Evaluation of Hydrophone Spatial Averaging Effect in Near Field Measurement for Determining Mechanical Index

Abstract

An evaluation method of the hydrophone spatial averaging effect in near field measurement using numerically calculated ultrasonic fields for determining the mechanical index related to diagnostic ultrasound is proposed. To demonstrate that the accurate evaluation can be achieved using the method, it is investigated whether a difference between acoustic pressures of an ultrasonic field radiated from a plane circular transducer measured by hydrophones with two different active element sizes is reduced by the correction using the evaluation. The results confirmed that the proposed method is available for evaluating the effect quantitatively.