Systems and methods for classifying tissue using quantitative ultrasound techniques. Parameters are calculated directly from raw echo signal data acquired from a region-of-interest during an ultrasound scan and parametric maps are produced using these parameters. These parameters can be calculated after normalizing the echo signal data using reference data so as to mitigate the effects of variations in instruments settings, ultrasound beam diffraction, and attenuation effects. First-order and second- order statistical measures are computed from these parametric maps, and are used to classify the tissue or tissues in the region-of-interest. Using these systems and methods, tissue can be classified with different levels of classification. For example, a tissue characterized as malignant cancer can additionally be graded (e.g., Grade I, II, or III).
