xray final

A small coiled wire called the ________ is located in a concave cup called the focusing cup

filament

The cathode is the ___ side of tube

negative

X-ray photon production occurs at the ____

anode

When depressing the "prep" switch, or initially pressing down halfway on the foot pedal on a rotating anode x-ray machine, you are effectively

Heating up the filament and spinning the rotating anode

During an exposure, electrons in the x-ray tube travel from the

Cathode to the anode

The low voltage circuit in the x-ray machine provides

amperage necessary to heat the filament

As the wavelength of x-ray photons shortens, the energy of the x-ray beam will..

Increase

Who discovered x-rays?

Wilhelm Roentgen

What does the acronym ALARA stand for?

As Low As Reasonably Achievable

Three methods of radiation protection are

time, distance, and shielding

Which of the following types of radiation is the most penetrating?

Gamma rays

What is a difference between Gamma rays and X-rays

Gamma rays are emitted from the nucleus of an atom; X-rays are emitted from the outside

The ____________ states that the intensity of radiation at a given distance from a point source is inversely proportional to the square of the distance of the object from the source

Inverse square law

________ refers to the patient's thickness and shape

Subject contrast

kVp affects the image, primarily in the range of

contrast

The 15% rule is primarily used

when the contrast on the image needs to be enhanced

Grids used for

absorb scattered radiation

MAS contributes mainly to

density

________ refers to the amount or degree of blackness on a radiograph

radiographic density

The function of the cathode is to produce ___

An electron cloud (space charge)

xrays travel in

straight line

kVp controls

mas controls

quality

quantity

List all the PPE that you would put on prior to taking a digital radiograph

Lead apron with a thyroid shield

Lead safety glasses

Lead gloves

Where should the beam be centered for a thoracic radiograph?

The caudal edge of the scapula

The cranial and caudal landmarks for an abdominal radiograph are

Three rib spaces cranial to the xiphoid; the greater trochanter of the femur

the cranial and caudal landmarks of a thoracic radiograph should be

The manubrium/thoracic inlet; approximately halfway between the xiphoid and last rib

You are positioning a patient for a left lateral thorax view; you will measure

Over the caudal border of the scapula over the thickest part of the thorax

What are orthogonal views

Radiographic images that are taken at 90° to each other

The 15% rule is primarily used

when the contrast on the image needs to be enhanced

The degree of difference between adjacent densities on a radiograph is referred to as

Radiographic contrast

The three rules of using a technique chart correctly include

Positioning on the table, measuring, and centering the central ray

Filters are used

remove low energy radiation

Grids increase ______ because their lead strips absorb the scatter radiation that creates a "fog" on the image. This allows for a more crisp image with higher contrast differences.

Contrast

The grid ratio describes

the height of the lead strips compared with the distance between them

Filtration of the x-ray beam reduces

dose to patient

Motion degrades the image _________:

because it detracts from resolution

_______________ is a result of an inefficient number of photons reaching the imaging plate due to an error in the preset exposure factors

quantum mottle

What is the proper order of manual processing of x-ray film?

develop, rinse, fix, wash, dry

The purpose of the developer chemical is to

Reduce the silver halide in the film emulsion to metallic silver

The ___________ is an invisible image on the x-ray film after it is exposed to ionizing radiation or visible light

latent

___________ is an instantaneous reaction in the intensifying screen that lasts as long as the phosphor is stimulated.

fluorescence

An atom that is in the process of radioactive decay is referred to as

radionuclide

You are to image the lateral shoulder joint of a feline patient. The field of view should include

Distal third of the scapula through the proximal third of the humerus

The CR imaging plate should "flashed" every morning or after a period of nonuse because

The plate may be "fogged" by background radiation within the clinic

It may retain the previous image

Uberschwinger or a rebound effect appears as a ________ around metal or areas where there is a large density difference between adjacent objects

Radiolucent halo

A lateral view is required of a ball python. It is best to

Place it in a tube and use a horizontal beam

High doses of patient radiation are possible during fluoroscopy if

The unit is too close and remains in exposure mode for too long

The field of view for a VD pelvis extended-leg will include

The tip of the iliac wings (to include the entire pelvis) and to the distal patella (to include the stifles)

An underexposed digital radiograph will appear

grainy

Attenuation

The loss of sound wave energy as it traverses the tissue or the medium due to absorption, reflection, or scattering

MRI magnet technology allows the atoms to respond according to their own polarity. Prior to exposure to the magnet the protons and neutrons spin and wobble around the nucleus. This wobbling is referred to as

Precession

In MRI, the varying shades of gray in the image are referred to as

Signal intensities

Anechoic

free from echoes and reverberations (dark)

Hyperechoic

Increased reflection of ultrasound waves (bright)

Hypoechoic

Low-level echoes within a structure (dark, fluid)

Isoechoic

describes structures with equal echo brightness (muscle,fat)

On ultrasound, urine in a bladder will appear

anechoic

________ is the appearance of tissues on ultrasound, based on the ability of the tissues to reflect sound waves.

Echogenicity

When performing a cardiac ultrasound, what would be the ideal transducer to choose?

phased array

Piezoelectric effect

When the sound waves are reflected back to the transducer from the tissues, they again make contact with the elements​

-electrical energy

Lateral spatial resolution

The ability to distinguish between two objects of echos that are next to each other, but perpendicular to the sound wave

Reverberation

Due to repeated back and fourth reflection of echoes trapped between two strong reflectors. Appears like a bright veil​

Acoustic Shadowing

Occurs when sound is attenuated or reflected at an acoustic interface, does not reach deeper structures​

-bone, calculus

Distant Enhancement

Occurs when sound wave transverses a cystic structure

how MRI works

Introduction of a radio frequency that matches the precessional frequency of hydrogen atoms in the body​

The atoms become excited, then the radio frequency is removed​

The atoms "relax" to align with the magnetic field and produce an "echo" that the machine interprets as an image​

acoustic impendence

How much resistance u/s beam encounters as it passes through tissue

-based on density and speed of sound

The purpose of an intensifying screen is to

convert the primary x-ray beam to light photons

If an intensifying screen continues to emit light after the photon source is removed, the effect is called

Phosphorescence

single greatest cause of artifacts on radiographic films

Processing

______ is a contrast agent solution that is completely insoluble, radiopaque, and physiologically inert

barium

SID contributes to

As SID decreases, beam intensity

beam intensity

increases