Chapter 15: Beam Restriction – Study Guide

Flashcards covering key terms and concepts related to beam restriction and its effects on radiographic imaging.

Beam Restriction

Controls the size and shape of the x-ray field, affecting scatter radiation, patient dose, and image quality.

Compton Scatter

Radiation that changes direction after hitting matter, causing image fog and reducing contrast.

Field Size (FS)

Refers to how open the x-ray beam is; larger FS produces more scatter and fog.

kVp (kilovolt peak)

Controls the energy of x-ray photons; increasing kVp increases energy but decreases contrast.

Penumbra

A fuzzy edge of an image caused by beam divergence, leading to less sharpness.

Positive Beam Limitation (PBL)

Automatically adjusts the x-ray beam field size to match the image receptor size.

Photoelectric Effect

An absorption process that increases image contrast by affecting the interaction of x-rays with matter.

Off-Focus Radiation

Unwanted radiation from areas outside the focal spot resulting in image shadows.

Ancillary Devices

Tools like lead blockers and compression devices used to control scatter and improve image contrast.

Compression

A technique that reduces patient thickness to decrease scatter and dose.