Use of low-energy contrast-enhanced spectral mammography (CESM) as diagnostic mammography-proof of concept

• Proof of same contrast detail resolution of low-energy CESM compared to FFDM.
• Suspicious mammographic findings can be displayed similarly with low-energy CESM and FFDM.
• This proof-of-concept study shows feasibility to use of low-energy CESM as diagnostic mammography.
• Diagnostic use of CESM can reduce radiation exposure of the breast by avoiding redundant exams.

Rationale and objectivesTo prove the diagnostic potential of low-energy images from contrast enhanced spectral mammography (CESM) by comparing low-energy CESM with full-field digital mammography (FFDM) with a contrast detail phantom and in patients.Materials and methodsLow-energy CESM and FFDM images of a contrast detail mammography phantom (CDMAM) were performed at different simulated breast thicknesses and automatically analysed with respect to contrast detail visibility, sensitivity, specificity, positive and negative predictive value and accuracy by two different software tools. Results from phantom studies were confirmed by comparing the detection of benign and suspicious findings of the breast in FFDM and low-energy CESM of 20 patients with breast cancer. Pearson correlation was calculated and agreement between measured sizes of benign and suspicious findings with FFDM and low-energy CESM was evaluated with Bland–Altman analysis.ResultsContrast-detail threshold of the low-energy CESM was equal to FFDM and below the acceptable and achievable limits given by the European Reference Organisation for Quality Assured Breast Screening and Diagnostic Services (EUREF). Sensitivity, specificity, positive and negative predictive value and accuracy of low-energy CESM were equal, or even better as FFDM. Size measurements of masses, parenchymal asymmetries, micro- and macrocalcifications with low-energy CESM significantly correlated with FFDM. No significant over- or underestimation of size of mammographic finding was seen using low-energy CESM compared to FFDM.ConclusionThese data prove the concept to use the low-energy CESM image as diagnostic mammography.