Ultrasound Elastography for Biomedical Applications and Medicine
by Ivan Z. Nenadic, Matthew W. Urban, James F. Greenleaf, Jean-Luc Gennisson, Miguel Bernal, Mickael Tanter
15 Dynamic Elasticity Imaging
Kevin J. Parker
Department of Electrical and Computer Engineering, University of Rochester, Rochester, NY, USA
15.1 Vibration Amplitude Sonoelastography: Early Results
Vibration amplitude sonoelastography entails the application of a continuous low‐frequency vibration (40–1000 Hz) to excite internal shear waves within the tissue of interest [1, 2]. A disruption in the normal vibration patterns will result if a stiff inhomogeneity is present in soft tissue surroundings. A real‐time vibration image can be created by Doppler detection algorithms. Modal patterns can be created in certain organs with regular boundaries. The shear wave speed of sound in the tissue of these organs can be ascertained with the information revealed by these patterns [3].
Figure 15.1 reproduces the first vibration‐amplitude sonoelastography image [1, 2], which marked the emergence of elastography imaging from the previous studies of tissue motion. The vibration within a sponge and saline phantom containing a harder area (the dark region) is depicted by this low resolution image. Range‐gated Doppler was used to calculate the vibration amplitude of the interior of the phantom as it was vibrated from below. By 1990, a modified color Doppler instrument was used by the University of Rochester group to create real‐time vibration‐amplitude sonoelastography images. In these images, vibration above a certain threshold (in the 2 µm range) produced a saturated color (
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access