This paper describes the field research, design and comparative deployment ofa multimodal medical imaging user interface for breast screening. The maincontributions described here are threefold: 1) The design of an advanced visualinterface for multimodal diagnosis of breast cancer (BreastScreening); 2)Insights from the field comparison of single vs multimodality screening ofbreast cancer diagnosis with 31 clinicians and 566 images, and 3) Thevisualization of the two main types of breast lesions in the following imagemodalities: (i) MammoGraphy (MG) in both Craniocaudal (CC) and Mediolateraloblique (MLO) views; (ii) UltraSound (US); and (iii) Magnetic Resonance Imaging(MRI). We summarize our work with recommendations from the radiologists forguiding the future design of medical imaging interfaces.