A prototype scanner for ultrasonic echo tomography through skullbone

A prototype scanner for ultrasonic echo tomography of the head was developed. The system consists of a personal computer, a single 1-MHz wide-beam transducer, transmitting/receiving electronics, and a water bath with scanning mechanics. Only a single scan is needed for data acquisition. Therefore, the scanner has a scanning time of only about 3 s and a reconstruction time of about 5 s for a 90° image. Two different reconstruction schemes can be used: the wavefront backward propagation algorithm (holographic approach) and the filtered backpropagation method (tomographic approach). Problems associated with in vivo imaging of the human head can be reduced with the method, which allows throughout the scan almost perpendicular transducer position of the skullbone. The results, especially in children, are encouraging and demonstrate the feasibility of the method for pediatric brain imaging