Objective To evaluate the feasibility of the posterior C2 pedicle screw placement (C2 PSP) by MPR techniques of helical CT.Methods Totally 250 patients (500 sides) who underwent head and neck CTA examination were enrolled.The bony parameters and the arterial parameters were measured after MPR.The bony parameters included pedicle diameter (D),isthmus height (T),internal height (H),and the arterial parameters included medial shifting:lateral (L),neutral (N),medial (M);and the degree of riding included below (b),within (w),above (a).The prevalence of narrow pedicles,high-riding vertebral arteries (HRVA) and the subtypes of IAVA in the general population were calculated,and the statistical analysis between narrow pedicles,HRVA,IAVA and C2 vertebral arteries groove (C2 VAG) injury were performed.Results The rate of narrow pedicles and HRVA were 14.40％ (72/500) and 24.60％ (123/500;x2=141.984,P＜0.001).When it came to the simulation of the C2 PSP inserting,the incidence of C2 VAG injuries was 19.40％ (97/500).In narrow pedicle and HRVA patients,the C2 VAG injuries incidence were higher than that of without narrow pedicle and HRVA patients (both P＜0.001).In 58 sides (58/500,11.60 ％),the narrow pedicles and HRVA occurred simultaneously.There were statistical significance differences of narrow pedicles and HRVA and the C2 VAG injuries in different types of IAVA (all P＜0.001),the subtypes of IAVA M-a consisted most common,which account for 55.56％ (40/72),46.34％ (57/123) and 48.45％ (47/97),respectively.Conclusion Most of the C2 VAG injuries happened in narrow pedicles,HRVA or IAVA M-a type patients.MPR can be used to comprehensively evaluate osseous and arterial parameters,which will provide anatomy foundation to the screw placement of C2 pedicles.

Objective: To investigate the impact of temperature changes between neighboring days (TCN) on the mortality risk of respiratory diseases, so as to provide the evidence for the study of deaths from respiratory diseases caused by climate change. Methods: The monitoring data of deaths from respiratory diseases in Zibo City from 2015 to 2019 were collected from Shandong Provincial Management Information System for Chronic Diseases and Cause of Death Surveillance. The meteorological and air pollutant data of the same period were collected from China Meteorological Data Website and ChinaHighAirPollutants dataset. The effect of TCN on the risk of deaths from respiratory diseases was examined using a generalized additive model combined with a distributed lag non-linear model, and subgroup analyses for gender and age were conducted. The disease burden attributed to TCN at different intervals was assessed by calculating attributable fraction. Results: Totally 11 767 deaths from respiratory diseases were reported in Zibo City from 2015 to 2019, including 6 648 males (56.50%) and 5 119 females (43.50%). There were 1 307 deaths aged <65 years (11.11%), and 10 460 deaths aged 65 years and older (88.89%). A monotonically increasing exposure-response relationship was observed between TCN and deaths from respiratory diseases in the general population, females, and the population aged 65 years and older. The 95th percentile of TCN (P95, 3.84 ℃) reached the peak at a cumulative lagged of day 11 (RR=2.063, 95%CI: 1.261-3.376). The results of subgroup analyses showed greater impacts on females and the population aged 65 years and older, with cumulative lagged effects peaking at day 12 (RR=3.119, 95%CI: 1.476-6.589) and day 11 (RR=2.107, 95%CI: 1.260-3.523). The results of attributional risk analysis showed that next-day warming might increase the attributable risk of deaths from respiratory diseases, and next-day cooling might decrease the attributable risk. Conclusion Next-day warming may increase the mortality risk of respiratory diseases, and has greater impacts on females and the population aged 65 years and older.

Purpose To investigate the effect of shortening the acquisition time of 18F-D6-AV133 PET/CT on image quality and diagnostic efficacy in Parkinson's disease.Materials and Methods A total of 51 participants(27 of Parkinson's disease,24 of healthy-controls)from the First Affiliated Hospital of Guangzhou Medical University from October 2021 to June 2022 were retrospectively selected.Images were obtained after the injection of the tracer 18F-D6-AV133(371.04±16.30)MBq for 60 min,with collection times of 10 min.Four sets of images were reconstructed using CT attenuation correction with acquisition times of 3,5,7 and 10 min.Semi-quantitative analysis was performed on the PET images,calculating the striatum-to-occipital lobe standardized uptake value ratio(SUVR).Two physicians independently conducted qualitative evaluations for each image group.The differences of SUVR and visual score results among four sets of images were performed.The optimal critical value of SUVR was obtained by analyzing the receiver operating characteristic curve of the subjects.Results The visual analysis of image quality had a strong consistency between the two doctors(ICC=0.853,P<0.001).The images with acquisition time of 5 min could reach the common quality level in clinical work,accounting for 78.4%(40/51).The semi-quantitative results of image quality showed that there was no significant difference between SUVR and diagnostic efficiency obtained by acquisition time 5 min and 10 min(Z=1.821,P=0.069),and the best critical value of the two groups was equal to 3.Therefore,properly shortening the acquisition time had no effect on the diagnosis of Parkinson's disease.Conclusion With the development and advancement of technical equipment,PET image quality is gradually improving and the scanning time is also gradually shortening.The acquisition time for 18F-D6-AV133 can be shortened from the conventional 10 min to 5 min.

Objective:To explore the effectiveness of 18F-deuterated-Florbetapir (D3FSP) PET/CT imaging in detecting β-amyloid (Aβ) deposition in the brain and its correlation with plasma biomarkers. Methods:A retrospective analysis was conducted on 79 patients (32 males, 47 females; age(66±7)years) who underwent 18F-D3FSP PET/CT imaging from June 2022 to November 2023 at the First Affiliated Hospital, Guangzhou Medical University, as a part of the Greater Bay Area Healthy Aging Brain Longitudinal Cohort Study (GHABS). Based on the Alzheimer′s Disease Neuroimaging Initiative cohort standard protocol, patients were categorized into cognitively unimpaired (CU) group, mild cognitive impairment (MCI) group, and Alzheimer′s disease (AD) group. Brain regions were segmented using the AW workstation and the SUV ratio (SUVR) was calculated with the cerebellum as the reference region. One-way analysis of variance, Bonferroni correction and Pearson correlation analysis were used to analyze data. The ROC curve analysis was used to analyze the cut-off value and the diagnostic efficacy of SUVR. Results:There were 48, 15 and 16 cases in CU, MCI and AD groups respectively. During the transition from CU to MCI and then to AD, there was a rising trend in SUVR ( F values: 11.15-22.38, all P<0.001) across the whole brain and various brain regions (bilateral frontal lobes, bilateral anterior cingulate gyrus, bilateral precuneus, bilateral parietal lobes, bilateral lateral temporal lobes, and bilateral occipital lobes). SUVRs of the right anterior cingulate gyrus and bilateral precuneus were different between the CU and MCI groups (all P<0.017), and those of bilateral frontal lobes, right precuneus, bilateral parietal lobes, bilateral lateral temporal lobes, and bilateral occipital lobes were different between the MCI and AD groups (all P<0.017). SUVRs of brain regions were negatively correlated with cognitive scale scores ( r values: from -0.57 to -0.37, all P<0.001), and were positively correlated with plasma phosphorylated tau181 (p-tau181, r values: 0.50-0.61, all P<0.001). The ROC curve analysis suggested that the cut-off value of SUVR in the precuneus for distinguishing CU from AD was 1.20, with the AUC, sensitivity, specificity and accuracy of 0.85, 12/16, 91.7%(44/48)and 87.5%(56/64), respectively. Conclusion:18F-D3FSP PET/CT imaging has good clinical application value in assessing the deposition sites and the extent of Aβ in the brain, which is related to clinical cognition and plasma p-tau181 level.