Stereotactic Transcranial Focused Ultrasound Targeting System for Murine Brain Models

Abstract

An inexpensive, accurate focused ultrasound stereotactic targeting method guided by pre-treatment MRI images for murine brain models is presented. Uncertainty of each sub-component of the stereotactic system was analyzed. The entire system was calibrated using clot phantoms. The targeting accuracy of the system was demonstrated with an in vivo mouse glioblastoma (GBM) model. The accuracy was quantified by the absolute distance difference between the prescribed and ablated points visible on the pre- and post-treatment MR images, respectively. A pre-calibration phantom study (N= 6) resulted in an error of 0.32 ± 0.31, 0.72 ± 0.16, and 1.06 ± 0.38 mm in axial, lateral, and elevational axes, respectively. A post-calibration phantom study (N= 8) demonstrated a residual error of 0.09 ± 0.01, 0.15 ± 0.09, and 0.47 ± 0.18 mm in axial, lateral, and elevational axes, respectively. The calibrated system showed significantly reduced (p<0.05) error of 0.20 ± 0.21, 0.34 ± 0.24, and 0.28 ± 0.21 mm in axial, lateral and elevational axes, respectively in the in vivo GBM tumor-bearing mice (N= 10).