One aspect of the present invention relates to methods of embolizing a vascular site in a mammal comprising introducing into the vasculature of a mammal a composition comprising an inverse thermosensitive polymer, wherein said inverse thermosensitive polymer gels in said vasculature, which composition may be injected through a small catheter, and which compositions gel at or below body temperature. In certain embodiments of the methods of embolization, said composition further comprises a marker molecule, such as a dye, radiopaque, or an MRI-visible compound.
