1. A method to analyze breast density based on magnetic resonance imaging (MRI) of a breast of a patient comprising: segmenting an MR image of the breast from one set of three-dimensional breast MRI images; determining the three dimensional morphological parameter of compactness of the breast tissue of the patient wherein compactness=S fibro 3/2 /V fibro , where S fibro is the surface area of fibroglandular tissue and where V fibro is the total volume of fibroglandular tissue; and analyzing the amount of dense tissue and the morphological distribution of the dense tissue.