoCA score 13.44±7.35). The cranial MRI demonstrated significant asymmetric atrophy of frontal and parietal lobes, especially in the pre- and post-central gyrus. Fluorodeoxyglucose PET of 12 patients showed asymmetric frontal lobe and basal ganglia (especially caudate and putamen) hypometabolism (obviously on the contralateral side of the affected limb). Tau PET was implemented in 11 patients and displayed that abnormal tau protein deposition was positive in the cortex and/or subcortex in all patients. Of the 4 cases, who completed amyloid PET, amyloid protein deposition was positive in the cortex of 2 patients. As a result, 6 patients were diagnosed as progressive supranuclear palsy, 1 patient was diagnosed as corticobasal degeneration, and 5 patients were diagnosed as Alzheimer′s disease.Conclusions:The etiology of CBS is heterogeneous. The combination of clinical manifestation, cranial MRI and multi-mode PET/CT helps the differential diagnosis of CBS.

Objective:To investigate characteristics and differences of cerebral glucose metabolism in patients with anti- N-methyl- D-aspartate receptor (NMDAR) encephalitis from the perspective of different trigger factors of antibodies. Methods:A total of 15 patients (8 males, 7 females, age (30.5±17.7) years) with anti-NMDAR encephalitis between January 2016 and January 2019 in Huashan Hospital, Fudan University were recruited retrospectively. All patients underwent resting state cerebral 18F-FDG PET imaging. The characteristics of brain glucose metabolism were analyzed, and the SUV ratio (SUVR) was semi-quantitatively compared with that in 12 healthy subjects (HS; 7 males, 5 females, age (51.5±9.6) years). Independent-sample t test was used to analyze the data. Results:Among 15 patients, 5 patients were viral encephalitis-related anti-NMDAR encephalitis, showing focal decreased metabolism in unilateral temporal lobe or basal ganglia (SUVR: patients: 0.659±0.219; HS: 1.754±0.203; t=-9.58, P<0.001), with increased metabolism in contralateral temporal lobe or basal ganglia (SUVR: patients: 2.275±0.244; HS: 1.960±0.227; t=2.55, P=0.022) in 18F-FDG PET imaging. Six patients were cryptogenic anti-NMDAR encephalitis, showing asymmetric increased metabolism in frontal, temporal, parietal and basal ganglia (SUVR: patients: 2.482±0.395; HS: 1.754±0.203; t=5.23, P<0.001), with decreased metabolism in bilateral occipital lobes. The remaining 4 cases were paraneoplastic origin accompanied by teratoma, showing increased metabolism in bilateral temporal and basal ganglia (SUVR: patient: 2.359±0.181; HS: 1.960±0.227; t=3.16, P=0.007), with mild decreased metabolism in bilateral occipital lobe. Conclusions:The abnormal changes of cerebral glucose metabolism in patients with anti-NMDAR encephalitis can be divided into at least three patterns according to different trigger factors. A comprehensive understanding of these characteristic metabolic changes is helpful for detecting disease, and may provide potential value in indicating different causes.

Multi-centre clinical trials on PET/CT brain imaging are complex to organize and require careful co-ordination and management. This article describes considerations, which are necessary when designing and starting a multi-centre clinical trial on PET/CT brain imaging, based on guidelines and multi-center clinical brain imaging studies, providing references for further studies.

Objective:To explore the potential application of combining 18F-FDG PET imaging and radiomics in the diagnosis of Parkinson′s disease (PD) and atypical parkinsonian syndromes (APS). Methods:A total of 154 subjects of two cohorts (training set and validation set) were enrolled from Huashan Hospital, Fudan University from March 2015 to August 2020 in this cross-sectional study, including 40 normal controls (NC; 23 males and 17 females, age: (60.2±10.5) years), 40 PD patients (20 males and 20 females, age: (64.7±6.3) years), 40 progressive supranuclear palsy (PSP) patients (20 males and 20 females, age: (64.1±5.9) years), and 34 multiple system atrophy (MSA) patients (19 males and 15 females, age: (65.0±9.2) years). 18F-FDG PET images and clinical scale were selected, and one-way analysis of variance was used to compare differences of clinical scale among groups. Radiomic features extraction and feature selection were carried out. Two and three classification models were constructed based on logistic regression, and the ROC curves of clinical model, radiomics model and combined model were calculated. Independent classification tests were conducted 100 times with 5-fold cross validation in two cohorts. Results:There were significant differences in the scores of unified PD Rating Scale (UPDRS) and Hoehn-Yahr rating scale (H&Y) among different groups in cohort 1 and cohort 2 respectively ( F values: 4.83-17.95, all P<0.05). A total of 2 444 imaging features were extracted from each subject, and after features selection, 15 features for classification were obtained. In the two classification experiment, the AUCs of the three models in binary classification of PD/MSA/PSP/NC group were 0.56-0.68, 0.74-0.93 and 0.72-0.93, respectively. The classification effects of the radiomics model were significantly better than those of the clinical model ( z values: 1.71-2.85, all P<0.05). In the three classification experiment, the sensitivity of the radiomics model reached 80%, 80% and 77% for PD, MSA and PSP, respectively. Conclusion:18F-FDG imaging combined with radiomics has potential in the diagnosis of PD and APS.

Objective:To investigate the efficacy and safety of the modified gasless unilateral axillary approach (MGUAA) endoscopic thyroid surgery in treatment of papillary thyroid microcarcinoma (PTMC) .Methods:From Jan. 2019 to Dec. 2019, 90 patients receiving PTMC (cT1N0M0, cI stage, 8th, 2017 AJCC) therapy by modified gasless unilateral axillary approach endoscopic thyroid surgery (MGUAA group, n=41) , and conventional open thyroid surgery (OS group, n=49) were retrospectively analyzed. Ninety patients were enrolled in the study, including 14 males and 76 females,with the mean age (42.1±12.0) years.The effectiveness of central lymph node dissection (CLND) , the operation time, the types of operation, the amount of drainage, the duration of hospital stay, the related complications, the postoperative pain of neck and axillary and the cosmetic satisfaction were compared between the two groups.SPSS 25.0 statistical software was used for statistical analysis, the measurement data was expressed by ±s, paired t test was used to compare the measurement data between groups, and Chi-square test was used to campare the count date between groups. Results:The mean age (35.0±8.6) years and the amount of surgical bleeding (12.3±7.3) ml in the MGUAA group were significantly lower than those (48.1±11.1) years and (16.1±4.3) ml in the OS group ( P<0.01) , while the mean operation time (99.1±19.5) min, the mean amount of drainage (221.4±67.9) ml and the postoperative drainage tube placement time (5.0±0.8) days were significantly higher than those of (70.6±17.8) min, (98.3±63.7) ml and (3.8±1.0) days in the MGUAA ( P<0.01) . There was no significant difference in the number of lymph nodes of CLND or the duration of hospital stay between the two groups ( P>0.05) . In terms of surgical complications, the transient recurrent laryngeal nerve injury, the postoperative hematoma, the postoperative infection, and the lymphatic leakage had no significant difference between the two groups ( P>0.05) . The MGUAA group had significant advantages in avoiding the postoperative dysphagia in front of neck, the postoperative pain of neck, and cosmetic satisfaction over the OS group [ (0.0% vs 28.6%) , (14.6% vs 71.4%) , (1.1±0.3) score vs (2.4±0.5) score ( P<0.01) ]. Whereas in axillary area pain on the surgical side, the MGUAA group was inferior to the OS group ( P<0.01) . Conclusion:The modified gasless unilateral axillary approach endoscopic thyroid surgery is a feasible, safe and cosmetically operation for PTMC (cT1N0M0, cI stage, 8th, 2017 AJCC) .

Objective:To summarize the clinical features and therapeutic outcomes of patients with hyperinsulinemic hypoglycemia (HH) auxiliarily diagnosed by 18F-DOPA positron emission tomography (PET) CT scanning. Methods:The clinical data of 123 patients who were diagnosed with hyperinsulinemic hypoglycemia by comprehensive clinical diagnostic procedures in the Department of Pediatric Endocrinology and Inherited Metabolic Diseases, Children′s Hospital of Fudan University between January 2016 and December 2020 were retrospectively analyzed. Clinical data such as gender, age of onset, province, concurrent serum insulin level measured during hypoglycemia, lesion type of pancreas by 18F-DOPA-PET CT scanning, genetic test results, and treatment were collected successively. The clinical features and therapeutic outcomes were compared between patients with focal and diffuse pancreatic lesions. T test, Rank sum test, and χ2 test were used for comparison between groups. Results:A total of 123 patients with hyperinsulinemic hypoglycemia (72 males and 51 females), whose average age of onset was 3 days (ranging from 1 day to 4 860 days), were recruited from 24 provinces. The concurrent serum insulin level was 7.1 (0.4-303.0) mU/L during hypoglycemia. 18F-DOPA-PET CT scanning identified focal lesions in 25.2% (31/123) and diffuse lesions in 74.8% (92/123) of the patients; 64.2% (79/123) of the HH cases were found to have pathogenic gene variants, in which 88.6% (70/79) were found to have K ATP channel related genes (61 in ABCC8 and 9 in KCNJ11 mutations). Thirty-seven patients (17 focal and 20 diffuse) received surgical treatment with a success rate of 67.6% (25/37). The effective rate of diazoxide for children with diffuse type was significantly higher than that of children with focal group (28.3% (26/92) vs. 9.7% (3/31), χ2=10.31, P=0.001). Conclusions:18F-DOPA-PET CT scan can improve the success rate of surgery. Comprehensive diagnosis of the etiology of hyperinsulinemic hypoglycemia by genetic analysis and 18F-DOPA-PET CT scanning can result in better treatment and prognosis.