Why elastography?

It has been well known for centuries that many diseases are associated with alteration in tissue stiffness. This has led to the use of manual palpation to examine tissue stiffness for disease assessment. Manual palpation, however, is a qualitative method with low sensitivity. As such, elastography techniques have recently emerged for diagnosing pathologies based on stiffness alterations. In these techniques, external static compression or harmonic shear waves are applied to the tissue for stimulation. The resulting tissue displacements are then acquired using conventional imaging modalities such as ultrasound and MR imaging (MRI). These displacements are finally used to reconstruct tissue stiffness using inversion technique based on tissue biomechanical model.