Molecular magnetic resonance imaging of atrial clots in a swine model

• Published in: Circulation (New York, N.Y.) N.Y.), 2005-07, Vol.112 (3), p.396-399
• Main Authors: SPUENTRUP, Elmar, FAUSTEN, Bernd, BUSCH, Thomas, GÜNTHER, Rolf W, BUECKER, Arno, KINZEL, Sylvia, WIETHOFF, Andrea J, BOTNAR, Rene M, GRAHAM, Philip B, HALLER, Stephan, KATOH, Marcus, PARSONS, Edward C, MANNING, Warren J
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Blood and lymphatic vessels; Blood. Blood coagulation. Reticuloendothelial system; Cardiology. Vascular system; Cardiovascular system; Diseases of the peripheral vessels. Diseases of the vena cava. Miscellaneous; Heart Atria; Heart Diseases - diagnosis; Investigative techniques, diagnostic techniques (general aspects); Magnetic Resonance Imaging; Medical sciences; Models, Animal; Pharmacology. Drug treatments; Radionuclide investigations; Swine; Thrombosis - diagnosis
• ISSN: 0009-7322; 1524-4539
• DOI: 10.1161/CIRCULATIONAHA.104.529941

The detection and differentiation of intracardiac masses is still challenging and may include neoplasms and thrombi. The aim of this study was the investigation of a targeted, fibrin-specific contrast agent (EP-2104R) for molecular targeted magnetic resonance imaging (MRI) of left atrial clots. Chronic human thrombi were surgically implanted in the left atrial appendage of 5 swine. Molecular MRI was performed with a navigator-gated, free-breathing, cardiac-triggered 3D inversion-recovery, black-blood, gradient-echo sequence before and after systemic administration of 4 micromol/kg EP-2104R. MR images were analyzed by 2 investigators, and the contrast-to-noise ratio was calculated. Location of clots was confirmed by autopsy, and the gadolinium concentration in the clots was assessed. Before contrast agent administration, thrombi were not visible on black-blood MR images. After contrast administration, all atrial clots (n=5) were selectively visualized as white spots with a high contrast-to-noise ratio (clot/blood, 29.7+/-8.0). The gadolinium concentration in the clots averaged 74+/-45 micromol/L. The fibrin-specific MR contrast agent EP-2104R allows for selective and high-contrast visualization of left atrial clots by means of molecular targeted MRI.