Fluoro Mock Test C
which of the following individuals may perform fluoroscopic procedures if they possess a proper, valid, and up to date certificates or permit issued by the state
-a certified radiologic technologist -a licentiate of the healing arts (physician)
the radiosensitivity of tissues depends on which of the following
-degree of mitotic activity -number of undifferentiated cells -length of time the cells of the tissue are in active proliferation
which of the following factors result in a brighter image being produced at the output phosphor of an image intensifier
-flux gain -minification
characteristics which describe contrast media or contrast agents are
-high atomic number -low toxicity
which of the following describe the correct usage of the "boost" position or high level control in fluoro
-increases the tube current and potential above normal limits -continuous manual activation is required -continuous audible signal is required
the california radiation control regulation define does to mean radiation absorbed per unit mass. whole body dose means exposure to which of the following
-major portion of the whole body -head and truck -gonads -lens of the eye -active blood forming organs -whole body -all of the above
film badges are used by radiation workers, because
-they are a practical means of providing long term expo records -they can measure exposure to the worker with reasonable accuracy
if you convert 12mR to roentgens (R) you will obtain.
0.012 roentgens
the recognition or integration time of the human eye is the time it takes for recognition of an image. how long is this time
0.2 sec
during fluoro, the bucky tray is moved to the end of the examination table, leaving an opening in the side of the table approx two inches wide at the gonadal level. this opening must be automatically covered with at least
0.25mm lead equivalent material
the california radiation control regulations require that protective aprons used during fluoro shall be of at least
0.25mm of lead equivalent
the california radiation control regulations require that the minimum lead equivalence of gonadal shielding must be
0.50mm lead
a certain x-ray tube, at some given kVp, delivers 4mR per one mAs at 40in distance. at 80in distance, the radiation output from the x-ray tube in (mR/mAs) will be
1
if 3 grams of tissue absorb 300 ergs of x-rays, what is the dose
1 rad
the california radiation control regulations specifically limit the occupational whole body dose equivalent for persons over 18 years of age to
1,250mR per calendar quarter
the normal viewing distance for binocular vision is
10 to 15inches
what is the approx exposure a patient would receive during 5 minutes of fluoroscopy
10-30 roentgens
fluoroscopic equipment manufactured after aug 1, 1974, equipped with automatic expo controls (AEC) shall not be operable at any combination of tube potential and current which will result in an expo rate at the point where the useful x-ray beam enters the patient in excess of
10.0 roentgens /minute
if an UGI examination of a pregnant patient resulted in a total skin exposure of 5 roentgens, what is approx dose to the fetus
100 milirads
what is the approx dose to a patients gonads resulting from a barium enema exam
1000mR
a high radiation area is any area, accessible to individuals, in which there exists radiation at such levels that an individual could receive in any one hour a dose to the whole body in excess of
100mR
what film size in spot filming cameras results in the greatest dose to the patient
105mm
for mobile c-arm fluoro equipment, inherent provisions must ensure a minimum source to skin distance of
12inches
the national council on radiation protection and measurements (NCRP) in their report Medical Exposure of Pregnant and Potentially considered to be negligible at 5 rad or less when compared to the other risks of pregnancy, and the risk of malformations is significantly increased above control levels only at doses above
15 rad
what is a typical setting for mA during spot filming
150
a cardiac catheterization examination results in a bone marrow dose of approx
190 milirads
during a CINE exam in which 35mm film and a frame rate of 30 frames/second are utilized what is the approx skin exposure
2-5 roentgens /minute
the intensity of the xray beam at the table top during fluoro should not exceed how many roentgen(s) per minute for each mA of operating tube current at 80kVp
2.2
you are fluoroscoping a patient using 80kVP technique. at this kVp the intensity of the xray beam at table top should not exceed how many roentgens per minute for each mA of current
2.2 roentgens per minute
an image intensified fluoro sys is switched to the magnification mode so that the center 6in of the input screen is now visualized over the entire 9in diameter input screen. under automatic brightness control which constant kVp, what relative increase in exposure rate has occurred
2.25
the ca radiation control regulations require that the total filtration permanently fixed in the useful beam for fluoro may not be less than
2.5 mm aluminum equivalent
how long does it typically take for a fluoro table to move from the horizontal to the vertical position
20-30 seconds
if at one foot from the radiation source the intensity of exposure is 240mR per hour and you remain at this location for 10 minutes, you will receive an exposure of 40mR. what would be your exposure if you moved 2ft away from the radiation source and remained there for 20 minutes
20mR
what is the most commonly used video frame rate
30 frame/ sec
the mA setting for fluoro is typically less than
5
the california radiation control regulations require that a cumulative manual-reset timer activated by the expo switch that produces an audible signal or temporarily interrupts the xray beam when the fluoro time has exceeded a predetermined time limit must be provided. this predetermined time limit must not exceed
5 minutes
fluoro equipment manufactured after aug 1,1974, without AEC shall not be operable at any combination of x-ray tube potential and current which will result in an exposure rate at the point where the center of the useful x-ray beam enters the patient in excess of
5.0 roentgens
what is the maximum expo a pregnant occupational worker may receive during a nine month gestational period
500 milirems
a protective curtain should be interposed between the operator and the patient because scattered radiation exposure at 1ft from the patient could be as high as
500mR per hour
what is the average number of horizontal lines on a TV monitor
525
a "radiation area" is any area accessible to personnel, in which there exists radiation at such levels that a major portion of the body could receive in any one hour a dose in excess of
5mR
during a 2 minute fluoro exposure time routine UGI series examination, a typical x-ray expo to the patient is
6.0 roentgens
if a protective apron of 0.25mm lead is worn, what is the typical exposure reduction
97%
what is quantum mottle
a grainy appearance in an image caused by statistical fluctuation of absorbed x-ray photons
a correct position to wear a film badge during fluoroscopy is
above the apron at collar level
when x-rays are directed toward the patient, most are
absorbed by the patient
the rem is the unit of
absorbed dose equivalent
a "controlled area" is
an area in which radiation safety rules are enforced and the occupational exposure of personnel is under the supervision of the radiation safety officer
when a c-arm is used for an AP chest view, in which direction is there the most scatter
at 135 degrees from the primary beam
which of the following is not required on mobile fluoroscopic equipment
automatic brightness control
the greatest contribution of unnecessary radiation exposure to the patient comes from the x-ray operators failure to
collimate the x-ray beam to the area of clinical interest only
what is vignetting
decrease in light intensity at the periphery of an image
if the exposure area is doubled by opening the collimator, patient dose and exposure to the operator will
double
doubling the exposure time of the patient _______ the total exposure to the patient
doubles
all of the following must be posted in areas where x-ray producing machines are utilized except
each physician's license for the healing arts
the state of california radiation control regulations require record-keeping for all of the following except
each x-ray technologist who is hired by a hospital
genetic dose refers to
effects exhibited in future offspring of persons who have been irradiated
in an image intensifier, electronic intensification occurs when
electrons are moved at high speed from the photocathode to the output phosphor
the roentgen is the unit of
exposure
before doing any radiographic or fluoroscopic procedure all except which of the following must be done
film badges should be worn under the lead apron at gonadal level
according to the california radiation control regulations all except which of the following is defined as an occupational dose? the dose received by any occupationally exposed person
for his/her own medical or dental diagnosis
the SI unit which is analogous to the rad is the
gray
a closed circuit TV system
has all its signals carried through cables
if the x-ray tube is moved rapidly during fluoroscopic examination, the image will blurr. this is the result of which of the following
image intensifier tube lag
the best description of virtual image is
image that cannot be projected and exists only for computational purposes
for a fluoro sys equipped with an automatic brightness control (AEC) mechanism and where the x-ray tube is fixed below the table, moving the image intensifier away from the patient will
increase patient dose
the california radiation control regulations require that individual radiation monitoring records shall be preserved by the employer after termination of employment by a technologist or x-ray technician
indefinitely
during fluoro procedures a problem that occurs when utilizing television vidicon cameras is the blurring or lag of the image as the camera is moved during the procedure. this lag or blurring occurs because
it takes a certain amount of time for the image to build up and decay on the vidicon target
which of the following has been called an occupational related disease of radiologists, particularly early radiologist
leukemia
all of the following influence the table top exposure rate except
light in the fluoro room
how is resolving power measured
line pairs per milimeter
the most conservative type of dose effect curve and also the curve upon which radiation protection guides and regulatory requirements are based is the
linear nonthreshold curve
which of the following is directly proportional to the exposure delivered to the patient
mA
the function of an automatic brightness control (automatic exposure control) mechanism of an image intensified fluoroscopic system is to
maintain a fixed dose rate to the image intensifier
the largest percentage of exposure to the population from man made radiation comes from which source
medical
the output intensity of a fluoro tube is measured in
miliroentgens
when switching from a 15in to a 19in TV screen does that number of horizontal lines change
no
if an occupational worker receives an exposure of 5 rems to the skin of the whole body, the state must be notified
no notification is needed
a disadvantage of thermoluminescent dosimeters (TLDs) is
no permanent record is provided since dose is cancelled when TLD is read
as the kVp is increased and the mAs correspondingly decreased, which of the following occurs
patient skin exposure decreases
the major source of secondary radiation in radiography is the
patients body
which of the following gives the least patient exposure
plumicon tv camera
what kind of barrier, if any, must be in all walls, floors and ceilings exposed to the useful primary beam
primary barrier
which of the following types of cells is most sensitive to the effects of radiation
red bone marrow
a film badge report expresses an individuals radiation dose equivalent in
rems
the central portion of the image intensifier tube possesses the greatest
resolution
the SI unit which is analogous to the rem is the
seivert
how many rads of acute x-radiation in the diagnostic energy range to the eyes will result in the formation of cataracts
several hundred rads
which method of gonadal shielding is best for use during fluoro
shaped, contact shielding
the biological effects of radiation are known to be influenced by all of the following except the
size of the cells in the tissue exposed
what is image contrast
the brightness ratio of the periphery to the center of the output intensifying screen
the half value layer is
the thickness of a specified substance which reduces the exposure rate of the primary beam by one half
all of the following effect patient exposure except
three phase generators
what is the purpose of synchronization in CINE
to operate the camera shutters at the same frequency as x-ray pulses and thus decrease patient dose
the rad is the
unit of absorbed dose
the ability of the human eye to perceive detail is called
visual acuity
the california radiation control regulations require that tube potential kVp and current mA be monitored
weekly
all fluoro machines must have an exposure switch that is of a "dead man" type. this type of switch is one that stops
when the pressure on it is released
if an occupational worker receives an exposure or 2 rems in a calendar quarter, the state must be notified
within 30 days
the best protective eyewear for the operator to utilize during fluoro is
wraparound (side panel) lead glass eyeglasses
