Objective:To explore the value of 18F-fibroblast activation protein inhibitor (FAPI) PET/CT in the assessment of early-stage graft fibrosis (S1-S2) after liver transplantation (LT). Methods:From November 2021 to April 2022, 17 adult liver transplant recipients (12 males and 5 females; age (52.6±7.9) years) in the Affiliated Hospital of Qingdao University were enrolled retrospectively in this study. All 17 patients received laboratory examinations, FibroScan, 18F-FAPI PET/CT and liver biopsy. According to the Scheuer scoring system, hepatic tissue was divided into no fibrosis (S0) and early fibrosis (S1-S2). Independent-sample t test was used to compare SUV max between two groups, and Mann-Whitney U test was used to compare liver stiffness measurement (LSM). ROC curve analysis was used to evaluate the diagnostic efficacy of LSM and SUV max in the early fibrosis of liver grafts. Delong test was used to compare the difference of AUCs. Results:Among 17 adult LT recipients, 11 were in stage S0, 5 were in stage S1, and 1 was in stage S2. There were significant differences in LSM and SUV max between no fibrosis group and early fibrosis group (LSM: 5.4(4.7, 6.6) vs 12.9(5.6, 19.9) kPa, z=-2.01, P=0.044; SUV max: 1.7±0.8 vs 3.9±1.6, t=-3.14, P=0.019). The threshold value of LSM in predicting early-stage graft fibrosis was 8.2 kPa and the AUC was 0.80 (95% CI: 0.54-0.95), which was 2.0 and 0.92 (95% CI: 0.78-1.00) for SUV max respectively. There was no significant difference in AUC between the two tools ( z=0.80, P=0.421). Conclusion:18F-FAPI PET/CT can precisely evaluate the early fibrosis of allografts, with the similar diagnostic efficacy with FibroScan (LSM), which is expected to be a new non-invasive diagnostic tool for predicting the early-stage of graft liver fibrosis.

Objective:To estimate the influence of metabolic parameters in 18F-FDG PET/CT and clinically relevant indicators on the prognosis of patients with cervical cancer. Methods:A total of 174 patients with cervical cancer (age (53.6±11.1) years) who underwent baseline 18F-FDG PET/CT examination in the Affiliated Hospital of Qingdao University from May 2011 to December 2020 were retrospectively collected. Metabolic parameters (metabolic tumor volume of primary lesion (MTV p), total lesion glycolysis of primary lesion (TLG p), MTV sum of total lesions (MTV total) in the whole body, TLG sum of total lesions (TLG total)) and clinical parameters (International Federation of Gynecology and Obstetrics (FIGO) stage, tumor maximum diameter ( Dmax), et al) were collected. Cox regression and Kaplan-Meier method were performed to evaluate the prognostic and predictive values of those parameters. Results:The follow-up time was 6-120 months, during which 52 patients (29.9%, 52/174) developed progression. The 5-year overall survival (OS), progression-free survival (PFS), local control (LC) and distant metastasis-free survival (DMFS) rates were 83.3%(145/174), 70.1%(122/174), 75.3%(131/174) and 82.8%(144/174), respectively. Cox regression showed that FIGO stage and MTV total were independent factors for predicting PFS, OS and LC (hazard ratio ( HR): 1.005-11.605, all P<0.05). FIGO stage and TLG total were independent factors for predicting DMFS ( HR: 1.002-12.258, all P<0.05). Conclusion:MTV total and FIGO stage are effective predictors of patients with cervical squamous cell carcinoma.

Obstructive sleep apnea (OSA) is a sleep disorder characterized by recurrent upper respiratory tract obstruction, sleep fragmentation, and hypoxia during sleep. This disease often leads to cognitive, emotional, and memory related neurological damage, and its mechanism is closely associated with the disruption of the blood-brain barrier (BBB). This article mainly discusses the relationship between BBB damage caused by OSA and vascular cognitive impairment (VCI), as well as the role of early prevention, intervention, and repairing BBB on reducing VCI.

Objective:To investigate the correlation between paroxysmal slow-wave events (PSWEs) and cerebral small vessel disease (CSVD) and CSVD-related cognitive impairment.Methods:Patients with CSVD visited Weihai Municipal Hospital from March 2021 to April 2022 were included, and sex- and age-matched healthy controls were recruited for cross-sectional analysis. The patients with CSVD were further divided into cognitive impairment group and non-cognitive impairment group. The self-developed Python script was used to detect the PSWE parameters in electroencephalogram records. Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE) were used to evaluate cognitive function. Multivariate logistic regression analysis was used to determine whether PWSE parameters were the independent related factors of CSVD and CSVD-related cognitive impairment. Multiple linear regression analysis was used to determine the correlation between the PSWE parameters and overall cognitive function (MoCA total score) in patients with CSVD. Results:A total of 76 patients with CSVD (including 41 patients with cognitive impairment and 35 patients without cognitive impairment) and 45 healthy controls were included. Compared with the healthy control group, PWSEs in the F3 (left frontal area) and O1 (left occipital area) regions of the CSVD group occurred more frequently and lasted longer (all P<0.05). Multivariate logistic regression analysis showed that the frequency (odds ratio [ OR] 1.080, 95% confidence interval [ CI] 1.023-1.140; P=0.005) and duration ( OR 1.006, 95% CI 1.001-1.011; P=0.023) of PWSEs in the left frontal area, as well as the frequency ( OR 1.052, 95% CI 1.010-1.095; P=0.014) and duration ( OR 1.003, 95% CI 1.000-1.006; P=0.028) of PWSEs in the left occipital region were the independent related factors for CSVD. The frequency ( OR 1.106, 95% CI 1.033-1.183; P=0.004) and duration ( OR1.010, 95% CI 1.003-1.017; P=0.004) of PWSEs in the left frontal area were the independent risk factors for cognitive impairment in patients with CSVD. Multiple linear regression analysis showed that the frequency ( β= –0.242, P=0.045) and duration ( β= –0.235, P=0.046) of PWSEs in the left frontal region were negatively correlated with the overall cognitive function score in patients with CSVD. Conclusions:The frequency and duration of PSWEs in some brain regions of patients with CSVD increase, and there is an independent correlation between PSWEs and cognitive impairment, suggesting that the damage of blood-brain barrier may participate in the pathogenesis of cognitive impairment in patients with CSVD.

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 value of 18F-FDG PET/CT imaging signs and metabolic parameters in predicting tumor spread through air spaces (STAS) of stage Ⅰ lung adenocarcinoma. Methods:From January 2019 to December 2021, clinical, imaging and metabolic parameters of 381 patients (126 males, 255 females, age (61.2±9.2) years) with stage Ⅰ lung adenocarcinoma were retrospectively analyzed in the Affiliated Hospital of Qingdao University. According to the postoperative pathological results, patients were divided into STAS positive group and STAS negative group. According to the operation time, patients were divided into training set ( n=254) and verification set ( n=127). χ2 test or Mann-Whitney U test was used to compare the differences of different parameters between patients with STAS positive and negative, and binary logistic regression analysis was used to select the predictors of STAS status. The prediction model was established, and ROC curve was used to evaluate the predictive efficacy. Results:There were 49(19.3%, 49/254) patients with STAS positive and 205(80.7%, 205/254) patients with STAS negative in the training set, while those were 35(27.6%, 35/127) and 92(72.4%, 92/127) in the verification set. In the training set, the differences of age ( z=-2.30, P=0.021), type of lesions ( χ2=6.81, P=0.009), spiculation ( χ2=12.64, P<0.001), bronchus truncation ( χ2=6.98, P=0.008), ground glass ribbon sign ( χ2=26.93, P<0.001) and SUV max ( z=-4.62, P<0.001) between the two groups were statistically significant. Multivariate logistic regression analysis showed that age (odds ratio ( OR)=1.048, 95% CI: 1.004-1.094, P=0.032), ground glass ribbon sign ( OR=3.857, 95% CI: 1.693-8.788, P=0.001) and SUV max ( OR=1.133, 95% CI: 1.001-1.282, P=0.049) were independent predictors of STAS status in stage Ⅰ lung adenocarcinoma patients. The logistic regression model was P=1/(1+ e - x), x=-5.292+ 0.480×age (year)+ 1.493×ground glass ribbon sign+ 0.170×SUV max. The AUCs of the model in the training set and verification set were 0.770 and 0.801, with the sensitivity of 81.6%(40/49) and 82.9%(29/35), and the specificity of 69.8%(143/205) and 65.2%(60/92), respectively. Conclusion:Age, ground glass ribbon sign and SUV max have good predictive effects on the occurrence of STAS in stage Ⅰ lung adenocarcinoma.

Objective:To establish an intelligent registration algorithm under the framework of original-mirror alignment algorithm to construct three-dimensional (3D) facial midsagittal plane automatically. Dynamic Graph Registration Network (DGRNet) was established to realize the intelligent registration, in order to provide a reference for clinical digital design and analysis.Methods:Two hundred clinical patients without significant facial deformities were collected from October 2020 to October 2022 at Peking University School and Hospital of Stomatology. The DGRNet consists of constructing the feature vectors of key points in point original and mirror point clouds (X, Y), obtaining the correspondence of key points, and calculating the rotation and translation by singular value decomposition. Original and mirror point clouds were registrated and united. The principal component analysis (PCA) algorithm was used to obtain the DGRNet alignment midsagittal plane. The model was evaluated based on the coefficient of determination (R 2) index for the translation and rotation matrix of test set. The angle error was evaluated on the 3D facial midsagittal plane constructed by the DGRNet alignment midsagittal plane and the iterative closet point (ICP) alignment midsagittal plane for 50 cases of clinical facial data. Results:The average angle error of the DGRNet alignment midsagittal plane and ICP alignment midsagittal plane was 1.05°±0.56°, and the minimum angle error was only 0.13°. The successful detection rate was 78% (39/50) within 1.50° and 90% (45/50) within 2.00°.Conclusions:This study proposes a new solution for the construction of 3D facial midsagittal plane based on the DGRNet alignment method with intelligent registration, which can improve the efficiency and effectiveness of treatment to some extent.

Objective:To investigate the effect of the possibility of sleep-disordered breathing (SDB) as assessed by the four-variable score on the platelet function and the risk of stroke recurrence in patients with acute ischemic stroke.Methods:Patients with acute ischemic stroke admitted to the Department of Neurology, Weihai Municipal Hospital from January 2020 to January 2021 were enrolled prospectively. Main inclusion criteria: admission within 24 h of onset; National Institutes of Health Stroke Scale score ≤3; Receiving aspirin + clopidogrel dual antiplatelet therapy. All patients were divided into a high possibility group and a low possibility group of SDB according to the four-variable score. 7±2 d after dual antiplatelet therapy, PL-12 multi-parameter platelet function analyzer was used to detect the maximum aggregation rate (MAR). The patients were followed up for 6 months after discharge and the recurrence of ischemic stroke was observed. The mediating effect model was established with the high possibility of SDB as the independent variable, MAR as the intermediary variable and stroke recurrence as the dependent variable. Firstly, MAR as the dependent variable and high probability of SDB as the independent variable were analyzed by linear regression; then, a binary logistic regression analysis was performed with ischemic stroke recurrence as the dependent variable and the high probability of SDB and MAR as independent variables. Results:A total of 213 patients were enrolled in the study. The average age of the patients was 62.70 ± 10.04 years old. There were 146 male (68.5%) and 121 patients (56.8%) were in the high possibility group (56.8%). During the follow-up period, 24 patients (11.3%) had stroke recurrence. Univariate analysis showed that arachidonic acid (AA) induced MAR (MAR-AA) and adenosine diphosphate (ADP) induced the MAR (MAR-ADP) in the high possibility group of SDB were significantly higher than those in the low possibility group (all P<0.05); MAR-AA and MAR-ADP in the recurrent group were significantly higher than those in the non-recurrent group (all P<0.05), and the proportion of high possibility of SDB in the recurrent group was significantly higher ( P=0.008). Binary logistic regression analysis showed that homocysteine (odds ratio 1.132, 95% confidence interval 1.048-1.223; P=0.002) and having high possibility of SDB (odds ratio 6.351, 95% confidence interval 1.134-35.566; P=0.035) were the independent risk factors for stroke recurrence in patients treated with dual antiplatelet therapy. Intermediary effect analysis showed that MAR had a significant intermediary effect on the risk of stroke recurrence in patients with high probability of SDB. Conclusion:The MAR and stroke recurrence rates in the high possibility group of SDB were significantly higher than those in the low possibility group, and its stroke risk was probably mediated by platelet hyperreactivity.

Objective:To investigate the value of 18F-FDG PET/CT metabolic parameters in predicting perineural invasion (PNI) in patients with non-metastatic rectal cancer. Methods:From August 2012 to April 2020, 81 patients (51 males, 30 females, median age: 63 years) who received PET/CT examination and pathologically confirmed as rectal cancer in the Affiliated Hospital of Qingdao University were retrospectively analyzed. The 18F-FDG PET/CT metabolic parameters including SUV max, metabolic tumor volume (MTV) and total lesion glycolysis (TLG), and clinicopathological factors including gender, age, carcinoembryonic antigen (CEA), carbohydrate antigen (CA)19-9, maximum tumor diameter, degree of differentiation, T stage, lymph node metastasis, and TNM stage were recorded. Mann-Whitney U test and χ2 test were used to compare the differences of each parameter between PNI positive group and PNI negative group. Multivariate logistic regression was used to analyze the independent predictor of positive PNI. ROC curve was used to analyze its predictive efficacy. Results:Of 81 patients, 32(39.51%) were PNI positive and 49(60.49%) were PNI negative. There were significant differences of T stage ( χ2=10.73, P=0.010), lymph node metastasis ( χ2=6.21, P=0.013), TNM stage ( χ2=7.61, P=0.022), MTV (14.6(10.4, 24.7)and 9.0(5.4, 14.5) cm 3; U=-3.48, P=0.001) and TLG (108.588(72.749, 182.707) and 65.365(35.593, 117.682) g; U=-2.79, P=0.005) between PNI positive group and PNI negative group. Multivariate logistic regression analysis showed that MTV was the independent predictor of positive PNI in non-metastatic rectal cancer patients (odds ratio ( OR)=1.130, 95% CI: 1.025-1.245, P=0.014). The optimal threshold of MTV was 9.53 cm 3 and AUC was 0.73 with the sensitivity of 81.82%(27/33) and the specificity of 59.18%(29/49). Conclusion:18F-FDG PET/CT metabolic parameter MTV can predict PNI in non-metastatic rectal cancer with high sensitivity.

Radiomics can quantitatively analyze and process large amounts of image features from medical image data to quantify tumor heterogeneity and non-invasively evaluate tumor biological behavior. Radiomics in nuclear medicine, especially in PET is developing rapidly. This article reviews the application of radiomics in the tumor identification and prognosis evaluation, and discusses the challenges and prospects for radiomics, in order to raise the awareness of radiomics in PET.