Final answer:
CTA images are derived from a helical computed tomography (CT) scan, which uses cross-sectional X-ray images to construct detailed two-dimensional or three-dimensional views of the body's internal structures.
Step-by-step explanation:
CTA images come from a helical scan. A computed tomography (CT) or CAT scan is a sophisticated imaging technique designed to provide detailed, cross-sectional X-ray images of the body. In this process, a patient is positioned on a motorized platform and a scanner rotates around them, capturing X-ray images from various angles. These multiple X-ray images, or "slices," are then processed by a computer to produce a two-dimensional view of a specific area or can even be further analyzed to construct detailed three-dimensional images. The technology is centered around the principle that X-rays are absorbed or reflected differently by various types of tissue in the body. The result is a highly detailed image that provides greater insight into the body's internal structures, which is particularly useful for medical diagnosis and treatment. Computed tomography stands out for its ability to produce images that reveal minute details about structures within the body, which has fundamentally changed the landscape of modern diagnostic medicine.