In 2025,the Response Assessment in Neuro-Oncology(RANO)working group and the European Association for Neuro-Oncology jointly released the updated guidelines for the clinical use of PET imaging in gliomas.Building upon the methodological framework established in the 2024 PET RANO 1.0 criteria,the new guidelines systematically integrate clinical evidence for amino acid PET and achieve alignment with MRI RANO 2.0 in imaging assessment logic,marking a paradigm shift of amino acid PET from a research tool to a clinical decision-making tool.This article provides a comprehensive analysis of key updates in the guidelines and evaluates the application value and recommendation levels of amino acid PET across critical clinical scenarios.Furthermore,it emphasizes the advantages of integrated PET/MR imaging in multimodal information integration for glioma management.

Objective To observe the correlation between brain abnormal glucose metabolism and striatal dopaminergic neuron damage in early-stage Parkinson disease(PD)patients.Methods Thirty-two early-stage PD patients(PD group)and 18 healthy individuals(control group)were prospectively enrolled,and 18F-FDG and 18F-9-fluoropropyl-(+)-dihydrotetrabenazine(18 F-FP-DTBZ)PET/MR brain imaging were performed.The degrees of uptake were compared between groups,and the correlation between brain abnormal glucose metabolism and striatal dopaminergic neuron damage was analyzed.Results Compared with control group,18F-FDG PET showed that in PD group glucose metabolism decreased in bilateral frontal and parietal lobes but increased in bilateral putamen,pons and bilateral cerebellum(all P＜0.05),while18 F-FP-DTBZ PET showed that in PD group glucose metabolism decreased in bilateral caudate nucleus,anterior putamen and posterior putamen(all P＜0.05).In PD group,the mean standard uptake value(SUVmean)of putamen was positively correlated with the standard uptake value ratio(SUVR)of contralateral caudate nucleus(r=0.305,P=0.014),while SUVmean of frontal cortex was positively correlated with SUVR of contralateral and symptomatic caudate nucleus(r=0.352,0.324,both P＜0.05)as well as anterior putamen(r=0.300,0.314,both P＜0.05),SUVmean of the partial cortex in parietal lobe was positively correlated with SUVR of contralateral and symptomatic caudate nucleus and contralateral anterior putamen(r=0.329,0.303,0.330,all P＜0.05).Conclusion Brain abnormal glucose metabolism had certain correlation with striatal dopaminergic neuron damage in early-stage PD patients.

Objective To observe the change patterns of functional connectivity(FC)of basal forebrain subregions in Alzheimer disease(AD)patients.Methods Totally 42 AD patients(AD group)and 41 healthy controls(HC group)were retrospectively enrolled.Seed-based FC analysis was performed on basal forebrain subregions(Ch123 and Ch4)based on their resting-state functional MRI data and compared between groups.Results Compared with HC group,FC between left Ch4 and left hippocampus as well as left posterior cingulate gyrus significantly decreased,but between right Ch4 and right precentral gyrus,as well as right postcentral gyrus increased in AD group(GRF correction,voxel level P＜0.001,cluster level P＜0.05).Meanwhile,FC between left Ch123 and left superior temporal gyrus,left insula,between right Ch123 and left superior temporal gyrus,left temporal pole significantly increased,while between right Ch123 and right orbital superior frontal gyrus,right orbital inferior frontal gyrus significantly decreased in AD group(GRF correction,voxel level P＜0.001,cluster level P＜0.05).Conclusion FC changes of different basal forebrain subregions in AD patients were various.

Objective To explore the value of 18F-flortaucipir tau PET combined with APOE ε4 genotype status for diagnosing mild cognitive impairment(MCI).Methods A total of 213 MCI patients(MCI group)and 402 healthy controls(HC group)were selected from Alzheimer's disease neuroimaging initiative(ADNI)database.The neuropsychological information,APOE ε4 gene carrier status,tau PET and high-resolution structural MRI data were recorded.The random forest algorithm was used to screen the most informative brain regions of tau PET for diagnosing MCI,and the efficacy of tau PET for distinguishing MCI with or without APOE ε4 gene and HC were compared.Results Amygdala,parahippocampal gyrus,entorhinal cortex,posterior cingulate gyrus,inferior temporal gyrus,fusiform gyrus and middle temporal gyrus in turn were the important brain regions of tau PET for diagnosing MCI.The accuracy and the area under the curve(AUC)of tau PET standardized uptake value ratio(SUVR)model for identifying MCI with APOE ε4 gene and HC was 86.68％and 0.784,respectively,both higher than those for identifying MCI and HC,as well as MCI without APOE e4 gene and HC(with accuracy of 70.57％and 75.05％,and AUC of 0.711 and 0.609).Conclusion 18F-flortaucipir tau PET SUVR model established based on amygdala,parahippocampal gyrus,entorhinal cortex,posterior cingulate gyrus,inferior temporal gyrus,fusiform gyrus and middle temporal gyrus could be used to diagnosing MCI.Combining with APOE ε4 gene could further improve its efficacy.

Objective To observe the functional connectivity and glucose metabolism of insular subregions in behavior variant of frontotemporal dementia(bvFTD)patients,also their correlations with cognitive function.Methods Thirty-eight bvFTD patients(bvFTD group)and 44 healthy individuals(control group)were retrospectively enrolled.The average time series signals of insular subregions were extracted as seed points based on functional MRI(fMRI)and 18F-FDG PET,then whole brain functional connectivity map was obtained.Meanwhile,the pons was selected as the reference brain region,and the standard uptake value ratio(SUVR)of insular subregions were calculated.The above parameters were compared between groups,and the correlations of SUVR of insular subregions with clinical cognitive function scale scores in bvFTD group were analyzed.Results Compared with control group,the functional connections between all insular subregions and bilateral frontal lobe,temporal lobe,anterior cingulate gyrus,anterior cingulate gyrus and middle cingulate gyrus,as well as between some subregions and bilateral parietal and occipital lobes were weakened in bvFTD group(GRF correction,voxel level all P＜0.001,cluster level all P＜0.05).SUVR of all insular subregions significantly decreased(GRF correction,voxel level all P＜0.001,cluster level all P＜0.05),which in right ventral agranular insula(vIa),dorsal agranular insula(dIa),dorsal dysgranular insula(dId)and left dorsal agranular insula(dIa)were negatively correlated with frontal behavioral inventory(FBI)score in bvFTD group(r=-0.452--0.330,all P＜0.05).Conclusion In bvFTD patients,the functional connectivity and glucose metabolism of insular subregions changed,and SUVR of right vIa,dIa,dId and left dIa were negatively correlated with FBI score.

Objective To observe the change patterns of functional connectivity(FC)of basal forebrain subregions in Alzheimer disease(AD)patients.Methods Totally 42 AD patients(AD group)and 41 healthy controls(HC group)were retrospectively enrolled.Seed-based FC analysis was performed on basal forebrain subregions(Ch123 and Ch4)based on their resting-state functional MRI data and compared between groups.Results Compared with HC group,FC between left Ch4 and left hippocampus as well as left posterior cingulate gyrus significantly decreased,but between right Ch4 and right precentral gyrus,as well as right postcentral gyrus increased in AD group(GRF correction,voxel level P＜0.001,cluster level P＜0.05).Meanwhile,FC between left Ch123 and left superior temporal gyrus,left insula,between right Ch123 and left superior temporal gyrus,left temporal pole significantly increased,while between right Ch123 and right orbital superior frontal gyrus,right orbital inferior frontal gyrus significantly decreased in AD group(GRF correction,voxel level P＜0.001,cluster level P＜0.05).Conclusion FC changes of different basal forebrain subregions in AD patients were various.

Objective To observe the correlation between brain abnormal glucose metabolism and striatal dopaminergic neuron damage in early-stage Parkinson disease(PD)patients.Methods Thirty-two early-stage PD patients(PD group)and 18 healthy individuals(control group)were prospectively enrolled,and 18F-FDG and 18F-9-fluoropropyl-(+)-dihydrotetrabenazine(18 F-FP-DTBZ)PET/MR brain imaging were performed.The degrees of uptake were compared between groups,and the correlation between brain abnormal glucose metabolism and striatal dopaminergic neuron damage was analyzed.Results Compared with control group,18F-FDG PET showed that in PD group glucose metabolism decreased in bilateral frontal and parietal lobes but increased in bilateral putamen,pons and bilateral cerebellum(all P＜0.05),while18 F-FP-DTBZ PET showed that in PD group glucose metabolism decreased in bilateral caudate nucleus,anterior putamen and posterior putamen(all P＜0.05).In PD group,the mean standard uptake value(SUVmean)of putamen was positively correlated with the standard uptake value ratio(SUVR)of contralateral caudate nucleus(r=0.305,P=0.014),while SUVmean of frontal cortex was positively correlated with SUVR of contralateral and symptomatic caudate nucleus(r=0.352,0.324,both P＜0.05)as well as anterior putamen(r=0.300,0.314,both P＜0.05),SUVmean of the partial cortex in parietal lobe was positively correlated with SUVR of contralateral and symptomatic caudate nucleus and contralateral anterior putamen(r=0.329,0.303,0.330,all P＜0.05).Conclusion Brain abnormal glucose metabolism had certain correlation with striatal dopaminergic neuron damage in early-stage PD patients.

In 2025,the Response Assessment in Neuro-Oncology(RANO)working group and the European Association for Neuro-Oncology jointly released the updated guidelines for the clinical use of PET imaging in gliomas.Building upon the methodological framework established in the 2024 PET RANO 1.0 criteria,the new guidelines systematically integrate clinical evidence for amino acid PET and achieve alignment with MRI RANO 2.0 in imaging assessment logic,marking a paradigm shift of amino acid PET from a research tool to a clinical decision-making tool.This article provides a comprehensive analysis of key updates in the guidelines and evaluates the application value and recommendation levels of amino acid PET across critical clinical scenarios.Furthermore,it emphasizes the advantages of integrated PET/MR imaging in multimodal information integration for glioma management.

Objective To explore the value of 18F-flortaucipir tau PET combined with APOE ε4 genotype status for diagnosing mild cognitive impairment(MCI).Methods A total of 213 MCI patients(MCI group)and 402 healthy controls(HC group)were selected from Alzheimer's disease neuroimaging initiative(ADNI)database.The neuropsychological information,APOE ε4 gene carrier status,tau PET and high-resolution structural MRI data were recorded.The random forest algorithm was used to screen the most informative brain regions of tau PET for diagnosing MCI,and the efficacy of tau PET for distinguishing MCI with or without APOE ε4 gene and HC were compared.Results Amygdala,parahippocampal gyrus,entorhinal cortex,posterior cingulate gyrus,inferior temporal gyrus,fusiform gyrus and middle temporal gyrus in turn were the important brain regions of tau PET for diagnosing MCI.The accuracy and the area under the curve(AUC)of tau PET standardized uptake value ratio(SUVR)model for identifying MCI with APOE ε4 gene and HC was 86.68％and 0.784,respectively,both higher than those for identifying MCI and HC,as well as MCI without APOE e4 gene and HC(with accuracy of 70.57％and 75.05％,and AUC of 0.711 and 0.609).Conclusion 18F-flortaucipir tau PET SUVR model established based on amygdala,parahippocampal gyrus,entorhinal cortex,posterior cingulate gyrus,inferior temporal gyrus,fusiform gyrus and middle temporal gyrus could be used to diagnosing MCI.Combining with APOE ε4 gene could further improve its efficacy.

Objective To observe the functional connectivity and glucose metabolism of insular subregions in behavior variant of frontotemporal dementia(bvFTD)patients,also their correlations with cognitive function.Methods Thirty-eight bvFTD patients(bvFTD group)and 44 healthy individuals(control group)were retrospectively enrolled.The average time series signals of insular subregions were extracted as seed points based on functional MRI(fMRI)and 18F-FDG PET,then whole brain functional connectivity map was obtained.Meanwhile,the pons was selected as the reference brain region,and the standard uptake value ratio(SUVR)of insular subregions were calculated.The above parameters were compared between groups,and the correlations of SUVR of insular subregions with clinical cognitive function scale scores in bvFTD group were analyzed.Results Compared with control group,the functional connections between all insular subregions and bilateral frontal lobe,temporal lobe,anterior cingulate gyrus,anterior cingulate gyrus and middle cingulate gyrus,as well as between some subregions and bilateral parietal and occipital lobes were weakened in bvFTD group(GRF correction,voxel level all P＜0.001,cluster level all P＜0.05).SUVR of all insular subregions significantly decreased(GRF correction,voxel level all P＜0.001,cluster level all P＜0.05),which in right ventral agranular insula(vIa),dorsal agranular insula(dIa),dorsal dysgranular insula(dId)and left dorsal agranular insula(dIa)were negatively correlated with frontal behavioral inventory(FBI)score in bvFTD group(r=-0.452--0.330,all P＜0.05).Conclusion In bvFTD patients,the functional connectivity and glucose metabolism of insular subregions changed,and SUVR of right vIa,dIa,dId and left dIa were negatively correlated with FBI score.