Automated Breast Ultrasound: Dual-Sided Compared with Single-Sided Imaging

Abstract

We report the design and performance of a mammographically configured, dual-sided, automated breast ultrasound (ABUS) 3D imaging system. Dual-sided imaging (superior and inferior) is compared with single-sided imaging to aid decisions on clinical implementation of the more complex, but potentially higher quality dual-sided imaging. Marked improvement in the image quality and coverage of the breast is found in dual-sided ultrasound over single-sided ultrasound. Among hypoechoic masses imaged, there are increases in the mean contrast-to-noise ratio (CNR) of 57% and 79%, respectively, for spliced dual sided vs. superior or inferior single-sided imaging. The fractional breast volume coverage, defined as the percentage volume in the transducer field of view that is imaged with clinically-acceptable quality, is improved from 59% in both superior and inferior single-sided imaging to 89% in dual-sided imaging. Applying acoustic coupling to the breast requires more effort or sophisticated methods in dual-sided imaging than in single-sided.

Technical Note: Development of a combined molecular breast imaging/ultrasound system for diagnostic evaluation of MBI‐detected lesions

“…The ultrasonic transparent mesh membrane was found to work well, but may limit good ultrasonic coupling for lesions at the edges of the breast. Other investigators have reported achieving good ultrasonic coupling at the breast periphery in this geometry with a mesh compression paddle or with a transducer in oil under the breast . Repositioning of the breast should enable adequate acoustic coupling for most lesions.…”

“…Other investigators have reported achieving good ultrasonic coupling at the breast periphery in this geometry with a mesh compression paddle or with a transducer in oil under the breast. 8,9 Repositioning of the breast should enable adequate acoustic coupling for most lesions. Future iterations of an MBI/US system would ideally integrate the sonographically compatible mesh compression paddle into an existing dual-head MBI unit, with modifications to retract one MBI detector and allow ultrasound scanning to be performed.…”

“…In cases of lesions with a subtle presentation on ultrasound, or in complex cases where multiple masses and cysts are present, the difference in the shape of the breast between MBI and ultrasound may make it difficult to correlate the anatomical information from ultrasound with the functional information from MBI. Recent developments of automated breast ultrasound systems that utilize dual‐sided imaging, where the breast is imaged in an analogous manner to MBI or mammography, may greatly increase the likelihood of detecting a sonographic correlate to the MBI finding . Alternatively a combined MBI and ultrasound imaging system that images the lightly compressed breast in the same configuration for both modalities may also facilitate better lesion correlation, and may reduce the number of follow‐up MBI examinations or the need to proceed to contrast‐enhanced breast MRI.…”

“…Recent developments of automated breast ultrasound systems that utilize dual-sided imaging, where the breast is imaged in an analogous manner to MBI or mammography, may greatly increase the likelihood of detecting a sonographic correlate to the MBI finding. 8 Alternatively a combined MBI and ultrasound imaging system that images the lightly compressed breast in the same configuration for both modalities may also facilitate better lesion correlation, and may reduce the number of follow-up MBI examinations or the need to proceed to contrast-enhanced breast MRI. The practicality of a dual-modality system has been recently demonstrated by Vaughan et al who reported on a combined digital mammography and automated breast ultrasound system, and showed its potential as a screening device.…”

Acoustic beam anomalies in automated breast imaging

“…[29][30][31] Figure 1 shows the signal dropout areas presented in three different B-mode images, acquired from three different patients using our mammography-configured automated ultrasound scanner developed inhouse. [32][33][34] As can be seen, signal dropout areas occurring around the papilla could negatively result in misinterpretations in breast cancer diagnosis and substantially increasing further procedures for definitive diagnosis. Considering this, it is of particularly interest that automated ultrasonic imaging of the breast in the mammographic geometry, where the ultrasound signal goes through couplant and penetrates the skin at an angle (nonperpendicular direction), oftentimes misses much information of the subareolar tissues due to bending of the acoustic beam by refraction and reflection, leading to the low signal-to-noise ratio (SNR).…”