Direct comparison of ultrasound and tactile imaging in measuring lesion diameter in breast phantoms

Previous clinical study has shown tactile imaging (TI) is better than ultrasound at measuring breast lesion diameter. Given continuing research in this area, and significant respective advancements over the last 20 years, this needs revisited. This paper compares TI and ultrasound in accurately measuring breast lesions (4-18 mm) in chicken breast and silicone phantoms; revealing comparative strengths/weaknesses to combine strengths in a future integrated prototype. The results show that ultrasound has greater accuracy than TI on chicken breasts (Mean Absolute Error=9.28% vs 16.02%) and silicone (28.50% vs. 33%) phantoms. This contrasts previous studies where TI was more accurate than ultrasound, due to technological advancements over time. However, TI offers user-friendly rapid imaging, with simpler visualization of lesions, due to large field-of-view, vs. ultrasound, with lower training burden. This work directly compared modern TI and ultrasound, indicating ultrasound is better for lesion characterization and TI better for initial detection. This provides a baseline for future integration of these techniques for simple screening, following the recent drive for hybrid imaging systems.