Midterm 1 Review Flashcards by Lindsay Kirkpatrick

In the diagnostic range, which tissue is most likely to undergo a photoelectric interaction?
a. Adipose
b. Lung
c. Bone
d. Muscle

bone

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Which variety of timer gives values in 1/60th of a second?
a. Electronic
b. Egg
c. Synchronous
d. Automatic Exposure Control

Synchronous

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A smaller focal spot will result in:
a. Higher resolution
b. Increased radiation to the patient
c. Lower resolution
d. No change in resolution

Higher resolution

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The effect at the cathode filament whereby electrons are “boiled off” of the filament is known as:
a. Thermionic emission
b. Inverse square law
c. Space charge effect
d. Cathode heel effect

Thermionic emission

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True or false: X-ray photons have no effect on photographic emulsion?
a. True
b. False

False

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When you need to modify your radiographic factors because the values on the technique chart produced an overexposed x-ray, which of the following should you change when you retake the film?
a. Line compensation
b. mAs
c. kVp
d. Focal spot

mAs

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Electromagnetic energy demonstrates what relationship?
a. Inversely proportional to frequency, inversely proportional to wavelength
b. Directly proportional to frequency, inversely proportional to wavelength
c. Directly proportional to frequency, directly proportional to wavelength
d. Inversely proportional to frequency, directly proportional to wavelength

Directly proportional to frequency, inversely proportional to wavelength

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Which of the following techniques can be used to compensate for the anode heel effect?
Select all that apply (1-4 correct answers)
a. Use a compensation filter
b. Position the X-ray tube so that the anode side is positioned towards the thicker anatomy
c. Collimate as tightly as possible to the area of interest
d. Increase the focal film distance

Use a compensation filter
Collimate as tightly as possible to the area of interest
Increase the focal film distance

(Also position the cathode side of x-ray tube towards thicker anatomy)

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The limitation in thermionic emission from the cathode caused by the increase negative charge around the cathode is known as:
a. Space charge effect
b. Electromagnetic induction law
c. Inverse square law
d. Anode heel effect

Space charge effect

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An electron strikes a tungsten K-shell electron, ejecting the electron. The resulting empty space in the K-shell is replaced by an M-shell electron, resulting in the release of an X-ray photon. Using the information below, calculate the approximate energy of the produced X-ray:
Tungsten K-shell electron binding energy= 69 keV
Tungsten M-shell electron binding energy= 2.8 keV
a. 69 keV
b. 71.8 keV
c. 2.8 keV
d. 66.2 keV

66.2 keV

(Photon energy = K-shell binding energy - M-shell binding energy)

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X-rays are an example of which type of radiation?
a. Particulate
b. Gamma
c. Electromagnetic
d. Quantum

Electromagnetic

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When designing your x-ray suite, your control panel is 10 feet away from your patient. What percentage of radiation scattered toward you from the patient will reach you?
a. >99%
b. <1%
c. 5%
d. 50%

<1%

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Converting wall current (AC) to the current required for an x-ray machine (DC) is called what?
a. Rectification
b. Line conversion
c. Voltage ripple
d. Bidirectionality

Rectification

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The energy of X-rays typically used in diagnostic imaging is usually:
a. 30-150 kVp
b. <10 kVp
c. 200kVp-1MVp
d. 10-20 kVp

30-150 kVp

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Image contrast is primarily the result of which photon interaction?
a. Compton
b. Characteristic
c. Coherent
d. Photoelectric

Photoelectric

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What effects will result from increasing kVp of the x-ray beam? Select all that apply (2-4 correct answers)
a. Decrease total number of photon interactions
b. Decrease optical density of the film
c. Decrease image contrast (Select this one. We’ll talk about it next week)
d. Decrease overall patient dose

Decrease total number of photon interactions
Decrease image contrast (Select this one. We’ll talk about it next week)
Decrease overall patient dose

(Increase optical density)

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Isotropic radiation production means what?
a. Radiation is emitted equally in all directions
b. Radiation is emitted at the cathode
c. Radiation is emitted in a single energy level
d. Radiation is emitted in only one orientation

Radiation is emitted equally in all directions

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What is the purpose of a step wedge?
a. Compensate for the anode heel effect
b. Measure the focal spot size
c. Prevent backscatter of X-rays
d. Measure Xray beam penetrability

Measure Xray beam penetrability

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True or False: X-ray photons cannot be reflected using a mirror
a. True
b. False

True

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Which of the following are synonyms of the source image distance? Mark all that apply, 1-4 correct answers
a. No correct answer listed
b. TFD
c. FFD
d. OID
e. SOD

TFD
FFD

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You are performing a 3 view cervical spine series. After taking the AP and APOM, you go to take the lateral. You dial in the factors for the lateral view at 70 kVp and 15 mAs, but you forgot to move the tube stand to 72”. By leaving the tube stand at 40”, which of the following represents the approximate relative intensity of the beam?
a. 70 kVp and 48.6 mAs
b. 226.8 kVp and 15 mAs
c. 70 kVp and 4.6 mAs
d. 2.16 kVp and 15 mAs

70 kVp and 48.6 mAs

(Using inverse square law)

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As a result of the anode heel affect, the relative strength of the X-ray beam is highest where?
a. In the center of the field
b. Anode side
c. Equal across the entire field
d. Cathode side

Cathode side

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An autotransformer is used for what purpose?
a. Compensate for large variation (>50 amps) in line amperage
b. Compensate for large variation (>50 volts) in line voltage
c. Compensate for small changes (<20 volts) in line voltage
d. Compensate for small changes (<20 amps) in line amperage

Compensate for small changes (<20 volts) in line voltage

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As you move closer toward a constant radiation source, what happens to the intensity of the radiation striking your body?
a. Decreases by the square of the distance
b. Increases linearly
c. Increases by the square of the distance
d. Decreases linearly

Study These Flashcards

Increases by the square of the distance

The quality of the X-ray beam is controlled principally by: a. Neither kVp nor mAs b. mAs c. kVp d. Both kVp and mAs

kVp

An electron strikes an inner shell electron, ejecting the electron. The resulting empty space in this shell is replaced by an outer shell electron, resulting in the release of an X-ray photon. This form of radiation is known as: a. Compton radiation b. Characteristic radiation c. Bremsstrahlung radiation d. Coherent radiation

Characteristic radiation

The device which is used to convert alternating current from the electrical company into direct current to pass through the X-ray tube is called: a. Capacitor b. Resistor c. Diode d. Stator

Diode

Select all that apply (1-4 correct answers). In the context of diagnostic imaging X-ray production, voltage ripple should be avoided because: a. It increases the patient dose b. It increases the necessary exposure time c. It results in very inefficient x-ray production d. It decreases the quality of the X-ray beam

all of the above

How much bones loss is required before such a change can be detected by plain film radiography? a. 30-50% b. 3-5% c. 70-90% d. 10-20%

30-50%

Electron interactions involving which electron energy shells are most important for the production of diagnostically useful X-ray photons? a. L and M shells b. All shells are equally important c. K shells d. P and Q

K shells

Who is credited with the discovery and first in-depth investigation into the nature of X-rays? a. William Crookes b. Thomas Edison c. Marie Curie d. William Roentgen

William Roentgen

A projectile electron travels near the electron travels near the nucleus of a target atom, resulting in a deviation in the path of an electron. As a result, an X-ray photon is produced. This form of radiation is known as: a. Compton radiation b. Characteristic radiation c. Bremsstrahlung radiation d. Coherent radiation

Bremsstrahlung radiation

Which interaction is most responsible for the poor image contrast that is often seen in radiographs of overweight/obese patients? a. Bremsstrahlung b. Compton c. Photoelectric d. Coherent

Compton

All things being equal, which type of transformer will produce the highest quality and "hardest" X-ray beam? a. Single phase with full-wave rectification b. High frequency with full-wave rectification c. Single phase with half-wave rectification d. Third phase with full-wave rectification

High frequency with full-wave rectification

The quantity of X-ray photons in the X-ray beam is controlled principally by: a. mAs b. Both kVp and mAs c. kVp d. Neither kVp nor mAs

mAs

In the diagnostic range, attenuation is the result of which of the following? Select all that apply (1-4 correct answers) a. Transmitted x-rays b. No correct answer is listed c. Bremsstrahlung d. Photoelectric effect e. Compton scatter

- Photoelectric effect - Compton scatter

As the wavelength of an electromagnetic signal increases, the energy: a. Stays the same b. Increases c. Decreases

Decreases

When using the same kVp and double the mAs, what type of difference would you note in the optical density of your x-rays? a. Double b. Quarter c. Half d. Quadruple

Double

According to the rule of thumb, what will result if you increase the kVp by 15%? a. Halving the optical density of the film b. Doubling the optical density of the film c. Quartering the optical density of the film d. Quadrupling the optical density of the film

Doubling the optical density of the film

What is/are the effect(s) of increasing the anode target angle from 12 degrees to 20 degrees? Select all that apply (1-4 correct answers) a. Increased image resolution b. Increased thermal load dissipation c. Decreased effective focal spot size d. Decreased patient dose

Increased thermal load dissipation

You perform a lateral cervical neutral x-ray at 72" SID, with 80 kVp and 20 mAs. The film density and contrast are perfect, but the patient's large shoulders prevent you from properly visualizing C7, so you decide to follow up with a swimmer's lateral view at 40" SID. How would you alter the factors at the console in order to produce a swimmer's lateral radiograph of identical optical density and contrast to the original lateral cervical neutral? a. 24 kVp and 20 mAs b. 80 kVp and 65 mAs c. 80 kVp and 6.5 mAs d. 80 kVp and 20 mAs

80 kVp and 6.5 mAs (Using square law)

What type of photon interactions are predominately responsible for backscatter and film fog? a. Coherent b. Classic c. Compton d. Photoelectric

Compton

A transformer has 200 turns of wire in the primary coil and 600 turns of wire in the secondary coil. What will be the net effect on the amperage in the secondary coil? a. It will decrease b. It will increase c. It will remain the same

It will decrease

In the diagnostic range, which interaction results in the absorption of a photon? a. Classic b. Photoelectric c. Bremsstrahlung d. Thompson

Photoelectric

Which of the following has the highest electron binding energy? a. K-shell electron in a hydrogen atom b. N-shell electron in a tungsten atom c. K-shell electron in a tungsten atom d. Electron binding energy is the same in all shields of all atoms

K-shell electron in a tungsten atom

A conventional radiograph is performed at 40" SID with 8 mAs and 50 kVp. The radiograph is repeated at 72" SID. If no other changes are made, what is the intensity at 72" SID? a. 0.5 mAs b. 16 mAs c. 2.5 mAs d. 26 mAs

2.5 mAs (Using inverse square law)

True or false: The efficiency of X-ray photon production decreases with increasing kVp a. True b. False

False

Increasing the kVp results in: (Select all that apply) a. Decrease quality of X-rays b. Increase quality of X-rays c. Increase quantity of X-rays d. Decrease quantity of X-rays

- Increase quality of X-rays - Increase quantity of X-rays

At a kVp setting of 120, the peak of the resulting Bremsstrahlung X-ray energy spectrum is: a. 40 keV b. 120 kEv c. 60 keV d. 30 keV

40 keV (Peak = 1/3 kVp)

The portion of the X-ray tube that creates the electron beam is: a. Anode b. Cathode c. Tube window d. Rotor

Cathode

At a setting of 100 kVp, what is the maximum possible X-ray photon energy? a. 100 keV b. 33 keV c. 69 keV d. 100 kVp

100 keV (Max photon E = kVp)

Electrons in energy shells closer to the nucleus of an atom have an electron binding energy that is: a. Lower than those in shells farther from the nucleus b. The same as those in shells farther from the nucleus c. No correct answer listed d. Higher than those in shells farther from the nucleus

Higher than those in shells farther from the nucleus

You take an AP lumbopelvic radiograph of your patient. After developing the film, you see that the image is underexposed. What change in the radiographic factors would best correct this? a. Increase the kVp by 15% and leave the mAs the same b. Leave the kVp the same and increase the mAs by at least 50% c. Decrease the kVp by 15% and leave the mAs the same d. Increase the kVp by 15% and increase the mAs by at least 50%

Leave the kVp the same and increase the mAs by at least 50%

What characteristic of tungsten makes it an appropriate material from which to make the cathode filament? a. Maximal photon production b. Maximal vaporization c. Extensive thermal expansion d. High melting point

High melting point

Which of the following examinations on an adult patient would be most likely to require a large focal spot? a. Elbow b. Cervical c. Lumbar d. Wrist

Lumbar

In the diagnostic range, what percentage of the kinetic energy of projectile electrons is converted to heat? a. 1% b. 50% c. 99% d. 25%

99% (Thermal dissipation)

In order to produce the required kilovoltage for your x-ray machine, what type of transformer is required? a. Autobot b. Autotransformer c. Step-down d. Step-up

Step-up

The majority of the X-ray beam projected from the X-ray tube is of which radiation type? a. Compton radiation b. Coherent radiation c. Characteristic radiation d. Bremsstrahlung radiation

Bremsstrahlung radiation

Midterm 1 Review Flashcards

(58 cards)