Previous Exam Guides Flashcards
(136 cards)
1
Q
QA program monitors
A
ppl
2
Q
QC program is for
A
film processors, CT scanners, XR tubes
3
Q
most QC testing on rad equipment is done
A
annually
4
Q
all general purpose rad units must have a min. of _____ mm Al filtration
A
2.5
5
Q
filtration is measured w _______ measurements
A
HVL
6
Q
focal spot size is measured w
A
pinhole/star/slit camera
7
Q
it is acceptable to perform a ______ test instead of measuring the focal spot size
A
line pair
8
Q
the measured kVp should be +/- ____ of the kVp indicated on the console
A
10%
9
Q
what is the testing device used to measure cassette screen-film contact?
A
wire-mesh
10
Q
comparing the mR output ay 50 mA @ 0.2 sec, 100 mA @ 0.1 sec, & 200 mA @ 0.05 sec is part of a test for _______
A
linearity
11
Q
when a light in a viewbox is out, then
A
bulb must be replaced, all bulbs in viewboq must be replaced, all bulbs must match adjacent viewboxes
12
Q
processor crossover racks should be cleaned out on a _______ basis
A
daily
13
Q
processors should be monitored every day for
A
densitometric measurements, water/chem temps, & replenishment tank levels
14
Q
an artifact can be
A
an object that is not part of the XRed anatomy, pt motion, improper grid, or warped cassette
15
Q
a ________ is an example of an exposure artifact
A
foreign object
16
Q
a static mark artifact is created during ______ of the film
A
handling
17
Q
what sort of artifact is a guide-shoe mark?
A
processing artifact
18
Q
the largest # of repeat exams is generally caused by ________ types of artifacts
A
exposure
19
Q
misalignment of the processor turnaround assembly can cause?
A
guide-shoe marks
20
Q
thin lines on the leading/trailing edge of a film are
A
guide-shoe marks
21
Q
a bi-color chem stain on an XR
A
curtain effect, or dichroic stain
22
Q
low humidity in the darkroom can cause
A
tree static
23
Q
a streak of high optical density on the finished XR can be caused by
A
light leaks in the cassette/darkroom
24
Q
when a QC test for exposure linearity is performed, adjacent mA stations must be w/in this amount of one another
A
10%
25
when a QC test for exposure reproducibility is performed, successive exposures must be w/in this amount of one another
5%
26
when QC test for collimator accuracy is performed, result must be w/in this amount
2% of SID
27
when a QC test for accuracy of kVp is performed, the result must be w/in _____ of the control panel setting
10%
28
the accuracy of collimation at a 72" SID must be
+/- 1.44"
29
unwanted markings on a XR are called
artifacts
30
small marks on XR about 3.1416" apart are called
pi lines
31
when insufficient light is produced, the img will be grainy, a condition known as
quantum noise
32
the aspect of a film-screen system that may be examined by conducting a wire mesh test is the
film-screen contact
33
what can cause img blur on the finished XR?
pt motion
34
which artifact occurs when the grid lines are II to the laser lines in a CR?
Moiré
35
a math process of assigning a digi value to a dead pixel based on recorded values of adjacent pixel is known as
interpolation
36
the effect or irregular pattern (variations in img brightness) can be minimized by
flat fielding
37
a software correction that is performed to equalize the response of ea pixel to a uniform XR beam is known as
flat fielding
38
what is a histogram?
a plot of the frequency of appearance of a given object char.'s; a graph of frequency of occurrence v digital value intervals
39
about 80% of breast cancer occurs in
ductal tissue
40
it is recommended that women obtain their 1st baseline mammo before the age of
40
41
a target of Mo or Rh is preferable in mammo bc it reduces the?
scatter
42
breast compression has the advantage of lowering
pt dose, motion blur, & superimposition
43
breast compression is used to ____ pt dose, and _____ focal spot blur
lower, reduce
44
breast compression increases
contrast & spatial res.
45
mammograms are taken w _______ cassettes
single screen
46
mammography currently uses ______ film
single-emulsion
47
screening mammo requires _____ view(s) of ea breast, whereas diagnostic mammo requires _______ views
2, 2+
48
the ________ is responsible for supervising QA
chief radiologist
49
the purpose of QA program is to maintain max ________ w min _________
quality mammos, pt dose
50
the avg glandular dose to mammo pt's must be tested annually by the
medical physicist
51
the team of _________________ is responsible for mammo QC
mammographer, radiologist, & medical physicist
52
the ________ is responsible for selecting the medical physicist & mammographers responsible for QC
radiologist
53
when is the QC eval of the equipment performed?
once a year or when major components are replaced
54
the role of a medical physicist includes
performing annual performance evals of equipment, consult w mammographers concerning QC, & review QC records to check for compliance
55
the mammographer should ________________ on a monthly basis
complete a visual checklist
56
how often should mammographer perform the QC test for screen-film contact?
semi-annually
57
during tomography the XR tube & IR move around an imaginary pivot point called the
fulcrum
58
the tomographic angle determines the
section thickness
59
as tomographic angle _______ the tomographic section _______
increases, becomes thinner
60
which structures are most blurred in a tomographic img?
structures farthest from fulcrum
61
heigh of fulcrum determines the
level of object plane
62
thickness of tomo layer is affected by ___________ of the tube
multidirectional movement & tomo angle
63
what is the formula for the magnification factor using img & object size?
MF = img size/object size
64
if the img size of an object is 3 cm and the MF is 1.5, then what is the actual object size?
2.0 cm
65
the radiologist has requested that the img for a cerebro angio be magnified 100%. where would you set the SOD of the head if the SID is set at 20"?
10"
66
what is the true size of a lesion if its magnified img measures 3 cm and the MF is 1.5?
2.0 cm
67
what is the formula for MF using the SID?
MF = SID/SOD
68
it is essential that a ___________ be used in magnification rad to preserve img detail
small focal spot
69
Mo produces char XRs w energy of ____ keV
19
70
Rh produces char XRs w energy of ____ keV
23
71
mammo uses a tube tilt of
6º
72
mammo uses an anode angle of
23º
73
in mammo, the total beam filtration should not be less than ____ mm of Al equivalent
0.5
74
which target material is best for mammo of a pt w thick dense breast tissue?
Rh
75
most mammo systems now have a moving grid w ratio of
5:1
76
the electronic noise in digital mammo can be reduced by
cooling the detector
77
a min of ________ mammon must be included in a repeat analysis
250
78
a wire mesh test must be performed
semiannually
79
tomo angle & slice thickness are
indirectly proportional
80
a tomo w a tomo angle of 10º or less is known as
zonography
81
a panoramic tomo is used to XR what structure?
mandible
82
which tube trajectory will produce the max blurring of the unwanted structures?
spiral
83
where is the AEC located in the mammo unit?
underneath the IR
84
which has the highest spatial res.?
screen film mammo
85
as the effect focal spot size increases, the spatial res. will
decrease
86
mammo uses grid frequencies of?
30-50 lines/cm
87
if the pt is halfway btw the IR and the focal spot, then the MF is
2
88
the output phosphor of the I.I. is composed of
zinc cadmium sulfide
89
the output phosphor of the I.I. converts _____ to _______
e-'s, light
90
photocathode of I.I. convert _______ to _______
light, e-'s
91
brightness of fluoro img depends on the following factors
anatomy being examined, kVp, mA
92
scattered rad in the form of XRs, e-'s, & particularly light can reduce the contrast of I.I. tubes through a process called
veiling glare
93
____________ is the reduction in brightness at the periphery of the img
vignetting
94
in a 25 cm/17 cm/12 cm I.I. which mode will display max anatomy?
25 cm mode
95
in a 25 cm/17 cm/12 cm I.I. which mode will display the highest spatial res.?
12 cm mode
96
in a 25 cm/17 cm/12 cm I.I. which mode will cause the highest pt dose?
12 cm mode
97
compared to 25 cm fluoro mode; in a 12 cm fluoro mode, the focal point will?
move away from the output phosphor
98
how magnified is the img of a 36/25/12 I.I. in the 12 cm mode compared w the 36 cm mode?
3 x's
99
what is the photoconductive layer of the I.I.?
target plate
100
what is the material used in the photoconductive layer?
antimony trisulfide
101
in DF, the spatial res. is limited by
pixel size
102
during DF, the under-table XR tube actually operates in the ________
radiographic mode (increased mAs)
103
in DF, the T required for the XR tube to be switched off is called ________
extinction T
104
in DF, the fraction of T that the XR tube is energized is called the ________
duty cycle
105
img-guided catheter navigation is possible w
FPIR
106
the SNR of DF is
1000:1
107
what produces a sharper img w less flicker (in fluoro)?
progressive mode
108
speed of img acquisition, processing & transfer to the output device is determined by
dynamic range of ea pixel, # of pixels, & storage method
109
what is the mA used during conventional fluoro?
0-5 mA
| ≤5 mA
110
ability of the eye to detect the differences in brightness levels is termed
contrast perception
111
the ____ in the retina are stimulated by ____ light
rods, low
| cones, bright
112
XRs that exit the pt & enter the I.I. first interact w the ______
input phosphor
113
the input phosphor of the I.I. is composed of
cesium iodide (Ce-i)
114
the input phosphor converts _____ to _____
XR, light
115
the _______ in the I.I. emits e-'s when it is stimulated by light photons
photocathode (thru photoemission)
116
the # of light photons emitted w/in the I.I. is ______ to the amount of XR photons exiting the pt
directly proportional
117
calculate the flux gain of an I.I. that is equipped w a 25 cm input phosphor & 5 cm output phosphor
cannot be calculated (need # of light in output and # of XR in input)
118
an I.I. has a 12 cm input phosphor and a 4 cm output phosphor. about 50,000 light photons were produced at the output phosphor when the input phosphor received 100 XR photons from the pt. calculate the total brightness gain.
4500
119
e-'s hit the _____ after exiting the anode
output phosphor
120
the ______ is the product of the minification gain & the flux gain
brightness gain
121
the ratio of XRs incident on the input phosphor to light photons exiting the output phosphor is called
flux gain
122
capability of an I.I. to increase the illumination level of the img is called
brightness gain
123
an I.I. tube is identified by the diameter of its _____
input phosphor
124
fluoro for an air contrast barium enema is generally done at ___ kVp
80-90
125
viewing the fluoro img in magnification mode increases
contrast/spatial res. & pt dose
126
ABC maintains the brightness of the img by varying
kVp & mA
127
the T it takes to turn on the DF XR tube & reach the selected mA & kVp is the
interrogation T
128
a CCD used in DF provides high _______
spatial res, SNR, & detective quantum efficiency
129
a principal advantage of DF is the
img subtraction capability
130
DF systems w hybrid capabilities use both _______
temporal & energy subtraction
131
remasking may be required due to _______
noise artifacts, motion artifacts, &/or technical factors
132
the combo of temporal & energy subtraction techniques is called
hybrid subtraction
133
the T-interval delay mode is principally used in ____ imaging
cardiac
134
DF dose rate is lower than that for continuous analog fluoro (T/F)
true
135
the _____ on the retina are stimulated by ______ light
cones, bright
| rods, low
136
fluoro was invented by
thomas edison
