Spiral CT examination obtains information on a continuous level and yields a flat image, while 3D CT integrates the images obtained from a CT scan using a computer and yields a three-dimensional image. Spiral CT refers to a type of CT machine that is a scanning method in which the X-ray bulb tube rotates continuously around the body while the scanning bed is automatically fed into the bed at a uniform speed so that the sweeping lines are scanned in a spiral shape on the body, obtaining continuous level information. Spiral CT obtains coronal, sagittal, and transverse cross-sectional images, which are two-dimensional flat images. Three-dimensional CT is based on spiral CT scanning, enhancement scanning and other examinations, the use of computers to obtain two-dimensional image analysis, integration, the formation of three-dimensional images, so as to clearly and intuitively observe the lesions. Compared with spiral CT, 3D CT can more clearly show subtle lesions, such as blood vessels, airways, nerves, bones, organ surfaces and other parts of the lesions. Usually, patients will be examined by spiral CT first, and if lesions are found and cannot be diagnosed conclusively, 3-D CT can be used as prescribed by the doctor to assist in the diagnosis of the disease.