Deformation correction in ultrasound images using contact force measurements

During an ultrasound scan, contact between the probe and the skin deforms the underlying tissue. This can be considered a feature (as in elastography), but is in general undesirable, particularly for 3D scanning. In this paper we propose a novel system to correct this deformation by measuring the contact force at the time of the ultrasound scan and then using an elastic model to predict the tissue deformation. The inverse of this deformation is then applied to the image, generating the image that would have been seen had there been no contact with the probe. A prototype system has been implemented using an a priori finite element model to predict the deformation. This has been tested on gelatine phantoms and shown to remove the contact deformation and so give improved 3D reconstructions