Tumor Characterization by Sonoelastography and Contrast-Enhanced Ultrasound

Tissue stiffness and perfusion are two complementary biophysical properties that can be quantified by sonoelastography and contrast-enhanced ultrasound (CEUS) to characterize tumor lesions. While state-of-the-art sonoelastography techniques such as strain elastography and shear wave elastography (SWE) are used in clinical routines to detect and classify mechanically altered masses, CEUS is used to differentiate focal lesions in terms of blood perfusion and vascularization patterns. This chapter provides an overview of the clinically relevant techniques of sonoelastography and CEUS and their diagnostic role in clinical routine. Sonoelastography will be discussed based on applications in breast lesions and thyroid nodules. It will be shown that tissue stiffness measured with high spatial resolution improves the diagnostic specificity of multiparametric diagnostic ultrasound. CEUS has been established primarily in the field of liver tumor characterization, while other areas such as renal cyst assessment are emerging. With a low rate of adverse effects, CEUS can be used in patients with impaired renal function or contraindications to CT or MRI contrast agents. Taken together, sonoelastography and CEUS have expanded the role of classic B-mode ultrasound in oncology by providing differential diagnosis and improved standardization in tumor classification and staging.