A comparison of digital mammography and phase contrast tomography for visualisation of breast cancers.

Abstract

Purpose: Two-dimensional (2D) digital mammography (DM) is the current gold standard in breast cancer screening and diagnostic imaging however limitations exist with superimposition tissues and poor contrast between healthy and cancerous tissues, particularly in dense breasts. Phase-contrast computed tomography (PCT) is a novel three-dimensional (3D) imaging approach utilising both absorption properties and refraction information of X-rays. PCT has the potential to provide additional information for breast cancer diagnosis1. This study aims to assess the clinical usefulness of PCT imaging compared with DM via radiological subjective visualisation of excised cancers. Method(s): Thirty patients underwent mastectomies, and the excised samples were subsequently imaged with PCT. The pre-surgery DM images were obtained as well as the post-surgical histological results. The 30 cases included benign cases, 22 breast cancers of varying types and a range of breast densities. A training package to allow radiologists to interpret the PTC images was developed and after completion, 2 expert breast imaging radiologists read the DM and PCT images, giving a rating of confidence as to visualisation of the cancers. Result(s): The results show that most of the lesions were adequately visualised and detectable in PCT and DM (88%, 19/22 cases). Lower confidence was expressed with visualising high-grade DCIS lesions and LCIS lesions in DM imaging, compared with PCT and lower confidence of visualisation of Invasive Lobular Carcinoma with PCT than DM. A pictorial essay of cases is included. Conclusion(s): PCT subjective visualisation of excised cancers was equal to DM, with new research underway to image women pre-surgery.