Healthcare Technology Problem Solving 25% Flashcards by Jason Davern

A radiologist wants to improve the spatial resolution of the anatomy being examined. The change most likely to lead to this is:

-decreased collimation.
-increased matrix size, same field of view.
-selection of a smoothing algorithm.
-increased field of view, same matrix size.

-increased matrix size, same field of view.

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Which of the following has the highest patient dose assuming all other parameters are the same?

-mA =150, rotation time = 3 seconds
-mA =200, rotation time = 2 seconds
-mA =200, rotation time =1 second
-mA =400, rotation time =1 second

-mA =150, rotation time = 3 seconds

(highest mAs)

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The mathematical technique that involves the estimation of an unknown value from values on either side of it is known as:

-Interpolation
-Filtering
-Convolution
-Summation

Interpolation

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The slip ring on continuous rotation CT scanners:
1. prevents the high voltage cable from winding up
2. allows the exam to commence more rapidly
3. eliminates the need for the reversal of gantry frame rotation
1 and 2 only
1 and 3 only
1, 2, and 3
3 only

1, 2, and 3

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The major technical challenge in cardiac CT is:

-Three-dimensional reconstruction
-Temporal resolution
-Contrast resolution
-Spatial resolution

-Temporal resolution

(Resolution of moving parts)

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Which of the following reconstruction methods is used by most modern CT scanners?

-Back projection
-Filtered back projection
-Iterative method
-Fourier transform

-Filtered back projection

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An accurate, modern CT scanner is capable of spatial resolution of up to _________:
20 lp/mm
100 lp/cm
10 lp/mm
20 lp/cm

20 lp/cm

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Pixels representing tissues with average attenuation coefficients greater than that of water have which of the types of values?

-Negative
-None are correct
-Positive
-Extremely small

Positive

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During a CT examination, the mA setting determines the:

-quantity of x-ray photons
-energy level of the x-ray photons
-slice thickness
-coefficient of attenuation

-quantity of x-ray photons

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What indicates a light leak on a film after developing?

Fog along the developed film edge

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Compton scatter is similar to characteristic radiation, True or False.

TRUE

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The filament voltage in an x-ray tube are measured in mA, True or False?

False, mA is a current measurement

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Focal spots remain constant over the life of the tube,
True or False?

False, it increases in size with age

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99% of the energy created by an x-ray tube is heat, True or False?

True, even after 107 plus years of development

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What are the 4 items recorded on the QA program of a film processor?

Base fog, speed, contrast, (sometimes called density readings), and temperature.

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A high frequency power supply provides less consistent x-ray output then a 12 pulse power supply system,

True or False?

False, a high frequency power supply provides the most consistent output

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If fog is increased on a diagnostic image, which of the following occurs
a. Contrast decreases
b. Contrast increases
c. Density decreases
d. Contrast is unchanged

a. Contrast decreases

A major problem w/over processing is that it increases
fog which contributes to decrease in contrast.

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A cracked anode is most likely caused by

a. Using the unit at high KVp and low mA
b. Using the unit at low KVP and low mA for 2 seconds
c. Making a high kVp exposure with a cold tubes
d. Making a 100mA -110kVp, 0.5 sec exposure on tube

c. Making a high kVp exposure with a cold tubes

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Which of the following is a common treatment for breast cancer
a. Mammogram
b. Bone Densitometry
c. Oncology Simulation
d. Intensity Modulated radiation therapy

d. Intensity Modulated radiation therapy

IMRT has been used in limited situations to treat breast cancer.

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Spatial resolution is measured in
a. Parallel white lines
b. Parallel Black lines
c. Line pairs per millimeter
d. Contrast to sharpness ratio

c. Line pairs per millimeter

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A radiographic technique calls for a 90 kVp , 80mA, 200mS, and a SID of 100cm. What is the mAs?
a. 4
b. 16
c. 40
d. 160

b. 16 mAs

.08 x .2 =.016

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With technique factors constant, as the SID is increased, film density will
a. Increase
b. Decrease
c. Double
d. Remain the same

b. Decrease

Inverse square law

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Radiology technician reports the X-Ray table does not tilt, which of the following should be checked first?

a. Tilt motor
b. Table leveling
c. Safety interlocks
d. Technique settings

c. Safety interlocks

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Changing the grid ratio from 5:1 to 12:1 requires which of the following to maintain the same density?

a. Lowering kVp
b. Raising mAs
c. Lowering mAs
d. No exposure changes

b. Raising mAs

Amount of radiation delivered to the patient’s body must be increased to compensate for the radiation absorbed by the grid.

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Which of the following is most likely to cause an underexposed X-Ray film a. KVP too high b. mA too low c. Exposure time too long d. Source to image distance too short

b. mA too low – too little mA = underexposure

Barium as a radiographic contrast medium is a. Radiolucent b. Radiopaque c. radioactive d. radio luminescent

b. Radiopaque -absorbes x-rays

In third generation CT scanners, if detectors are faulty or mis-calibrated, what artifact may appear a. Ring b. Motion c. compression d. Beam-hardening

a. Ring

Which of the following best describes digital image enhancement? a. Smoothing and edge enhancement only b. Edge enhancement and mask reregistration only c. Mask reregistration and smoothing only d. Smoothing, edge enhancement, and mask reregistration

d. Smoothing, edge enhancement, and mask reregistration

What is the fog level for nonradiated unprocessed film? a. 0.2.0D b. 2.0.0D c. 4.2.0D d. 6.0.0D

a. 0.2.0D Pick lowest answer Typically .15 to .2 OD

Line compensation adjust for? a. The line feedback transformer b. KV roller variations during the exposure c. 220 VAC at the output of the high voltage transformer primary d. Periodic variations in the incoming line voltage

d. Periodic variations in the incoming line voltage

In most cases, manufacturers rate a NiCd battery unusable when capacity drops below what percentage of its original value? a. 40% b. 50% c. 80% d. 90%

c. 80%

As compared to a film screen cassette, the X-Ray technique setting for a CR cassette must be a. Lower b. The same c. Higher d. Doubled

a. Lower -CR imaging plate is more sensitive

If service calls are received at the same time for CT during an abdominal study., CathLab during a pacemaker implant, X-ray during the examination of a femur fracture, and an ER chest pain case using a portable X-Ray, which service should be prioritized first? a. ER Chest pain b. CT abdominal Study c. X-Ray Femur fracture d. Cath Lab pacemaker implant

d. Cath Lab pacemaker implant Patient risk of injury or death.

Three phase X-Ray equipment normally requires the feed balanced-to-ground output from what type of distribution transformer a. Delta b. Wye c. Step up d. Isolation

b. Wye Secondary has 3 windings connected to common point providing a neutral connection for grounding.

Which of the following are contrast agents used in imaging? a. Gadolinium, barium sulfate, and iodine b. Sodium sulfate, barium sulfate, and iodine c. Silver sulfide, gadolinium, and barium sulfate d. Sodium chloride, barlium sulfate, and silver sulfate

a. Gadolinium, barium sulfate, and iodine -Gadolinium, used in MRI for contrast enhancement -Barium Sulfate, used in X-ray ie GI study -Iodine, used in various modalities for vascular imaging and enhancement

According to 21 CFR Part 1020, what is the maximum mAs limit for an automatic exposure control unit being operated at or above 51kVp? a. 60mAs b. 600mAs c. 1,200mAs d. 2,000mAs

600mAs

Increasing the high voltage to a photomultiplier will make it? a. More sensitive to light b. More sensitive to heat c. Less sensitive to artifact d. Less sensitive to vibration

More sensitive to light

Luminance is measured in a. NITs b. curies c. degrees d. coulombs

a. NITs -candelas per square inch

The half value layer is an indication of an X-Ray beam’s a. Speed b. Quality c. Quantity d. Reaction

b. Quality

A technician measures 0.8Ω ground resistance on a medical device using a safety analyzer. Which of the following should be checked first? a. Power outlet b. Safety Analyzer’s probe resistance c. Power cord and / or plug d. Power outlet

c. Power cord and / or plug

Technician receives a call from a nurse that the cardiac monitor for a patient is broken, and the monitor will only display lead III even if another lead is selected. Which of the following should the technician recommend first? a. Check LA electrode b. Check LL electrode c. Check RA electrode d. Request a new monitor

C Check RA electrode 1=LA-RA 2=RA-LL 3=LL-LA

Which of the following is used to control the release of an electron from the space charge region of an electron gun? a. Grid b. Anode c. Cathode d. Filament

a. Grid

The abruptness of the boundary between two anatomical structures ? a. Density b. Blur c. Contrast d. Sharpness

d. Sharpness -How clearly the boundary or edge of a structure is visualized.

While planning electrical power for an X-Ray system impedance should be determined at the a. Lowest incoming line voltage using the maximum load b. Highest incoming line voltage using the maximum load c. Lowest incoming line voltage using the minimum load d. Highest incoming line voltage using the minimum load

Highest incoming line voltage using the maximum load

The optimal resolution of an LCD panel is a. Size of the monitor measured diagonally b. Pixel count of the monitor length by width c. Lowest resolution the monitor accepts d. Highest resolution the monitor accepts

Highest resolution the monitor accepts

Which of the following would be considered a therapeutic device as opposed diagnostic device a. Pacemaker b. CT Scanner c. ECG d. Magnetic resonance imager

a. Pacemaker

When measuring the timer accuracy of a single phase 60hz full wave rectified generator, 12 pulses are measured. What is the decimal time equivalent? a. 0.01 seconds b. 0.05 seconds c. 0.10 seconds d. 0.20 seconds

c. 0.10 seconds (120 pulses per second in full wave rectification. 60 pulses per second in a half wave or self rectification.)

On an image intensified fluoroscopic system with SID of 50cm, both the length and the width of the X-Ray field exceeded the visible area of the image receptor by 5cm each. This indicates ? a. No adjustments are required b. Length and width errors should be adjusted to 3cm or less each c. The length error should be adjusted to 2cm or less d. The sum of the length and width errors should be adjusted to 1 cm or less each

Best Answer: d. The sum of the length and width errors should be adjusted to 1 cm or less each 1cm is 2% of 50cm L and W should not exceed visible area by more than 3% in any direction or by 4% in both directions.

An operator has a clinical technique of 90KVP at 100mAs, 40in SID, and an 8:1 ratio grid. What mA would be required when utilizing a standard non-grid cassette? a. 15 mAs b. 28.6 mAs c. 50.8 mAs d. 100mAs

Best answer is b 28.6 Grid Ration 8:1=mAs factor of 4. Thus 100mAs with grid is lowered to about 25mAs with no grid.

With linear tomography system, an exposure is made which produces a sharp focused image1.0 mm thick where a 10.0mm thick image was expected. The problem was a result of the tube traveling? a. Too fast b. Too slow c. Over too large an angle d. Over too small an angle

c. Over too large an angle

What is the general purpose of a grid for diagnostic imaging?

Filter scatter radiation and improve image quality

When using a 10:1 ratio grid as apposed to an 8:1 ratio grid, what can you expect the difference in patient entrance exposure to be?

A 10:1 ratio grid will increase patient dose vs 8:1 grid. Higher grid ratios have better image quality but also higher dose penalty(Bucky Factor)

What unit of measure in the United States is typically used to define an absorbed dose?

US=rad(Radiation absorbed dose) International System (SI)= the gray (Gy)

What is measured by the unit of measure Angstrom?

Unit of displacement, also used to express lengths of wavelength of visible light, UV light, X-rays, and gamma rays.

What part of an x-ray tube does the diagnostic photon energy originate from?

Target Material-Anode

What part of the x-ray tube does the free electron stream originate from?

Cathode

What is the advantage of a rotating anode as apposed to a stationary anode tube?

Heat dissipation

What is the purpose of Half Value Layer?

-Measures beam quality/penetrability. -Specifically refers to thickness of material needed to reduce the intensity of X-ray beam by half

When and how is high voltage switching utilized in diagnostic imaging?

HV switching is used when applying HV to the X-ray tube. Switching mechanism controls the timing of the HV applied to tube.

What modalities in Radiology do not use x-ray?

-Ultrasound -MRI -Nuclear Medicine

What are the 3 principles of radiation safety?

-Shielding, Time, Distance STD!

Define the relationship between atomic number and attenuation of a radiation beam.

The higher the atomic number of the material, the greater the ability to attenuate radiation.

Which modality is regulated by MQSA?

Mammography (Mammography Quality Standards Act)

When utilizing a CR or DR system, what is the significance of the exposure factor number indicated on each image?

Exposure factor referred to as EI, exposure index, or DEI, detector exposure index, provides feedback about Exposure quality assurance, Exposure consistancy, Image Rejection Criteria, and Dose Monitoring.

Per the 2018 ACR Digital Mammography Quality Control Manual, the performance criteria for phantom scoring require visibility of greater than or equal to: 2 fibers, 3 speck groups, 2 masses 1 fiber, 1 speck group, 1 mass 5 fibers, 5 speck groups, 5 masses 3 fibers, 5 speck groups, 7 masses

2 fibers, 3 speck groups, 2 masses

There are three (3) sets of objects within the mammography phantom to simulate structures and objects that might be within a breast. These are the: masses, threads, and spots masses, threads, and specks masses, strings, and spots masses, fibers, and specks

masses, fibers, and specks

Uncorrected flood field non-uniformities cause __________ artifacts in tomographic reconstruction. Irregular Circular Dropout Undulating

Circular

All are complications of ultrasound, EXCEPT: Cavitation Local heating Increased risk of tumors in pregnant patients Mechanical damage to cell membranes

Increased risk of tumors in pregnant patients

Ultrasound interference: -Always produce a wave form of reduced amplitude -Are more common with continuous wave ultrasound -May be of value to ultrasound -May occur when two waves interact

May occur when two waves interact

Poor magnetic field homogeneity may affect image quality in the following ways: -Poor fat suppression -Shading artifacts -Spatial distortion -All answers are true

-All answers are true

Pushing the "big red button" near the door to a room housing an MRI scanner: -Immediately opens the door even if scanning is in progress -Turns off all electric power to the scanner and room -Initiates a controlled quench of the magnetic field -Calls emergency providers (911) and sounds an alarm

-Initiates a controlled quench of the magnetic field

Magnetic field gradients for imaging are typically measured in units of: Tesla (T) Gauss per second (G/s) Millitesla per meter (mT/m): Tesla per meter per second (T/m-s)

Millitesla per meter (mT/m):

The basic coil configuration used to generate the z-gradient in a cylindrical -MR scanner is known as: -Double saddle -Maxwell pair -Golay -Fingerprint

-Maxwell pair

Which component of a superconducting MR scanner does not require specialized cooling to maintain function? -Gradient amplifiers -Radiofrequency coils -Main coil windings -Gradient coils

-Radiofrequency coils

A common location for RF-leakage into the scanner room is: -Along the junction of copper plates in the scanner room’s walls -At the penetration panel -Along seals of the scanner window -Around the door

-Around the door

Artifacts in an MRI can be the result of all the of following execpt? a. RF interference b. Signal averaging c. Aliasing d. Distortions

b. Signal averaging

What is used to ensure the magnetic field is as close as possible to isocenter? 1. Shims 2. Gradient coils 3. RF coil 4. Gauss line

1. Shims

These substances exhibit a very slight negative or repelling effect when placed in externally applied magnetic field. They have low and negative susceptibility. A. Diamagnetic B. Paramagnetic C. Superparamagnetic D. Ferromagnetic

A. Diamagnetic Diamagnetic material have low and negative magnetic susceptibility, meaning they generate a magnetic field in the opposite direction to the applied field. Wood, water, plastic, and some metals like copper are examples of diamagnetic material.

Which of the following commonly encountered postoperative items should be further scrutinized as a potential MR safety hazard: 1. Skin staples 2. IV catheter and tubing (no metal clamps) 3. EKG Pads (non certified) 4. Penrose drain

3. EKG Pads (non certified)

Which aspect is crucial for ensuring patient safety and image quality in mammography? A) Utilizing Higher KV technique to improve image quality B) Optional compression of breast tissue C) Adherence to standardized positioning protocols D) Utilization of high-frequency ultrasound waves

C) Adherence to standardized positioning protocols

Although breast __________ are usually noncancerous (benign), certain patterns — such as tight clusters with irregular shapes and fine appearance — may indicate breast cancer or precancerous changes to breast tissue. -calcifications -lobules -cysts -glandular lobules

-calcifications

A grid is used in mammography (as in other x-ray procedures) to absorb scattered radiation and improve contrast sensitivity. Compared to grids for general x-ray imaging, grids for mammography have a __________ ratio, and the material between the strips is selected for __________ x-ray absorption. Higher, high Lower, high Higher, low Lower, low

-Lower, low

Good __________ of the breast is one of the essentials of effective mammography (and a common source of patient discomfort and concern). -image processing -filtration -image quality -compression

-compression

Whereas most x-ray machines use aluminum or "aluminum equivalent" to filter the x-ray beam, mammography uses filters that work on a different principle and are used to enhance contrast sensitivity. Some systems allow the operator (or automatic control function) to select either __________ or a __________ filter to optimize the spectrum for specific breast conditions. -molybdenum, rhodium -aluminum, copper -lead, graphite -molybdenum, copper

-molybdenum, rhodium

Most signs of breast pathology are in the form of soft-tissue masses that are: -not very different from the surrounding tissue -distinct from the surrounding tissue -of higher contrast -visible only under high kV x-ray

-not very different from the surrounding tissue

Mammography requires the highest __________ of all x-ray procedures. -average energy -peak energy -beam penetration -image quality

image quality

The typical MRI has a magnetic strength in the range of: 12 – 24 Tesla 3 – 6 Tesla 1.5 – 3 Tesla 6 – 12 Tesla

1.5 – 3 Tesla

The cryogen used for the MRI superconducting magnet is: Liquid oxygen Xenon Liquid nitrogen Liquid helium

Liquid helium

The bulk magnetic properties of matter derive primarily from: Protons Electrons Neutrons Whole nuclei

Protons

The direction of magnetic field lines surrounding a wire can be determined using? Faraday's Law Lenz' Law The left-hand rule The right-hand rule

The right-hand rule

The basic coil configuration used to generate the z-gradient in a cylindrical MR scanner is known as: Golay Fingerprint Maxwell pair Double saddle

Maxwell pair

The units for slew rate are given in: Tesla per second (T/s) Tesla per meter per second (T/m/s) Millitesla per meter (mT/m) Milliseconds (ms)

Tesla per meter per second (T/m/s) -Slew Rate is rate at which the magnetic field gradients can be switched. Higher slew rate allows for faster image sequences and higher image quality.

The fringe fields of cylindrical superconducting magnet are highest: In the x-direction (transverse and horizontal to the axis bore) They are equal in all directions In the z-direction (along the axis bore) In the y-direction (transverse and vertical to the axis bore)

In the z-direction (along the axis bore)

A device that allows a plastic oxygen hose to be passed through the wall of an MR scanner room without disrupting the integrity of the RF-shielding is called a: Faraday cage Penetration panel Waveguide Bandstop filter

Waveguide Fiber optic cables, hoses for pneumatic (air) or hydrolic (liquid) system can pass through the penetration panel via the wave guides.

As ultrasound frequency increases: imaging depth decreases propagation speed decreases imaging depth increases wavelength increases

imaging depth decreases

As ultrasound frequency increases, the attenuation coefficient: decreases attenuation coefficient not affected by frequency increases stays the same

increases

Which one of the following quantities varies the most with distance from the transducer face? Axial resolution Lateral resolution Wavelength Frequency

Lateral resolution ) ( ) ( ) ( ) *( )** ( ) * ) Lateral Spatial

The best Ultrasound image resolution is obtained: At the transducer surface In the focal zone In the near field In the far field

In the focal zone

The lateral resolution of a transducer is primarily determined by: the beam width applied voltage the acoustic impedance of tissue spatial pulse length

the beam width

The characteristic(s) of computed tomography (CT) which give(s) it a distinct advantage over conventional radiography is/are: Better contrast sensitivity Fewer artifacts. Lower noise. Higher visibility of detail

Better contrast sensitivity (low contrast detectability)

Two x-ray energies are used in DEXA bone densitometry in order to: -Find the optimal energy to image the bones -Cancel out soft tissue attenuation -Decrease radiation dose -Determine the minerals present in the bones (calcium vs. phosphorus)

Cancel out soft tissue attenuation

A hardened beam has what effect on the CT appearance of soft tissue: Darker with poorer contrast Darker with better contrast No change Brighter with the same contrast

Darker with poorer contrast

Beam hardening in x-ray imaging refers to: -Increase in a photon's energy as it is scattered by a dense material -Increased average x-ray energy as a beam passes through a dense material -Decreasing x-ray beam strength as it passes through a dense material -Decreased average x-ray energy as a beam passes through a dense material

Increased average x-ray energy as a beam passes through a dense material

Iodine is a good CT contrast agent because: -It simulates the attenuation of bone -The k-edge (33 keV) is near the average diagnostic x-ray energy produced by a 120 kV tube -The k-edge (33 keV) is much lower than x-ray energies produced by a 120 kV tube -We can achieve very high concentrations in target organs

The k-edge (33 keV) is near the average diagnostic x-ray energy produced by a 120 kV tube

The major determinant of temporal resolution in CT is: Fan-beam angle Reconstruction algorithm Gantry rotation speed Detector collimation

Gantry rotation speed

In soft tissue, Compton scattering becomes the most important interaction process above: 5 keV. 75 keV. 25 keV. 50 keV.

25 keV.

The intensity of an X-ray beam increases and the subject contrast remains unchanged by: Increasing the kVp. Decreasing the filtration in the beam. Changing from a single phase generator to a three phase one. Increasing the exposure (mAs).

Increasing the exposure (mAs).

As the kV is increased, the contrast between soft tissue and bone seen in a radiographic image: Decreases regardless of the choice of image receptor. Increases up to 69.5 kV but then remains constant. Decreases up to 69.5 kV but thereafter increases due to tungsten K-radiation. Increases above 80 kVp, especially in Computed Radiography.

Decreases regardless of the choice of image receptor.

In comparison with a single phase HV generator of the same kVp, the effective energy of the X-rays from a medium frequency generator is: Twice. Higher. Lower. The same.

Higher.

The anode of a diagnostic X-ray tube is angled: -To create higher beam homogeneity. -To allow the escape of some of the X-ray photons which are emitted perpendicular to the direction of the electron current -To give a smaller actual focal spot. -To give a smaller effective focal spot.

To allow the escape of some of the X-ray photons which are emitted perpendicular to the direction of the electron current

For fixed kVp and filtration, which will produce a beam with the largest Half Value Layer (HVL): Constant potential generator. The HVL would be the same for all three. Single phase generator. Mobile capacitor discharge unit.

Constant potential generator.

The design of an intensifying screen is a compromise between the twin desires of low patient dose and low quantum mottle. Which of the options below best satisfies this compromise: High detection efficiency and high conversion efficiency. Low detection efficiency and low conversion efficiency. High detection efficiency and low conversion efficiency. Low detection efficiency and high conversion efficiency.

High detection efficiency and high conversion efficiency.

The scattered radiation during a diagnostic X-ray examination arises mainly as a result of the: Photoelectric absorption. Compton effect. Coherent scattering. All of these.

Compton effect.

The finite size of the X-ray tube focal spot gives rise to: Penumbra Quantum mottle. Magnification. Pseudo-linear transformation.

Penumbra

The X-ray tube current (mA) influences which ONE of the following parameters: Patient penetration Number of X-ray photons Maximum X-ray energy Mean energy (quality) of the X-rays

Number of X-ray photons

When a filter is used to harden a diagnostic energy X-ray beam, it does so mainly by: Compton effect. Photoelectric absorption. Coherent scattering. Unaltered scatter.

Photoelectric absorption.

An X-ray beam with a high HVL is: Likely to result in a larger skin absorbed dose. Said to be more penetrating. Less likely to produce scatter. Said to be soft.

Said to be more penetrating.

The type of X-ray interaction with matter in which all of the energy of the incident photon is expended in dislodging a bound electron is called: None of above. Pair. Photoelectric effect. Compton effect.

Photoelectric effect.

The inverse square law relationship between radiation intensity and distance from a point source of radiation (e.g. XRT focal spot) is due to: Scatter in air. Absorption in air. Divergence of the X-ray beam. Chance.

Divergence of the X-ray beam.

The number of gray shades that an imaging system can reproduce is called its __________. spatial resolution contrast spatial frequency dynamic range

dynamic range

In digital imaging, spatial resolution is ultimately limited by? focal spot size spatial frequency contrast resolution pixel size

pixel size

The output signal from the photostimulable phosphor plate is converted from analog to digital by the? ADC optical system photodetector (PM tube) drive mechanism

ADC

Computed radiography uses (a) __________ for latent image formation. thin film transistors photosensitive silicon chips semiconductor material photostimulable phosphor

photostimulable phosphor

The phosphor most likely to be used in indirect digital radiography is: A-Si CsI a-Se NaI:Tl

CsI (Cesium Iodide)

The area of the TFT that is capable of recording information in comparison to the portion of the TFT that houses electronics is referred to as: DQE Fill factor Pixel pitch None are correct

Fill factor

With regard to computed radiographic (CR) imaging: -Unlike photographic film, CR plates are impervious to “fogging” by background radiation during storage. -Good quality diagnostic images can be acquired with radiation exposures which are similar to those required for film/screen imaging. -An automatic exposure control (AEC) is not required. -Images with the same CR exposure index are all obtained with the same radiation dose to the patient.

-Good quality diagnostic images can be acquired with radiation exposures which are similar to those required for film/screen imaging

In DR, where are the electrical charges stored? Thin Film Transistors TFTs Titanium Film Transistors TFTs Thin Photodiode Transistors TPTs Thin Plate Transistors TPTs

Thin Film Transistors TFTs

The CR imaging plate reader uses a laser to scan the imaging plate, releasing the energy stored in the conductive layer as ______ light. White Ultraviolet Infrared Blue

Blue

The process of scanning the moving CR imaging plate is known as: Transition Digitization Translation Raster scanning

Transition

What are the layers of a CR Imaging Plate? -Protective, phosphor, conductor, support, shield, backing -Protective, Conducive, Reflective, Protective, Intensifying screen -Phosphor, conductive, support, reflective, intensifying screen -Protective, phosphor, reflective, support

Protective, phosphor, conductor, support, shield, backing CRES question

What is a scintillator? Absorbs light and converts to gamma rays Absorbs light and converts energy to x-rays Absorbs x-rays and converts to carbon Absorbs x-rays and converts energy to light

Absorbs x-rays and converts energy to light

The "latent image" in a CR imaging plate is stored by the: Sensitivity speck Photomultiplier tube Trapped electrons in phosphor center Analog to digital converter

Trapped electrons in phosphor center

Poor magnetic field homogeneity may affect image quality in the following ways: Poor fat suppression Spatial distortion Shading artifacts All answers are true

All answers are true

What is the order of operation of a film processor after film is inserted?

Developer->Fixer->Water Rinse->Dryer

Decreasing kV in CT is advantageous because: Scan times are reduced X-ray penetration improves Tissue contrast improves Metal streak artifacts are improved

Tissue contrast improves

An accurate, modern CT scanner is capable of spatial resolution of up to _________: 20 lp/cm 10 lp/mm 100 lp/cm 20 lp/mm

20 lp/cm

Which of the following numbers reported by the scanner best reflects the total amount of radiation delivered to the patient? Effective mAs Pitch Dose-length product (DLP) CT Dose Index (CTDI)

Dose-length product (DLP)

The magnification mode of an image intensifier is switched from 15 cm to 30 cm. In order to maintain the same image brightness, the exposure at the image intensifier input phosphor must roughly: halve remain the same double quadruple

quadruple

A 22 cm multi-mode image intensifier is switched to the 11 cm mode. As a result, the image will be _________ and the automatic brightness control system will _________ the exposure to the image intensifier and the patient. minified; decrease magnified; increase minified; increase magnified; decrease

magnified; increase

Lower, low

An appropriate kV range for mammography would be: 24kV to 32kV 35kV to 50kV 50kV to 75kV 7kV to 15kV

24kV to 32kV

2 fibers, 3 speck groups, 2 masses

In order to decrease dose in large mammo patients: Decrease kV and improve image noise Increase kV and improve image contrast Increase kV and improve image noise Decrease kV and improve image contrast

Increase kV and improve image noise

Iodine is an effective contrast agent because: -It has a high likelihood of Compton interaction at diagnostic x-ray energies -It has a high mass density -It has a high electron density -It has a high likelihood of photoelectric interaction at diagnosticx-ray energies

-It has a high likelihood of photoelectric interaction at diagnostic x- ray energies

The part of the image intensifier tube that functions to change the visible light image into an electronic image is the: Focusing lens Photocathode Input phosphor Output phosphor

Photocathode

The usual range of mA required for an image intensified fluoroscopy is about: 25-100 mA 6-10 mA 100-600 mA 1-5 mA

1-5 mA

The concept of clinical SPECT/CT system can be described as: A CT scanner positioned in front of a single-head scintillation camera A CT scanner positioned in front of a dual-head scintillation camera A dual-head scintillation camera positioned in front of a CT scanner A single-head scintillation camera positioned in front of a CT scanner

A dual-head scintillation camera positioned in front of a CT scanner

The process of aligning images so that corresponding features can easily be related is called: Image smoothing Image processing Image registration Image filtering

Image registration

False-negative PET scans in lung cancer imaging occur predominantly because of: Lesions that are too superficial to be evaluated by PET Lesions that are too big to be evaluated by PET Lesions that are too small to be evaluated by PET Lesions that are too deep to be evaluated by PET

Lesions that are too small to be evaluated by PET

In the PET/CT acquisition, the CT component is performed for? Scatter correction Motion correction Attenuation correction Random correction

Attenuation correction

The property of the scintillation detector described as the number of scintillations produced by each incident photon is called: The decay constant Energy resolution The stopping power The light output

The light output

In PET scanning process raw data acquired and identified as coincidence events along their line of response (LOR) are stored in the raw data format called: Sinograms Dextrograms Pictograms Histograms

Sinograms

The positron has the same mass as an electron and an electric charge of: +1 0 −1 –2

The sum of the weighted equivalent doses in all the tissues and organs of the body is called: Shallow dose equivalent Committed dose equivalent Whole-body dose Effective dose

Effective dose

PET tracers have demonstrated significant potential utility and application in the following clinical areas EXCEPT: Oncology Neurology Pulmonology Cardiology

Pulmonology

Truncation artifacts in PET/CT imaging are produced by? Contrast medium Difference in size of FOV between PET and the CT Difference in scanning time between PET and the CT Beds overlapping

Difference in size of FOV between PET and the CT

The exposure rate of an activity of 1 millicurie (mCi) measured at 1 centimeter (cm) is called? Roentgen man equivalent (REM) Total effective dose equivalent (TEDE) Kilobecquerel (kBq) The exposure rate constant (ERC)

The exposure rate constant (ERC)

The detector of PET is made of _________ Gadolinium Silver Lead Tungsten

Gadolinium

What makes PET and SPECT so unique when it comes to nuclear imaging? Do not require X – Rays They give more details about the imaged organ/tissue They show metabolic functions Do not require dyes

They show metabolic functions

What does the ‘P’ in SPECT stand for? Positron P – orbital Proton Photon

PHOTON SPECT = Single Photon Emission Computed Tomography

Which of the following isotopes is not a radioisotope? Sulphur-35 Carbon-13 Tritium Carbon-14

Carbon-13

Which of the following detection methods is not commonly used to detect isotopically labelled drug metabolites? Mass spectrometry Nuclear magnetic resonance spectroscopy Scintillation counting Infrared spectroscopy

Infrared spectroscopy

What is detected during positron emission tomography (PET)? Positrons Neutrons Electrons Photons

Photons

Which of the following components is where a gamma camera adds all the signals in order to determine where each scintillation event occurred in the detector? Position circuitry Detector crystal Collimator Photo multiplier tubes

Position circuitry

What does the ‘P’ in PET stand for? Proton Positron P – orbital Photon

Positron PET: Positron Emission Tomography: nuclear imaging technique to produce detailed, 3D images of the inside of body. Detects gamma rays produced with collisions of decayed isotope with electrons in the body. 2 gamma rays produced with each collision.

Tissue contrast is generated by what type of interaction? Coherent (Rayleigh) scatter Photoelectric effect Beam hardening effect Incoherent (Compton) scatter

Photoelectric effect

In order to decrease dose in large patients: Decrease kV and improve image contrast Increase kV and improve image contrast Decrease kV and improve image noise Increase kV and improve image noise

Increase kV and improve image noise -Increased KV with shorter exposure to control dose.

Switching from a molybdenum to a tungsten anode demonstrates what trade-off? Lower dose, worse contrast Higher dose, better contrast Lower dose, worse heat capacity Higher dose, better heat capacity

Lower dose, worse contrast

molybdenum, rhodium

The number of gray shades that an imaging system can reproduce is called its __.

dynamic range