High contrast power Doppler imaging using intravascular ultrasound

The ability to predict likelihood of plaque rupture could be used to determine the course of treatment in coronary artery disease. One indicator of vulnerability is intra-plaque neovascularization, the development of blood vessels within plaque. In order to visualize these vessels with rotational, side-viewing intravascular ultrasound (IVUS), a new approach for imaging blood flow in small vessels is proposed based on compounding adjacent angular acquisitions. This approach was evaluated in tissue mimicking phantoms and ex vivo porcine vessels using both conventional and singular value decomposition (SVD) filtering. Flow was imaged at a rate of 5.6 mm/s in 200 μm tubes adjacent to the lumen of ex vivo porcine arteries to mimic microvessels. As a result of compounding, the Doppler CNR increased from 5.3 ± 0.95 to 7.2 ± 1.3 (conventional filtering) and from 23 ± 3.3 to 32 ± 6.7 (SVD filtering). Applying these strategies could allow increased sensitivity to slow flow in side-viewing intravascular ultrasound imaging.