CAT scan, spiral means: Spiral CAT scanning is a very advanced CAT scanning technique. It involves the continuous movement of the patient though the scanner. This allows for faster scans and better definition of internal structures. Spiral-CAT scanning allows for better visualization of internal tissues and blood vessels, including those in the chest cavity. This scanner can be especially useful in rapid assessment of severe injuries such as those from automobile accidents.
(in Medical Dictionary)

What else does CAT scan, spiral mean?

Spiral CAT scan: Conventional computerized axialtomography scan. CAT scan (or CT scan) is an xray procedure that combines multiple xray images with the help of a computer. It generates cross-sectional views, and, where necessary, 3-D images of internal organs and structures. A CAT scan can be used to identify abnormal and normal structures within the body, or to assist with procedures such as the precise placement of instruments and treatments.
(in Medical Dictionary)

The spiral CAT scan can also be referred to by the helical scan.
(in Medical Dictionary)