Correlation of ultrasound phase with physical skull properties.

摘要: Abstract Noninvasive treatment of brain disorders using focused ultrasound (US) requires a reliable model for predicting the distortion field due to skull physical parameters obtained in vivo . Previous studies indicate that control US phase alone is sufficient producing focus through phased array. The present study concentrates on identifying methods estimate distortion. This will be critical future clinical use noninvasive therapy. Ten ex human calvaria were examined. Each sample was imaged water computerized tomography (CT). information used determine inner and outer surfaces, thickness as function position, internal structure. Phase measurement over series points by placing fragment between transducer receiver with normal transducer. Correlation found shift. A linear fit data follows predicted homogeneous when average speed sound 2650 m/s used. Large variance (SD = 60°, mean 50°) indicates additional role bone density fluctuations. In an attempt reduce variance, first studied three-layer Next, density-dependent fluctuation introduced both single-layer models. It determined adjustment propagation speeds improves overall prediction. Results demonstrate it possible from CT images predict induced accurately enough therapeutic aberration correction. addition, measurements provide coefficients dependence can treatments. (E-mail: clement@bwh.harvard.edu)