A mechanical, three-dimensional, ultrasound-guided breast Biopsy apparatus

Abstract

We have designed a prototype three-dimensional ultrasound (US) guidance apparatus to improve breast biopsy outcomes. Features from stereotactic mammography and free-hand US guided biopsy have been combined with 3D US imaging. This breast biopsy apparatus (BBA) accurately guides a needle into position for firing into target tissue. We have evaluated the BBA in three stages. First, by testing the placement accuracy of a needle in a tissue mimic. Second, with tissue mimic phantoms that had embedded lesions for biopsy. Finally, by comparison to free-hand US-guided biopsy, using chicken breast phantoms. The first two stages of evaluation quantified the mechanical biases in the BBA. Compensating for these, the BBA achieved a 96% success rate in targeting 3.2 mm ‘lesions’ in chicken breast phantoms. The expert radiologists performing biopsies with free-hand US guidance achieved a 94% success rate. This has proven an equivalence between our apparatus and free-hand biopsy, for 3.2 mm lesions in -vitro, with a 95% confidence.