Mosby Review Flashcards
1004 - Early somatic effects of a substantial dose of ionizing radiation include:
- Nausea
- Epilation
- Formation of solid malignant tumors
1 and 2 only
Although these two effects can occur early, it takes a high dose of radiation to cause them. Tumors are a long-term effect.
1006 - Which of the following must be increased to increase the quality of the x-ray beam?
- Filtration
- kVp
- mAs
1 and 2 only
Both kVp and filtration affect the wavelength of the beam, and consequently the quality of the beam. Because either or both is increased, beam quality increases. mAs affect the intensity of the beam, that is, the number of rays.
1008 - Which of the following are classified as controlled areas?
- Radiographic room
- Hallway
- Unattended elevators
1 only
In the radiographic room, personnel are instructed in the use of radiation and wear dosimeters. The other areas are generally populated only by the general public.
1010 - Protective shielding, which includes lead apron, curtain, and Bucky slot cover, provides:
maximum protection for the radiographer during fluoroscopy.
1011 - One of the purposes of the backup timer used with automatic exposure control (AEC) devices is to:
prevent excessive exposure to the patient
The backup timer will terminate the exposure when it goes beyond a safe level.
1012 - Two x-ray photons from the primary beam have interacted with atoms in a patient’s body. After the interaction, one of the two photons was absorbed and the other photon scattered in a direction away from the image receptor. Both of these photons may now be classified as:
attenuated photons
Attenuation is any change in the beam as it traverses the patient. Hence both of these photons have been attenuated, one by photoelectric interaction and the other by Compton interaction
1016 - The age of the radiographer in years multiplied by 10 mSv may be used to determine:
cumulative exposure for occupationally exposed individuals
This calculation is used for lifetime accumulated dose for occupationally exposed individuals. In traditional units of measurement this would be the age of the radiographer multiplied by 1 rem.
1017 - Which of the following is not effective in reducing exposure to the patient during a diagnostic examination?
Decreasing kVp
For ALARA (as low as reasonably achievable) purposes, the lowest doses are high kVp, low mAs techniques.
1021 - Which of the following will not provide radiation protection for the radiographer?
OSL dosimeter
The dosimeter records the dose received, but does not contribute to Safety.
1025 - Which of the following is essential for protection of the radiographer who is performing a mobile radiographic examination?
1. Protective lead apron
- Primary protective barrier
- Six-foot exposure cord
1 and 3
A primary protective barrier is one that is struck by the primary beam. In this example, there is no need for a primary protective barrier. A lead apron should always be worn for mobile examinations. Maximum use of the 6-foot cord is essential
1027 - Which of the following devices should be used to reduce exposure to the mammary glands during a juvenile scoliosis examination?
Breast Shield
Although not used often, breast shields are very important to use for a scoliosis series.
1028 - A nonpregnant relative to a 2-year-old child volunteers to help restrain the child while AP and lateral radiographs are obtained in the upright position. This person should be provided with:
appropriate protective apparel
It is not necessary to monitor this person’s dose, but all available protective apparel must be worn, and the individual should be kept out of the primary beam.
1046 - Computed radiography may be part of an integrated system of images and text called:
PACS
Picture archival and communication systems (PACS), the computer system used for digital imaging, is a digital communication network of many systems, not an imaging method in itself.
1053 - Which of the following grid errors will result in an image that shows normal IR exposure in the middle but decreased IR exposure on the sides and may follow removal and replacement of the grid?
Upside-down grid
This describes the error that occurs when a grid is positioned upside down during replacement. Grid-focus decentering results in the same type of problem on the radiograph, but this error is caused by a violation of the grid radius, not by incorrect positioning of the grid during replacement. An off-level grid will cause image-forming rays to be absorbed all across the radiographic field, with decreased density (cutoff) visible over the entire radiograph. Lateral decentering of the grid results in visible cutoff more to one side of the radiograph. Be sure to review grid errors.
1058 - When kVp is increased, which of the following happens?
Scale of contrast lengthens
An increase in kVp results in a lengthened scale of contrast because there is more uniform penetration of the part by shorter-wavelength rays. Decreased kVp results in increased contrast and decreased density. Recorded detail is not controlled by kVp.
1060 - The lowest contrast would be produced by which of the following sets of exposure factors?
A. 60 mAs, 80 kVp, 40-inch SID, 4-inch OID
B. 30 mAs, 92 kVp, 40-inch SID, 4-inch OID
C. 120 mAs, 92 kVp, 20-inch SID, 4-inch OID
D. 15 mAs, 100 kVp, 40-inch SID, 4-inch OID
D. 15 mAs, 100 kVp, 40-inch SID, 4-inch OID
kVp, rather than mAs or source-to-image distance (SID), is a controlling factor in the level of contrast. Higher kVp results in lower contrast; therefore, choice D, with the highest kVp, is correct.
1066 - mAs controls the:
quantity of x-rays produced at the anode
mAs controls the quantity of x-rays produced at the anode; this is proportional to the tube current. The quality of x-rays produced is controlled by kVp.
107 - This changes electric voltage and current into higher or lower values and operates on the principle of mutual induction, so it requires alternating current. This is called the:
transformer.
This describes the transformer, of which two are used in x-ray production. An autotransformer operates on the principle of self-induction. A rectifier converts AC to DC. The timer is used to regulate the duration of x-ray exposure.
1076 - kVp determines what aspect of the x-ray beam?
Penetrating ability
1079 - As the wavelength of the x-rays increases, penetrating ability
decreases
The relationship between wavelength and penetrating ability is inverse; longer-wavelength rays have decreased penetrating ability.
1080 - As the wavelength of the x-rays decreases, penetrating ability:
increases
The relationship between wavelength and penetrating ability is inverse; shorter-wavelength rays have increased penetrating ability.
1087 - The grid conversion factor for a 12:1 grid is:
5
For a 12:1 grid, multiply mAs by 5. Choice A is the grid conversion factor for a 5:1 grid; choice B, for an 8:1 grid; and choice D, for a 16:1 grid.
1093 - Differences in adjacent densities on a radiograph defines:
contrast
This is the simple definition of contrast. Density is the amount of blackness on a given area of a radiograph. Detail is the sharpness with which anatomic structures are displayed on the image receptor. Distortion is any misrepresentation that alters the size or shape of an anatomic structure on the image receptor.
1095 - An image with few gray tones, mainly black and white, is referred to as:
high contrast
A high-contrast image is mainly black and white, with few gray tones. High contrast is also known as a short-scale contrast.
1098 - An image with many gray tones is referred to as:
long-scale contrast.
An image with many gray tones is said to have long-scale contrast, also known as low, not high, contrast.
1105 - The portion of contrast represented by the anatomy and physiology is:
Subject contrast
is the portion of contrast that is inherent to the patient; that is, it already exists by nature of the patient’s anatomy, physiology, and pathology.
1108 - Spatial resolution may also be known as:
- sharpness.
- definition.
- image resolution
1, 2 and 3
Spatial resolution is also known as detail sharpness, definition, or image resolution. All of these terms refer to the same thing.
1124 - Magnification may be caused by:
short SOD
Short source-to-object distance (SOD), excessive (not short) object-to-image distance (OID), and insufficient (not long) SID can all cause magnification. Focal-spot size is a factor influencing recorded detail, not distortion. Be sure to keep all of these factors straight.
1140 - A focused grid must be used with specific ranges of:
SID
A focused grid must be used within specific ranges of source-to-image distance (SID). The distance between the source of radiation and the image receptor must be within this range so that the divergence of the beam coincides with angle of the strips.
1141 - The SID at which a focused grid must be used is called:
grid radius.
The source-to-image distance (SID) at which a focused grid must be used is called the grid radius (also called focal distance or focal range). Violating this distance will cause grid cutoff.
1149 - Using an increased OID that allows scatter to miss the IR is called:
air gap technique.
1151 - The density (mass per unit volume) of the patient or part under study can affect:
- radiographic density.
- radiographic contrast.
- differential absorption.
1, 2, and 3
1157 - One of the factors that causes magnification of the radiographic image is:
a decrease in the source-to-object distance.
Magnification may also be caused by decreased source-to-image distance (SID) or increased object-to-image distance (OID).
1161 - Which of the following equations expresses grid ratio?
r = h/d
Grid ratio is expressed as the height of the lead strips divided by the space between them.
1165 - A radiographic grid should be used when:
- the body area to be radiographed measures more than 10 cm.
- a field size larger than 10 × 12 inches is used.
- more than 60 kVp is required to penetrate a body part.
1 and 3 only
Field size is unrelated to the use of a grid. Part measurement and kVp are both directly related to the increase in scatter being produced.
1171 - Click/Touch the area on the image that represents: Photocathode
see picture
1173 - Click/Touch the area on the image that represents:
Lateral condyle
see picture
1190 - Click/Touch the area on the image that represents:
Glenoid cavity
see picture
1192 - Coracoid process
see picture
1199 - Intercondylar eminence
see picture
1216 - Click/Touch the area on the image that represents: Lamina
….
1218 - Click/Touch the area on the image that represents:
Greater sciatic notch
see picture
1219 - Click/Touch the area on the image that represents:
Ischial spine
see picture
126 - High-frequency full-wave rectification produces what percentage of ripple?
1 With high-frequency generators, voltage ripple is about 1%.
Voltage never drops to zero and is nearly constant. With three-phase, six-pulse, full-wave rectification, ripple is approximately 13%; with three-phase, 12-pulse, full-wave rectification, 4%; and with single-phase full-wave rectification, 100%
128 - The voltage actually used in three-phase, 12-pulse units is about:
96% of the kVp set on the control panel
Because three-phase, 12-pulse, full-wave rectification results in a voltage ripple of approximately 4%, the actual voltage used is about 96% of the kVp set on the control panel. High-frequency generators use about 99% of the kVp, and three-phase, six-pulse units use about 87%.
129 - The voltage actually used in high frequency is about:
A. 99% of the kVp set on the control panel.
Because high-frequency generators result in a voltage ripple of approximately 1%, the actual voltage used is about 99% of the kVp set on the control panel. Three-phase, 12-pulse units use about 96% of the kVp, and three-phase, six-pulse units use about 87%.
132 - Filaments are primarily made of ____________ because of its high melting point.
Tungsten
Because of its high melting point, tungsten, not gold, silver, or platinum, is primarily used to make filaments. A small amount of thorium may be added to reduce vaporization.
140 - Rotation of the target allows for:
greater heat dissipation.
Rotation of the target allows greater heat dissipation, which extends the life of the tube
144 - What is contained within the x-ray tube to prevent the filament’s electrons from colliding with the atoms of gas?
Vacuum
A vacuum is contained within the glass envelope of the x-ray tube so that electrons from the filament do not collide with atoms of gas. Be sure to be familiar with all parts of the x-ray tube.
146 - Inside the tube housing, what is the x-ray tube immersed in to assist with cooling and additional electrical insulation?
Oil
The tube housing contains oil, not plastic, water, or coolant. This is an often-forgotten part of the tube assembly
15 - What type of current is required for proper operation of the x-ray tube?
Direct
The x-ray tube requires a direct current (DC) to operate properly. The rectifier changes AC to DC.
156 - A device in which the x-ray tube and image intensifier are located on opposite cusps of a semicircular arch is called a:
C-ARM
The c-arm is the feature of portable (mobile) fluoroscopic units.
162 - This diagram illustrates:
Brems x-ray production
This diagram illustrates the production of Brems x-rays, in which projectile electrons are slowed near the atomic nucleus.
163 - This diagram illustrates:
characteristic x-ray production.
167 - In this diagram, D is the
Label D is the step-up transformer, where voltage is boosted to kilovoltage levels.
Be sure to know these major parts of the x-ray circuit.
173 - Which of the following is equivalent to the speed of light in a vacuum? 1. 3 × 108 meters per second 2. 3 × 1010 cm per second 3. 186,000 miles per second
1, 2 and 3 all are ways of saying the speed of light
195 - The diagnostic useful range of x-rays is from:
0.1 to 0.5 angstrom This range is the result of the various kVp settings used for imaging
198 - The negative electrode of an x-ray tube is termed the:
cathode This is the source of the electrons, which carry a negative charge. The anode is the positive electrode.
203 - How many kilovolts equal 70,000 volts?
70 Kilo means “thousands.”
205 - X-ray photons have no: 1. energy. 2. electric charge. 3. mass.
2 and 3 only X-ray photons are bundles of energy with no mass or charge.
206 - Electron flow from negative to positive is:
electric current Like charges repel, so the electrons flow from negative to positive.
216 - Which of the following bones has nasal conchae?
Ethmoid bone
218 - Which of the following bones has a coronoid process?
Mandible The coronoid process is located on the ramus of the mandible and serves as the attachment site for the temporalis muscle.
221 - Which of the following bones has (have) no body?
Atlas The atlas, or C1 vertebra, has no body. The axis has a small body, whereas the thoracic and lumbar vertebrae have larger bodies.
242 - The part of the urinary system located between the renal pelvis and the bladder is called the:
ureter. The ureter is located between the renal pelvis and the bladder. The cortex, medulla, and nephron are all components of the kidney.
243 - The functional unit of the kidney is called the:
nephron The functional unit of the kidney is the nephron. The medulla is the inner part of the kidney; the outer part is the cortex.
244 - For an AP projection of the thumb, the hand is turned in extreme:
internal rotation
247 - For the AP axial projection of the clavicle, the central ray is angled:
25 to 30 degrees cephalad The correct angle of the central ray for an axial projection of the clavicle is 25 to 30 degrees cephalad if performed anteroposteriorly. For a posteroanterior (PA) axial projection, the central ray should be angled 25 to 30 degrees caudad.
250 - For a lateral projection of the ankle, the central ray is directed perpendicular to the:
medial malleolus. For a lateral projection of the ankle, the central ray is directed vertical through the medial malleolus. Choice B would be the correct answer for an anteroposterior (AP) projection of the ankle.
271 - The talus distributes body weight from the:
tibia to the tarsals. Occupying the uppermost and central portion of the tarsus, the talus distributes body weight from the tibia above to the other tarsal bones.
273 - The trachea is located
in front of the esophagus
274 - The length of the trachea is about
12 cm The trachea is about 12 cm (not inches) long
281 - A central ray angle of 25 to 30 degrees caudad is required for what projection?
PA axial clavicle The posteroanterior (PA) axial projection of the clavicle requires that the central ray be angled 25 to 30 degrees caudad (25 to 30 degrees cephalad for anteroposterior [AP]).
282 - Directing the central ray to the base of the third metatarsal is done for what projection?
AP foot For the anteroposterior (AP) projection of the foot, the central ray is angled 10 degrees toward the heel, entering the base of the third metatarsal.
297 -The vertebral border is labeled:
III
Label III marks the vertebral border. The structure designated as label I is the axillary border. Label II is the acromion, and label IV is the scapular notch
311 - The coronoid fossa is labeled
II The structure designated as label II is the coronoid fossa. Label I marks the radial head. Label III is the lateral epicondyle, and label IV is the trochlea.
313 - The trochlea is labeled
Label IV is the trochlea. The structure designated as label I is the radial head. Label II marks the coronoid fossa, and label III is the lateral epicondyle.
316 - The triquetrum is labeled
The triquetrum is designated by label IV. The distal interphalangeal joint is marked by label I. Label II is the metacarpophalangeal joint, and the structure designated as label III is the ulna.
32 - The amount of matter in an object best defines:
Mass Mass is the amount of matter in an object—similar to, but not the same as, weight. Energy is the ability to do work. Matter is that which has form and occupies space.
320 - The capitate is labeled
The capitate is designated by label VI. Label I is the distal interphalangeal joint. The metacarpophalangeal joint is marked by label II, and label IV is the pisiform.
323 - The capitulum is labeled
label E points to the capitulum
324 - The radial head is labeled
B
329 - The zygomatic arch is labeled
E
334 - The foramen magnum is labeled
The foramen magnum is designated by label J
336 - The lesser tubercle is labeled
The lesser tubercle is designated by label D.
338 - The surgical neck is labeled
Label F marks the surgical neck