Chapter 6: XRay Components Review

Focal spot

section of target struck by electron beam

As an anode is angles, focal spot size ___ in the image

changes

Effective Equation

Original x Sin(ϴ)

ϴ in the effective equation represents…

the angle of the anode relative to the photon beam

A ___ angle leads to a ___ field, which makes resolution worse

bigger; larger

Heel effect

part of beam is attenuated by the anode and is therefore weaker

Automatic Exposure Control (AEC)

meters that turn off the beam when it approaches a dose limit/exposure level

Emission vectors

qQuality, quantity, exposure

Quality

energy variance

Quantity

number of particles

Exposure

charge is produced in the object

Penumbra

non-uniform edge of X-ray fields caused by columnators

The penumbra is the region where ___ intensity is found

80%-20%

The shielding is responsible for ___

preventing radiation from escaping

The transformer oil is responsible for ___

reducing the heat produced by the machine

The cathode is responsible for ___

producing electrons

The anode is responsible for ___

producing the x-rays

The x-ray tube insert is responsible for ___

maintaining the vacuum that keeps air from escaping

The red is the ___

raw Bremmstrahlung

The yellow is the ___

filtered Bremmstrahlung

The blue is the ___

90 keV maximal photon energy

the purple is the ___

characteristic

The filter is used for removing ___ energies, as they do not ___ to image and ___ dose to the patient

low; contribute; increase

Auger electrons are when x-ray is not produced, and energy is ___

shifted to a higher shell

A Bremmstrahlung is ___ effective, and ___ heat

3%; 97%

Ejected electrons contribute to ___

scatter/ noise

Bremmstrahlung is the “breaking radiation” that is caused by electrons ___ which causes ___

em fields interacting with nucleus em fields; electrons to shed energy of photon to change direction

For Bremmstrahlung, energy is lost ___ to distance from nucleus

proportional