Objective To study the changes of hippocampal caspase-3 and PSD-95 expression levels in the mice exposed to ketamine 30 mg/(kg·d)for three months. Methods Forty C57BL/6 mice were randomly divided into two groups,and the chronic ketamine addiction model was established by giving mice a three month course of daily intraperitoneal injections of ketamine. Immunohistochemical study and Western blot-ting were applied to observe the expression of caspase-3 and PSD-95 protein. Results There were more expression of caspase-3 and less of PSD-95 in ketamine group as detected by immuohistochemistry. Western blotting results showed caspase-3 active fragment level significantly increased com-pared to saline group,but PSD-95 protein level was decreased. Conclusion The increased level of caspase-3 protein and reduced expression of PSD-95 are observed after long-term ketamine administration. These findings may provide an evidence for the neurotoxicity in mouse hippocampus of chronic ketamine addition as a recreational drug.

Objective To access the value of three dimensional gradient echo two-point Dixon water-fat separation sequence (3 D-DIXON) in quantitative diagnosis of non-alcoholic fatty liver disease(NAFLD) by comparing with in-phase/opposed-phase (IN/OPP)and proton magnetic resonance spectroscopy (1 H-MRS).Methods A total of 69 patients with NAFLD diagnosed by CT were divided into two groups by the ratio of liver spleen in CT (group A,low-grade fatty liver,n=32;group B,moderate and severe fatty liver,n=37).All patients underwent MR 3D-DIXION,1H MRS and IN/OPP examination twice within 1 week after CT examination.Fat fraction(FF) was evaluated and analyzed respectively.Results Pearson linear correlation analysis showed significant positive correlation between group A and group B about FF3D-DIXON,FFMRs and FFIN/OPP.Area under ROC curve (AUC) was different:AUCsYNTHESIZE＞AUCMRs＞AUCIN/OPP＞AUC3D-DIXON.Kruskal-Wallis H revealed significant difference among the three sequences no matter in group A or group B (P＜0.05).FF values of the three sequences (FF3D-DIXON,FFMRs and FFIN/OPP) were negatively correlated with CT liver/ spleen ratio in each group.The cut-off value of 3D-DIXON,IN/OPP and 1 H-MRS to diagnose presence or absence of fatty liver was 4.9 3 9 ％,5.2 8 4 ％ and 10.4 6 0 ％.Conclusion FF values measured by MRI methods might significantly vary based on different sequences.1 H-MRS is also the main method for quantitative assessment of fatty liver,3D-DIXON showed significant advantage in quantifying moderate and severe fatty liver.

Objective To evaluate the application value of percutaneous angle positioning system based on augmented reality in improving the accuracy of liver puncture.Methods A canine liver with an embedded marking ring was used as the target for puncture.A skilled physician with over 5 years of experience in liver puncture and a novice physician with limited experience in liver puncture separately performed liver puncture using either the augmented reality-based percutaneous angle localization system(navigation)or CT-guided technique alone(non-navigation).The corresponding puncturing data of non-navigation skilled group(Group A),non-navigation non-skilled group(Group B),navigation skilled group(Group C),and navigation non-skilled group(Group D)were obtained.The differences in the evaluation indicators,including the number of CT scans,number of needle adjustment,time spent for operation,and distance of error,between Group A and Group B,between Group C and Group D,between Group A and Group C,and between Group B and Group D,were analyzed.Results Statistically significant differences in the number of CT scans,number of needle adjustment,time spent for operation,and distance of error existed between Group A and Group B,between Group A and Group C,and between Group B and Group D(all P＜0.0 5),while the differences in the number of CT scans,number of needle adjustment,time spent for operation,and distance of error between Group C and Group D were not statistically significant(all P＞0.05)Conclusion In performing liver puncture,the use of percutaneous angle localization system can reduce the number of CT scans,number of needle adjustment,time spent for operation and distance of error,and improve the puncture accuracy as well,which provides a basis for the clinical utilization of this system and the employment of this system-guided puncture technology in primary hospitals.(J Intervent Radiol,2024,33:507-511)