The effect of transducer bandwidth on ultrasonic image characteristics.

PURPOSE: This study was conducted to determine the effect of transducer bandwidth on the characteristics of ophthalmic ultrasound images.

METHODS

B-scan images produced using two transducers, one with a narrow bandwidth and the other with a broad bandwidth, both having nominal center frequencies of 10 MHz, were evaluated. Comparative scans were made of a tissue-mimicking phantom, an intraocular tumor, and a vitreous hemorrhage.

RESULTS

Results showed that broadband transducers gave improved resolution and finer speckle texture, but had lower sensitivity. Broadband transducers were most suitable for situations in which resolution was more important than sensitivity, such as imaging of tumors. The greater sensitivity of the narrowband probe made it most useful for evaluation of vitreous complications, such as hemorrhage and membranes.

CONCLUSION

In addition to transducer frequency, bandwidth should be taken into account when choosing a transducer for a specific ophthalmic imaging application. Both broad- and narrowband transducers have relative advantages in particular applications.