Evaluation of ultrasound sensors for transcranial photoacoustic sensing and imaging

Thomas Kirchner; Claus Villringer; Jan Laufer

doi:10.1016/j.pacs.2023.100556

Evaluation of ultrasound sensors for transcranial photoacoustic sensing and imaging

Photoacoustics. 2023 Sep 17:33:100556. doi: 10.1016/j.pacs.2023.100556. eCollection 2023 Oct.

Authors

Thomas Kirchner¹, Claus Villringer^{1

2}, Jan Laufer¹

Affiliations

¹ Institut für Physik, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 3, 06120 Halle (Saale), Germany.
² Technische Hochschule Wildau, Hochschulring 1, 15745 Wildau, Germany.

Abstract

Photoacoustic imaging through skull bone causes strong attenuation and distortion of the acoustic wavefront, which diminishes image contrast and resolution. As a result, transcranial photoacoustic measurements in humans have been challenging to demonstrate. In this study, we investigated the acoustic transmission through the human skull to design an ultrasound sensor suitable for transcranial PA imaging and sensing. We measured the frequency dependent losses of human cranial bones ex vivo, compared the performance of a range of piezoelectric and optical ultrasound sensors, and imaged skull phantoms using a PA tomograph based on a planar Fabry-Perot sensor. All transcranial photoacoustic measurements show the typical effects of frequency and thickness dependent attenuation and aberration associated with acoustic propagation through bone. The performance of plano-concave optical resonator ultrasound sensors was found to be highly suitable for transcranial photoacoustic measurements.

Keywords: Optoacoustic; Photoacoustic; Transcranial; Ultrasound sensors.