Position-Indicating Device
Also written as: PID
A cylindrical or rectangular tube attached to the X-ray tube head that directs and collimates the X-ray beam toward the image receptor during intraoral radiography.
Full Definition
The position-indicating device (PID) is an integral component of the intraoral X-ray unit, serving to guide beam direction, standardise source-to-receptor distance, and provide additional beam collimation. PIDs may be cylindrical (round) or rectangular, with rectangular PIDs preferred because they limit beam area more precisely, thereby reducing patient dose. The PID is sometimes informally called a 'cone', though this term is technically inaccurate for modern devices, which are not conical. Editors should render the full form as 'position-indicating device' (hyphenated compound modifier before a noun: 'position-indicating-device length') and the abbreviation as 'PID' after first use. Confusion with 'cone' should be corrected in copy.
Usage
Usage note: Abbreviate as 'PID' after first use. Discourage informal use of 'cone' in formal reports. Hyphenate as compound modifier.
In Context
- "A rectangular position-indicating device was used to reduce radiation scatter and improve image sharpness." — Radiographic technique report
- "The PID was aligned using the film-holding device to ensure correct horizontal and vertical angulation." — Dental radiography protocol document