Background Removal and Vessel Filtering of Non-Contrast Ultrasound Images of Microvasculature
A clutter removal method is proposed that utilizes spatiotemporal coherence of the ultrasound plane wave imaging data to significantly suppress tissue clutter signal obtained over extended ensembles. Nonlinear filtering via morphological operations and Hessian-based analysis are proposed to provide superb background rejection and vessel enhancement. This new imaging method, solely based on ultrasound, enables visualization of the small vessels that may find applications in both preclinical and clinical settings. In clinical applications, this method may provide a versatile tool for monitoring angiogenesis which may provide invaluable diagnostic and prognostic information.
Automated In Vivo Sub-Hertz Analysis of Viscoelasticity (SAVE) for Evaluation of Breast Lesions
An ultrasound-based imaging method is proposed to visualize viscoelastic properties of the breast masses at sub-Hertz frequencies. The method utilizes an automated compression device with closed-loop feedback control that houses an ultrasound probe. A ramp-and-hold creep test is performed on the tissue while ultrasound is used to image tissue deformation. A classic viscoelastic Kelvin-Voigt model is then used to estimate viscoelasticity parameters….
Unambiguous Identification and Visualization of an Acoustically Active Catheter by Ultrasound Imaging in Real Time: Theory, Algorithm, and Phantom Experiments
To enable better intracardiac guidance and visualization, a prototype of an acoustically active catheter with a piezoelectric element on its distal end is used. The unique symmetric Doppler shifts from the piezoelectric element are detected by the proposed algorithm and the distal end is visualized with a unique color (yellow) in real-time (22- 50 Hz). The algorithm is robust to interference from blood flow with a localization range of few millimeters.
Automated Compression Device for Viscoelasticity Imaging
Non-invasive measurement of tissue viscoelastic properties is gaining more attention for screening and diagnostic purposes. Recently, measuring dynamic response of tissue under a constant force has been studied for estimation of tissue viscoelastic properties in terms of retardation times.