helical scanning


Also found in: Medical.

helical scanning

[′hel·ə·kəl ′skan·iŋ]
(communications)
A method of facsimile scanning in which a single-turn helix rotates against a stationary bar to give horizontal movement of an elemental area.
(electronics)
A method of recording on videotape and digital audio tape in which the tracks are recorded diagonally from top to bottom by wrapping the tape around the rotating-head drum in a helical path.
(engineering)
A method of radar scanning in which the antenna beam rotates continuously about the vertical axis while the elevation angle changes slowly from horizontal to vertical, so that a point on the radar beam describes a distorted helix.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Einstein and a team of researchers compared the radiation exposure incurred during a coronary CT angiography procedure using a 64-detector row helical scanning and volume scanning, using a 320-detector row volume CT scanner.
Using standard 64-detector row helical scanning as the benchmark, the effective radiation dose was reduced by 91 percent from 35.4 millisieverts (mSv) to 4.4 mSv using optimized 320-detector row volume scanning.
Normal axial CT is largely dependent on kVp and mAs, but with helical scanning, there is the added parameter known as pitch.
Bits of data can be recorded parallel to the tape motion in one or more tracks, diagonally in helical scanning approaches or perpendicular to the tape motion in rotary traverse schemes (see "Swallowing Planets" in the October 1989 JED).
Typically, imaging of the liver is performed with dynamic scanning or helical scanning. Dynamic scanning refers to the acquisition of images one at a time.
It is important for the technologist to assess the size of the liver before scanning because helical scanning of the entire liver in one scan is critical.[9]