title: Time-dependent hardening of blood clots quantitatively measured in vivo with shear-wave ultrasound imaging in a rabbit model of venous thrombosis.
abstract: OBJECTIVE
  Provide in vivo blood clot hardening evolution with ultrasound using supersonic imaging of shear waves.
  
  
  METHODS
  We conducted a prospective study in flow stasis-induced venous thrombosis within jugular veins of white female New Zealand rabbits. Blood clot elasticity was noninvasively measured in vivo using the Young's modulus (in kilopascals), on a 2-hour and a 2-week periods after thrombus induction. Monitoring was followed by a necropsy and ex vivo mechanical characterization to validate the existence and elasticity of explanted thrombi.
  
  
  RESULTS
  Stagnant blood in the region of interest underwent clotting and progressive hardening with thrombus aging. The mean Young's moduli varied from 1.0 ± 0.6 kPa (at 10 min) to 5.3 ± 1.6 kPa (at 2 hours), then to 25.0 ± 6.8 kPa (at 14 days) post-surgery. Mean ex vivo moduli of 6.2 ± 0.7 kPa at 2 hours and 29.0 ± 2.4 kPa at 2 weeks agreed with in vivo measures.
  
  
  CONCLUSIONS
  Supersonic imaging of shear waves provides consistent quantitative non-invasive elasticity measurements not available with standard compression ultrasound imaging for diagnosing and following venous thromboembolism. This information translatable to humans could aid in determining whether continued anticoagulant treatment is necessary, especially in the setting of unprovoked venous thromboembolism.
authors: Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center (CRCHUM), Montreal, QC, Canada.
authors: Etienne
authors: E
authors: Mfoumou
authors: Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center (CRCHUM), Montreal, QC, Canada.
authors: Julien
authors: J
authors: Tripette
authors: Division of Hematology, Department of Medicine, Sir Mortimer B. Davis Jewish General Hospital, Montreal, QC, Canada.
authors: Mark
authors: M
authors: Blostein
authors: Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center (CRCHUM), Montreal, QC, Canada; Department of Radiology, Radio-Oncology and Nuclear Medicine and Institute of Biomedical Engineering, University of Montreal, Montreal, QC, Canada. Electronic address: guy.cloutier@umontreal.ca.
authors: Guy
authors: G
authors: Cloutier
mesh_terms: D000818:Animals; D001777:Blood Coagulation; D055119:Elastic Modulus; D005260:Female; D007601:Jugular Veins / Q000000981:diagnostic imaging; D011817:Rabbits; D014463:Ultrasonography; D020246:Venous Thrombosis / Q000097:blood / Q000000981:diagnostic imaging*
keywords: Animal experimentation; Blood clot hardening; Elasticity imaging techniques; Shear wave elasticity imaging; Thrombus aging; Ultrasonography; Ultrasound; Venous thrombosis; Young’s modulus