The Distal Acoustic Spotlight: a novel method to visualize the distal acoustic space on ultrasound

Abstract

Objective: We have developed a novel computer-aided diagnosis (CAD) visual aid tool called the Distal Acoustic Spotlight (DAS). The objective of the current study was to test whether our method could accurately highlight the distal acoustic effects of a wide variety of structures commonly found in ultrasound imaging, and whether this would improve interpretation of such images by radiology trainees. Methods: Twenty ultrasound images were examined. Half of these contained structures that exhibited distal acoustic shadowing, whereas the other half featured objects that displayed distal acoustic enhancement. We applied the DAS to each such image, tracing out a region-of-interest (ROI) around the shadowing/enhancing structure. The algorithm then generates lines that estimate the projection of shadowing/enhancement in the distal acoustic space and overlays these onto the original grayscale image. Results: By blinded consensus of two expert radiologists, the DAS accurately highlighted the distal acoustic shadowing or enhancement in ninety percent of the images. By anonymous survey of nineteen radiology residents, the method improved confidence in their assessment of distal acoustic shadowing or enhancement for roughly a third of all images interpreted. Conclusions: The DAS accurately identifies and improves trainee assessment of distal acoustic shadowing/enhancement on ultrasound. The approach can thus be a useful CAD tool in evaluating clinically significant distal acoustic effects.