Spiral CT thumb|Drawing of CT fan beam and patient in a CT imaging system thumb|CT scan of the thorax. The axial slice (right) is the image that corresponds to number 2/33 on the coronal slice (left). Spinning tube, commonly called spiral CT, or helical CT, is an imaging technique in which an entire X-ray tube is spun around the central axis of the area being scanned. These are the dominant type of scanners on the market because they have been manufactured longer and offer a lower cost of production and purchase. The main limitation of this type of CT is the bulk and inertia of the equipment (X-ray tube assembly and detector array on the opposite side of the circle) which limits the speed at which the equipment can spin. Some designs use two X-ray sources and detector arrays offset by an angle, as a technique to improve temporal resolution.
Spiral CT thumb|Drawin,g of CT fan beam and patient in a CT imaging system thumb|CT scan of the thorax. The axial slice (right) is the image that corresponds to number 2/33 on the coronal slice (left). Spinning tube, commonly called spiral CT, or helical CT, is an imaging technique in which an entire X-ray tube is spun around the central axis of the area bein?g scanned. These are the dominant type of scanners on the market because they have been manufactured longer and offer a lower cost of production and purchase. The main limi!tation of this type of CT is the bulk and inertia of the equipment (X-ray tube assembly and detector array on !the opposite side of the circle) which limits the speed at which the equipment can spin. Some designs use two X-ray sources and detector arrays offset by an angle, as a technique to improve temporal resolution.