Harvested SIPA clot and SEM images. (A) A SIPA clot retrieved from the large glass tube was formalin fixed and dehydrated with ethanol. (B) Schematic of a SIPA clot with regions of interest (R1-R5). (C) A SIPA clot cut in half to expose the cross section. (D) The platelet-rich white region is highlighted in green, showing fingers of platelet aggregates (white arrows). (E-G) SEM image of SIPA clot region of interest R4. (E) Low magnification SEM image of the SIPA clot showing the dense core of the thrombus. (F) Moderate magnification SEM image of the SIPA clot illustrating a textural surface of platelet aggregates. (G) High-magnification SEM image of the SIPA clot showing amorphous platelets that are likely activated with degranulation. (H) Platelet density from SEM images of regions R1 to R5.