Real-time ultrasound elastography in neurosurgery

Abstract

This study furthers previous work by this group [1] on the use of ultrasound elastography intra-operatively in the brain. Real-time 2-dimensional (2D) ultrasound elastograms were acquired during neurosurgical operations for brain and spinal cord tumors, and, in select cases, approximately real-time 3-dimensional (3D) elastograms (volumes of axial strain data) were acquired in the brain. For the first time, elastograms were successfully generated in the spinal cord using vascular pulsations to generate internal strains. The results revealed strain data that correlated well with the surgeon's assessment of the stiffness of the tissues, and areas of reduction in cross-correlation coefficient and very high axial strain at tumor boundaries were found to correspond to cleavage planes. Off-line axial normal strain and axial shear strain calculation assisted in image interpretation. Benefits of this method in neurosurgery include pre-informing the surgeon as to the stiffness of the lesion and identification of dissection planes, both of which can lead to safer surgery.