Abstract #2677

Zhu M, Hiroki M, Ay H, Sorensen A, Lopez C, Menezes N, Singhal A, Melinosky C

MCA susceptibility sign demonstrates paramagnetic deoxyhemoglobin in red thrombus in acute stroke. A segment of filling defect on CTA reveals the site and size of MCA occlusion. In this study, a complex thrombus containing diamagnetic material was diagnosed if CTA occlusion is >20% larger than susceptibility sign, others were considered as a red thrombus. In 31 CTA identified MCA occlusions, red thrombi were found in 61% while 39% had complex thrombi. Susceptibility sign may underestimate the MCA occlusion. The composition of acute MCA thrombus is heterogeneous in term of magnetization property.