Fauber Chapter 3

absorption

Complete \___________________ of the incoming x-ray photon occurs when it has enough energy to remove (eject) an inner-shell electron.

Image receptor (IR)

To produce a radiographic image, x-ray photons must pass through tissue and interact with an \_____________________________(\____), a device that receives the radiation leaving the patient.

Differential absorption

\_____________ \______________ is a process whereby some amount of the x-ray beam is absorbed in the tissue and some passes through (transmits) the anatomic part.

bone

Anatomic parts composed of \__________ absorb more x-ray photons than parts filled with air.

beam attenuation, absorption, and transmission

Creating a radiographic image by differential absorption requires several processes to occur: \_________________, \__________________, and \______________.

ionization

The ability to remove (eject) electrons, known as \_________________, is a characteristic of x-rays.

photoelectric effect

\_________________________ is when there is complete absorption of the incoming x-ray photon occurs when it has enough energy to remove (eject) an inner-shell electron. The ionized atom has a vacancy, or electron hole, in its inner shell, and an electron from an outer shell drops down to fill the vacancy.

Scattering

Some incoming photons are not absorbed but instead lose energy during interactions with the atoms comprising the tissue. This process is called \_____________________.

Compton effect

\____________________ is when there is a loss of energy of an incoming photon when it ejects an outer-shell electron from a tissue atom. The remaining low energy x-ray photon changes direction and may leave the anatomic part to interact with the IR.

Compton

The probability of a \_________ interaction occurring depends on the energy of the incoming photon. It does not depend on the atomic number of the anatomic tissue.

Tissue thickness, Type of tissue, Tissue Density, and Quality of x-ray beam

What four factors influence beam attenuation?

higher, lower

Beam attenuation decreases with a \_____________ energy x-ray beam and increases with a \________energy x-ray beam.

transmission

If the incoming x-ray photon passes through the anatomic part without any interaction with the atomic structures, it is called \________________.

exit, remnant

When the attenuated x-ray beam leaves the patient, the remaining x-ray beam, referred to as \_____________ radiation or \_____________ radiation.

transmitted, scattered

Exit radiation/remnant radiation is composed of both \____________ and \____________ radiation.

fog

Scatter radiation creates unwanted exposure on the image called \____________.

increase

If I increase tissue thickness my beam attenuation will \_____________.

increase

If I increase tissue thickness my absorption will \__________________.

decrease

If I increase tissue thickness my transmitted x-rays will \________________.

decrease

If I decrease atomic \# of tissue, my beam attenuation will \____________.

increase

If I increase tissue density, my beam attenuation will \_______________.

increase

If I decrease beam quality my beam attenuation will \_________________.

latent, or invisible image

The exit radiation interacting with an image receptor creates the \____________ image.

manifest image, or visible image

The latent image is not visible until it is processed to produce the \__________image, or \________ image.

visibility, accuracy

The \____________ of the anatomic structures and the \_____________ of the recorded structural lines determines the overall quality of the radiographic image.

brightness and contrast

The visibility of recorded detail refers to \_____________ and \_________________ of the image.

spatial resolution, distortion

The accuracy of the structural lines is achieved by maximizing the amount of \_______________ \______________ and minimizing \____________________.

Brightness

\_______________ is the amount of luminance (light emission) of a display monitor.

Density

\_______________ is the amount of overall blackness on the processed film image.

image contrast

In addition to sufficient brightness or density, the radiograph must exhibit differences in the brightness levels or densities (\_______________ \_____________).

contrast resolution

The term \_________ \____________ is used to describe the ability of an imaging receptor to distinguish between objects having similar subject contrast.

spatial resolution

\____________ \_______________ refers to the smallest object that can be detected in an image.

spatial resolution

The accuracy of the anatomic structural lines recorded in the radiographic image is determined by its \____________ \____________.

Distortion

\______________ results from the radiographic misrepresentation of either the size (magnification) or shape of the anatomic part.

SID, OID

The \______ and \______ play important roles in minimizing the amount of size distortion of the radiographic image.

Elongation

\_______________ refers to images of objects that appear longer than the true objects.

Foreshortening

\_________________ refers to images that appear shorter than the true objects.

Shape distortion

\______________ \______________ can arise from inaccurate central ray (CR) alignment of the tube, the part being radiographed, or the image receptor.

Scatter

\_______________ or unwanted exposure recorded on the image has the effect of decreasing the contrast by masking the desired brightness of the image and changing the degree of differences.

Quantum noise

\_________ \__________ is a concern in digital imaging and is photon dependent. It is visible as brightness or density fluctuations in the image.

artifact

An \__________ is any unwanted image on a radiograph.