Objective To get a MR imaging protocol for coronary arterial wall in vitro. Methods MR examinations were performed in 10 fresh porcine hearts. Three dimensional fast imaging employing steady state acquisition (3D FIESTA) was used to delineate left anterior descending artery (LAD), while 2D spin-echo T1W was performed with 8-channel head surface coil, temporomandibular surface coil and knee coil with the same parameters. T1WI was obtained with 384×256 and 512×512 in matrix using temporomandibular surface coil, and then T1WI, PDW and T2WI with fat saturation were obtained with different NEX using temporomandibular surface coil after injecting Resovist in LAD. Signal of the LAD wall, lumen, fat tissue adjacent to LAD, myocardium of anterior part of interventricular septum and noise were respectively measured. Signal-to-noise ratio (SNR) of image, contrast to noise ratio (CNR) between the wall and lumen (CNR1), CNR between the wall and surrounding fatty tissue (CNR2) were calculated. Results The SNR and CNR1, CNR2 of SE T1WI with temporomandibular coil were higher than those with 8-channel head surface coil and knee coil. SNR and CNR1, CNR2 of SE T1WI with 384×256 matrix were higher than those with 512×512 matrix. SNR and CNR1, CNR2 using 3 NEX were the highest. Conclusion Good SNR and CNR of porcine coronary wall can be achieved using temporomandibular surface coil, 384×256 in matrix and NEX of 3.

Objective:To investigate the effect of serum cystatin C level on the occurrence and its long-term prognosis of contrast agent-induced acute kidney injury(CI-AKI)after percutaneous coronary intervention(PCI)in elderly patients.Methods:A total of 848 elderly patients(≥60 years)undergoing PCI in our department between Mar 2015 and Dec 2017 were enrolled in a prospective cohort.The CI-AKI was defined as the increase of serum creatinine ≥44.2 μmol/L within 48-72 h after using iodine contrast agent or more than 25 % higher than base level within 48-72 h after PCI.A receiver operating characteristic curve was used to analyze the optimal cut-off value of Cystatin C for predicting CI-AKI after PCI.Patients were divided into 2 groups based on the optimal cut-off value of Cystatin C: the high Cystatin C group(Cystatin C ≥1.3 mg/L, n=178)and the control group(Cystatin C<1.3 mg/L, n=670). The differences in the incidence of CI-AKI after PCI and major adverse cardiac events(MACE)at 1 year follow-up were compared between the two groups.The Cox regression model was further used to analyze the predictors of the long-term prognosis after PCI.Results:Of 848 patients receiving PCI, the incidence of CI-AKI was 9.4%.The incidence of MACE at 1 year after PCI was higher in the high Cystatin C group than in the control group(15.7% vs.9.3%, χ2=6.524, P=0.011). Cox regression analysis confirmed that the high baseline level of Cystatin C was the most independent predictive factor for MACE at 1 year of follow-up( HR=16.244, P<0.001). Conclusions:The high baseline level of Cystatin C(≥1.3 mg/L)is an independent risk factor for CI-AKI and is also the most important predictor for the occurrence of long-term MACE in elderly patients undergoing PCI.

Objective To investigate the radiographic anatomical relationship between tibial plateau and distal femur and evaluate the impact of reset tibial plateau of various widths after reduction of the Schatzker Ⅳ-C tibial plateau fractures on postoperative outcomes.Methods We collected and reviewed the X-ray images of the normal knees of 207 standard neutrally-positioned adults(non-fracture group)and pre-and post-operative immediate anterior-posterior X-ray images of the knees of 60 patients with Schatzker Ⅳ-C fractures(fracture group)in our hospital from August 2012 to August 2022.We measured the proximal tibial joint width(TAW),distal femoral width(DFW),and distal femoral joint width(FAW)in both groups and calculated the TAW/DFW and TAW/FAW ratios.In the fracture group,the cases with TAW between FAW and DFW were assigned to the well-reduced group,while those with TAW outside this range between FAW and DFW to the poorly-reduced group.Both groups were assessed using the Hospital for Special Surgery knee score(HSS)one year after operation.Results In the non-fracture group,there were no significant differences in gender or affected side in terms of TAW/DFW and TAW/FAW ratios(P＞0.05),while in the fracture group,there were statistically significant differences in the TAW/DFW and TAW/FAW ratios compared to the non-fracture group(P＜0.05).There was a statistically signifi-cant difference in the one-year postoperative HSS scores between the well-reduced and poorly-reduced groups in the fracture group(P＜0.05).Conclusion The radiographic anatomical relationship between the tibial plateau and distal femur in normal adults is relatively constant,providing a radiological reference for resetting the tibial plateau to a satisfactory width during reduction of Schatzker Ⅳ-C fractures.TAW/DFW＞1 or TAW/FAW＜1 indicates a poor reduction of the fracture and predicts poor postoperative recovery of knee joint function.

To evaluate the advantages of using PBL case library in teaching circulatory system diseases to clinical medicine undergraduate students, a PBL case library was established and applied in teaching practice in the reform of circulatory system teaching. The PBL case library achieved the characteristics of combining theories with cases, morphology with functions, and basic knowledge with clinical knowledge. The PBL case library also realized the informatization, query, and update of cases. Preliminary application showed that the median practical score of students in the case library group was 94.00 points, which was significantly higher than the 92.00 points in the control group ( P=0.005). The average lesson preparation time for teachers in the case library group was (5.00±1.00) hours, which was significantly shorter than the (6.89±0.42) hours in the control group ( P<0.001). The difficulty score for lesson preparation among teachers in the case library group was significantly lower than that of the control group [(1.89±1.05) vs. (3.22±0.44), P<0.001]. However, there were no significant difference in theoretical scores and student satisfaction with teachers and courses. These results suggest that the construction of case library can improve practical teaching effectiveness and enhance the efficiency of lesson preparation for teachers.