Molecular magnetic resonance imaging of coronary thrombosis and pulmonary emboli with a novel fibrin-targeted contrast agent.
BACKGROUND
The differential diagnosis of acute chest pain is challenging, especially in patients with normal ECG findings, and may include coronary thrombosis or pulmonary emboli. The aim of this study was to investigate the novel fibrin-specific contrast agent EP-2104R for molecular targeted MR imaging of coronary thrombosis and pulmonary emboli.


RESULTS
Fresh clots were engineered ex vivo from human blood and delivered in the lungs and coronary arteries of 7 swine. Subsequent molecular MR imaging was performed with a navigator-gated free-breathing and cardiac-triggered 3D inversion-recovery black-blood gradient-echo sequence before and after systemic administration of 7.5 micromol/kg EP-2104R. Two swine served as the control group. MR images were analyzed by 2 investigators, and contrast-to-noise ratio and gadolinium concentration in the clots were assessed. Before contrast media application, no thrombi were visible. After contrast administration, all 32 pulmonary emboli, 3 emboli in the right heart, and 5 coronary thrombi were selectively visualized as white spots with a mean contrast-to-noise ratio of 32+/-19. The average gadolinium concentration from all 3 types of thrombi was 144+/-79 micromol/L.


CONCLUSIONS
Molecular MR imaging with the fibrin-targeted contrast-agent EP-2104R allows selective visualization of acute coronary, cardiac, and pulmonary thrombi.
Spuentrup
Elmar
E
Department of Diagnostic Radiology, University Hospital, Aachen Technical University, Aachen, Germany. spuenti@rad.rwth-aachen.de
Buecker
Arno
A
Katoh
Marcus
M
Wiethoff
Andrea J
AJ
Parsons
Edward C
EC
Botnar
Rene M
RM
Weisskoff
Robert M
RM
Graham
Philip B
PB
Manning
Warren J
WJ
Günther
Rolf W
RW
D000792:Angiography / Q000379:methods; D000818:Animals; D002637:Chest Pain / Q000209:etiology*; D003287:Contrast Media / Q000493:pharmacokinetics*; D003328:Coronary Thrombosis / Q000150:complications / Q000175:diagnosis* / Q000473:pathology; D003937:Diagnosis, Differential; D005337:Fibrin / Q000032:analysis*; D005682:Gadolinium / Q000493:pharmacokinetics; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010455:Peptides / Q000493:pharmacokinetics; D011655:Pulmonary Embolism / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D034421:Sus scrofa; D036542:Tomography, Spiral Computed
D003287:Contrast Media; C503783:EP-2104R; D010455:Peptides; D005337:Fibrin; D005682:Gadolinium