Thrombus imaging with fibrin-specific gadolinium-based MR contrast agent EP-2104R: results of a phase II clinical study of feasibility
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PURPOSE: To determine the feasibility of detecting thrombi using a fibrin-specific gadolinium-based magnetic resonance imaging contrast agent, EP-2104R.
METHODS: Subjects with confirmed thrombus in the venous system (n = 14), or in the heart, or arterial system (n = 38) were enrolled. Patients were imaged before and at various times following a 4 mumol/kg intravenous bolus injection of EP-2104R:
RESULTS: Overall, 29 thrombi were visible before contrast administration, 3 of 14 in the venous system, and 26 of 38 in the arteries and heart. Thrombi generally enhanced in signal after EP-2104R injection, and an additional 7 were visualized. After contrast, 4 of 14 thrombi were visible in the venous system, and 32 of 38 in the arteries and heart. Thrombi were more conspicuous when imaged at 2 to 6 hours post EP-2104R compared with within 1 hour, because of lower blood background. Quantitatively, the post: pre signal intensity ratio was 1.90 at 2 to 6 hours post injection (standard deviation = 1.08, N = 20, P
CONCLUSION: EP-2104R enhanced magnetic resonance imaging detects thrombi not readily visible in precontrast screening and gives additional enhancement of thrombi that are visible in precontrast imaging.