Objective:To analyze the clinical value of translocator protein (TSPO, 18kDa) radiotracer 18F- N, N-diethyl-2-(2-(4-(2-fluoroethoxy)-phenyl)-5, 7-dimethyl-pyrazolo[1, 5-a]pyrimidin-3-yl)-acetamide (DPA-714) PET/MR imaging for precise localization of epileptogenic zone in patients with drug-resistant epilepsy. Methods:From December 2022 to October 2023, 24 refractory epilepsy patients (12 males and 12 females, age (27.5±8.1) years) who underwent surgery in Xuanwu Hospital, Capital Medical University were retrospectively enrolled. All patients received hybrid 18F-DPA-714 PET/MR before surgery, with the surgical resection site and stereoelectroencephalography recordings of the seizure focus serving as the gold standard. Initial qualitative analysis of the images was performed, followed by semi-quantitative analysis using the ROI method to calculate the asymmetry index (AI) of the proposed epileptogenic zone, assessing the degree of increased abnormal uptake (area with AI>10% was considered as the epileptogenic zone). Follow-up assessment using the Engel classification was conducted at least one year postoperatively. Differences of lesion detection efficiency of conventional MRI and PET/MR were evaluated using McNemar test. Results:Among 24 enrolled patients, 13 cases (54.2%) showed positive findings on conventional MRI, while 21 cases (87.5%) exhibited single or multiple foci of abnormally increased tracer uptake on PET/MR imaging, indicating an improved lesion detection rate ( χ2=4.90, P=0.021). Of the MRI-positive patients, 12/13 also had positive findings on PET/MR, with a localization accuracy of 10/13. Among the MRI-negative patients, 9/11 showed positive PET/MR findings, with a localization accuracy of 6/11. At one year post-surgery, 75.0%(18/24) of patients had a favorable outcome (Engel Ⅰ). Conclusion:18F-DPA-714 PET/MR imaging can accurately locate epileptogenic foci, especially for MRI-negative lesions, providing reliable information for surgical planning to improve postoperative outcomes.

Objective:To investigate alterations in static regional homogeneity(ReHo) and dynamic regional homogeneity (dReHo) and glucose metabolism in MRI-negative refractory temporal lobe epilepsy (TLE) patients using resting-state PET-MRI, and to evaluate their efficacy in predicting surgical outcomes.Methods:This study was a cross-sectional design. A retrospective analysis was conducted on the clinical and imaging data of 30 patients with MRI-negative refractory TLE (patient group) treated at Xuanwu Hospital, Capital Medical University, between 2016 and 2020, and data from 30 healthy controls (control group). All MRI-negative refractory TLE patients underwent surgical treatment and were further divided into a good prognosis subgroup (Engel Class I, 16 cases) and a poor prognosis subgroup (Engel Class Ⅱ-Ⅳ, 14 cases) based on postoperative Engel classification. Analysis of variance was used to compare differences in static ReHo, dReHo, and glucose metabolism(SUVR) among the three groups. The correlation of static ReHo, dReHo, and SUVR values of differential brain regions with Engel grading was analyzed using Spearman. A support vector machine (SVM) model was constructed using the static ReHo, dReHo, and SUVR values from these differential regions to classify and predict patient prognosis. The predictive performance was evaluated using receiver operating characteristic curves and the area under the curve (AUC).Results:Differential dReHo regions among the good prognosis subgroup, poor prognosis subgroup, and control group were located in the right lateral middle temporal gyrus temporal pole, the right fusiform gyrus, the right insula subfrontal gyrus, the left cuneate lobe, the right medial and paracortical cingulate gyrus, and the right supraparietal gyrus; the differential static ReHo regions were primarily found in the bilateral inferior temporal gyrus, the supraparietal gyrus, and the right subfrontal gyrus, the left medial supraparietal gyrus, the left median frontal gyrus, and the right marginal supraparietal gyrus; SUVR differences were in the affected superior, middle and inferior temporal lobes, the internal olfactory cortex and the temporal pole region. dReHo of right middle temporal gyrus temporal pole in patients with MRI-negative TLE showed a positive correlation with Engel classification ( r=0.421, P=0.020). The SVM model based on dReHo combined with SUVR values classified patients with good and poor prognosis with an AUC of 0.825 and an accuracy of 73.3%. Conclusions:In MRI-negative refractory TLE patients, abnormal dReHo regions are predominantly located in the contralateral default mode network areas and are associated with Engel classification. Combined with glucose metabolism values, dReHo can predict postoperative outcomes in MRI-negative TLE 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 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 analyze the clinical value of translocator protein (TSPO, 18kDa) radiotracer 18F- N, N-diethyl-2-(2-(4-(2-fluoroethoxy)-phenyl)-5, 7-dimethyl-pyrazolo[1, 5-a]pyrimidin-3-yl)-acetamide (DPA-714) PET/MR imaging for precise localization of epileptogenic zone in patients with drug-resistant epilepsy. Methods:From December 2022 to October 2023, 24 refractory epilepsy patients (12 males and 12 females, age (27.5±8.1) years) who underwent surgery in Xuanwu Hospital, Capital Medical University were retrospectively enrolled. All patients received hybrid 18F-DPA-714 PET/MR before surgery, with the surgical resection site and stereoelectroencephalography recordings of the seizure focus serving as the gold standard. Initial qualitative analysis of the images was performed, followed by semi-quantitative analysis using the ROI method to calculate the asymmetry index (AI) of the proposed epileptogenic zone, assessing the degree of increased abnormal uptake (area with AI>10% was considered as the epileptogenic zone). Follow-up assessment using the Engel classification was conducted at least one year postoperatively. Differences of lesion detection efficiency of conventional MRI and PET/MR were evaluated using McNemar test. Results:Among 24 enrolled patients, 13 cases (54.2%) showed positive findings on conventional MRI, while 21 cases (87.5%) exhibited single or multiple foci of abnormally increased tracer uptake on PET/MR imaging, indicating an improved lesion detection rate ( χ2=4.90, P=0.021). Of the MRI-positive patients, 12/13 also had positive findings on PET/MR, with a localization accuracy of 10/13. Among the MRI-negative patients, 9/11 showed positive PET/MR findings, with a localization accuracy of 6/11. At one year post-surgery, 75.0%(18/24) of patients had a favorable outcome (Engel Ⅰ). Conclusion:18F-DPA-714 PET/MR imaging can accurately locate epileptogenic foci, especially for MRI-negative lesions, providing reliable information for surgical planning to improve postoperative outcomes.

Objective:To investigate alterations in static regional homogeneity(ReHo) and dynamic regional homogeneity (dReHo) and glucose metabolism in MRI-negative refractory temporal lobe epilepsy (TLE) patients using resting-state PET-MRI, and to evaluate their efficacy in predicting surgical outcomes.Methods:This study was a cross-sectional design. A retrospective analysis was conducted on the clinical and imaging data of 30 patients with MRI-negative refractory TLE (patient group) treated at Xuanwu Hospital, Capital Medical University, between 2016 and 2020, and data from 30 healthy controls (control group). All MRI-negative refractory TLE patients underwent surgical treatment and were further divided into a good prognosis subgroup (Engel Class I, 16 cases) and a poor prognosis subgroup (Engel Class Ⅱ-Ⅳ, 14 cases) based on postoperative Engel classification. Analysis of variance was used to compare differences in static ReHo, dReHo, and glucose metabolism(SUVR) among the three groups. The correlation of static ReHo, dReHo, and SUVR values of differential brain regions with Engel grading was analyzed using Spearman. A support vector machine (SVM) model was constructed using the static ReHo, dReHo, and SUVR values from these differential regions to classify and predict patient prognosis. The predictive performance was evaluated using receiver operating characteristic curves and the area under the curve (AUC).Results:Differential dReHo regions among the good prognosis subgroup, poor prognosis subgroup, and control group were located in the right lateral middle temporal gyrus temporal pole, the right fusiform gyrus, the right insula subfrontal gyrus, the left cuneate lobe, the right medial and paracortical cingulate gyrus, and the right supraparietal gyrus; the differential static ReHo regions were primarily found in the bilateral inferior temporal gyrus, the supraparietal gyrus, and the right subfrontal gyrus, the left medial supraparietal gyrus, the left median frontal gyrus, and the right marginal supraparietal gyrus; SUVR differences were in the affected superior, middle and inferior temporal lobes, the internal olfactory cortex and the temporal pole region. dReHo of right middle temporal gyrus temporal pole in patients with MRI-negative TLE showed a positive correlation with Engel classification ( r=0.421, P=0.020). The SVM model based on dReHo combined with SUVR values classified patients with good and poor prognosis with an AUC of 0.825 and an accuracy of 73.3%. Conclusions:In MRI-negative refractory TLE patients, abnormal dReHo regions are predominantly located in the contralateral default mode network areas and are associated with Engel classification. Combined with glucose metabolism values, dReHo can predict postoperative outcomes in MRI-negative TLE patients.

Objective:To evaluate the value of time-of-flight (TOF) combined with point spread function (PSF) reconstruction for the improvement of brain PET images and lesion localization in patients with temporal lobe epilepsy (TLE).Methods:A retrospective collection of brain 18F-FDG PET imaging data of 52 hospitalized patients with TLE (30 males, 22 females, age: (26.7±7.1) years) and 26 healthy volunteers (14 males, 12 females, age: ( 31.7±6.8) years) from Xuanwu Hospital between 2017 and 2019 was conducted. Images were reconstructed and divided into 4 groups based on different algorithms: ordered subset expectation maximization (OSEM), OSEM+ TOF, OSEM+ PSF, and OSEM+ TOF+ PSF. The image quality, clarity, noise, and the clarity of lesion display of all subjects were visually analyzed using a four-point scale. The signal-to-noise ratio (SNR), contrast, and asymmetry index (AI) of the lesions were calculated. Differences in visual scores, SNR, contrast, and AI among the 4 groups were analyzed using one-way analysis of variance. The ROC curve was used to analyze the efficiency of PET images in localization of epileptogenic foci. Results:The visual score of OSEM+ TOF+ PSF group was the highest (4.0±0.0) among healthy volunteers; compared with OSEM group, OSEM+ TOF+ PSF group showed lower SNR (decreased by 46.6%; the lower the SNR value, the better the image quality) and contrast (increased by 29.8%). Visual assessment of PET images of patients with TLE showed that the scores of OSEM+ TOF+ PSF group , OSEM+ PSF group , OSEM+ TOF group and OSEM group were decreased in order (4.0±0.0 vs 3.4±0.5 vs 2.3±0.4 vs 1.0±0.0; F=884.0, P<0.001); SNRs of those 4 groups were increased in order ((5.2±2.4)% vs (6.2±2.4)% vs (7.9±2.6)% vs (8.9±3.5)%; F=18.82, P<0.001). The contrast and AI of the lesions in 4 groups were as follows: OSEM+ TOF+ PSF (contrast: 0.81±0.03; AI: 0.28±0.05) > OSEM+ TOF (0.74±0.05; 0.23±0.06) > OSEM+ PSF (0.72±0.06; 0.22±0.07) > OSEM (0.64±0.05; 0.19±0.06) ( F values: 107.10, 19.94, both P<0.001). MRI found unilateral hippocampal sclerosis in 32 patients, and the rest 20 patients with TLE were MRI-negative. ROC curve analysis showed that visual analysis and SUV ratio (SUVR) of lesion/contralateral ROI based on OSEM+ TOF+ PSF PET image could localize epileptogenic foci efficiently, with AUC of 0.874 in MRI-positive patients, and AUC of 0.932 in MRI-negative patients. Conclusions:The application of TOF and PSF significantly improves the quality of PET images. The combined use of both techniques yields the best results and aids in the localization of epileptogenic foci in patients with TLE.

Objective To investigate the value of deep learning(DL)model based on integrated 18F-FDG PET/MRI for evaluating cerebral metabolic status around cerebral infarction.Methods A total of 46 patients with cerebral infarction caused by unilateral internal carotid artery(ICA)or middle cerebral artery(MCA)steno-occlusion were retrospectively collected.Based on integrated 18F-FDG PET/MRI,DL model was used to automatically segment cerebral infarction area.Asymmetry index(AI)was used to evaluate the volume of reduced metabolic areas in the segmented affected frontal lobe,temporal lobe,parietal lobe,occipital lobe and cerebral hemisphere of cerebral infarction area as well as their proportions,while their correlations with National Institutes of Health stroke scale(NIHSS)score of neurological function were analyzed.Results Among 46 patients,the volume of decreased metabolism in the affected temporal lobe,parietal lobe and cerebral hemisphere was(41.35±10.52)ml,(65.58±14.82)ml and(178.89±34.23)ml,respectively,all positively correlated with NIHSS scores(rs=0.359,0.343,0.362,all P＜0.05).The proportion of the reduced metabolic volume in the affected frontal lobe,temporal lobe,parietal lobe and cerebral hemisphere was(45.68±10.35)%,(42.32±10.19)%,(45.05±9.44)%and(44.11±8.63)%,respectively,all positively correlated with NIHSS scores(rs=0.344,0.340,0.439,0.393,all P＜0.05).Conclusion DL model based on integrated 18F-FDG PET/MRI was of important clinical value for evaluating cerebral metabolic state around cerebral infarction.

One patient with gallbladder mass had transient jaundice and was diagnosed with gallbladder carcinoma by abdominal ultrasonography， contrast-enhanced CT， MRCP， and PET-CT. Surgical exploration showed enlarged gallbladder and a mass in the neck of the gallbladder pressing against the hilum of the liver， with no manifestation of tumor invasion， and there were no signs of liver metastasis. Only cholecystectomy was performed for the patient. The pathological diagnosis was tubular adenoma of the gallbladder without carcinogenesis. This case is characterized by a large gallbladder tumor， without marginal infiltration on imaging or malignant transformation based on pathology.

Objective:To evaluate the value of integrated PET/MR in assessing myocardial viability in ischemic heart disease.Methods:A total of 39 patients (28 males, 11 females; age (60.1±12.0) years) diagnosed with ischemic heart disease in Xuanwu Hospital, Capital Medical University were retrospectively enrolled from September 2020 to December 2021. All patients underwent cardiac 13N-NH 3·H 2O and 18F-FDG PET/MR examinations. Late gadolinium enhancement (LGE) sequence was included in MRI scan. PET and MRI images were analyzed and myocardial viability of each myocardial segment was evaluated according to the American Heart Association (AHA) 17 segment method. The extent of left ventricular infarcted myocardium was measured based on PET and MRI images. Weighted Kappa test was used to evaluate the agreement of PET and MRI in assessing myocardial viability. The extent of infarcted myocardium measured by PET and MRI was compared by paired- t test, and Pearson correlation analysis was used to assess the correlation between them. Results:There was a moderate agreement between PET and MRI in assessing myocardial viability ( Kappa=0.532, P<0.001), with the agreement rate of 69.83%(463/663). There was no significant difference but strong correlation between the extents of infarcted myocardium measured by PET and MRI ((23.89±14.23)% vs (23.55±11.90)%; t=-0.24, P=0.809; r=0.79, P<0.001). In segments with normal perfusion and metabolism on PET, 22.52% (100/444) showed abnormal enhancement on MRI. On the other hand, 39.89% (73/183) of the segments classified as non-viable on MRI showed normal or viable on PET. Conclusion:Integrated PET/MR is able to take full advantage of the complementary nature of PET and MRI, achieving the comprehensive and accurate evaluation of myocardial viability.