THE EFFECT OF TRANSDUCER BANDWIDTH ON ULTRASONIC IMAGE CHARACTERISTICS

Purpose: This study was conducted to determine the effect of transduce r bandwidth on the characteristics of ophthalmic ultrasound images. Me thods: B-scan images produced using two transducers, one with a narrow bandwidth and the other with a broad bandwidth, both having nominal c enter frequencies of 10 MHz, were evaluated. Comparative scans were ma de of a tissue-mimicking phantom, an intraocular tumor, and a vitreous hemorrhage. Results: Results showed that broadband transducers gave i mproved resolution and finer speckle texture, but had lower sensitivit y. Broadband transducers were most suitable for situations in which re solution was more important than sensitivity, such as imaging of tumor s. The greater sensitivity of the narrowband probe made it most useful for evaluation of vitreous complications, such as hemorrhage and memb ranes. Conclusion: In addition to transducer frequency, bandwidth shou ld be taken into account when choosing a transducer for a specific oph thalmic imaging application. Both broad- and narrowband transducers ha ve relative advantages in particular applications.