an implement consisting of a broad blade or scoop attached to a long handle, used for taking up, removing, or throwing loose matter, as earth, snow, or coal. 2. any fairly large contrivance or machine with a broad blade or scoop for taking up or removing loose matter: a steam shovel. 3. a shovelful.
Advanced Cone Beam CT Technology. CBCT scanners, on the other hand, are based on volumetric tomography, using a 2D extended digital array providing an area detector. This is combined with a 3D x-ray beam (Fig. 1b). The cone-beam technique involves a single 360Â° scan in which the x-ray source and a reciprocating area detector synchronously move around the patientâs head, which is stabilized with a head holder. At certain degree intervals, single projection images, known as âbasisâ images, are acquired.
However, because of the curved surfaces of the lens, the bending causes the light rays in a beam either to come together (converge, picture on left-hand side) or to spread out (diverge, picture on right-hand side). Because a convex lens can cause rays of light to converge, it can produce an image on a screen.