This will vary vastly between specialty and specific program within that specialty. In my program, we had weekly Journal Club and Board Prep sessions, so that by the time we were off to truly study for the preliminary exam at the beginning of 3rd year (multiple choice that covers physics, anatomy, physiology/pathophys, radiation biology, journal articles), we'd seen all the information at least twice beforehand and were familiar. This is not so in other programs, where they will literally hand you textbooks or stacks of notes and just expect you to learn it all on your own, often only in the few weeks leading up to the exam. Also for ACVR, they have a very vague directive of knowing our journal's papers over the past 10 years, but questions that do not fit that description still show up. So yes, definitely reading a lot, making notes on papers that you can easily and quickly reference in the future for reviewing, and going through any pre-made mock exams or quizzes that other residents or faculty have made. ACVR also now has a committee that has created mock exams for residents in anatomy, physics, and a literature-based one which were helpful too. For the certifying exam, which is all image interpretation, you have basically prepared for that test your whole residency, so studying for it is very different, and it's all about seeing more and more cases and being prepared to work through anything they give you under a time crunch.