I believe you are pursuing your Integrated Program in Radiology from India. My advice for you will be study seriously, get good grades, do a couple or more internships in diverse organizations or eminent instituitons, and prepare yourself for the GRE and TOEFL Exam in your final year. GRE is a gateway for Ph.D abroad. For greater career scope and prospects in US, you will require a Ph.D from a reputed US University like John Hopkins or Harvard, which are good enough in your field of interest, have good faculty and research facilities. For more information do follow the link below

https://www.careers360.com/courses/radiology-course