I would also like to know the answer to this question. I got a great pediatric radiology case I want to write up soon, but I haven't the slightest idea how to go about getting it published as a medical student.
A quick and dirty guide:
1) Find a similar case report using Pubmed
2) Using it as a template, write up your own.
3) Find someone who is an attending at the hospital where you did the case who is willing to put their name on the article. Ideally they will be willing to edit, add some clinical knowledge, etc. For this they should get last author and you will get first. You will need an attending for the journal to take you seriously (even residents generally do).
4) Pick a journal. The attending should have an idea of where case reports are published. Likely they will throw out five names and you will find out that only one of them accepts case reports.
5) **Look at the "guidelines for writers" for THAT JOURNAL and adjust your article accordingly! If it says 1000 words, 2 pictures, and 3 references, you'd better trim your report accordingly. Ignoring this is a fast road to rejection.
6) Submit. Expect to be rejected a couple of times. Re-submit to other journals, following their format, and wait until one says "we will accept this if you make X corrections.
7) Victory.
Edited to add: while obviously you will go for a rads journal first, if it is an interesting clinical scenario you could also consider submitting it to a pediatrics journal instead. I had a couple of rads-related case reports in non-rads journals and interviewers did not care what it was published in, only that it was published and I was first author.
