Multiple T2 white matter
hyperintensities often cause a confusion while reporting an MRI. They may represent small vessel ischemia, Virchow Robbin (perivascular) space or just non-specific white matter changes. However, most often, it doesn't matter what these represent as there is no significant symptoms or specific treatment required for any of these. At most, a follow up MRI in 3-6 months maybe asked for.
The description in your scan fits that of Fazekas Grade 1-2 changes which are of no significance or worry, especially if you are above 40-50 years of age. However, if they worsen on follow up MRI, especially in young patients (less than 40 years), it maybe an indicator for predisposition to development of dementia
early in life.
The reporting radiologist
may have also considered the possibility of a demyelinating disease
(like multiple sclerosis
) and hence the exact number of lesions mentioned. However, demyelinating conditions usually have a strong clinical presentation and obvious symptomatology.
The small T2 hyperintense extra-axial lesion maybe a small arachnoid cyst
which again need not be a cause of worry.
Overall, the scan report seems to be quite innocuous, and you probably do not have anything much to worry about, especially if your an older individual (more than 50 years of age). If you are young (less than 30 years) then you need to meet a neurologist
early to evaluate various causes.