title: Fibrin-targeted contrast agent for improvement of in vivo acute thrombus detection with magnetic resonance imaging.
abstract: OBJECTIVE
  Plaque rupture leading to thrombosis and occlusion is a major source of acute coronary syndromes. Methods for accurate detection of thrombosis in veins or arteries may expand our capacity to predict clinical complications and guide therapeutic decisions. We sought to demonstrate the feasibility of in vivo acute thrombus detection using a fibrin-targeted gadolinium based magnetic resonance contrast agent (EP-1242).
  
  
  METHODS
  Carotid thrombosis was induced in 12 guinea pigs by external injury and blood stasis. MR images were obtained after thrombus formation pre- and post- EP-1242 injection, using a T1-weighted high-resolution fast spin-echo sequence.
  
  
  RESULTS
  An occlusive fibrin-rich thrombus was achieved in all animals. Correlation for thrombus location was excellent between MRI and histology (R=0.94; P<0.001). Contrast-enhanced MRI significantly improved thrombus detection when compared to non contrast-enhanced MRI (100% versus 41.6%; p<0.001). In addition, thrombus signal intensity (SI) was significantly increased after injection (SI(30 min-post)=4.39+/-0.12 versus 1.0; p<0.001). Contrast-to-noise ratio (CNR) was 43.8+/-7.2, 30 min post-injection (P<0.001). No enhancement was seen in the uninjured control arteries.
  
  
  CONCLUSIONS
  We demonstrate the feasibility of in vivo MRI for carotid thrombus detection using a novel fibrin-targeted contrast agent. This technique significantly improves detection of small size thrombi in an animal model of occlusive fibrin-rich thrombosis.
authors.affiliation: Department of Cardiology, Hôpital Lariboisière, Paris, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Sirol
authors.forename: Juan G S
authors.initials: JG
authors.lastname: Aguinaldo
authors.forename: Philip B
authors.initials: PB
authors.lastname: Graham
authors.forename: Robert
authors.initials: R
authors.lastname: Weisskoff
authors.forename: Randy
authors.initials: R
authors.lastname: Lauffer
authors.forename: Gabor
authors.initials: G
authors.lastname: Mizsei
authors.forename: Igor
authors.initials: I
authors.lastname: Chereshnev
authors.forename: John T
authors.initials: JT
authors.lastname: Fallon
authors.forename: Ernane
authors.initials: E
authors.lastname: Reis
authors.forename: Valentin
authors.initials: V
authors.lastname: Fuster
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Toussaint
authors.forename: Zahi A
authors.initials: ZA
authors.lastname: Fayad
mesh_terms: D000208:Acute Disease; D000818:Animals; D002341:Carotid Artery Thrombosis / Q000175:diagnosis*; D003287:Contrast Media / Q000737:chemistry / Q000494:pharmacology*; D004195:Disease Models, Animal; D005337:Fibrin; D006168:Guinea Pigs; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010456:Peptides, Cyclic / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D003287:Contrast Media; C506893:EP-1242; D010456:Peptides, Cyclic; D005337:Fibrin