Is there a way to tell from an mri report if the locations of brain lesions/hyperintensities are indicative of migraine versus ms?

Yes: Mri is one of the diagnostic methods that will help diagnose ms with these lesions and will differentiate between migraines and ms. However, to truly rule out ms early on, you also need an MRI of the spine as well as lesions can appear there also, sometimes before the brain. Hope this helps!

Distinction: It is hard to distinguish brain lesions due to migraine from those due to MS, especially by their location. With that in mind, MS often causes lesions around the ventricles, and migraine does not. MS often causes numerous lesions when it is not treated, migraine tends to cause a small number of small lesions. MS causes lesions that enhance with contrast (sometimes), migraine never causes these.

Patterns differ: The MRI lesions from migraine are usually posterior and do not appear to be peri-ventricular or perpendicular, but on occasion, confusion can be present if there are diffuse lesions. Your doctor should be able to advise you of the clinical correlation.