I Need Very Exact Information On This Because It Will

I need very exact information on this because it will make a big difference in my diagnosis and treatment. Can the radiologist view inflammation in arterioles or capillaries on MRA? I believe they can only view inflammation or blockages in arteries...is this correct? Can they view arterioles on CT angiogram? Does it have better resolution? I believe it is not possible to envision capillary blood flow, unless using SPECT or PET, is this correct? Will SPECT indicate small vessel dysfunction or will it only show this if it is vasculitis, and not show intermittent vasospasms? Is there any way to se a radiculoneuropathy of blood vessels from infection which might be causig them to constrict abnormally? What would a vasodilating challenge show about whether it was vasculitis or a problem with nerve roots?