Fig.1 Superabsorbent polymer microspheres（SAP-MS, reconstituted size range 200〜300㎛）suspended in sodium meglumine ioxaglate 320 mgI/ml（Hexabrix 320, Terumo, Tokyo）. The swollen particles are spherical in shape and uniform in size.
Fig.2 Rabbit renal artery was embolized with 100〜300㎛ tris-acryl gelatin microspheres（Embosphere, Biosphere Medical, USA）. A single particle achieves cross-sectional occlusion of an artery corresponding to the particle size, and extends the internal elastic membrane. Note the wavy appearance of the internal elastic membrane of the adjacent normal artery.（Elastica van Gieson stain x100）