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The progression of thrombus in an ex-vivo shunt model evaluated by intravascular ultrasound radiofrequency analysis ULTRASOUND IN MEDICINE AND BIOLOGY Komiyama, N., Chronos, N. A., Uren, N. G., Moore, M. P., Kelly, A. B., Harker, L. A., Hanson, S. R., Metz, J. A., Yock, P. G., Fitzgerald, P. J. 1999; 25 (4): 561-566

Abstract

We tested the ability of ultrasound radiofrequency (RF) signal analysis to characterize thrombus accumulation in a Dacron graft incorporated into the exteriorized arteriovenous shunt in 3 baboons with constant blood flow for 60 min. Thrombus formation was quantified by sequential measurements of 111Indium-labeled platelet deposition. RF signals were acquired every 15 min at 2 sites in the graft, using a 2.9 Fr intravascular ultrasound catheter-based transducer (30 MHz) and digitized at 250 MHz in 8-bit resolution. Regions of interest were placed within a 0.5-mm perimeter adjacent to the graft wall. Integrated backscatter increased significantly (p < 0.001) with increasing platelet deposition. However, mean-to-standard deviation ratio of the RF envelope showed no significant change and the distribution pattern of the RF probability function remained constant and consistent with a Rayleigh scattering process. These results provide a basis for using RF analysis to monitor the time-course of thrombus formation.

View details for PubMedID 10386731