diagnostic imaging

purpose of a grid on x ray table

to prevent scatter radiation from reaching the film

rad technique chart indicates that you should use a KVP setting of 50 and mAs setting of 12.5, what would be appropriate

250 mA, 1/20 sec

correct order from least to most radiodense (darkest to whitest)

gas
fat
soft tissue and fluid
bone
metal

purpose of a grid on an x ray table

to prevent scatter radiation from reaching the film

difference btwn rad and rem

rem applies a quality factor to rad

where are electrons generated in x ray machines

at the filament of the cathode

what can be changed to increase the amount of exposure on a rad without affecting the amount of contrast

increase millamperage

which component or setting influences x ray beam quality

kvp and filteration

intervertebral disc spaces appear wider toward the center of the film and narrower towards the end of the film

true

the monitor has a large impact on image quality

true

a dorsoproximal-dorsodistal oblique radiograph of the carpus is frequently refered to as what type of rad

skyline view

you are taking a lateral rad of the left stifle of dog for suspected ccl tear, how should patient be oriented

left lateral with leg aginst the cassette

which bone articulates with the patella

femur

you must be over 18 to take rads

true

what principle will always improve radiographic image quality

use highest ma and lowest time to achieve desired mAs

function of the screen of an x ray cassette`

to decrease exposure necessary to create an image on film

when should you take a thoracic rad

full inspiration

when would an intravenous pyelogram be useful

ureteral stones

why is tungsten a good material for filament (target of x ray machine)

has a very high melting point

what would most likely be enlarged on chest films of a heartworm positive dog

pulmonary arteries

comparing new rad to old rad and older rad has a yellow-brown staining what was a likely cause

incomplete washing of the film

when taking a rad of the radius and ulna which of the following will occur if the x ray beam is perpendicular to the cassette but not to the long axis of the radius and ulna

the radius and ulna will appear foreshortened

what error when processing a rad would result in a completly clear film

the exposed film was put in fixer before developer

where are electrons generated in an x ray machine

at the filament of the cathode

when is a human embryo most sensitive to adverse effects of radiation

first trimester

when taking rad of tibia and fibula which will occur if x ray beam is perpendicular to the bones but not the cassette and film

the tibia and fibula will appear elongated

taking view of stifle joint and placing it on the viewer how should it be oriented

cranial/dorsal side of limb to left and proximal aspect towards the top of the viewbox

what body part of most sensitive to radiation

ocular lense

radiograph cassette is usually placed on table for what area on a medium sized dog

elbow

x rays have higher frequency and shorter wavelength compared to visible light

true

what things matter when considering minimization of exposure to radiation

time
distance
sheilding

craniocaudal rad of the stifle joint is being placed on viewer, how should it be oriented

lateral side of right limb on viewers left, lateral side of left limb should be on viewers right

earliest time you would expect to be able to see fetal skeletons on rad

43 days gestation

what can be done during a myelogram to decrease risk of post procedure complications

elevate the head

what is the maximum permissible dose of radiation they can receive in one year

50 mSv

a double contrast cystogram involves which of the following

soluable positive contrast media and air injected into the bladder

what stone (urinary) is lucent and does not typically show up on rad

urate

developed radiographs that appear yellow are usually due to a problem with what

fixer solution

film appears darker towards one side of the film why could this be

the x ray beam is usually more intense on one side of the field

what metallic element presents on rads that turn black when exposed and run through radiographic development process

silver

portion of the radiograph outside the body of the patient is completely black (exposed), what is the problem

x ray energy (kvp) too low

nervous tissue that is not myelinated is known as what

grey matter

taking rads to eval for lung metastasis in dog with splenic hemangiosarcoma what views should be taken

RL
LL
VD or DV

what is intended to shield the user from primart x ray beam

collimator

a fistulogram involves taking a rad after contrast agent is administered into what location

draining tract

what things typically appear hypeechoic (bright white) on ultrasound

bone and gas

linear artifacts are due to what

grid

a cystogram study is preformed to identify the position shape and lesions involving what structure

urinary bladder

what is a common preventing factor when taking rads on a horse

motion

barium for an upper GI rad series should not be given to a patient with what

aspiration pneumonia

arthrogram involves contrast admin into what region

joint

when taking a diagnostic rad what technique will reduce the amount of scatter radiation that reaches the film

use of a grid with a potter buckey diagram

non screen film is more sensitive to x rays

true

what position should a dog in resp distress be placed in

dorsal

what components or settings influence x ray beam quality

kvp and filteration

when taking a lateral thoracic rad of a dog where should the field be centered

5th rib and caudal border of scapula

what type of rad would be useful in confirming dx of free air or fluid

horizontal beam

ALARA stands for what

as low as reasonably possible

place lead letters to identify rads

true

boxing glove is indicative of what

gdv

ultrasound probes hace higher frequency and increased image resolution and decreased penetrating ability to relative lower frequency probes

true

where are the atlas and axis found

cervical region

what technical error in rad will result in increased film density

focal film distance is too short

what area is most sensitive to radiation therapy

bone marrow

MRI compatible materials are made of what

aluminium

which bone is btwn the scapula and radius

humerus

what are joints in the skull are reffered to as

sutures

why are oblique rad views of certain joints typically obtained

to decrease superimposition of structures

potter buckey diaphragms are used to what

eliminate grid lines on the film

best three methods to increase rad density

increase energy of x rays
increase number of photons
decrease distance from source to film

how early can mares that are pregnant be shown on ultrasound

11 days

how many days after fertilization will canine skeletons first appear on rads

42 days

what is the process of rad developing

first developer converts exposed silver crystals into black metallic silver and then fixer crystals into black metallic silver

components of x ray cassette in order

cassette front, padding, intensifying screen, film, intensifying screen, padding cassette back

where is the mediastinum located

in the chest

hinge joint connecting humerus to radius and ulna

elbow

what is the plantar surface

the underside of the hindpaw

what is a pneumocystogram

rad of bladder taken after having air injected into it

best dental rad angle to prevent distortion of teeth

bisecting angle technique

advantage of using larger filament

higher exposures can be used

GDV best rad position

RL abd rad

what is an example of a ball and socket joint

hip

horses do not have gall bladder

horse

what is the heel effect

x ray bea, intensity declines toward the anode side of the x ray machine

if pulmonary metastatic lesion is visible on right lateral rad but not on left, where is the lesion likely to be

one of the left lung lobes

if a region of the film does not come into contact with developer but does not run thru fixer and rest of processing steps what will this region look like

it will be clear

when should abdominal rads be taken

full expiration

what happens in x ray machine when you press the first part of button down

the anode rotates and the filament is heated

the unit absorbed dose equivalent used for radiation safety is what

the Sievert

Sv

what is the maximum permissible dose limits for annual exposure

whole body - 50msv/5rem

skin and extremidies- 500msv/50rem

eyes or lens-150msv/15rem

what are the most important times during pregnancy to not be exposed to radiation

first 3 months

principle guiding radiation protection is called what

ALARA

what should you do if the film is too light

adequate penetration: icrease mAs

inadequate: increase kVp

what should you do if the film is too dark

not overpenetrated: decrease mAs

overpenetrated: decrease kVp

you are unable to see the outline of structures, and the rad may look completely white - what does this mean

the film is under penetrated

what should you do if the film is under penetrated

increase kVp 20%

---if not then double mAs

if bone tissue is gray and not much contrast bone and adjacent soft tissue, too much penetration, overall gray apperance can result from high kVp

film is over penetrated

what should you do if the film is overpenetrated

decrease kVp 16%

subject densities from most dense to least dense

metal
bone
water
fat
air

what does kVp determine

peak energy of the x-rays

penetrating power

qualitypeak energy of the x-rays