After minimal echotexture of the liver and few mildly prominente blood vessels at the splenic hilum what a should be done an mri or a doppler?

Neither: It is not a good idea to undergo any testing if you are feeling well(actually you said great!). Doing unnecessary testing frequently misleads doctors into areas which may be minor variations of normal anatomy. So doing a test then forces you to do more tests and generates a lot of unwanted anxiety. If you already have anxiety probelms, then it is even more important to do no further testing unles.