A method for handheld quantitative micro-elastography of excised human breast (Conference Presentation)

Abstract

Approximately a quarter of patients undergoing breast conserving surgery will need further surgery as close or involved surgical margins suggest they may have residual tumour in the breast. Handheld imaging probes capable of scanning the surgical cavity during the surgery have the potential to improve intraoperative assessment of surgical margins in breast conserving surgery thus allow real time assessment of completeness of tumour excision. In this paper, we present a handheld optical coherence elastography (OCE) probe, allowing us to acquire a 3D quantitative elastogram of a 6×6×1.5 mm volume in 3.4 seconds. Our technique is based on a compression OCE technique, referred to as quantitative micro-elastography (QME), where a compliant silicone layer is incorporated to measure stress at the tissue surface. To perform handheld scanning, we implemented a rapid scan pattern to enable B-scan rates of 215 Hz using a microelectromechanical system (MEMS) scanner: minimizing the time difference between B-scan pairs used to generate displacement maps thus minimizing the motion artefact caused by hand motion. We present handheld scans acquired from silicone phantoms where the motion artefact is barely noticeable. In addition, freshly dissected human breast tissue from a mastectomy was scanned with the handheld probe. The breast tissue elastograms are validated using standard histology and demonstrate our ability to distinguish stiff regions of tumour from benign tissue using this probe.