XRAY 110 & lab Flashcards
1
Q
In what body habitus is the gallbladder most inferior?
A
asthenic
2
Q
The lordotic position is used for visualizing what?
A
lung apices
3
Q
What are the breathing instructions for an abdomen?
A
expiration
4
Q
If you are doing a lateral of the 5th digit, you’d rest the hand on which side?
A
medial side
5
Q
What view of the elbow shows the radial head free from superimposition?
A
lateral oblique
6
Q
The 1st radiographic grid was made in what year?
A
1913
7
Q
What is the most commonly performed oblique of the foot?
A
medial oblique
8
Q
If you increase screen speed, what does it do to contrast?
A
increases contrast
9
Q
Which bone is directly superior to the calcaneus?
A
talus
10
Q
What provides the location for the formation of the latent image?
A
sensitivity speck
11
Q
T/F. There is a definite divider between the abdominal cavity & the pelvic cavity.
A
False
12
Q
Which lung is shorter?
A
right lung
13
Q
Which quadrant does the liver lie in?
A
right upper quadrant
14
Q
What is the CR for a PA Oblique hand?
A
3rd MCP (metacarpal phalangeal)
15
Q
For a lateral elbow projection, the humeral epicondyles should be ________ to the IR?
A
perpendicular
16
Q
Which portion of the patella is the apex?
A
the bottom part
17
Q
What is the CR for an AP projection of the foot?
A
base of the 3rd metatarsal
18
Q
What type of grid is used for a moving grid?
A
focused grid
19
Q
If you increase screen speed, what happens to density?
A
density is increased (because more photons hit IR)
20
Q
Which layer of the film is the thickest?
A
the base
21
Q
What body habitus describes 50% of the population?
A
sthenic
22
Q
What is the recommended SID for a PA chest projection?
A
72” (183cm)
23
Q
What does the “U” stand for in KUB?
A
ureters
24
Q
What is the CR for digits 2-5 (for one of them, not all)?
A
PIP (proximal interphalangeal joint)
25
What is the central ray for an AP projection of the forearm?
midpoint of the forearm
26
How many tarsals are there in 1 foot?
7
27
The lateral malleolus is on what bone?
fibula
28
What was the first type of grid made?
cross or crosshatched
29
The thickest layer of the radiographic intensifying screen?
base
30
What type of film is commonly used today?
screen film
31
What portion of the skeleton supports the head & trunk?
axial skeleton
32
What size cassette should be used for a KUB abdomen image?
14"x17" (35x43cm)
33
The capitate is also known as what?
Os magnum
34
The CR for an AP projection of the shoulder?
1" inferior to the coracoid process
35
What date where x-rays discovered?
November 8, 1895
36
What oblique projection of the foot will best demonstrate the cuboid?
medial oblique
37
What is the position of the femoral condyles when the leg is properly positioned for an AP projection of the knee?
parallel to the IR
38
Begin with a technique of 120 kVp, 1.6 mAs, with a 12:1 grid. What technique would you need if you switched to an 8:1 grid?
120 kVp, 1.28 mAs
39
Protons are located where?
in the nucleus
40
When examining a hand, would you want a fast or slow screen?
slow
41
What is a recumbant position with a body plane tilted so the feet are lower than the head?
Fowler
42
What all must be included on a supine KUB?
pubic symphysis, kidneys, ureters, bladder
43
The distal end of the metacarpals is called what?
the head
44
How many degrees of flexion are required for a lateral projection of the elbow?
90°
45
The 1st radiographic patient had an image done on which body part?
wrist (Colles' fracture) or hand (Roentgen's wife)
46
When performing an AP oblique projection of the foot, the plantar surface of the foot should form a ____° angle with the IR?
30°
47
What is the CR angle for the axial plantodorsal projection of the os calcis?
40°
48
Which grid has the highest lead content?
16:1
49
Begin with a technique of 80 kVp, 50 mAs, 200 screen speed. What would be the new technique if a 400 screen speed was used?
80 kVp, 25 mAs
50
What is the formula for work?
W=fd (Work=force x distance)
51
Are lead markers considered an artifact?
no
52
What is the CR for a supine abdomen?
at level of iliac crests, on MSP
53
The head of each phalanx is what portion?
distal portion
54
The coranoid fossa is located on which surface of the humerus?
anterior surface
55
T/F. Early radiographers realized the dangers of radiation?
False
56
What is the CR for an AP projection of the knee?
1/2" below the patellar apex
57
For an AP oblique projection of the knee, how many degrees should the knee be rotated?
45°
58
What is the purpose of using a grid?
to clean up scatter
59
What is the factor for a 200 screen speed?
1
60
What is the standard unit of mass?
kg (kilograms)
61
24 x 30 cm film is what size in inches?
10 x 12
62
Free air within the abdomen is best demonstrated on what view?
upright abdomen
63
What is the largest carpal bone?
capitate (os magnum)
64
Which AP projection of the shoulder will best demonstrate the lesser tubercle?
internal rotation
65
Who found a way to measure the intensity of radiation, and now their last name is used as a basic unit of measurement?
Pierre and Marie Curie
66
Which tarsal bone lies directly anterior to the talus?
navicular
67
Which 2 large processes are located at the proximal end of the femur?
trochanters
68
What is the purpose of the reflective layer?
to reflect light back onto the film
69
A grid used in the radiography department has a strip height of 1800, a grid strip thickness of 50, and an interspace of 300, what is the grid ratio?
6:1 (1800:300 = 6:1)
70
What are the 2 main components of the x-ray film emulsion?
silver halide crystals & gelatin
71
72" is how many cm?
183
72
In an upright abdomen, it is most important to include ____ ?
the diaphragm
73
What is the joint located most distal to the elbow?
DIP (distal interphalangeal joint)
74
The capitulum of the humerus articulates with what bone?
radius
75
Who discovered x-rays?
Wilhelm Conrad Roentgen
76
The proximal end of the tibia contains 2 prominent process. What are they?
condyles
77
For an AP projection of the femur, what must be done to place it in true anatomic position?
rotate the feet medially 10°-15°
78
List the layers of the screen, in order.
base, phosphor, reflective layer, protective layerorprotective layer, reflective layer, phosphor, base
79
What is the latent image?
the invisible image captured but not yet processed
80
Which plane divides the body in equal anterior and posterior halves?
MCP (midcoronal plane)
81
What is the CR for an upright abdomen?
2" above the iliac crests on the MSP
82
How many carpal bones in each wrist?
8
83
On the humerus there are 2 fossa. Which one is posterior?
olecranon fossa
84
What year were x-rays discovered?
1895
85
Which bone in the lower extremity does not bear any weight?
fibula
86
For an AP projection of a femur on a typical adult, what must you do to ensure both joints are demonstrated?
make 2 images (proximal & distal)
87
What is the purpose of the base in a screen?
support & provide structure
88
In a radiographic grid, is the interspace material radiopaque or radiolucent?
radiolucent
89
What 2 layers of film do the adhesive layer hold together?
emulsion & base
90
What is the mAs if your technique is 76 kVp, 600ma, 1/5 of a second?
120 mAs
91
Which body plane divides the body into equal right and left halves?
MSP (midsagittal plane)
92
On the lateral chest x-ray, which is more anterior, the trachea or the esophagus?
trachea
93
What is the 1st bone located on the proximal row of the lateral side of the wrist?
scaphoid
94
How much rotation is required for an AP oblique of the elbow?
45°
95
T/F. The male pelvis is wider and shallower?
False
96
T/F. The most prominent point of the greater trochanter is in the same horizontal plane as the pubic symphysis?
True
97
What does Window Level control?
brightness
98
What does the term "projection" mean?
the path of the x-rays
99
How is a focused grid made?
strips and interspace material are angled as the x-ray beam goes out
100
Is milliampers (mA) the quality or quantity of the electrons in the x-ray beam?
quantity
101
What is the date your film badge is due back to the college each month?
18th of the month
102
On a PA Chest, how many posterior ribs should be seen above the diaphragm?
10
103
The elbow joint is what type of joint?
hinge
104
When positioning for a lateral humerus, the epicondyles should be ____ to the IR?
perpendicular
105
On an AP projection of the femur, where would the lesser trochanter be seen?
on the medial side of the femur
106
Which bone of the pelvis contains the ASIS?
ilium
107
How is a cross (cross-hatched) grid made?
2 parallel grids placed perpendicular to each other
108
What is density referred to in digital imaging?
brightness
109
What is the term "ventral" mean?
anterior
110
The body habitus that makes up 5% of the population and is characterized by a massive build?
hypersthenic
111
Your lead markers should be used when?
always
112
What is the CR for a PA chest?
T7 on MSP
113
Carpal bones are what type of bones?
short bones
114
What all must be included on an AP humerus?
shoulder joint & elbow joint
115
On an AP projection of the femur, what should you see in profile?
greater trochanter
116
What bones form the pelvis?
sacrum, coccyx, hip bone/os caxae (ilium, ischium, pubic bone)
117
What are the rows and columns of pixels that form the image?
matrix
118
What does the term "superficial" mean?
not deep/near the surface
119
What is grid cut-off?
improper use of a grid resulting in x-rays being cut off
120
Starting with a technique of 60kVp and 5 mAs, apply the 15% rule to help reduce motion.
69 kVp, 2.5 mAs
121
The scapula is which type of bone?
flat
122
Which oblique elbow shows the radial head free from superimposition?
lateral oblique
123
If you cannot see enough posterior ribs in a PA chest image, what would you do to fix it on the repeated image?
have the patient take in a deeper breath and hold it
124
When doing a lateral projection of the great toe, which side should the patient be placed?
unaffected side
125
What is the definition of the term "visceral?"
lining of the organs
126
A large Window Width will result in what type of contrast?
long scale
127
Find the kinetic energy of a truck that weighs 5,670 kg moving at a velocity of 50 m/s.
KE=7,087,500 J
128
If you increase grid ratio, what happens to patient dose?
patient dose increases
129
The thicker the film's emulsion, the ___ the speed?
faster
130
Using the 15% rule, increasing the kVp can be used to help control what?
patient dose & motion
131
What is the articulation located at the distal end of the clavicle?
AC (acromioclavicular) joint
132
What is the CR for a PA wrist?
midcarpal area
133
What is the hilum?
opening where the bronchi enter the lungs
134
Why would you want to angle on an AP projection of the toes?
to open up the joint spaces
135
Define inertia?
a body at rest will stay at rest, and a body in motion will stay in motion (at a constant speed & direction) unless acted upon by an outside force
136
Contrast is referred to as _____ in digital imaging?
greyscale
137
Explain how to place a patient in RPO position.
patient will be facing away from the IR, with the back of the right shoulder touching the IR
138
Which grid would require the highest technique out of the following - 6:1, 10:1, 12:1 ?
12:1
139
T/F. Film is manufactured with contrast already built into it?
true
140
Define density.
overall blackness on a film
141
List everything contained in the mediastinum.
Greater vesselsHeartEsophagusTracheaThymus
142
The shoulder joint is what type of joint?
ball and socket
143
How much should you angle the tube on an AP projection of the toes?
15° according to Merrill's (need to ask Amber bc she said 10° was answer)
144
What is another name for the scaphoid?
navicular
145
Define kinetic energy.
energy in motion
146
What does Window Width control?
greyscale
147
What does the term "hyper-extension" mean?
extended too far
148
What is the radiation that exits the tube through the window called?
primary radiation
149
Cross over is ____.
undesirable
150
An increase in kVp will do what to contrast?
decrease contrast
151
An increase in SID will do what to magnification?
decrease
152
The hand must be supinated on an AP examination of the forearm to prevent what?
the radius and ulna from being crossed over each other
153
On which method for lateral projection of the hip is the CR angled 20° cephalic?
Hickey method
154
Where is the intertrochanteric crest?
posterior side of the femur, between the trochanters
155
On CR (computed radiography), it is recommended to do how many images per IR?
1
156
How long does the most commonly used film processor take?
90 seconds (1.5 minutes)
157
Detail is referred to as ____ in digital imaging?
spatial resolution
158
A box has a mass of 45 kg, what is it's weight on Earth?
441 N
159
The efficiency of a grid at removing scatter radiation is related principally to the ___?
grid frequency
160
Which of the following is an important and frequently used radiographic positioning reference point? AIIS, ASIS, PIIS, PSIS
ASIS
161
An increase in SID will do what to patient dose?
decrease
162
Which forearm bone is on the lateral aspect?
radius
163
T/F. The highest point of the greater trochanter is in the same transverse plane as the midpoint of the hip joint.
T
164
How much rotation of the lower limb is required for an AP projection of the pelvis?
15°- 20°
165
T/F. Film/screen imaging is more sensitive to fog than CR/DR imaging.
F
166
What is the force of a 150 kg rock rolling down a hill with an acceleration of 20 m/s?
3,000 N
167
What is in a washer tank?
clean water
168
Technique is more critical in film/screen or CR/DR?
film/screen
169
If you increase grid ratio, what happens to contrast?
contrast increases
170
What is the strongest bone in the human body?
femur
171
An increase in screen speed will do what to patient dose?
decrease patient dose
172
Which forearm bone is smallest at the proximal end?
radius
173
How much rotation of the lower limb is required for an AP projection of the hip?
10°-15°
174
What is the breathing instruction given to the patient for an AP pelvis?
suspend respiration
175
Which has a wider latitude, film/screen or CR/DR?
CR/DR
176
What is the formula for force?
F=m x a (Force = mass x acceleration)
177
What is the order of the tanks for the automatic processing?
developer, fixer, washer, dryer
178
Image noise is ___?
bad
179
If you increase grid ratio, what happens to density?
density decreases
180
An increase in screen speed will do what to density?
increase density
181
An increase in mAs will do what to patient dose?
increase patient dose
182
An increase in field size will do what to density?
increase density (because of increased scatter)
183
On an AP shoulder x-ray, which rotation better shows the greater tubercle?
external rotation
184
Name the body habitus considered very frail.
asthenic
185
A picture element, one cell (in a matrix) of a digital image.
pixel
186
In CR/DR, window _____ is in the center of window _____?
window level is in the center of window width
187
How much rotation of the ankle is required to see the ankle mortise joint?
15°-20°
188
How many electrons can be in the "P" shell?
72
189
Define power.
the rate of doing work
190
An increase in mAs will do what to density?
increase density
191
An increase in grid ratio will do what to patient dose?
increase patient dose
192
An increase in OID will do what to detail?
decrease detail
193
What separates the supraspinous fossa and the infraspinous fossa?
spine of scapula
194
What is a suture?
a joint in the skull
195
In digital, what can be compared to a screen?
scintillator
196
What does PSP stand for?
photostimulable phosphor
197
How much rotation is required for an oblique foot?
30°
198
What is the formula for potential energy?
PE=mgh (PE= mass x gravity x height)
199
Define potential energy.
energy to do work by virtue of position
200
Short scale contrast is high or low contrast?
high
201
An increase in grid ratio will do what to density?
decrease density
202
An increase in kVp will do what to patient dose?
decrease patient dose
203
How far above the humeral head should the upper margin of the IR be placed for an AP projection of the humerus?
1 1/2" inches
204
What is the midcoronal plane?
a plane that divides the body into equal anterior & posterior halves
205
On CR/DR, window level controls ____?
brightness
206
On CR/DR, window width controls _____?
greyscale
207
How much rotation is required for an oblique ankle?
45°
208
What is the formula for power?
P=w/t (P= work/time)
209
What is the charge of an electron?
-1
210
What is the earliest reference to the term atom?
Greek atom
211
What type of atom do we still refer to today?
Bohr atom
212
What is the nucleus of an atom?
The positively charged core in the center of the atom.
213
What charge do protons have?
+1
214
What charge do electrons have?
-1
215
What is the Z number?
Atomic number
216
What is the A number?
Atomic mass
217
How many electrons could fit into the M shell?
18
218
What is an ionized atom?
An atom with an extra or missing electron
219
What is an isotope?
Atoms that have the same # of protons but different # of neutrons.
220
What is a radioisotope?
Radioactive atoms having the same # of protons.
221
Which radioactive decay process is a more violent process & could cause more harm to the body?
alpha decay
222
What is particulate radiation?
any subatomic particle capable of causing ionization.
223
What is electromagnetic or non-particulate radiation?
x-rays & gamma rays (photons)
224
What is matter?
anything that occupies space & has shape
225
What is mass?
constant quantity of matter within a physical object
226
Velocity can also be called what?
speed
227
What are Newton's 3 laws?
InertiaForceaction/reaction
228
What is the acceleration of gravity on earth?
9.8 m/s²
229
What is the acceleration of gravity on the moon?
1.6 m/s²
230
What is potential energy?
energy to do work by virtue of position.
231
What is kinetic energy?
energy in motion
232
What is electromagnetic energy?
the type of energy in an x-ray
233
List 3 ways heat can be transferred.
conductionconvectionradiation
234
What is the conversion factor for Celsius to Fahrenheit?
F=9/5C + 32
235
What is the conversion factor for Fahrenheit to Celsius?
C=5/9(F-32)
236
Velocity formula
V = d/tVelocity=distance/time
237
Acceleration formula
A = (Vf-Vo))/tAcceleration=(final velocity-initial velocity)/time
238
Force formula
F = maForce=mass X acceleration
239
Weight formula
Wt = mgWeight=mass X gravity
240
Work formula
W = fdWork=force X distance
241
Power formula
P=w/tPower=work/time
242
Kinetic Energy formula
KE=1/2mv²Kinetic Energy=1/2 X mass X velocity²
243
Potential Energy formula
PE=mghPotential Energy=mass X gravity X height
244
1 kg = ? lbs
2.2
245
1 inch = ? cm
2.54
246
1 yd = ? meters
0.9144
247
Define velocity.
measure of how fast something is moving
248
Define acceleration.
rate of velocity change with time
249
Define force.
force acted on an object with acceleration
250
Define weight
a force on the body caused by the downward pull of gravity on it
251
Define work.
the force applied, multiplied by distance over which it is applied
252
Define power.
rate of doing work
253
Define kinetic energy.
energy in motion
254
Define potential energy.
energy to do work by virtue of position
255
What is the unit of measure for velocity?
m/smeters per second
256
What is the unit of measure for acceleration?
m/s²meters per second squared
257
What is the unit of measure for force?
NNewtons
258
What is the unit of measure for weight?
NNewtons
259
What is the unit of measure for work?
JJoule
260
What is the unit of measure for power?
J/s or WJoules per second or Watts
261
What is the unit of measure for kinetic energy?
JJoule
262
What is the unit of measure for potential energy?
JJoule
263
Explain inertia.
a body will remain at rest or continue to move witha constant velocity in a straight line unless acted upon by an external force
264
Explain action/reaction.
for every action there is an equal & opposite reaction
265
1lb = ? Newtons?
4.5N
266
What is the unit of measure for heat?
Ccalorie
267
What is the smallest particle of an element?
atom
268
What is the smallest portion of a compound?
molecule
269
What is any material that has a definite constant composition?
element
270
What is a measurable quantity of one type of molecule?
compound
271
What does the atomic number (Z) of an atom denote?
total number of protons
272
What does the atomic mass (A) of an atom denote?
total number of protons & neutrons
273
Formula for electron limit per shell.
2n²2 X shell number²
274
What is the 1st shell called?
K
275
How many electrons can the outer shell of an atom hold?
8 maximum (no matter which shell it is)
276
What is the Principle Quantum Number?
the shell number
277
Define valence.
number of electrons in the outermost shell
278
Valence represents the capacity of an atom to do what?
bond
279
What is density?
The overall blackness on a radiographic film.
280
Radiolucent
X-rays penetrate the body.
281
Radiopaque
X-rays are absorbed by the body.
282
What is the major controlling factor for density?
mAs.
283
What are 2 ways to double density?
Increase kVp by 15% or Double mAs.
284
What is the 15% rule?
Increase kVp by 15%, decrease mAs by 1/2 = same density decrease kVp by 15%, double mAs + same density
285
If you increase mAs, what happens to density and why?
Increase mAs = increased density because more photons are reaching IR.
286
When you increase screen speed, what happens to density and why?
Increased screen speed = increased density because more light is hitting the film.
287
When you increase the grid ratio, what happens to density and why?
Increased grid ratio = less density because the grid os removing some of the photons.
288
When you increase kVp, what happens to density and why?
increase kVp + increased density because more x-rays are reaching IR (more penetration)
289
What is contrast?
Contrast is the difference in adjacent densities on a radioraphic film.
290
What is the major controlling factor for contrast?
kVp.
291
What are 2 types of contrast?
Long scale (low contrast)short scale (high contrast)
292
Explain short scale contrast.
Short scale = high contrast, more B&W used with extremities used with low kVp (below 70)
293
Explain long scale contrast.
Long scale = low contrast lots of grays use higher kVp's (above 70) used with chest and abdomen.
294
When you increase kVp, what happens to contrast and why?
Increased kVp = less contrast because of increased scatter.
295
When you increase grid ratio, what happens to contrast and why?
Increased grid ratio = more contrast because scatter is reduced.
296
What is brightness?
Measurement of luminance of a monitor calibrated in units of candela per square meteroverall lightness of an image.
297
What controls brightness?
Window level.
298
When you increase window level, what happens to brightness?
Brightness is decreased.
299
We think of mAs as ____ in CR/DR?
Data.
300
What is grayscale?
The difference in densities on digital image.
301
What happens to brightness when mAs or kVp are increased?
Nothing.
302
What controls grayscale?
Window width.
303
The smaller the window width the ____ the grayscale?
Shorter scale or higher contrast.
304
We think of kVp as ____ in CR/DR?
Penetration.
305
What happens to grayscale when kVp is increased?
Nothing.
306
What is detail?
Sharpness.
307
What is the major controlling factor for detail?
Focal spot size.
308
Will a larger focal spot size produce better or worse detail?
Worse.
309
If motion is increased, what happens to detail/
Detail decreases.
310
If OID is increased, what happens to detail and why?
OID increase = detail decrease because of magnification.
311
If SID is increased, what happens to detail and why?
SID increase = more detail because of decreased magnification.
312
If screen speed is increased, what happens to detail and why?
Increased screen speed = less detail because larger phosphors give less detail.
313
What is distortion?
Misrepresentation of true size or shape.
314
What are 2 types of distortion?
Size and shape.
315
Size distortion is called what?
Magnification.
316
What causes magnification?
Excessive OID or not enough SID.
317
What causes elongation?
Angle of tube or IR.
318
What causes foreshortening?
Angle of part (patient positioning)
319
What does ALARA stand for?
As Low As Resonably Achievable.
320
If a student needs to retake an image, who has to be with them?
The radiation technologist.
321
what are the 3 cardinal principles to protect yourself from radiation?
Time, distance, and shielding.
322
If you increase shielding, what happens to patient dose?
It decreases.
323
If you increase screen speed, what happens to patient dose?
It decreases.
324
If you increase grid ratio, what happens to patient dose and why?
Increased patient dose due to increase of technique required to image properly (because grid absorbs scatter)
325
When you increase kVp, what happens to patient dose and why?
Decrease patient dose because less mAs is required.
326
If you increase mAs, what happens to patient dose and why?
Increased patient dose because more photons are entering them.
327
If you increase body habitus,what happens to patient dose and why?
Increased patient dose because more photons are needed to properly expose image and penetrate part.
328
Define density.
overall blackness on a radiographic film
329
Describe an overexposed film.
one that contains too much density
330
Describe an underexposed film.
one that doesn't contain enough density
331
Define radiolucent.
objects that allow x-rays to penetrate them (show up black on an image)
332
Define radiopaque.
objects that absorb x-rays (show up white on an image).
333
Major controlling factor of density
mAs (increase mAs, increase density)
334
Define contrast.
difference in adjacent densities on a readiographic film (how many shades of gray)
335
What is high contrast used for?
bone work
336
What is low contrast used for?
abdomen/chest exams
337
Is high contrast short or long scale?
short scale
338
Is low contrast short or long scale?
long scale
339
What is the major controlling factor for contrast?
kVp
340
What does kVp stand for?
kilovolts peak
341
What does mAs stand for?
milliamperes seconds
342
What does mAs represent (film)?
the number of x-rays coming from the tube
343
What does kVp represent?
penetration power of x-ray beam
344
Define brightness.
measurement of the luminance of a monitor calibrated in units of candela (cd) per sq meter
345
What is the major controlling factor for brightness?
Window Level (WL)
346
We think of mAs as what in CR/DR (not film)?
Data
347
Define grayscale.
the difference of the densities on the digital image (same as contrast)
348
What is the major controlling factor of grayscale?
Window Width (WW)
349
Is high contrast (short scale) on CR/DR a smaller WW or larger WW?
smaller
350
Is low contrast (long scale) on CR/DR a smaller WW or larger WW?
larger
351
Define recorded detail.
Sharpness/Definition/Image Resolution
352
What is the major controlling factor of recorded detail?
FSS (Focal Spot Size)
353
With a large focal spot do you get more or less detail?
less
354
Define distortion.
misrepresentation of true size/shape
355
Name 2 types of distortion.
Size and Shape distortion
356
Define size distortion.
magnification
357
Define shape distortion.
misrepresentation of true shape of an object
358
Name 2 types of shape distortion.
Elongation and Foreshortening
359
What causes elongation?
angle of tube or IR
360
What causes foreshortening?
angle of part
361
What is the major controlling factor of distortion?
Patient Positioning
362
What image ID info must be on image?
Patient name/ID #DateInstitutionR or L marker
363
SID stands for?
Source to IR Distance
364
OID stands for?
Object to IR Distance
365
Define Umbra.
Sharpness
366
Define penumbra
Unsharpness
367
mAs is the product of what?
x-ray tube current (mA) and time (seconds)
368
If you double your mAs, what is also doubled?
density
369
Double density can be achieved by?
doubling mAsincreasing kVp by 15%
370
With CR/DR we think of kVp as what?
penetration
371
What is the major controlling factor of involuntary motion?
exposure time (use as short as possible)
372
What is the primary controlling factor of voluntary motion?
giving clear instructions
373
Define spatial resolution.
ability to image small objects that have high subject contrast (same as detail)
374
What is the primary controlling factor of spatial resolution?
pixel or sampling pitch
375
Define image noise.
deterioration of image by unwanted interference in x-ray signal detection
376
What are the 3 cardinal principles of radiation protection?
timedistanceshielding
377
What is the retroperitoneum?
space behind peritoneum (where kidneys and pancreas lie)
378
What is the largest gland in the body?
the liver
379
What does liver produce?
bile
380
What does gallbladder do?
store and concentrate bile
381
What grayscale is desired for an abdomen?
moderate
382
When is exposure taken for an abdomen?
at the end of expiration
383
What does KUB stand for?
kidneys, ureter, bladder
384
*What projection is used in lieu of an AP upright abdomen if the patient cannot stand?
left lateral decubitus
385
Where is the IR centered for a supine AP abdomen?
IR is centered to iliac crests
386
Where is the location of CR on supine AP abdomen?
enters pt on MSP @ level of iliac crests
387
Where is the IR centered on an AP upright abdomen?
IR centered 2" above iliac crests normallyIR centered on iliac crest if bladder is to be included
388
Where is location of CR on AP upright abdomen?
enters pt on MSP 2" above iliac crest normallyenters pt on MSP at iliac crest if bladder is to be included
389
What must be included on an AP supine abdomen?
pubic symphysis
390
What must be included on AP upright abdomen?
diaphragm (to demonstrate free air)
391
*Where is the marker placed on a lateral decubitus image?
on the side the patient is not laying on (R side if lying on L side)
392
Where is the CR on a lateral decubitus abdomen?
enters on MSP at level of iliac crestsenters on MSP 2" above iliac crests if diaphragm is to be included
393
Where is CR on lateral abdomen?
enters on MCP at level of iliac crestsenters on MCP 2" above iliac crests if diaphragm is to be included
394
Where is CR on dorsal decubitus abdomen?
enters MCP 2" above iliac crests
