Optimizing visualization of breast microcalcifications
We combine our results from a series of clinical, experimental, and analytical studies to present comprehensive recommendations for the improved visualization of breast microcalcifications with ultrasound. Such improved visualization would extend the utility of breast ultrasound in guiding biopsy and in the differentiation of breast lesions, particularly in the mammographically dense breast. The in vivo clinical data used to inform our recommendations were collected with a Siemens Elegra scanner and 7.5 and 10 MHz probes, and include breast tissue backscatter measurements (N = 16), channel-by-channel RF echo data from microcalcifications (N = 7), and measurements of speckle statistics in breast tissues (N = 16). Our measurements of speckle statistics suggest that echoes from these tissues do not exhibit fully-developed speckle (SNR = 1.3-1.4 vs. 1.85 control, 1.91 theoretical). Imaging parameters considered include sound speed error, phase aberration, probe frequency, spatial resolution, and speckle reduction by compounding. We compare the relative impact of these parameters on visualization using, among other performance metrics, the area under the ROC curve AUC. We identify the overall performance trends so demonstrated in the interest of guiding improvements in breast imaging with ultrasound.
