The chest CT scan, also known as thoracic CT is an imaging technique that uses X-rays to create cross-sectional images of the thorax and upper abdomen. The test lasts a few minutes is that the X-ray beam of the machine rotates around the patient. It is indicated performed after a chest injury; when a tumor is suspected; to determine the size, shape and position of organs and chest; also, to look for bleeding or fluid buildup, either in the lungs or other areas.