Microwave-induced thermoacoustic tomography through an adult human skull.

Abstract

To demonstrate the feasibility of microwave-induced thermoacoustic tomography (TAT) of adult human brain. We analyzed the electric field distribution radiated from an antenna to acquire homogeneous illumination. We first imaged the anatomical structures in a rat's trunk to validate the thermoacoustic contrast invivo. We then imaged an agar cylinder through an adult human skull exvivo todemonstrate transcranial penetration of both microwave and ultrasound. We also analyzed the specific absorption rate to show the conformance to the safety standard for human electromagnetic exposure. We successfully acquired cross-sectional images of the rat's trunk invivo. Major blood vessels and organs are clearly visible. The transcranial image shows that TAT can image through the adult human skull and reveal an agar enclosed by the skull. Microwave-induced TAT of a rat's trunk invivo and an agar phantom through an adult human skull exvivo has been demonstrated experimentally. This study demonstrates both the TAT contrasts invivo and the capability of transcranial imaging, showing potential of TAT for adult human brain imaging with high contrast and penetration.