Shear Wave Elastography May Add a New Dimension to Ultrasound Evaluation of Thyroid Nodules: Case Series with Comparative Evaluation
Figure 4
Phantom studies illustrating well-known physiologic phenomenon of increase of perceived tissue stiffness with applied increased pressure (e.g., during palpation of tissues). (a) on a breast phantom study a stiff inclusion (arrow) is seen with no pressure applied at ultrasound probe. The distance from the surface, the stiffness of the inclusion and surrounding medium (dotted circle) can be measured. (b) with application of pressure on the phantom with ultrasound probe, which is evident as a reduced distance of the inclusion to the surface of the phantom, the stiffness of the inclusion and surrounding medium is increased. Thus, the measurements of stiffness of tissues with supersonic shear wave elastography should be performed in a resting state without pressure on the ultrasound probe to avoid the unpredictable influence of the compression on the stiffness of the tissues.
