Rad Science Exam 2

What is the effect of increasing the distance between the X-ray source and the image receptor?

No effect on energy; Reduce intensity

T/ F Characteristic x-rays have a range of energies.

False

Ultrasound imaging uses:

High-frequency sound waves

What is the primary function of the x-ray tube?

accelerate electrons from the cathode to anode

Bremsstrahlung radiation is produced when:

High-speed electrons are decelerated near the nucleus of target atoms.

Hardware computer components include all of the following except:

Bits

All of the following are subject factors when assessing image quality, except:

Object position

Photometry is the science of the:

response of the human eye to visible light

A/an ___________ is an unwanted pattern on an image that does not represent anatomy.

Artifact

Increasing filtration _____________ the average energy of an x-ray beam and x-ray intensity _______________.

increases; decreases

Which body habitus is small, frail, sometimes emaciated, and often seen in elderly patients?

Asthenic

T/F Bremsstrahlung x-rays have a range of energies.

True

Scatter radiation is:

Radiation that changes direction after interacting with matter

What is increased by added filtration?

"Effective" Energy

Surface-Guided Radiation Therapy (SGRT) primarily uses:

Optical cameras to monitor a patient's external surface

Noise in an image refers to:

Unwanted random variations that reduce image quality

The number of x-rays in useful beam is known as ____________.

X-ray intensity

What is the purpose of image inversion in medical imaging?

Reversing grayscale values—black becomes white and white becomes black

Filters for x-ray beams are typically made or:

Aluminum

Bremsstrahlung X-ray energy is ________ proportional to its wavelength.

inversely

T/F Heat production also increases indirectly with increasing kVp (at least in the diagnostic range).

False

Which component of the x-ray tube is the positive electrode and target for electrons?

Anode

Which body habitus is typically big in frame and often overweight?

Hypersthenic

Cone-Beam Computed Tomography (CBCT) is commonly used for:

Image-guided patient positioning and localization

Pixels are:

The smallest elements of a digital image

T/F Radiolucent appears darker on a radiograph.

True

What is the primary benefit of using subtraction in Digital Subtraction Angiography (DSA)?

Improves image contrast by removing background structures

X-ray intensity is __________________ to the square of the distance from the source.

Inversely proportional

Magnetic Resonance Imaging (MRI) primarily uses:

Magnetic fields and radiofrequency pulses

In medical imaging, noise refers to:

deterioration of the radiographic image

Computed Radiography (CR) uses:

Imaging plates that are digitally processed

T/ F Characteristic x-rays have precisely fixed energies.

True

What is the purpose of defining a Region of Interest (ROI) in quantitative imaging?s

To measure the average pixel value for analysis

PACS primary purpose is to:

store and share images electronically

Adaptation of computer technology to mimic the human mind in cognitive activities is _______________.

Artificial Intelligence

Which of the following medical image techniques uses infrared sensors to capture surface anatomy:

SGRT

If the kVp are increased, then the electron kinetic energy will ____________.

increase

What is the result of increasing filtration in the X-ray beam?

Increase energy; Reduce intensity

Why is pixel shift used during image postprocessing?

To correct for patient motion and align images accurately

Scotopic vision is related to:

night vision

The primary purpose of SGRT is to:

Improve patient positioning and monitor patient motion during treatment

The cathode in an x-ray tube:

Serves as the negative electrode and source of electrons

T/F Sharpness of Image Detail describes the ability to see the detail on the image.

False

All of the following are types of filtration, except:

Compounding filters

Process by which very high-energy x-rays can escape interaction with electrons and the nuclear electric field and can be absorbed directly by the nucleus is:

Photodisintegration

In multislice CT, the protocol parameter collimation is:

A combination of beam collimation and detector array size

T/F Image artifacts can typically be minimized through proper alignment.

False

What x-rays are produced by the slowing down of an electron by the target atom's nuclear field?

Bremsstrahlung X-rays

T/F Square law is a corollary to the inverse square law.

True

The cones are:

used for photopic vision

Amorphous silicon is commonly found in:

Flat-panel detectors

Gadolinium is commonly used as:

An MRI contrast agent

Interfraction uncertainties refer to:

Variations occurring between treatment fractions that affect accuracy

When assessing image quality, which of the following would be considered a geometric factor?

Image Blur

Which of the following are considered X-ray interactions occurring with (body) matter? (Select 2 that apply.)

Photoelectrical absorption and Compton Scattering

Absorption of an x-ray by ionization is:

Photoelectric Effect

Which body habitus is described as "strong, active," and represents the average patient?

Sthenic

T/F When selecting technique factors, keep exposure time as high as possible to ensure penetrability.

False

What characteristic of radiographic quality is improved by using reduced x-ray exposure time?

Motion blur

X-ray beam hardening is:

increases the # of high energy x-rays in the beam by removing the lower-energy nonpenetrating x-rays.

A primary advantage of MR-Linac imaging is its ability to:

Visualize soft tissues during treatment and adapt radiation delivery in real time.

What is the result on the image when an anatomic structure is not equally magnified?

Distortion

What is the magnification factor?

Image Size/Object Size

What is the primary purpose of x-ray beam filtration?

to filter low energy x-rays

Ionization occurs when:

An atom gains or loses electrons

Hardware is the physical components of the system that include various input and output devices.

True

A detector array consists of:

Multiple detector elements arranged in a pattern

In imaging, density generally refers to:

The degree of image blackness or brightness

In the Photoelectric Effect:

The photon is completely absorbed by an inner-shell electron

What is Magnetic Resonance Linear Accelerator (MR-Linac) Imaging?

A radiation therapy system that combines MRI with a linear accelerator for real-time image guidance

If the mAs increase, the number of projectile electrons racing towards the target _____________.

increase

Detectors are used to:

Measure and capture radiation information

T/F Software is the computer programs that tell the hardware what to do and how to store and manipulate data.

True

How does magnification enhance image interpretation

By improving visualization and spatial resolution

Contrast resolution refers to

ability to distinguish between and to image similar tissues

Photon interacts with an outer shell atomic electron and the photon becomes redirected, or scattered, from its original path without a change in energy is

Coherent Scattering

The purpose of Digital Imaging and Communications in Medicine (DICOM) is to:

transfer images

What is the primary purpose of annotation in medical imaging

To label and identify structures within the image

Which body habitus is characterized by a thin but healthy appearance

Hyposthenic

Magnification factor =

SID/SOD

Distortion is a misrepresentation of object size & shape on the image (T or F)

true

The rods are used principally for which of the following?

dim vision

Onboard imaging systems are primarily used for

Treatment verification and patient alignment

What is the effect of increasing mAs on the X-ray beam?

No effect on energy; Increase intensity

Image Receptor sometimes referred to a cassette. (T or F )

F

The Inverse Square Law states that radiation intensity:

Decreases proportionally to the square of the distance from the source

T/F Air, when used as a contrast agent, is considered a positive contrast agent.

False

The Spiral Pitch Ratio in CT is the:

Table movement per rotation divided by beam width

Which of the following best refers to the digital imaging process?

Flat-panel detector

Spatial resolution refers to:

The ability to distinguish small objects that are close together

Attenuation is:

The reduction in X-ray intensity that results from absorption and scattering.

High penetrability = High ___________ rays

quality

PET/CT combines:

Functional PET imaging with anatomical CT imaging

Differential absorption increases as the ___ is reduced.

kVp

The bothersome magnification can be minimized by using:

Correct answer:

larger SID

T/F Radiopaque appears gray on a radiograph

False

T/F: The probability of Compton scattering depends on the atomic number of the target atom.

False

X-ray quality is the output intensity of an x-ray imagining system

False

Voxels are best described as the three-dimensional equivalent of:

pixels

MRI Safety Zones are designed to:

Organize access and improve safety around MRI systems