Towards Attenuation Imaging with Computed Ultrasound Tomography in Echo
Mode (CUTE)
Abstract
This work presents a novel attenuation imaging technique for pulse-echo
ultrasound systems. In contrast to state-of-the-art techniques, we
formulate the reconstruction in two dimensions relying on tissue
insonifications with different steering angles. By beamforming
backscattered echoes recorded by the transducer, we measure at each
location the changes in the amplitudes of detected echoes with different
transmissions and relate them to local tissue attenuation. This
relationship assumes ultrasound waves propagate in straight paths; thus,
we linearize the forward problem to provide suitable time-to-solutions
for clinical practice. The presented technique is the natural extension
of computed tomography in echo mode (CUTE), initially developed for
tissue speed-of-sound quantification. The performance of our method is
demonstrated in numerical examples with data computed using the k-Wave
numerical solver for wave-propagation simulations. These examples
consider tissue-mimicking media with varying heterogeneity in
attenuation and echogenicity. The results show that our method can
provide images with promising spatial and contrast resolution, as well
as attenuation estimates independent of tissue echogenicity. This work
represents a necessary first step towards multi-modal CUTE imaging of
speed of sound and attenuation in tissue.