CT scans can be used to identify disease or injury within various regions of the body. For example, CT has become a useful screening tool for detecting possible tumors or lesions within the abdomen. A CT scan of the heart may be ordered when various types of heart disease or abnormalities are suspected. CT can also be used to image the head in order to locate injuries, tumors, clots leading to stroke, hemorrhage, and other conditions. It can image the lungs in order to reveal the presence of tumors, pulmonary embolisms (blood clots), excess fluid, and other conditions such as emphysema or pneumonia. A CT scan is particularly useful when imaging complex bone fractures, severely eroded joints, or bone tumors since it usually produces more detail than would be possible with a conventional x-ray.NIBIB is funding research for development of a dedicated breast CT scanner that allows the breast to be imaged in 3D and could help radiologists detect hard-to-find tumors. The scanner produces a dose comparable to that of a standard x-ray mammogram and doesn’t require compression of the breast. In this breast CT scanner, a woman lies prone in a specially designed large table with her breast suspended in a special opening in the scanning bed. The scanner rotates around the breast, without passing through the chest, thus reducing the radiation that would be delivered to the chest in a conventional CT scanner. he amount of radiation required for a CT scan depends on a number of variables, including the size of the patient, the part of the body being scanned, and the diagnostic task at hand. For example, smaller patients require less radiation than larger patients, and scanning a denser part of the body, such as soft tissue near the pelvis, requires more radiation than scanning the lungs. In addition, diagnostic tasks that require high image clarity, such as locating a faint tumor, generally require more radiation. The goal of this project is to modify both the hardware and software of modern CT systems so that the device can adapt the shape, position, and intensity of the x-ray beam to the specific imaging scenario. The research leverages patient-specific anatomical models and mathematical models of imaging performance to direct where they are needed and, consequently, to avoid or to limit x-ray exposure where it is not needed. This will help maximize imaging performance for specific diagnostic tasks while minimizing radiation exposures..