Objective To investigate w hether the iterative reconstruction (iDose 4 ) technique improves imaging quality of the low-radiation-dose w hole brain CT perfusion (CTP). Methods Thirty-five consecutive patients w ith clinical y suspected ischemic stroke w ere col ected. Bril iance 256 iCT w as used to perform low-radiation-dose w hole brain CTP, and the filtered back projection (FBP) and iDose 4 algorithm w ere used to conduct image reconstruction. The noise and signal to noise ratio of the 2 kinds of reconstruction algorithms, as w el as the imaging quality of each parameter map w ere compared. Results The effective dose of the w hole brain CTP w as 2.2 mSv. Compared w ith FBP, the noise of each region of interest in the iDose4 Tmax map was decreased significantly ( P<0.05) and the signal to noise ratio was increased significantly (P<0.05). The imaging quality scores (median, interquartile range) reconstructed by FPB group w ere significantly low er than by iDose 4 for cerebral blood flow (CBF) map ( 5.00 [3.00-6.00]vs. 6.00 [5.00-6.00]; Z= -2.784, P=0.005), cerebral blood volume (CBV) map ( 6.00 [5.00-6.00] vs. 6.00 [6.00-7.00]; Z= -3.674, P<0.001), and mean transit time (MTT) map (4.00 [3.00-5.00] vs. 5.00 [4.00-6.00]; Z=3.394, P=0.001). The proportions of the poor quality in CBF map ( 34.3%vs. 11.4%;χ2 =7.036, P=0.030), CBV map (11.4%vs.2.9%; χ2 =7.485, P=0.024 ) and MTT map (28.6%vs.11.4%;χ2 =5.318, P=0.070) reconstructed by FBP w ere significantly higher than by iDose 4 . Conclusions The iDose4 technique may improve imaging quality of low er-radiation-dose CTP.

Objective:To assess causes for revision total knee arthroplasty (TKA) in China using the data of revision TKA in the past 15 years in our single center andcompare the differences in survival time, operation time and blood loss among different revision reasons.Methods:Data of 337 patients (345 knees) with revision TKAs at our institution from January 2007 to December 2021 (15 years) were retrospectively analyzed. The included population consists of 57 males and 288 females. The causes for first revision TKA were identified and compared according to the time of revision surgery as early (up to 2 years) and late revision (more than 2 years). The reason for revision before 2012 and after 2012 was also compared. Furthermore, the differences of survival time, operation time and blood loss among different revision reasons were compared.Results:The most common reasons for revision of knee joints in 345 cases were periprosthetic infection (133 knees, 38.6%), followed by aseptic loosening (97 knees, 28.1%) and joint instability (35 knees, 10.1%). Early revisions were performed in 171 knees (49.6%), while late revisions were performed in 174 knees (50.4%). Periprosthetic infection (96 knees, 56.1%) and aseptic loosening (86 knees, 49.4%) were the most common reasons for early and late revisions, respectively. There were 59 revisions performed before 2012 and 286 revisions performed after 2012, with periprosthetic infection being the main reason for revision in both groups. The percentage of revisions due to infection decreased from 64.4% before 2012 to 33.2% after 2012, and this difference was statistically significant (χ 2=18.790, P<0.001). The proportion of revisions due to aseptic loosening was 15.3% before 2012, which was significantly lower than the proportion of 30.8% after 2012 (χ 2=5.083, P=0.024). The median survival time of the prostheses in the included patients was 30 months, with shorter survival time observed in patients with stiffness, patellar complications, and periprosthetic infection, and longer survival time observed in patients with polyethylene wear and aseptic loosening. There were significant differences in operation time and blood loss among different reasons for revision ( P<0.001). Conclusion:In our specialized arthroplasty center periprosthesis infection was the most common reason for revision. Periprosthesis infection and aseptic loosening needed to be considered for early or late-stage revision. With the development of technique of total knee arthroplasty, the proportion of periprosthesis infection is decreasing, while the incidence of aseptic loosening is increasing.

Objective    To investigate the operation of transcatheter aortic valve replacement (TAVR), the use of TAVR instruments and the current situation of TAVR-related nursing in our country, to reveal the characteristics of TAVR in various hospitals in our country, and to provide reference data for improving perioperative nursing and industry development of TAVR. Methods    A questionnaire survey was conducted among the head nurses of the cardiac catheterization laboratories of 51 hospitals in China that carried out TAVR operations, with a total of 5 items and 23 questions. The current situation of TAVR operation methods, intraoperative instruments and nursing care in China were analyzed. Results    The number of hospitals in China which started conducting TAVR and the beginning year were: 2 in 2010, 1 in 2012, 1 in 2013, 1 in 2015, 11 in 2016, 13 in 2017, 15 in 2018 and 7 in 2019; the number of transfemoral TAVR in 2019: 32 (62.75%) hospitals conducted on less than 20 patients, 7 (13.73%) hospitals 20-<50 patients, 6 (11.76%) hospitals 50-100 patients and 6 (11.76%) hospitals more than 100 patients; TAVR strategies adopted by most hospitals were: general anesthesia (90.20%), the use of vascular sealers (80.39%), backing by cardiac surgeon (74.51%) and using homemade prosthetic valves. Conclusion     At present, the number of TAVR carried out in Chinese hospitals is still far behind that of developed countries in Europe and the United States. Our country has adopted the form of multi-disciplinary cardiac team cooperation and formed a TAVR nursing model with Chinese characteristics.