Title :
Exposimetry of unfocused pulsed ultrasound
Author :
Zhang, Xiaohui ; Harrison, George H. ; Balcer-Kubiczek, Elizabeth K.
Author_Institution :
Dept. of Radiat. Oncology, Maryland Univ. Sch. of Med., Baltimore, MD, USA
Abstract :
Therapeutic applications of unfocused pulsed ultrasound have recently been identified and require specialized exposimetry. Spatial distributions of pressure and several measures of intensity are presented for an unfocused pulsed ultrasound field produced by a PZT-4 transducer with diameter 3.8 cm and center frequency 2 MHz. Distributions of pressure I/sub tp/ and I/sub m/ were adequately uniform over a 4-cm/sup 2/ area in a transverse plane at an axial distance of 7 cm, but not so for I/sub ta/ and I/sub pa/, which both exhibited off-axis asymmetric maxima.<>
Keywords :
acoustic intensity measurement; biomedical ultrasonics; biothermics; radiation therapy; 2 MHz; 3.8 cm; PZT-4 transducer; US hyperthermia; axial distance; center frequency; intensity measures; medical US treatment; off-axis asymmetric maxima; pressure spatial distribution; therapeutic ultrasound; transverse plane; unfocused pulsed ultrasound exposimetry; Drugs; Focusing; Frequency measurement; Laboratories; Neoplasms; Pressure measurement; Pulse measurements; Student members; Temperature distribution; Ultrasonic imaging;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
