Technical note: dual compression mammography using computed radiography

On mammography most malignant growths may be seen as a tethered mass or architectural distortion. Benign lesions such as cysts and fibroadenomas have no focal tethering and are usually well circumscribed. Computed radiography (CR) is a direct digital system which may be used for mammography. One of the main advantages of CR is its wide exposure latitude allowing images to be acquired at lower exposures than required for film-screen systems. A technique was developed, utilizing the exposure latitude of CR, to acquire two mammograms of the same breast at two slightly different compressions, but using approximately the same exposure as a single film-screen mammogram. These images were then "animated" on a computer allowing the fibrous septa movement to be visualized. The movement of the fibrous septa in the presence of an abnormality was used to help confirm whether a lesion was benign or malignant. This technique may have clinical application in classifying architectural distortions and masses which are ultrasonically benign but later found to be malignant. Microcalcifications cannot be used as a diagnostic indicator with this technique because of the increased noise associated with the lower exposures. The increased noise did not affect the visualization of masses.