Image Production Kettering Audio Flashcards
(352 cards)
1
Q
Define Receptor Exposure:
A
The overall amount/quantity of x-ray radiation that reaches the IR
2
Q
The main controlling factor of receptor exposure:
A
mAs
3
Q
The relationship between mAs and Receptor Exposure:
A
Directly Proportional
4
Q
If you increase the mAs, what happens to receptor exposure?
A
Increases
5
Q
Double mAs: __________ Receptor Exposure
A
Double
6
Q
Define Contrast:
A
The difference in adjacent areas
7
Q
Kvp is the main controlling factor of:
A
Subject Contrast
8
Q
The main controlling factor of image contrast:
A
Look Up Table (LUT)
9
Q
The relationship between kvp and contrast:
A
Inversely Proportional
10
Q
Increase kVp, contrast _______
A
Decreases
11
Q
Increase mAs, _______ contrast
A
No effect
12
Q
The relationship between SID and Receptor Exposure:
A
Inversely proportional
13
Q
Increase SID, _________ receptor exposure
A
Decrease
14
Q
Increase SID, _________ Contrast
A
No effect
15
Q
The relationship between Receptor Exposure and kVp:
A
Directly Proportional
16
Q
Increase in kVp: ________ receptor exposure
A
Increase
17
Q
Increase kVp: ______ contrast
A
Decrease
18
Q
The relationship between kVp and contrast:
A
Inversely Proportional
19
Q
Increase Grid Ratio: ________ Receptor Exposure
A
Decrease
20
Q
The relationship between Grids (Grid Ratio) and Receptor Exposure:
A
Inversely proportional
21
Q
What do grids do?
A
Clean up scatter radiation and have the contrast more black and white by appearance (high contrast)
22
Q
Increase Beam Filtration: what happens to receptor exposure and contrast
A
Decrease
23
Q
Define Subject Density:
A
How tightly compacted at the atomic level
24
Q
List in order from least to greatest attenuation:
Air Fat Bone Muscle
A
Air
Fat
Water
Muscle
Bone
25
List in order from greatest to least attenuation:
Bone
Muscle
Water
Fat
Air
26
If more radiation reaches the IR, receptor exposure ________
Increase
27
If more radiation gets absorbed in the patient, _____ contrast
Increase
28
What kind of kV do you use on a mammogram?
25-30 kV
29
What would you do with the kV for soft tissue examination of the neck?
Drop it
30
When things have the same attentuation:
Drop the kV, maximal differential absorption
31
Responsible for the blacks and whites on an image:
Photoelectric Effect
32
Why is air dark black on an image?
Shows a high rate of radiation reaching the IR (less attenuation)
33
Anything white or opaque on an image:
Shows high rates of absorption (high attenuation) low rates of radiation reaching the IR
34
Increase in subject density, ________ contrast, ________ receptor exposure
Increase, decrease
35
Additive pathology, ________ receptor exposure, ________ contrast
Decrease, Increase
36
Destructive pathology, ___________ receptor exposure, __________ contrast
Increase, decrease
37
Increase beam restriction= _________ field size, ________ receptor exposure, _______ contrast
Smaller, decrease, increase
38
Increasing collimation (beam restriction) results in:
Decreasing Field Size
Decreasing Receptor Exposure
Decreasing the amount of scatter reaching the IR
39
Increase Collimation=
Decrease in receptor exposure, decrease in contrast
40
Increase field size=
Increase in receptor exposure, decrease contrast
41
Distortion:
Misrepresentation
42
What affects size distortion?
SID
OID
43
Shape Distortion:
Foreshortening and Elongation
44
If you increase SID, what happens to magnification? Recorded Detail (spatial resolution)?
Decreases, Increases
45
Why do you do a PA Chest Erect at 72 inches?
To reduce heart magnification
46
Increase OID, magnification? Spatial Resolution?
Increase magnification, decrease spatial resolution
47
Which had the greatest effect on magnification? SID or OID?
OID
48
For every 1 inch for OID, increase SID by?
7 inches or 8 inches
49
Increase SID:
Decrease magnification
50
Increase OID
Increase Magnification
51
Two focal spot sizes:
Small and Large
52
If you increase focal spot size:
Decrease Spatial Resolution
53
If motion is present on an image:
Compromised spatial resolution
54
If motion is present on an image:
REPEAT IT
55
As a technologist you forget the AP Axial Projection of the sacrum, you forget to angle the tube and come in perpendicular, what will the resulting image look like?
Foreshortening (Shape Distortion)
56
Define Matrix:
Number of rows times the number of columns
57
More rows and more columns=
Greater pixel coverage
58
Increase matrix size=
Increase spatial resolution, better pixel coverage
59
Increase pixel size:
Decrease Spatial Resolution
60
As PSP plate size increases:
Spatial resolution decreases
61
The main controlling factor of spatial resolution is:
Sampling Frequency or (focal spot size)
62
As the field of view increases for a fixed matrix size:
Spatial resolution decreases (increase pixel size)
63
Increase in the flat panel DEL,
Decrease spatial resolution
64
Receptor Exposure Define:
Overall amount/quantity of radiation that reaches the IR
65
Definition of Radiographic Contrast:
Difference in adjacent areas
66
If an image has high contrast: more/less blacks and whites
MORE
67
Low contrast:
Lots of shades of grey, less blacks and whites
68
Seperate mA and time in a question. Multiply in the question and match in the answer.
Law of reciprocity
69
Define inverse square law:
Intensity is inversely proportional to the square of the distance
70
If distance gets ever gets doubled or cut in half the intensity will change by a factor of:
4
71
If you double the distance intensity is:
4 times less
72
If you cut the distance in half intensity is:
4x more
73
Direct Square Law Equation:
mAs1/mAs2 = (SID1/SID2)^2
74
What new mAs will be used to MAINTAIN:
Direct square law/receptor maintenance formula
75
The 15% kVp rule states:
If you increase or decrease the kVp by 15% you either double or cut the receptor exposure in half
76
Double the receptor exposure by applying the 15% kVp Rule, at 80 kVp and 30 mAs, what is the new technique?
92 kVp and 30 mAs!
77
Cut the receptor exposure in half by applying the 15% rule, 80 kVp and 30 mAs. What is the new technique?
68 kVp and 30 mAs
78
“The receptor exposure is sufficient, but the contrast needs to be increased”
Use the 15% kVp rule. Increase kVp. Cut the mAs in half on the backend. Decrease kVp, double the mAs
79
Grid Ratio=
H/D
80
In a diagram, height of the lead strips (use), thickness of lead strip (not use), distance between the interspace (use):
H/D
81
Non-Grid:
1
82
5:1 Grid:
2
83
6:1 Grid:
3
84
8:1 Grid:
4
85
10:1/12:1 Grid:
5
86
16:1 Grid Ratio:
6
87
A Radiographic examination is performed 80 kV, 10 mAs, 100 cm SID, with a 5:1 Grid Ratio. A new exposure is made with a 16:1 Grid Ratio to increase the contrast. What is the new technique?
Old mAs/new mAs= Old Grid/new Grid
88
A Radiographic examination is performed with 70 kV, 10 mAs, 100 cm SID, with a 200 speed image receptor, a new exposure is made with a 8:1 grid. What is the new technique?
Apply the non grid=1
Have to go with the closest number to the calculator. Old mAs/New mAs = old grid/new grid
89
The purpose of filtration:
Cleans up longer wavelength x-rays, soft x rays, reduces the ESE
90
As part thickness increases:
Increase in attenuation
91
Attenuation
Reduction in x-ray intensity that passed through matter
92
As atomic number increases:
Attenuation increases
93
Define pathology:
94
Define Atalacticis:
Collapsed lung
95
Define Ascities:
Accumulation of Fluid
96
Define pneumothorax:
97
Define spondolotithesus:
Displacement of one vertebra on top of another vertebra
98
Additive pathology: what happens to technique?
Increase technique
99
Destructive pathology; what happens to technique?
Decrease technique
100
A patient presents in the ED department fever shortness of breath, cough:
Pneumonia (pneumonic infiltrate)
101
The patient presents with diapheretic, cool clammy to the touch, fever:
Congestive heart failure
102
So T-spine, place the cathode over: and the anode:
Lower t-spine, upper t-spine
103
Always place the cathode over the:
Proximal joint
104
Always place the cathode:
On the thoracic and abdominal cavities
105
The cathode goes:
Lower t-spine, lower thorax, lower diaphragm
106
On a average adult, lateral T-Spine it requires: 3 views Ap Lateral the lateral cervical thoracic projection (Swimmers).
Put the cathode up
107
Short scale contrast:
Black and white appearance
108
I’m a myeologram we inject intrathecally:
Within the spinal canal
109
The three things that effect the production of scatter radiaiton
High kVp
large thick parts
large field sizes
110
All of the following effect the production of scatter radiation except:
The use of a Grid
111
Long scale:
More gray appearance
112
Increase kVp
Decrease contrast (forward scatter)
113
What controls image contrast on a chest x-ray?
LUT
Computers algorithm
Histogram analysis
114
With the use of filtration the beam becomes:
More homogenous
115
Umbra
Clear concise center
116
Penumbra
Blurring around the edges
117
The penumbra (geometric unsharpness) is always greater on the:
Cathode side of the beam
118
If you increase the OID:
Increase magnification, decrease spatial resolution
119
A heart on an IR measures 15.2 cm at its widest point but its true width in the chest cavity is 13.6 cm. How much magnification?
Image size/object size, always bigger on the image (big/small)
120
A Radiographic examination is performed with 180 cm SID, but the anatomical part has a 20cm OID. How much magnification?
SID/OID
SID-OID=SOD
180-20= 160
180/160= 1.125
121
When the day how much magnification: use what formula
SID/SOD
122
Increase SID:
Decrease magnification, increase Spatial resolution
123
What effects size distortion and spatial resolution:
OID and SID
124
What is the best way to control voluntary motion? Respiration, peristalsis, Parkinson’s disease
Clear concise instruction
Proper communication
125
What is the best way to control involuntary motion:
Shortest possible exposure time
126
Increase in focal spot size:
Decrease in spatial resolution
127
Sampling frequency controls:
Spatial Resolution
128
Define Actual Focal Spot:
Electrons actually strike the target
129
Define effective focal spot:
Gets projected down to the patients
130
Which is larger the actual or effective focal spot?
Actual
131
The incorporated design of the line focal principle creates:
Larger actual focal spot
smaller effective focal spot
132
Which of the following anode angles gives you the greatest spatial resolution:
Pick the smallest angle!
133
If you are doing a hand X-ray and doing it table top, is it the use of APR or AEC?
APR (anatomically programmed radiography)
134
Caliper:
Device used to measure part thickness.
135
Fixed kVp
kV stays fixed for the exam.
60 kv on every hand, 70 kv on every knee, 80 kV on every pelvis but it is appropriately fixed for that examination.
136
kVp is determined by using ______ to accurately measure the thickness of the body part being evaluated
Caliper
137
Variable kVp
Always use 10 mAs on every knee, 20 mAs on every hip, 30 mAs on every pelvis. The kVp changes.
138
A set of calipers an anatomical part (pelvis) to be 20cm, 21 cm, 22cm you would use how much kV?
80 kV, 82 kv, 84 kv
139
For every cm of part thickness increase, increase ____ kVp per.
2
140
A patient falls hurts their wrist, plaster cast on wrist, what new kVp?
8-10 kVp increase
141
2 months later the patient is going to see if they can take the cast off, it is perfectly drive how much kVp increase?
5-7 kVp increase
142
Fiber glass cast is a how much kVp increase?
3-4 kVp increase
143
Anytime an anatomical part exceeds how many cm you need to get a grid:
10 cm rule
144
What cell would you select for a PA projection of chest?
The two outer cells
145
What cell would you select for the axial skeleton? (Skull to coccyx)
Center Cell
146
The ala of the pelvis (wings of the pelvis) what cell would you select?
Outer Cells
147
Pelvis and concentrate on Sacrum or Coccyx what cell would you select?
Center cell
148
Abdomen with a concentration of the spine what cell would you select?
Center Cell
149
Abdomen with a concentration of the kidneys, what cell would you select?
Outer cells
150
what is the main/single most disadvantage when using the AEC device?
Inaccurate or inadequate or improper positioning
151
Spatial resolution definition:
The ability of the system to record small adjacent structures. The sharpness of the structural edges recorded in an image.
152
What is spatial resolution measured in?
Line pairs per mm (lp/mm)
153
Define pixel:
Picture element
Smallest area depicted in an image
Two-dimensional square that contains discrete gray shades
154
Define Pixel size:
Measurement from one end to the other end
155
As pixel size increase, ________ spatial resolution.
Decrease
156
Pixel pitch define:
Measured from center to center.
157
As pixel pitch increases, ________ spatial resolution
Decreases
158
Pixel Density:
Number of pixels per millimeter
Determined by the pixel size and pixel pitch.
159
As pixel size decreases, pixel density _______.
Increases
160
Matrix:
Number of rows times the number of columns
161
An increase in matrix size:
Greater spatial resolution
162
Smaller matrix size, larger pixel:
Spatial resolution decreases
163
Bigger matrix size, smaller pixel:
Increase spatial resolution
164
Define sampling frequency:
The number of pixels sampled per millimeter as the laser scans each line of the imaging plate.
165
The main controlling factor of sampling frequency is:
Spatial resolution
166
A CR cassette, the PSP plate gets withdrawn, and it runs underneath, the laser scans the imaging plate the more pixels it reads:
The greater the spatial resolution
167
Increasing sampling frequency=
Increase spatial resolution
168
Nyquist Frequency definition:
The relationship between sampling frequency (number of pixels/mm scanned by the laser at a rate that is 2xs highest frequency present) and the spatial resolution (resulting image detail)
169
As the DEL increases, _________ spatial resolution
Decreases
170
When we do extremities such as carpals and tarsals we want what size DEL?
Small
171
The relationship between DEL and spatial resolution:
Inversely Proportional
172
Dynamic range:
Range of acceptability
173
Quantum mottle definition:
An insufficient quantity of x-rays to reach the IR
174
The main controlling factor of Quantum mottle:
mAs
175
Signal to Noise Ratio Definition:
Ratio between signal or meaningful information and noise or background information
176
Which of the following SNRs gives the greatest spatial resolution?
2:1
4:1
8:1
16:1
16:1
(16 signal/contrast to 1 noise)
177
Who owns the image?
The institution maintains ownership
178
All of the following are mandated on the image to make the document legal and binding in the court of law except:
DOB
POST EXPOSURE MARKER
PATIENT AGE
179
Every complement of the x-ray tube is internal except:
Stators
180
What charge is the cathode:
Negative charge
181
Glass envelope function:
Helps protect the internal components of the x-ray tube
Maintains a vacuum environment within the radiographic tube
182
What is the glass envelope material:
Pyrex glass
183
What charge is the cathode?
Negative electrode
184
What components make up the cathode?
Filament Wires
Focusing Cup
185
What material is the focusing cup?
Molybdenum or Nickle
186
What material is the filament wires?
Thoriated Tungsten
187
The focusing cup functions to:
Maintain a predetermined number of electrons around the filament prior to exposure
188
The focal spot (where the size of the focalpot direct toward the image receptor) is smaller/larger than the focal spot measured on the surface of the anode:
Smaller
189
What does the focusing cup do?
Operates at a saturation current- maximum current level at a given tube current
190
Which part of the x-ray tube is outside of the vacuum tube?
Stator
191
Leakage radiation should not exceed:
100 mR/hra in air at 1 meter
192
Why is the actual focal spot larger than the effective focal spot?
Line focus Principle (the anode is angled)
193
The flow of electrons:
Always negative to positive
Cathode to anode
One way flow
194
Anode material:
Tungsten Target with Rhenium
195
Materials or choice of materials for the neck and the base of the anode:
Copper, molybdenum, graphite
Because they provide weight savings if the anode assembly
196
The induction motor:
Two components make up the induction motor: Rotor and stator
The name of the motor that drives or powers the anode during exposure
197
Isotropically:
Equal intensities in all directions
198
A properly designed lead lines protective housing will reduce the leakage radiation to:
1 mGya per hour at 1 meter
100 Mr/hra at 1 meter
199
Three chest x-rays, 8 year old, 80 year old female hypodermic and ammonia and a 40 year old hyperstenic:
Photo time all of them (AEC)
200
What is the purpose of using a back up timer when using an AEC device?
Patient safety device in case of equipment malfunction
201
Minimum Response Time (MRT) definition:
The time it takes for a system to respond and sends signal to terminate the exposure
202
PBL:
Positive beam limitation device
Automatic collimation
203
The use of beam restriction does the following:
Decrease Dose, Decrease Receptor Exposure, Increase Contrast
204
Aperture Diagram:
Simplest type of beam restricting device, a lead plate with a hole cut in the middle that is slightly smaller than the image receptor size
205
Variable Aperture Collimation:
Controlled by the radiographer
Permits the adjustment of the length and width of the radiation light field
Utilizes a light localization device to estimate the size and shape of the radiation field
206
Cylinders or Cones:
Attaches to the bottom of the collimation housing
Creates a circular shaped collimation field
Maximum beam restriction occurs with increased length and decreased diameter of the cylinder or cone
207
How does collimation affect patient dose, receptor exposure, contrast?
Patient dose decreases, receptor exposure decreases, contrast increases
208
Use of any beam restriction device:
Patient dose decreases, contrast increases
209
Ohm’s Law definition:
V= IR
210
V measures=
Voltage or electric potential
211
I measures=
Amperes
212
R measures=
Resistance measured in Ohms
213
If you have a 100 mA station, 25 m/s what is the mAs?
0.025 seconds
214
A parallel circuit had 4 resistor elements of 5, 10, 20 ohms. What is the total resistance?
3.43 ohms approximately
215
A series circuit has 4 resistant elements of 5, 10, 15, 20 ohms. What is the total resistance?
50 ohms
216
Where can you find the auto transformer?
Primary/Low Voltage Side
217
Where can you find the exposure timer?
Primary/Low Voltage Side
218
Where can you find the x-ray tube?
High Voltage/Secondary
219
Where can you find the mA selector?
Filament
220
Where can you find the focal spot selector?
Filament
221
Where can you find the step down transformer?
Filament transformer
222
The electrical energy supplied to the x-ray unit is:
Alternating Current (AC)
223
Any induction self/mutual requires what current?
AC current
224
Source of EMF/electric potential:
Voltage
225
The focusing cup is positioned around the:
Filament wires
226
Electric potential is the unit of the:
Volt
227
Auto transformer
Single coil of winding
Works on the principle of self induction
Determines the amount of line voltage that will be sent to the step up transformer
228
All induction requires what current:
A/C
229
Which of the following transformers is considered the most efficient?
Shell Core
230
A transformer has 10,000 turns on its secondary side and 500 turns on its primary. What is the turns ratio for this transformer?
TS/TP
10,000/500
20:1
20 secondary to every 1 primary
231
A transformer has 5000 turns on its primary side and 100 turns on its secondary side. What is the turns ratio for this transformer?
100/5000= 1:15 (1/50)
Secondary divided by primary only.
232
A transformer has a turns ratio of 200:1. If 150 volts are supplied to the transformer, what is the output voltage?
Always supply the primary coil
Vs (x)/ 150
200/1
Vs/VP = TS/TP
200 (150); x= 30,000 volts or 30 kV
233
Where is the auto transformer located?
The primary or low voltage circuit between the incoming line voltage and the primary side of the step-up transformer.
234
What is the source for kVp?
Auto transformer.
235
Where is the line voltage compensator located?
Located within the primary or low voltage circuit of the x-ray unit and connected to the primary side of the auto transformer
236
What does the line voltage compensator do?
Maintains a constant voltage/turns ratio within the auto transformer
237
What is the step up transformer also known as?
High voltage or high tension transformer
238
What does the step up transformer operate on the priniciple of?
Electromagnetic mutual induction (two wires)
239
Where or when does voltage become kilovoltage?
Step up transformer
Secondary side or output side of the step up transformer
240
Filament transformer is also known as:
Low voltage or step down transformer
241
Where is the filament transformer located?
Low voltage filament circuit
242
The step up transformer gives the desired _______ the step down delivers the ________ _______.
Voltage, Thermionic Effect
243
The filament transformer works off of the principle of:
Electromagnetic mutual induction (two wires)
244
Current is ______ to the transformers turns ratio
Inversely proportional. This means that the current will be reduced by a step up transformer and increased by a step down transformer.
245
An mA station is considered to be a:
Variable resistor
246
The pre-reading kVp meter reads:
Voltage
247
Where is the pre-reading kVp meter located?
Low voltage side
248
All of the following are examples of exposure timers except:
mAs
Electronic
Synchronous
Recipricating
Answer: recipricating
249
Which of the following timer devices is considered the most accurate?
Electronic Timing Devices
250
What is the main controlling factor of spatial resolution?
Sampling frequency/Focal Spot Selector
251
Two types of focal spot sizes:
Small and Large
252
Use a small focal spot on:
Carpals and Tarsals (things that require a lot of detail)
253
The main advantage of the small focal spot is:
Greater spatial resolution
Greater Recorded Detail
254
The disadvantage of the small focal spot size is:
Can not withstand the heat
255
The large focal spot advantage:
Can withstand high speed electrons bombarding it
256
The disadvantage of the large focal spot size:
Does not give good spatial resolution or recorded detail
257
Which is larger the actual focal spot size or effective focal spot size?
Actual
258
In the United States, electrical energy is supplied in a __________ cycle alternating current
60 second
259
1000:1
Goes back and forth 60 times in one direction
Cathode anode and exits down to the patient
260
What does rectification do?
Converts AC to DC
261
Single Half wave rectified voltage ripple and how many useful pulse per second?
100%
60/sec
262
Single Full Wave Rectified voltage ripple and how many pulse/sec?
100%
120/sec
263
3 phase Six Pluse voltage ripple and how many useful pulse/sec:
13%
360/sec
264
3 phase 12 pulse voltage ripple and how many useful pulse/sec?
4%
720/sec
265
High frequency voltage ripple:
Less than 1%
266
Image Intensifier:
To increase overall brightness
To convert x-ray beam into a bright visible light
267
X-rays with interact with the input phosphor and gets converted to:
Light
268
What does the photocathode do?
Converts light photons from the input phosphor into free electrons
269
Anode in Flouroscopy Unit:
Metal plate with a hole in the middle
270
XLELM
X-rays to light, light to electrons, electrons back to light, and to the monitor
271
What material makes up the input phosphor?
Cesium Iodide
272
What does the photocathode do?
Converts light photons from the input phosphor into free electrons
273
What does the electrostatic lens do?
Directs or focuses the path of electrons from the photocathode to the surface of the output phosphor screen
274
What does the output phosphor do?
Converts electrons sent from the photocathode into light photons.
275
What is the material of the output phosphor?
Zinc cadmium sulfide
276
Define Brightness Gain:
Minification Gain times Flux Gain.
BG= minification x flux
277
Define minification:
The diameter of the input squared Divided by the diameter of the output squared
278
An image intensification tube with an input phosphor size of 17 cm and an output phosphor size of 2.5 cm with a flux gain of 100. What is the brightness gain?
Minification gain= 17^2/2.5^2, Minification gain = 46 x 100 = 4600 lumens brighter with an image intensifier vs without
279
Which one controls the bright light vision (photopic)?
Cone of the eye
280
Which controls Low light or night vision (scotopic)?
Rods of the eyes
281
Define vignetting:
Loss of detail and fall off of brightness along the edge of the fluoroscopic image
282
Loss of resolution around the periphery? (Fluoro)
Vignetting
283
Loss of resolution around the periphery of the image?
Vignetting (looks like a pin cushion)
284
Which of the following recording devices gives the highest patient dose?
Cine fluoroscopy
Recording
10xs the next competitor
285
When you are in fluoroscopy and you move from a thicker part to a thinner part you do not have to move and adjust the technique:
The machine will adjust the increase/decrease kVp and mAs through the ABC or AERC device.
286
When magnification takes place in flouroscopy, _________ patient dose.
Increase
287
Anterior surface of the foot is called:
Dorsum (dorsal) Surface
288
In the mag mode in flouroscopy _________ spatial resolution and _______ contrast resolution
Improve both
289
The disadvantage of magnification mode is:
Increase patient dose
290
Flouroscopy is the greatest source of:
Acute radiation exposure to the patient in the diagnostic radiology environment
291
Cr is a cassette based system what are the types:
1. (PSP) Photostimulable phospher plate
2. Flat panel detector/thin film transistor (FPD/TFT)
3. PSP plate with a charged couple device (CCD)
292
What is the imaging plate used in a CR Cassete?
PSP (photostimuable phospher)
293
What are the PSP materials made of?
Europium activated barium flourohalide
294
Phospher or Active Layer Definition:
Contains the photostimuable phospher that traps electrons during the Radiographic exposure
295
Latent
Invisible
296
Manifest
Visible
297
Manifest
Turning an latent image into a visible image
298
A technologist is using a CR cassette operating off of a PSP system x rays blow through the anatomy of interest and you get a disruption of valance band electrons: what do you do?
Latent image exists
Place the cassette on the workstation
Imaging plate is removed by the cassette
Gets scanned by the laser
Electrons that got distrusted that are trapped
Voiolet light releases them
299
The S system has a ______ relationship
Inverse
300
If the range of acceptability is 200-400, as an operator your goal is to be:
Directly in the middle of the range
301
If the exposure range is 200-400 and your S value is 125. What does this mean?
Over exposed the patient
302
If the exposure range is 200-400 and your S value is 450. What does this mean?
Underexposed
303
EI and the Lgm are ________ proportional
Directly
304
DR is:
Casetteless
305
The DR cassette less system consists of:
1) FPD/TFT
2) CCD
3) CMOS (complimentary metal oxide semiconductor)
4) PSP Plate with a CCD
306
Indirect DR:
3 step process, scintillator based uses cesium iodide or gadolinium oxysulfide
307
Direct DR:
Non-scintillator based systems does not use a material that converts x-rays to light
308
What is the name of the device used to convert x-ray photons into light?
Schintillator
309
Scintillator based systems use:
Cesium iodide (CSI) or gadolinium oxysulfide
310
Direct DR material:
Amorphous selenium (a-Se)
311
What are the materials used in indirect capture?
Cesium Iodide (Csi) or gadolinium
Amorphous silicon (a-Si)
312
What are the materials used in direct capture?
Amorphous selenium (a-Se)
313
ADC stands for:
Analog to digital converter
314
What is the main controlling factor of contrast:
LUT (look up table)
315
Equalization definition:
Method of image processing using the histogram of the image to adjust contrast. Allows for the demonstration of a wide range of anatomical structures without overall loss of image quality
316
What does equalization improve?
Display range
317
Interventional radiology DVT anuerysm, Evaluate flow in the vessels. Why do you want the bone in the way?
You don’t. You want to make it or through the process of subtraction you have masking
318
Leg length, scoliosis series question:
Stitch!!
Stitch images together to combine multiple images for anatomy that is too large for a single exposure, resulting in a seamless image
319
Shuttering definition:
Removes or replaces the background information
320
Which of the following matrix sizes will give you the greatest spatial resolution
1020 x 780
1919 x 708
*the biggest number is the answer*
321
Define Hounsfield Unit/CT number:
Each pixel is given a numerical value based on the receptor exposure in the pixel
322
FOV definition:
The diameter of image reconstruction
323
Voxel (volume element) definition:
Volume of tissue imaged is given a value
324
Window level allows you to adjust the:
Brightness
325
Window width allows you to adjust:
Image contrast
326
A narrow width:
Short scale appearance
White and black
327
A wide window width:
More shades of grays
Long scale of contrast
328
DICOM stands for:
Digital imaging and communication in medicine
329
Exchanging images is done by the process of:
DICOM
330
PACS stands for:
Picture archiving and communication system
331
PACS definition:
Consists of digital acquisition equipment, workstations for display, and manipulation of images and interconnected storage devices that communicate in the same language of DICOM
332
Definition of teleradiology:
Process of remote transmission and viewing of images
333
HIS:
Hospital Information System
Contains full patient information
334
RIS
Radiology Information System
Contains radiology specific information about the patient including the radiologists report (modality work list)
335
EMR:
Electronic medical record
336
EHR:
Electronic health record
337
What is the minimum change to show a perceptible difference?
Minimum of 30%
338
PSP plate can only be cleaned with:
Anhydrous ethanol
339
Outside of the CR cassette can be cleaned with:
ANY disinfectant
340
Light field of radiation field alignment QC:
Plus or minus 2% of the source to image distance
341
PBL must be within:
2% of the SID
342
SID indicator must be within:
+/- 2%
343
CR must be within:
1.25 cm (0.5 inches) of the indicator
344
Linearity:
+/- 10%
345
Filtered beam in mgy must be at least:
50% of the unfiltered beam
346
Beam must be within ______ degree of perpendicular
1 degree
347
Exposure timer QC:
+/- 5%
348
kVp QC:
+/- 5%
349
QCs should be performed:
Daily for technologist
350
Imaging plates that have been unexposed for longer than ________ should be erased.
24 hours
351
Which of the following will increase spatial resolution?
Increase SID
Decrease FOV
Decrease OID
352
Which of the following is inversely proportional to IR exposure?
SID
Grid Ratio
Filtration
