IVC filters are attached to the vena cava via hooks on their ends. Some are compression springs, which compress outward onto the side wall of the vena cava; however, they still have small hooks that retain their location. These hooks aid in the anchoring and healing process, as they allow the tissues to 'ingrow' around them, securing the IVC in place. It is unlikely, then, after 4 to 6 weeks of healing, that an MRI of 1.5 tesla, up to 3 tesla, will cause any level of dislodging to occur to the IVC filter.