In vivo 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. Results in phantoms are in excellent agreement with that predicted with finite element analysis. 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 the frame-to-frame changes in strain image contrast appear to be unique to specific lesion types. In addition, the size of a lesion displayed in a strain image, relative to that in a standard B-mode image, is about the same for benign lesions but the size is considerably larger for malignant lesions. The observations will likely significantly improve the discrimination of radiologically indeterminant lesions.