X-ray Interaction With Matter Ch 10 Flashcards
Five Ways of X-ray Interaction With Matter
Coherent, Compton, Photoelectric Effect,
Pair Production & Photodisintegration
It interacts with whole atom
Low-Energy X-ray
It interacts with electrons
Moderate-Energy X-ray
It interacts with nuclei
High-Energy X-ray
The incident x-ray interacts with a target
atom, causing it to become excited
Coherent Scattering
The general graying of an image
Image Noise
The incident x-ray interacts with the outershell electron & ejects it from the atom
Compton Effect/Scattering
X-rays scattered back in the direction of the
incident x-ray beam
Backscatter Radiation
Compton scattering reduces…
image contrast
The incident x-ray interacts with the innershell electron
Photoelectric Effect
The photoelectric effect is
total x-ray absorption
The incident x-ray interacts with the nuclear
force field
Pair Production
A process wherein the mass of positron &
electron is converted to energy
Annihilation Radiation
The incident x-ray interacts directly into the
nucleus
Photodisintegration
Different degrees of absorption in different
tissues
Differential Absorption
Two Other Factors Important in Making a
Radiograph
- X-ray emission spectrum
- Mass density of patient tissue
A generalized dulling of the image by x-rays not representing diagnostic information
Image Noise
It results from approximately 0.5% of the xrays emitted by the x-ray tube
Radiographic Image
The quantity of matter per unit volume
Mass Density
Compounds used as an aid for imaging
internal organs with x-rays
Contrast Agent
It produces excellent high-contrast
radiographs of the organs of GI tract
Low-kVp Technique
It is used to outline the organ under
investigation & penetrate the CM to
visualized the lumen of the organ more
clearly
High-kVp Technique
Examination that uses air & barium for
contrast
Double Contrast Examination
The interaction in which x-ray disappears
Absorption Process
The removal of x-ray from a beam via the photoelectric effect
Absorption
The interaction in which x-ray is partially
absorbed
Scattering Process
The total reduction in the number of x-rays
remaining in an x-ray beam after penetration
through a given thickness of tissue
Attenuation
Attenuation is the product of..
Absorption and Scattering
