ObjectivesTo　simulate　hemodynamic　changes　after　extraluminal　compression　in　pulsatile　tinnitus　(PT)　patients　with　a　prominent　transverse-sigmoid　sinus　junction　(PTSJ).　MethodsOne　patient-specific　case　was　reconstructed　based　on　computed　tomography　venography　(CTV)　images　of　a　PT　patient.　The　compression　degree　served　as　a　new　index　in　this　study.　Cases　with　10,　20,　30,　40,　50,　60,　70,　80,　and　90%　of　the　compression　degree　of　the　control　subject　were　constructed.　Steady-state　computational　fluid　dynamics　(CFD)　were　assessed.　The　wall　pressure　distribution,　wall　maximum　pressure　(P-max)　and　flow　pattern　(velocity　streamlines　and　velocity　vector)　of　the　PTSJ　were　calculated　to　evaluate　hemodynamic　differences　among　all　cases.　ResultsWith　increasing　compression,　the　wall　pressure　at　the　compression　point　and　downstream　of　the　PTSJ　decreased　but　increased　upstream.　When　the　compression　degree　exceeded　70%,　the　upstream　pressure　increased　significantly.　Above　50%　compression,　the　blood　flow　pattern　downstream　of　the　sigmoid　sinus　tended　to　spiral,　especially　after　80%　compression.　Beyond　60%　compression,　the　blood　flow　pattern　under　the　compression　axis　became　more　medial.　ConclusionMechanical　compression　of　PTSJ　changes　wall　pressure　and　blood　flow　patterns.　The　degree　of　compression　should　be　carefully　observed　to　avoid　possible　complications　or　reoccurrence.