Computed Tomography (CT)
Computed tomography is an X-ray based method to generate three dimensional images. The word tomography means slice-picture because the images generated by CT are often shown as slices through tissues. Whereas simple X-ray images including breast mammography show a shadow or projection of the patient so that different tissues on top of one another can’t be separated, CT separates these structures and shows a true model of what is in tissue. Although ordinary CT scanners deliver too much radiation and have too low resolution to be used for breast screening, new CT scanners specially designed for breast scanning are being tested.
In a CT scan, an X-ray tube is rotated around the patient to make lots of X-ray images from many different angles, so that it is similar to having many small X-ray mammograms. These images are combined by a computer to generate the three dimensional image. Specialized breast CT uses special high resolution detectors similar to those used in digital mammography. The patient lies prone with a breast hanging down, and the detector and X-ray rotate around the breast so that radiation does not get blocked by the rest of the patient.
For more information, visit: http://radiology.rsna.org/content/246/3/725.figures-only