https://www.selleckchem.com/products/pembrolizumab.html 14%) underwent TAVR. One-third of enrolled patients were female, and the majority of the patients were White with a mean age of 65.9 ± 15.1 years. TAVR use for BAV stenosis significantly increased from 0.39% in 2011 to 4.16% in 2014 (P less then 0.001), which represents a 3.77% overall growth in procedure rate. The median length of stay decreased significantly throughout the study period (mean 12.2 ± 8.2 days to 7.1 ± 5.9 days, P less then 0.001). There was no statistically significant difference between SAVR and TAVR groups in the in-hospital mortality (0% vs. 5.9%; adjusted P = 0.119). Conclusion There is a steady increase in TAVR use for BAV stenosis patients along with a significant decrease in length of stay. Copyright © 2020 Avicenna Journal of Medicine.Aim The aim of this study was to evaluate awareness and knowledge about radiation risks and safety principles among medical students at the College of Medicine, University of Hail, Hail, Saudi Arabia, in their clinical years. Materials and Methods In this cross-sectional study, an anonymous electronic questionnaire was sent to 174 randomly selected students in clinical years 4-6. The questionnaire contained 38 questions. The respondents' answers to these questions were used to classify them according to their demographic characteristics and to evaluate their knowledge about common imaging modalities, radiation risks, and safety measures. The data were analyzed using the Statistical Package for the Social Sciences (SPSS) software, version 22. Results Seventy-five (51.7%) of 145 respondents were female and 70 (48.3%) were male. Fifty-five respondents (37.9%) were in year 4, 38 (26.2%) were in year 5, and 52 (35.9%) were in year 6. The mean score for knowledge about common imaging modalities was 4.10 ± 2.030 of 10, that for knowledge about the risks of radiation was 3.17 ± 1.954 (range, 0-8) of 13, and that for knowledge about radiation protection measures wa