Detection of blunt force trauma liver injuries using shear wave elastography.

Abstract

Violent impacts, such as vehicle accidents, frequently yield injuries of the liver due to its size and its location in the abdominal cavity. Frequently these injuries are fractures which may lead to life-threatening hemorrhage. Currently, a fast means of non-invasively visualizing areas of injuries in the liver due to blunt force trauma does not exist; hence there is a need to develop better imaging modalities of hepatic injuries to assist in clinical assessments. In this study, we investigate the feasibility of visualizing liver fractures using shear wave elastography. We hypothesize that there is a shear modulus discontinuity between the two edges of a fracture, and we expect that these discontinuities can be observed from the imaging at the boundary of the split. In testing the hypothesis, we first use optical methods to track and study the displacements and motion trajectories of different regions of a hepatic injury phantom in response to shear wave excitations. Then, following Fink et al. [Proc.-IEEE Ultrason. Symp. 1767 (2002)], we implement similar methods with a Verasonics ultrasound system and examine the propagation of shear waves induced by the acoustic radiation force in tissue-mimicking phantoms and ex vivo liver. [Work supported by NIH 1R01GM77318.]