Biomedical Physics & Engineering Express, 2016 V2(3) 035016 DOI:10.1088/2057-1976/2/3/035016
Over the past two decades the feasibility for using transcranial ultrasound as both a therapeutic and diagnostic tool has been established. Various aberration-correction techniques have been proposed to achieve transcranial focusing, including CT-derived model based corrections, ultrasound-derived model based corrections, magnetic reso- nance acoustic radiation force (MR-ARFI) techniques, and techniques involving the invasive introduction of an acoustic source or receiver into the brain. Here, we inves- tigate the correlation between transcranial infrared light (IR) and transcranial ultra- sound, where we examine whether IR could be an indicator of any of the key acoustic properties that affect transcranial transmission (signal attenuation, speed of sound, and bone density). Nine human skull samples were utilized in the study. The interior of each sample was illuminated over its inner surface using a diffuse light source. Light transmitted to the outer surface was detected by a 3-mm diameter 940-nm infrared sensor. Acoustic measurements were likewise obtained in a water tank using a 12.7-mm diameter 1-MHz source and a needle hydrophone receiver. Results reveal a positive correlation between the acoustic time-of-flight and optical intensity (the correlation coefficient is between 0.5 and 0.9). Subsequent investigation shows this correlation to hold independent of the presence or absence of dura mater on the samples. Poor cor- relation is observed between acoustic amplitude and optical intensity (the correlation coefficient is between 0.1 and 0.7).
Copyright © 2016 IOP
This article may be downloaded for personal use only. Any other use requires prior permission of the publisher.
Clinic Ultrasound Laboratory (クレメント超音波研究室)
Cleveland Clinic (クリーブランド・クリニック),
Lerner Research Institute
Case Western Reserve University