rad 1 exam 1 Flashcards
higher energy photons are present with which?
higher frequency
dosimerty is used for what?
detecting radiation
which year was the x ray discovered
1895
what is the primary factor for radiographic contrast
kV
what effect would reducing the FFD have?
the number of x rays reaching the film increases
what is considered the standard tube distance for SID?
40 & 72
what is the purpose of the rectifiers?
changes the current from alternating to direct
the calculation of mA X time X kVp determines which of the following?
the heat units
which of the following with reduce penumbra?
small focal spot
which of the following is the usual tube warm up?
2 exposures with the 2nd using 2 times the mAs
if you wanted to produce more x rays what would you do?
increase the mA
a decrease in the anode angle would have whiich effect?
a smaller effective focal spot
anode heel effect refers to what?
a reduced intensity of the x ray beam on the anode side of the tube
what is the method of choice for limiting the size of an xray beam?
collimator
where should compensating filtration be used when taking a lateral thoracic film?
the lower thoracic spine
“added” filtration is a term used for what?
filtration that is between the port and collimeter
the tube stand should only be moved after what has occured?
the lock has been released
the 10 day rule refers to which of the following?`
10 days after the onset of menses is the safest times for x raying
“added” filtration is a term used for what?
filtration that is between the port and collimator
the tube stand should only be moved after what has occurred?
the lock has been released
how much lead equivalency do most shielding devices have in them?
0.5 mm
radon comes in use in which form?
alpha particles. gas
natural background radiation accounts for about how much of the average annual exposure of ionizing radiation?
80%
which of the following is NOT a property of x ray?
they are stored in matter
how many rads are in a gray?
100
which unit measure is usually used for reporting occupational exposure to radiation?
REM
the focal spot size is usually set in conclusion with what?
the high voltage circuit
what would happen if you lengthened the time of an exposure?
you would increase the number of photons hitting the patient
what is the primary factor responsible for the “quality” of an x ray beam?
mA
the mA setting determines what?
the current going thru the filament
what would have the least fluctuation in the kV level?
high frequency
what propels the electrons in an x ray tube?
the kV
what part of the xray tube is the target located in?
anode
the term “ thermionic emission” if most closely related to what?
the cloud of electrons at the filament
what is true about the dual focus tube?
has 2 filaments
the purpose of the collimator shutters is to..
absorb unneeded x rays
what is the best way to identify a patients film?
a flash on label before processing
what is true about x rays?
some materials fluoresce when exposed to them
the initials FFD TFD and SID refer to what?
the distance between the source of the x ray and the film
what is the most commonly used dosimeter?
a film badge
the number of electrons id controlled by the …
low voltage circuit
what effect would a smaller anode angle have compared to a larger one?
it would create a clearer image
what is a characteristic of an x ray?
a short wave length
of the different types of radiation which is associated with biological effects?
ionizing
what is the most helpful in producing a good quality AP full spine x ray?
having the anode toward the cervical
positive beam limitation systems PBL would include what?
semiautomatic collimation
what is used to tell us that the xray beam is pentered to the part being radiographed?
the light and mirror
at a set FFD and film size the less collimation used the …..it will me
darker
from where does the electron cloud dorm?
the filament
what part of the tube complex allows one to move the tube stand?
the tube track
the 10 day rule concerns
patients during a 10 dat period from the onsets of menses
who is credited to the discover of x rays?
WC Roentgen
if you had a film that is too dark what would solve your problem?
decrease the mAs
the :useful beam” exits which part of the tube?
window
what is the international unit designated for the rad?
gray
the filament is surround by what structure?
the focusing cup
what limits the size of the useful x ray beam
collimator
year x ray was discovered?
1895
what is recommended for a full spine film?
compensating filtration
what part of the tubes main function is to remove the soft rays?
the tube filters
where is oil found normally in the tube complex?
between the tube and the tube housing
kV is the primary controlling factor of what?
contrast
what is the last thing you should do before pressing the expose button?
activate the rotor
the main purpose of the oil in the tube is to aid in…
cooling the tube
what type of anode should you use>
rotating
what is the : half value layer” HVL used for?
for filtration recommendations
what is the “half value layer” HVL used for?
for filtration recommendations
of our body systems which will require the most reaction in an acute blast to affect it?
nervous system
if you had a film that was too dark what would you do?
decrease the mAs
what would cause a penumbra?
a large focal spot
the x ray is produced by which tube part?
the target
what is the anode heel responsible for?
a reduction in the beam intensity
what part of the tube prevents the electron cloud from dispensing beyond desired location?
the focusing cup
the filtration of the x ray beam as it thru the collimator if mostly due to the ..
shutters
if you were taking an AP open mouth film for an upper cervial what would you use?
use selective filtration over the eyes
the single greatest risk for a fetus from ionizing radiation is…
childhood leukemia
if you took a radiogragh at 72” and then took another of the same view at 40” what would you have to do maintain the same radiograohic density?
decrease the mAs by 1/3
what are examples of ionizing radation?
x rays and gamma radiation
what type of dose is attributed to have harmful effects from low levels of radiation?
gecetic
the large or small focal spot is usually set simultaneously with what?
the millamperes
if you wanted to increase the the number of photons reaching your film what would you do?
increase the mA
what govern the speed of electrons
kV
what is responsible for changing AC current to DC current?
a rectifier
how would one figure heat units of one wanted?
mA X time X kVp
how much of the energy created by an exposure in an xray tube is useful for the producction of a radiograph
1%
what is the function of the anode?
to stop the electrons
what produces thermionic emission?
the low voltage circuit
the “boiling off” of electrons is known as what?
thermionic emissions
where is the added filtration located?
on the port of the tube housing
Which is the largest contributor to the average persons annual exposure from man made sources?
Diagnostic X-ray
On the average, which of the following accounts for over 50% of the typical person’s annual radiation exposure
Radon
Of the following what makes x-ray potentially dangerous
They are ionizing
which of the following travels at less than the speed of light?
Radon
ALPHA particles are MOST harmful in people when they do what with them
Inhale them
the FIRST radiographic print was of what body part?
Hand
kV is the primary controlling factor for which of the following?
Contrast
when would you apply the inverse (70/42)
When changing the tube distance
the initial FFD, TFD, SID refer to what?
the distance between the source of the ray and film
What does the P, in kVP stand for?
Peak
the number of electrons is controlled by the
low voltage circuit
what connects the transformer with the tube
the cables
what is the minimum anode angle that can be used if you are going to take a 14/36 full spine film
14 degrees
if you looked into the port of a used x-ray tube and saw that the entire surface of the anode had bumps, what term would describe its appearance
anode pitting
which structure is responsible for confining the cloud of electrons
the focusing cup
the purpose of the collimator shutters is to
absorb unneeded rays
which is the most common reason that compensating filtration is used
to reduce film density
which of the following parts of the tube complex contains lead?
the tube housing
An acute exposure of 4 rads would probably have what effect on a pregnant female’s fetus?
none, 4 rads is too little
