High filling factor vs . high channel count : which one wins in 3 T breast imaging ?

Target Audience: Clinicians/scientists designing coils and/or interested in better breast imaging Purpose: Higher signal to noise ratio (SNR) can translate in higher specificity of breast cancer detection. High temporal resolution dynamic contrast enhanced (DCE)-MRI imaging, enabling good kinetic data modeling, and high resolution diffusion weighted imaging, all afforded by higher image SNR, are generally accepted means to reduce the number of un-needed MRI triggered biopsies [1-2]. While increasing the channel count of an array is a straightforward solution for the image SNR problem, the choice of array geometry for this anatomy is difficult. Since breast sizes in the wide population vary between 125ml and 1900ml [3], an array that has the highest number of coils and the highest filling factor for each subject is usually not an option. While multiple cup size coils can be a choice in a research environment [4], such approach is not commercially viable, due to the high cost incurred to build these multiple options. Commercial breast coil design has to usually make the upfront choice between rigid setups, that use the maximum number of channels for all subjects (at the expense of small filling factors in certain subjects), to semi-rigid/movable coils that preserve good filling factors in all subjects, at the expense of using fewer coils in women with small breasts. We will analyze the trade-offs between the two choices in a 3T, flexible, 31 channel breast array, that has the capability of working efficiently in both scenarios.