I'm new to database design, and new to this forum. This is a very basic question, but it's something I've run into often enough that I want to sort it out.

Here's an example of when I encounter the problem:

If I were designing a medical database say, and I have a patient who gets an MRI brain scan, there are about 30 options for the different types of results/diagnoses there can be, would I create an MRI_Result table with columns: mri_id, mri_result_id(foreign key that links to a Result_Type table), and mri_date, or would I create only one table (i.e. no Result_Type table with result types and descriptions) where the mri_result column has a drop-down menu limited to the 30 or so options I would otherwise have put in the Result_Type table?

I don't think the result types would change often at all, and I'm thinking the drop-down menu would be simplest, but I want to make sure that won't cause problems I haven't thought about. Is one option better normalized than the other? Is one more "best practicey" than the other?

Any help, suggestions, or explanations would be appreciated.