Objective:To investigate the effect of different acquisition duration of brain image of 18F-florbetaben(18F-FBB)positron emission tomography(PET)on standardized uptake value(SUV).Methods:Eight subjects who underwent 18F-FBB PET examination in Chinese PLA General Hospital from May 2021 to June 2021 were selected,including 5 persons of healthy control and 3 patients with mild cognitive impairment(MCI).All subjects underwent 18F-FBB PET imaging,and the dynamic PET images of them on brains were continuously acquired for 20 min between 90 and 110 min after the 18F-FBB injection was injected as(3.7-5.5 MBq/kg).Under the situation that other reconstruction parameters did not change,the images were reconstructed at 0-1,0-3,0-5,0-10,0-15 and 0-20 min,respectively.The same of region of interest(ROI)ranges were delineated in bilateral frontal cortex,bilateral temporal cortex,bilateral parietal cortex,posterior cingulate gyrus and cerebellar cortex of each group of images.And then,the corresponding mean standardized uptake value(SUVmean)of each region was obtained.The differences of SUVmean values of different ROI values between each group of data images and the images of 0-20 min were compared and analyzed.Results:There were significant differences in SUVmean between the acquired images in 0-1,0-3,0-5 and 0-10 min and the acquired standard images of 0-20 min(t=-7.569--2.410,P<0.05),respectively.There were no significant differences in SUVmean between the acquired images of 0-15 min and the acquired standard images of 0-20 min in the bilateral frontal lobe,bilateral temporal lobe,bilateral parietal cortex and posterior cingulate gyrus(P>0.05),only there was significant difference in the cerebellar cortex area between them(t=-5.597,P<0.001).Conclusion:The results of 15 min can reach to the similar results of 20 min in acquiring images,which can shorten the time of examination,and enhance the degrees of comfort and cooperation of patients in examination.It has clinical application value.

Objective To explore the value of 11C-methionine(MET)PET/CT radiomics model for evaluating isocitrate dehydrogenase1(IDH1)status of glioblastoma.Methods Data of 157 patients with glioblastoma who underwent 11C-MET PET/CT examination,including 68 cases of IDH1 mutation and 89 cases of IDH1 wild-type were retrospectively analyzed.The patients were divided into training set(n=125)and validation set(n=32)at the ratio of 8:2.Based on PET/CT images,lesions ROI were delineated and radiomics features were extracted and screened to establish radiomics models with logistic regression(LR),support vector machine(SVM)and decision trees(DT),respectively.Meanwhile,the nomogram based on patients'age and radiomics features was drawn.The efficacy of radiomics models and clinical-radiomics nomogram for evaluating IDH1 status were comparatively observed.Results The area under the curve(AUC)of DT radiomics model for evaluating IDH1 status of glioblastoma in training set was 0.910,higher than that of LR(0.697)and SVM(0.698)models(both P＜0.05).In validation set,the AUC of DT model for evaluating IDH1 status of glioblastoma was 0.805,which was higher than that of LR model(0.740)and clinical-radiomics nomogram(0.704)(both P＜0.05).Conclusion 11C-MET PET/CT radiomics model based on DT was helpful for evaluating IDH1 status of glioblastoma.

Objective:To evaluate the value of 18F-prostate specific membrane antigen (PSMA)-3Q PET/CT imaging in prostate cancer patients with serum prostate specific antigen (PSA) less than 1.00 μg/L after radical prostatectomy. Methods:From May 2021 to August 2022, 18F-PSMA-3Q PET/CT images and clinical data of 58 patients with prostate cancer (age 52-82 years) after radical prostatectomy with PSA less than 1.00 μg/L in Chinese PLA General Hospital were analyzed retrospectively. According to the level of PSA, patients were divided into three groups (0-0.19 μg/L group, 0.20-0.49 μg/L group, and 0.50-0.99 μg/L group). 18F-PSMA-3Q PET/CT images were analyzed according to the standardized evaluation criteria of molecular imaging, and lesions with the scores of molecular imaging PSMA (miPSMA)≥1 were defined as recurrent or metastatic lesions. The detection rates of 18F-PSMA-3Q PET/CT for patients in different PSA level groups were compared ( χ2 test). The PSA levels of patients with positive and negative scans were compared by using independent-sample t test. Results:Of the 58 patients, 36(62.1%, 36/58) patients and 85 lesions were found by 18F-PSMA-3Q PET/CT. There was 91.7%(33/36) with oligofocal lesions (1≤number of foci≤3) and 8.3%(3/36) with multiple lesions (number of foci>3). According to the location, 5.2%(3/58) of the recurrent lesions were found in the prostatic bed, 39.7%(23/58) in the bone lesions, 37.9%(22/58) in the pelvic lymph nodes, 12.0%(7/58) in the retroperitoneal lymph nodes and 5.2%(3/58) in the left clavicular lymph node metastases. There were 15 cases in 0-0.19 μg/L group, 22 cases in 0.20-0.49 μg/L group, and 21 cases in 0.50-0.99 μg/L group. The detection rates of 18F-PSMA-3Q PET/CT in the above groups were 5/15, 59.1%(13/22) and 85.7%(18/21), respectively ( χ2=10.33, P=0.006). There was significant difference in PSA level between patients with positive ( n=36) and negative ( n=22) 18F-PSMA-3Q PET/CT scans ((0.48±0.28) vs (0.28±0.25) μg/L; t=2.67, P=0.010). Conclusions:18F-PSMA-3Q PET/CT can be used to detect the recurrence or metastasis in prostate cancer patients with PSA level lower than 1.00 μg/L after radical prostatectomy. In this kind of patients, the common sites of lesions are bone, pelvic lymph nodes, retroperitoneal lymph nodes, left clavicular lymph nodes and prostatic bed, and oligofocal patients are more common.

Objective:To investigate the risk factors of recurrence after surgical resection of differentiated thyroid carcinoma combined with iodine-131 and TSH（Thyroid stimulating hormone） inhibition therapy. Methods:From January 2015 to April 2020, the clinical data of patients with structural recurrence and without recurrence were retrospectively collected after surgical treatment combined with iodine-131 and TSH inhibition therapy in the First Medical Center of PLA General Hospital. The general conditions of the two groups of patients were analyzed and the measurement data in line with the normal distribution was used for comparison between groups. For measurement data with non-normal distribution, the rank sum test was used for inter-group comparison. The Chi-square test was used for comparison between the counting data groups. Univariate and multivariate regression analyses were used to determine the risk factors associated with relapse. Results:The median follow-up period was 43 months（range 18-81 months） and 100 patients（10.5%） relapsed among the 955 patients. Univariate analysis showed that tumor size, tumor multiple, the number of lymph node metastases>5 in the central region of the neck, and the number of lymph node metastases>5 in the lateral region were significantly correlated with post-treatment recurrence（P<0.001, P=0.018, P<0.001, P<0.001）. Multivariate analysis showed that tumor size（adjusted odds ratio OR: 1.496, 95%CI: 1.226-1.826, P<0.001）, tumor frequency（adjusted odds ratio OR: 1.927, 95%CI: 1.003-3.701, P=0.049）, the number of lymph node metastases in the central neck region>5（adjusted odds ratio OR: 2.630, 95%CI: 1.509-4.584, P=0.001） and the number of lymph node metastases in the lateral neck region>5（adjusted odds ratio OR: 3.074, 95%CI: 1.649-5.730, P=0.001） was associated with tumor recurrence. Conclusion:The study showed that tumor size, tumor multiple, the number of lymph node metastases in the central region of the neck>5 and the number of lymph node metastases in the side of the neck >5 are independent risk factors for recurrence of differentiated thyroid cancer after surgical resection combined with iodine-131 and TSH inhibition therapy.
Humans ; Thyroid Cancer, Papillary/surgery* ; Lymphatic Metastasis/pathology* ; Retrospective Studies ; Neck Dissection ; Thyroidectomy/adverse effects* ; Neoplasm Recurrence, Local/pathology* ; Thyroid Neoplasms/surgery* ; Risk Factors ; Adenocarcinoma ; Thyrotropin ; Lymph Nodes/pathology*

Objective:To explore the application value of overall nursing intervention in PET/MR imaging in children with epilepsy.Methods:A total of 48 pediatric epilepsy patients who underwent PET/MR imaging in the Nuclear Medicine Department of the First Medical Center of the PLA General Hospital from July 2018 to October 2019 were enrolled. Among them, 24 patients with overall nursing intervention were used as the experimental group, and 24 patients were routine nursing intervention patients, who were served as the normal control group, and the examination time, Self-Rating Anxiety Scale (SAS) scores and patient satisfaction scores (filled in by the patient′s guardian) of the experimental group and the control group were collected and compared.Results:The inspection time of the experimental group was (15.1±0.5) min, significantly lower than (24.8±1.3) min of the control group ( tvalue was 32.940, P<0.01); the SAS score of the experimental group was (35.7±4.2) points, lower than(43.8±3.3) points of the control group ( tvalue was 7.357, P<0.01), and the patient satisfaction score was (92.8±5.5) points, higher than (69.8±11.1) points of the control group ( tvalue was 9.088, P<0.01 or 0.05). Conclusion:Overall nursing intervention in PET/MR imaging of pediatric patients with epilepsy can significantly cut down the examination time, reduce the anxiety of patients′ family members and improve the satisfaction of nursing care. It lays the foundation for clinicians to further accurately diagnose epilepsy foci and has important application value.

Objective:To compare the accuracy of visual qualitative assessment and semi-quantitative analysis for 18F-florbetaben ( 18F-FBB) β-amyloid (Aβ) imaging in the diagnosis of Alzheimer′s disease (AD) and to explore their clinical application value. Methods:From January 2019 to October 2019, 17 patients (8 males, 9 females, age (74.1±8.5) years) with mild/moderate-stage clinically probable AD and 17 cognitive normal control (NC; 9 males, 8 females, age (64.5±6.3) years) were prospectively enrolled in this study. All patients underwent dynamic 18F-FBB PET/CT brain imaging in the Chinese PLA General Hospital. Visual qualitative assessment and semi-quantitative analysis methods were used to analyze PET brain imaging results. The difference of standardized uptake value ratio (SUVR) between the two methods was analyzed by using independent sample t test. The consistency of the two methods and clinical results was analyzed by Kappa test. The cut-off value of SUVR for the diagnosis of AD was determined by receiver operating characteristic (ROC) curve. Results:The sensitivity, specificity and accuracy of visual qualitative assessment to diagnose AD were 14/17, 16/17 and 88.2% (30/34). The global SUVR of NC and AD group were 1.09±0.85 and 1.75±0.25 ( t=-10.263, P<0.001), and the composite SUVR were 1.16±0.57 and 1.89±0.15 ( t=-10.789, P<0.001), respectively. The cut-off value of SUVR for the diagnosis of AD was 1.47, with the sensitivity of 15/17, the specificity of 16/17 and the accuracy of 91.2%(31/34). The visual qualitative assessment and semi-quantitative analysis had good consistency with clinical diagnosis results with Kappa value of 0.765 and 0.824 respectively (both P<0.001). Conclusion:The visual qualitative assessment and semi-quantitative analysis methods used in 18F-FBB Aβ imaging to diagnose AD patients show high accuracy and can provide effective value for clinical diagnosis, but the visual qualitative assessment method is concise and easy to grasp, which is worth further promotion and use in clinical.

Fibroblast activation protein (FAP) is highly expressed in most epithelial tumors, and FAP inhibitors (FAPIs) have been used in tumor diagnosis and treatment. Taking FAP as the target, new kinds of tumor imaging and therapeutic radiopharmaceuticals can be developed. FAPIs have been used in the preclinical and clinical researches as the carrier of tumor imaging and treatment. This article reviews the research progress of FAPIs in nuclear medicine imaging and treatment.

Objective:To investigate the neuroimaging relationship between tau protein deposition and brain atrophy, and assess their relationships with cognitive decline in Alzheimer′s disease (AD) patients.Methods:From April 2017 to October 2019, 26 AD patients (12 males, 14 females, age (70.7±12.2) years) and 19 cognitively normal controls (CN; 9 males, 10 females, age (65.6±8.1) years) in Chinese PLA General Hospital were retrospectively enrolled. All subjects received (S)-6-[(3- 18F-fluoro-2-hydroxy)propoxy]-2-(4-methylaminophenyl)quinoline ( 18F-THK5317) PET/MR and the standardized uptake value ratio (SUVR) and gray matter volume (GMV) were measured. General linear model (GLM) was used to evaluate the differences of SUVR and GMV between two groups. Pearson correlation analysis was used to assess the relationships between SUVR and GMV, and relationships of SUVR and GMV with Mini-Mental State Examination (MMSE) scores in AD patients. Results:Compared with CN, the AD patients showed significantly increased 18F-THK5317 retention in lateral temporal, frontal, posterior cingulated/precuneus and occipital cortex with significant differences of SUVR between two groups (2.18±0.54 vs 1.78±0.09, 2.13±0.50 vs 1.82±0.06, 2.03±0.45 vs 1.69±0.08, 2.18±0.57 vs 1.76±0.10, t values: 2.58-6.57, all P<0.001). The AD patients also showed decreased GMV in medial temporal, posterior cingulated/precuneus and orbitofrontal cortex ( t values: 3.67-8.85, all P<0.001). In AD patients, SUVR was negatively associated with GMV in bilateral lateral temporal cortex, pre-frontal cortex and orbital frontal cortex ( r values: from -0.52 to -0.43, all P<0.05). Both SUVR ( r=-0.599, P=0.001) and GMV ( r=0.443, P=0.023) were significantly correlated with MMSE scores in AD patients. Conclusion:AD patients have neocortical 18F-THK5317 abnormal uptake and GMV reduction, which are significantly correlated with cognitive decline.

Objective:To assess the value of 18F-fluorodeoxyglucose (FDG) PET/MR parameters and their changes in predicting and evaluating the curative effect in patients with locally advanced rectal cancer before and after neoadjuvant chemoradiotherapy (NCRT). Methods:From June 2017 to June 2020, 13 patients (9 males, 4 females; age (52.2±13.2) years) with locally advanced rectal cancer confirmed pathologically and underwent NCRT in Chinese PLA General Hospital were retrospectively enrolled. All patients performed the first PET/MR within one month before NCRT and the second PET/MR within one month before operation. PET/MR parameters including maximum standardized uptake value (SUV max), mean standardized uptake value (SUV mean), metabolic tumor volume (MTV) 2.5, total lesion glycolysis (TLG), minimum apparent diffusion coefficient (ADC min), and their changing percentage (Δ) before and after NCRT were collected. Patients were divided into pathologically complete remission (pCR) group and non-pCR group or response group and non-response group according to the postoperative pathological results as the gold standard. Mann-Whitney U test and logistic regression analysis were used for data analysis. The cut-off values of related parameters and their diagnostic efficiencies were determined by receiver operating characteristic (ROC) curve analysis. Results:Of 13 patients, 5 reached pCR and 8 had histological reaction (response). There were no significant differences in parameters (SUV max, SUV mean, MTV 2.5, TLG, ADC min) between different groups before treatment ( U values: 8.00-19.00, all P>0.05). There were significant differences in SUV max, SUV mean, MTV 2.5, TLG and ΔADC min between pCR group and non-pCR group after treatment ( U values: 0.00-6.00, all P<0.05), but only SUV max was correlated with pCR after treatment (odds ratio ( OR)=0.335, 95% CI: 0.123-0.917, P=0.033). The area under curve (AUC) was 0.95 and the cut-off value of SUV max was 3.055, with the sensitivity of 100%, the specificity of 80.0% and the accuracy of 92.3%. There were significant differences in SUV max, SUV mean, TLG, ADC min, ΔSUV max and ΔADC min between the response group and non-response group after treatment ( U values: 0.00-6.00, all P<0.05), but only ΔSUV max was correlated with the response results ( OR=2.022, 95% CI: 1.100-4.130, P=0.048). The AUC was 0.90 and the cut-off value of ΔSUV max was 69.0%, with the sensitivity of 87.5%, the specificity of 80.0% and the accuracy of 84.6%. Conclusions:PET/MR has high accuracy in evaluating NCRT for locally advanced rectal cancer. SUV max is an independent predictor of pCR after treatment, while ΔSUV max is an independent predictor of histological reaction (response).

Objective:To investigate the value of multiple parameters and the combined model based on 18F-fluorodeoxyglucose (FDG) PET/MR in the differential diagnosis of benign and malignant pancreatic tumors. Methods:A total of 76 patients (50 males, 26 females, age (45.2±18.0) years) with clinically suspected pancreatic tumor who underwent PET/MR between December 2012 and September 2020 in First Medical Center of Chinese PLA General Hospital were retrospectively selected. All patients had definitive diagnoses. PET/MR sequences included T 1 weighted imaging (WI; convention and contrast enhancement), T 2WI, diffusion weighted imaging (DWI) and 18F-FDG PET sequences. Morphological characteristics and scores of lesions in MRI were evaluated. Parameters including parameters of PET and DWI, as well as parameters derived from histogram analysis of apparent diffusion coefficient (ADC) and standardized uptake value (SUV) (maximum (max), minimum (min), mean, median, standard deviation (SD), skewness, kurtosis, entropy) were measured. Independent-sample t test or Mann-Whitney U test were used for data analysis. PET/MR combined model was measured based on logistic regression analysis. Receiver operating characteristic (ROC) curve analysis was used to calculate the differential diagnosis efficacy of PET/MR multiparameters and combined model for benign and malignant lesions. Results:Among 76 patients, 55 were malignant and 21 were benign. (1) Visual evaluation. The main manifestations of pancreatic cancer were unclear margin, abnormal internal MR signal and enhancement, decreased ADC signal and increased radioactive uptake. The main manifestations of benign tumor lesions of pancreas were clear margin, even signal and enhancement, no reduction of ADC, decreased radioactive uptake. (2) Diagnostic efficacy. Multiparameter model established based on logistic regression analysis included SUV max, SUV SD, ADC entropy and ADC skewness. The efficiency of differential diagnosis for benign and malignant pancreatic tumors were shown as follows: multiparametric diagnostic model>ADC entropy>MR score>SUV max>SUV SD>ADC skewness. The multiparametric diagnostic model had the best diagnosis efficiency with the area under curve (AUC) of 0.86, the sensitivity of 69.1%(38/55), and the specificity of 100%(21/21) ( z=-8.73, P<0.001). Conclusions:MR score and multiple quantitative parameters obtained from 18F-FDG PET/MR can be used to differentiate benign and malignant pancreatic tumors. Compared with independent parameter of PET/MR, multiparametric model can further improve the diagnostic efficiency.