Before this new technology can be used in the clinic routinely, it is necessary to perform a large number of studies to find the optimal way to use it. In this study, the investigators are aiming to find how thick the slices or layers representing the breast should be in the image when shown to the radiologist. The difference between these two thicknesses in how useful the images are to the radiologist could be important. The investigators are trying to determine if slicing the image of the breast into thicker slices will make the job of the radiologist easier or not when deciding to recommend or not a biopsy (laboratory analysis) of what the previous mammogram found. To find the answer to this question, the investigators will image patients with their tomosynthesis machine and look at the tomosynthesis images with the thin and thick slices. The radiologists that read each image will decide if they would have recommended the patient to get a biopsy based only in each of these images. The recommendations based on the images with thin slices and the recommendations based on the images with thick slices will be compared with what was actually recommended using the standard clinical tests. The investigators hope to find that the thicker slices help more than the thinner slices when trying to decide if biopsy is needed or not.