Figure 4
From: Quantitative tissue perfusion imaging using nonlinear ultrasound localization microscopy
Plane-wave nonlinear imaging enables ULM processing of microcirculatory flow. Amplitude modulated plane-wave ensembles (a) are subjected to the singular value decomposition (SVD) to segment and independently analyze flow components based on their relative velocity. By cancelling linear signal components characteristic of tissue clutter, spectral overlap between tissue motion and the slowest moving microbubbles is negated. The lowest projections from the SVD therefore contain signal representing microcirculatory flow, which can be subjected to microbubble localization (b) in the same manner as signal from larger vessels (c). Following subsequent inter-frame tracking, tracks are accumulated to generate super-resolved images of either tissue perfusion (d) or spatially resolved vascular flow (e) from the same initial acquisitions. Images were acquired axially at cervical level 5 in the rat spinal cord.
