Lecture by: Chris L. de Korte, Medical UltraSound Imaging Centre (MUSIC), Radboud University Medical Centre, Nijmegen The Netherlands
With ultrasound imaging, functional information of tissues can be assessed. In this lecture, the focus is on deformation imaging, quantitative ultrasound imaging, and photoacoustics.
The deformation of tissue can be measured. When a force is applied on the tissue, the tissue is deformed. Quantification of tissue deformation can be used to assess the mechanical properties of tissue (elastography). In arteries, the presence of vulnerable plaques may lead to acute events like stroke and myocardial infarction. Consequently, timely detection of these plaques is of great diagnostic value.
Non-invasive ultrasound strain compounding is currently being evaluated as diagnostic tool to identify the vulnerability of plaques. Strain imaging can also be applied in breast to identify and characterize tumors. We extended 2D strain imaging to full 3D strain imaging using an Automated Breast Volume Scanning (ABVS) system by incorporating strain imaging in combination with ultrafast plane wave imaging. Validation studies in a breast phantom reveals the feasibility of this technique.
Liver steatosis (fatty liver) is a major cause of morbidity in the Western World. With quantitative ultrasound, parameters like residual attenuation and speckle size can be determined. Using a cow animal model we demonstrated an excellent sensitivity and specificity to quantify liver steatosis. Similar results were obtained in different patient cohorts demonstrating that quantitative ultrasound is a useful new diagnostic tool.
In photo-acoustic imaging, a short laser pulse is used to detect the presence of chromophores. The combination of light and ultrasound results in an imaging method that has the sensitivity of light and the localization of ultrasound. Photo-acoustic imaging to guide tumor treatment by High Intensity Focused Ultrasound reveals functional as well as molecular information to evaluate the success of the treatment.