In Vivo Results of Real-time Freehand Elasticity Imaging

We are developing a system for real-time estimation and display of tissue elastic properties using a clinical ultrasonic imaging system. Our hypothesis is that real-time feedback of elasticity images is essential in obtaining high-quality data. Extensive experience with laboratory fixtures and off-line processing of elasticity data showed that problems occurring in data acquisition often resulted in poor elasticity image quality. Our experience with real-time freehand elasticity imaging shows that images with high contrastto-noise can be obtained. Results in volunteer patients have shown that high quality elasticity images are easily obtained in vivo in breast and thyroid pathologies. The key element to successful scanning is real-time visual feedback which guides the patient positioning and compression direction. Results show that individual images of axial strain in tissues can be quite misleading and that a ‘movie loop’ of strain images provides significantly more information adding to intuition.