Purpose To explore the application value of combining 18F-FDG PET images with interpretable deep learning radiomics(IDLR)models in the differential diagnosis of primary Parkinson's disease(IPD)and atypical Parkinson's syndrome.Materials and Methods This cross-sectional study was conducted using the Parkinson's Disease PET Imaging Benchmark Database from Huashan Hospital,Fudan University from March 2015 to February 2023.A total of 330 Parkinson's disease patients underwent 18F-FDG PET imaging,both 18F-FDG PET imaging and clinical scale information were collected for all subjects.The study included two cohorts,a training group(n=270)and a testing group(n=60),with a total of 211 cases in the IPD group,59 cases in the progressive supranuclear palsy(PSP)group,and a group of 60 patients with multiple system atrophy(MSA).The clinical information between different groups were compared.An IDLR model was developed to extract feature indicators.Under the supervision of radiomics features,IDLR features were selected from the features collected by neural network extractors,and a binary support vector machine model was constructed for the selected features in images of in testing group.The constructed IDLR model,traditional radiomics model and standard uptake ratio model were separately used to calculate the performance metrics and area under curve values of deep learning models for pairwise classification between IPD/PSP/MSA groups.The study conducted independent classification and testing in two cohorts using 100 10-fold cross-validation tests.Brain-related regions of interest were displayed through feature mapping,using gradient weighted class activation maps to highlight and visualize the most relevant information in the brain.The output heatmaps of different disease groups were examined and compared with clinical diagnostic locations.Results The IDLR model showed promising results for differentiating between Parkinson's syndrome patients.It achieved the best classification performance and had the highest area under the curve values compared to other comparative models such as the standard uptake ratio model(Z=1.22-3.23,all P<0.05),and radiomics model(Z=1.31-2.96,all P<0.05).The area under the curve values for the IDLR model in differentiating MSA and IPD were 0.935 7,for MSA and PSP were 0.975 4,for IPD and PSP were 0.982 5 in the test set.The IDLR model also showed consistency between its filtered feature maps and the visualization of gradient-weighted class activation mapping slice thermal maps in the radiomics regions of interest.Conclusion The IDLR model has the potential for differential diagnosis between IPD and atypical Parkinson's syndrome in 18F-FDG PET images.

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 discuss the protective effect of polygonatum odoratum polysaccharide(POP)on the mice with cisplatin-induced acute kidney injury(AKI),and to clarify its possible mechanism.Methods:Forty male C57BL/6 mice were randomly divided into control group,model group,POP group,and ferroptosis inducer Erastin combined with POP(Erastin+POP)group,and there were 10 mice in each group.The mice in POP group and Erastin+POP group were given intragastric administration of POP(400 mg·kg-1),and on the 7th day,the mice in model group,POP group,and Erastin+POP group were intraperitoneally injected with cisplatin(20 mg·kg-1)to establish the AKI models,the mice in control group were injected with the same volume of normal saline,and the mice in Erastin+POP group were intraperitoneally injected with Erastin(40 mg·kg-1)one day in advance(on the 6th day of the experiment).After 9 d,the mice were killed and the serum and kidney tissue were collected,and the levels of serum creatinine(Scr)and blood urea nitrogen(BUN)and the levels of malondialdehyde(MDA)and glutathione(GSH)in kidney tissue of the mice in various groups were detected by kit;HE staining was used to observe the pathomorphology of kidney tissue of the mice in various groups;the expression levels of ferroptosis suppressor protein 1(FSP1),ferritin heavy chain 1(FTH1),and glutathione peroxidase 4(GPX4)proteins in kidney tissue of the mice in various groups were detected by immunohistochemistry;Western blotting method was used to detect the expression levels of nuclear factor-E2-related factor 2(Nrf2)and heme oxygenase-1(HO-1)proteins in kidney tissue of the mice in various groups.Results:Compared with control group,the levels of Scr and BUN of the mice in model group were significantly increased(P＜0.01),the level of MDA in kidney tissue was significantly increased(P＜0.01),and the level of GSH was significantly decreased(P＜0.01);most kidney tubules were dilated,the epithelial cells were swollen,the vacuolar degeneration and epithelial cells fell off,and the protein-like tubules could be seen in the lumen;the expression levels of FSP1,FTH1,GPX4,Nrf2,and HO-1 proteins in kidney tissue were decreased significantly(P＜0.05 or P＜0.01).Compared with model group,the levels of Scr and BUN of the mice in POP group were significantly decreased(P＜0.01),the level of MDA in kidney tissue was significantly decreased(P＜0.01),and the level of GSH was significantly increased(P＜0.01);the dilatation of kidney tubular lumen,epithelial cell swelling,vacuolar degeneration,and epithelial cell exfoliation were decreased;the expression levels of FSP1,FTH1,GPX4,Nrf2,and HO-1 proteins in kidney tissue of the mice in POP group were significantly increased(P＜0.05 or P＜0.01).Compared with POP group,the levels of Scr and BUN of the mice in Erastin+POP group were significantly increased(P＜0.01),the level of MDA in kidney tissue was increased(P＜0.05),and the level of GSH was significantly decreased(P＜0.01);the pathological injury of kidney tissue was aggravated obviously;the expression levels of FSP1,FTH1,GPX4,Nrf2,and HO-1 proteins in kidney tissue were significantly decreased(P＜0.05 or P＜0.01).Conclusion:POP can reduce the AKI in the mice induced by cisplatin,and its mechanism may be related to the inhibitory effect of POP on the ferroptosis induced by cisplatin.

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.