Plane-Wave Compounding in Automated Breast Volume Scanning: A Phantom-Based Study

Abstract

The goal of this study was to assess whether it is viable to implement plane-wave imaging in the Automated Breast Volume Scanner (ABVS) to speed up the acquisition process. This would allow breath-hold examinations, thus reducing breathing artifacts without loss of imaging quality. A calibration phantom was scanned in an Automated Breast Volume Scanner-mimicking setup using both dynamic receive focusing with a fixed transmit focus and unfocused plane-wave compounding. Contrast-to-noise ratio and lateral resolution were compared using two beamforming schemes, delay-and-sum and Stolt's f-k algorithm. Plane-wave compounding using only 11 compounding angles and Stolt's f-k algorithm provided image quality similar to that of focused transmission with dynamic receive focusing (contrast-to-noise ratios = 10.3 and 10.8 dB for Stolt's f-k migration with Hann apodization and focused transmission, respectively; full width at half-maximum = 0.38 and 0.4 mm, respectively; all at 30-mm depth with transmit focus at 30 mm) with a higher signal-to-noise ratio at all depths. Furthermore, a full 3-D volume of a breast-mimicking phantom was scanned using this optimal set of compounding angles and different speeds (10, 20 and 50 mm/s) to assess the impact of scanning time on image quality. Only minor differences in contrast-to-noise ratio were found (cyst 1: 6.0 ± 0.3 dB, cyst 2: 5.5 ± 0.2 dB, cyst 3: 5.7 ± 0.5 dB). These differences could not be correlated to the movement speeds, indicating that acquisition speed does not significantly affect image quality. Our results suggest that plane-wave imaging will enable breath-hold automated breast volume scanning examinations, eliminating breathing artifacts while otherwise preserving similar image quality.

Keywords: Automated Breast Volume Scanner; Breast ultrasound; Fourier-domain beamforming; Plane-wave imaging; Ultrafast imaging.