A method, system and apparatus for manufacturing anatomically and functionally accurate soft tissue phantoms with multimodality characteristics for imaging studies is disclosed. The organ/tissue phantom is constructed by filling a container containing an organ having inner vasculature therein with a molten elastomeric material; inserting a plurality of rods with bumps thereupon through the container and the organ; allowing the molten elastomeric material to harden and cure; removing the organ; replacing the organ with a plurality of elastomeric segments; and removing an elastomeric segment and replacing the void created thereupon with molten PVA to create a PVA segment; allowing the molten PVA segment to harden and cure; and repeating the creation of PVA segments until all the elastomeric segments have been removed, such that each successive molten PVA segment adheres to and fuses with the previous hardened PVA segment so as to form an approximately complete organ phantom cast. The organ/tissue phantom is completed by inserting the approximately complete organ phantom cast inserting upside-down into a fixture made from the bottom-most elastomeric segment, which contains molten PVA; and allowing the molten PVA to harden and cure.