Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CT > Safety & Dose > Flashcards

Safety & Dose Flashcards

1
Q
  1. Three Primary Systems in Production of XRay
  2. Where is filament & anode located?
  3. What is required of filament & anode prior to CT Scan?
A
  1. Operating Console, Generator & Tube
  2. In tube
  3. Tube Warmup
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q
  1. What heats the filament?
    - When does this occur?
  2. What is required to begin exposure & image acquisition?
  3. What determines amount of electricity that flows through the filament?
A
  1. Anode within xray tube
    - Prior to the image acquisition
  2. Electricity to flow through the filament.
  3. Determined by the mA previously selected
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q
  1. As the filament heats, ____________ occurs and an electron cloud is formed around the filament.
  2. mA determines __________ in regards to xray tube
  3. What rotates & heats up for image acquisition?
A
  1. thermionic emission
  2. amount electricity that flows through filament
  3. Anode rotates & heats up filament
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q
  1. What is thermionic emission?
  2. What occurs simultaneously with above?
    - Results in?
  3. How & Where are x-rays created?
A
  1. process that occurs when a filament becomes heated, and releases electrons.
    **CLOUD OF ELECTRONS
  2. Simultaneously, the kV previously selected begins to flow through the x-ray tube
    - causes projectile electrons to move from the cathode to the anode target.
  3. impact of the projectile electrons with the anode target results in a conversion of the electrons to heat and x-rays.
    - @ Anode
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q
  1. What is the process that occurs when a filament becomes heated, and releases electrons.
  2. What causes projectile electrons to move from the cathode to the anode target.
  3. Electrons impacting anode target create what?
A
  1. Thermionic Emission
  2. kVp
  3. Photons & Heat
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q
  1. Two types radiation?
    - Differences:
  2. Explain Steps of photon production:
A
  1. Primary radiation- the x-rays that are produced from, and exit through the x-ray tube.
    - Exit or Remnant Radiation- are x-rays that have passed through the patient, and strike the detector, which are then used to form the image. Exit radiation consists of both primary and scattered x-rays.
  2. mAs selected & determine electricity to tube
    - Anode begins spin & heat filament
    - Thermionic Emission / Cloud Electrons formed
    - kVp selected flow electrons from cathode to anode
    - Strike Anode Target
    - Produce photons & heat
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q
  1. What is Primary radiation?
  2. What is Remnant Radiation?
  3. Which forms the image?
A

1.- the x-rays that are produced from, and exit through the x-ray tube.
BEFORE REACHING PATIENT

  1. AKA EXIT RADIATION
    - x-rays that passed through the patient, and strike the detector,
  2. Exit / Remnant
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q
  1. What does exit radiation consists of?
    - Results in?
    - AKA?
  2. What do electrons convert to at anode target?
  3. Two primary types of radiation that are created from the x-ray tube?
A
  1. both primary and scattered x-rays.
    - Image Production
    - Remnant Radiation
  2. Photons & Heat
  3. Characteristic & Brems
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q
  1. Where is primary radiation created?
  2. Summarize Characteristic Radiation
  3. Summarize Bremsstrahlung Radiation
A
  1. From xray tube / at anode target
  2. Characteristic x-rays are created when an outer shell electron interacts with an inner shell electron and removes it.
  3. Bremsstrahlung x-rays are created when an electron is slowed as it passes the nucleus of an atom.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q
  1. Which radiation involves an outer shell electron filling void of inner shell electron?
  2. How often does this occur?
  3. Which shell are utilized in xray production?
    - Why?
A
  1. characteristic
  2. This process repeats until the electron shells are stable.

3.Only K shell have energy high enough to be utilized in x-ray.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q
  1. What action actually creates the characteristic xray?
  2. Which rays are created when an electron is slowed as it passes the nucleus of an atom.
  3. What occurs as electron passes nucleus?
A
  1. It is the action of the outer shell electron moving into the inner shell that creates the characteristic x-ray.
  2. Bremsstrahlung
  3. As the electron passes the nucleus, it is slowed down. The slowing of the electron causes it to lose some or all of its energy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q
  1. What action actually creates the bremstra xray?
  2. How fast do x-rays travel?
  3. What can x-rays do to matter?
A
  1. This loss of energy results in Bremsstrahlung x-rays.
  2. Speed of light
  3. Ionize matter & gas
    - Cause biological changes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q
  1. Basic Characteristics of all Xray Properties:
  2. What is Quantity?
    - Biggest Driving Factor?
  3. What is Quality?
    - Biggest Driving Factor?
A
  1. X-rays consist of photons that:
    - travel at the speed of light
    - penetrate objects.
    - ionize matter and gas
    - cause biological changes.
  2. Quantity = number of x-rays produced.
    - mA.
  3. Quality = ability to penetrate tissue.
    - kV.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q
  1. The quantity of xray is ______ proportional to mAs.
    - When mAs is doubled, what occurs to quantity?
  2. The quality of xray is ______ proportional to kV.
    - As kV increases, beam quality ______.
  3. If a beam is “high quality” this means?
    - Low Quality?
A
  1. The quantity of x-rays is directly proportional to the mAs.
    - When mAs is doubled, the quantity of x-rays produced is also doubled.
  2. Quality directly proportional
    - As the kV is increased, so is the beam quality.
  3. beams with high levels of penetration are considered high quality,
    - low-levels of penetration are low quality
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q
  1. What occurs when mAs is doubled?
  2. Beam that is low penatrating is called what?
    - High?
  3. kV controls what?
A
  1. Quantity is doubled
  2. Low = Low Quality
    - High = High Quality
  3. Quality
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q
  1. Photons travel through space as ____A___ & ____B____. Each ____C___ has its own specific ___D___ & ___E___
  2. What is the distance from any point on the wave, to the next corresponding point?
  3. What is the number of wavelengths that pass a given point in a measured time.
A
  1. A. Waves
    B. Particles
    C. Wave
    D. Wavelength
    E. Frequency
  2. Wavelength
  3. Frequency
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q
  1. Do photons travel as particles or waves through space?
  2. How is Wavelength measured?
  3. Define Frequency
A
  1. BOTH
  2. Can be measured from crest to crest or bottom to bottom.
  3. Number of wavelengths that pass a given point in a measured time.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q
  1. Relation between Wavelength & Frequency:
  2. What does Increase Square Law state?
A
  1. inversely proportional
    - Increase in wavelength=Decrease in frequency
    - Decrease wavelength= Increase frequency
    - Increase in frequency =Decrease in wavelength
    - Decrease in frequency = Increase in wavelength
  2. If there is an increase in the distance of an object from the x-ray source, the dose decreases.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q
  1. If you double the distance of an object from the source, the dose is ___________.
  2. If the distance between an object and the source is decreased by half, the ____________.
  3. Relation between distance & dose?
    - Why?
A
  1. reduced by a factor of 4
  2. dose is increased by a factor of 4
  3. INVERSE RELATIONSHIP
    - Increasing distance from source to object = decrease in dose
    - due to the x-ray beam dispersing and spreading out over a larger area.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q
  1. What are the interactions with matter?
  2. Which interaction is complete absorption?
  3. Which interaction involves an outer shell electron?
A
  1. Photoelectric, Compton Scatter & Classic (Coherent) Scatter
  2. Photoelectric
  3. Compton
    (Straight OUT OF Compton)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q
  1. What Occurs in Photoelectric Interaction?
    - Results In?
  2. What Occurs in Compton Interaction?
    - Results In?
  3. What Occurs in Classical Interaction?
    - Results In?
A
  1. x-rays interacting with inner shell electrons & being absorbed.
    - Results in complete absorption of the x-ray and the K shell electron being ejected from the atom.
  2. incident x-ray interacting with an outer shell electron. The outer shell electron is ejected from the atom, which results in ionization of the atom. - Results in incident x-ray in a different direction, with less energy & ejected electron (AKA Compton electron)
  3. incident x-ray interacting with an atom, which causes the atom to vibrate.
    - Results in a release of energy in the form of a scattered x-ray with the same energy of the incident x-ray, but in a different direction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q
  1. Which Interaction results in k-shell electron being ejected?
  2. Which Interaction Results In a Compton Electron?
  3. Which Interaction Results In Scatter X-Rays with SAME Energy of Incident?
    - Same or Different Direction of Incident?
A
  1. Photoelectric = Absorption & K Shell Ejected
  2. Compton Electron = Incident Xray in DIFF Direction / LESS Energy && Ejected Outer Electron (Compton Electron)
  3. Classical / Coherent = Scatter X-Ray in DIFF Direction / SAME Energy as Incident
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q
  1. Which Interaction Involves a decrease in incident energy?
  2. Which Interaction Involves Inner Shell Electron?
    - Which Involves Outer?
  3. Which Interaction Changes incident x-ray’s direction?
A
  1. DECREASE IN INCIDENT = COMPTON
  2. INNER = PHOTOELECTRIC / K SHELL
    - OUTTER = COMPTON / COMPTON ELECTRON
  3. COMPTON & COHERENT/CLASSICAL
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q
  1. Interactions When Radiation Passes Object?
  2. What is result of Photoelectric Effect?
    - What does it look like in a diagram?
  3. What does Compton Interaction look like in a diagram?
A
    • Beam may be attenuated.
      - Beam may be hardened.
      - Beam may photoelectric effect.
      - Beam may Compton scattering.
  2. Complete Absorption of X-Ray & K-Shell Electron being Ejected (PHOTOELECTRON)
    - Squiggly X-Ray Line to Electron in Atom, Ejected Electron & No More Squiggly
  3. Squiggly Xray Line to Electron, Ejected Electron (COMPTON ELECTRON) In one direction & Lower Energy Squiggly Xray in DIFF Direction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q
  1. Technical Factors impact ______ & ______.
  2. What 2 KEY Concepts ar eimportant for a tech in CT?
  3. Patient Dose Depends On:
A
  1. Image Quality & Patient Dose
  2. ALARA & Time, Distance & Shielding
  3. Source to Detector Distance
    - Source to Iso-Center of Gantry &/or Detectors
    - Filtration
    - Patient Positioning
    - Detectors
    - Cone Beam
    - Overranging
    - Recon Algorithms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q
  1. Relation Between Patient Dose & Source To Detector Distance:
  2. Relation Between Patient Dose & Source to Iso-Center of Gantry &/Or Detectors:
  3. Relation Between Patient Dose & Filtration:
A
  1. INVERSE
    - Decrease In Distance between Source (XRAY TUBE) & Detectors = INCREASE Patient Dose
  2. INVERSE
    - Decrease In Distance between Source (XRAY TUBE) & Iso-Center of Gantry = INCREASE Patient Dose
  3. INVERSE
    - INCREASE FILTRATION = DECREASE DOSE (Filtration is absorbing lower energy photons that contribute to patient dose)
27
Q
  1. How does Filtration decrease patient dose?
  2. If the x-ray tube gets closer to the iso-center of the gantry or closer to the detectors, the radiation dose received by the patient ___________
  3. As the x-ray tube gets _______ to the detectors, the radiation dose received by the patient increases.
A
  1. Filtration is absorbing lower energy photons that contribute to patient dose / absorbed by patient
  2. INCREASES
  3. CLOSER = INCREASE
28
Q
  1. Can patient positioning impact patient dose?
    -Why / Why not?
  2. What can occur if patient dose is too low?
  3. How do detectors impact patient dose?
A
  1. YES
    - By positioning the patient iso-center in the gantry, the technologist ensures that accurate calculations are made when utilizing automated tube current modulation.
  2. Sub-optimal imaging
  3. absorption efficiency and the arrangement of the detectors impact the overall radiation dose
29
Q
  1. The better the detectors are able to ___________, the less radiation is needed.
  2. What spacing of detectors is better for patient dose? (Closer spacing or Further spacing?
    - Why?
  3. What type of detectors use Cone Beam?
    - Why?
A
  1. able to absorb transmitted photons
  2. Closer Spaced Detectors
    - CLOSER = MORE Info obtained per exposure. Thereby will reduce patient dose
  3. Multidetector CT (MDCT)
    - cone beam is utilized in order to expose the entire row of detectors evenly to radiation.
30
Q
  1. What is Penumbra?
  2. What occurs to overcome penumbra?
  3. Does This INCREASE or DECREASE Patient Dose?
A
  1. Partially shaded outer region / Edges of Detector shadow cast by an opaque object.
  2. Overbeaming
  3. Results in increased radiation dose to the patient.
31
Q
  1. Use of Overbeaming _________ patient dose.
  2. What is Overranging?
    - Does this increase or decrease dose?
  3. What does Overranging ensure?
A
  1. Increased dose
  2. Occurs when the radiation exposure begins prior to and after the image acquisition.
    - INCREASE
  3. Ensure that there is enough data acquired from the beginning and end of the acquisition for reconstruction
32
Q
  1. How do Reconstruction Algorithms impact patient dose?
  2. One of the most efficient ways to ensure that a patient is receiving an acceptable radiation dose is to:
  3. How is this (^) done?
A
  1. Used to remove the effects of noise during reconstruction.
    - This can allow for lower radiation doses to be utilized during acquisition
  2. Optimize a scanning protocol to each patient.
  3. Adjust technical parameters and scanning range of a protocol based on patient size, age, and ROI
33
Q
  1. What should mA & kV be kept to?
  2. If mA is halved, Radiation dose is _______.
  3. If kV is increased, patient dose is ______.
A
  1. mA and kV should be kept to the lowest possible levels to acquire optimal images to keep the patient’s radiation dose to a minimum.
  2. 1/2 mA = 1/2 Dose
  3. Increase kV = Increase Dose
33
Q
  1. What is adjusted for optimal dose?
    -What is it based on?
  2. Does mA have proportional or imprortional relationship to radiation dose?
  3. Does kV have direct or indirect effect on patient dose?
A
  1. technical parameters and scanning range
    -Based on patient’s size, age, & ROI
  2. mA has a proportional relationship to radiation dose. If mA is halved, the radiation dose is halved.
  3. direct effect on patient dose. As the kV is increased, the patient’s radiation dose is also increased.
33
Q
  1. Does collimation have direct or indirect impact on patient dose?
  2. What is Dose Profile?
  3. What Does Wide Collimation Mean?
    - Narrow Collimation?
A
  1. INDIRECT
    - Collimation of beam impacts dose profile
    - By Limiting Dose Profile / ROI = LESS Area receiving radiation
  2. Area of the patient that is exposed to radiation.
  3. Wide = Patient’s dose will be increased in the z-axis (thick slices)
    - Narrow = Patient dose will be decreased in the z-axis (thin slices).
34
Q
  1. Wide Collimation = ____ Slices & _____ Dose.
  2. Narrow Collimation = ____ Slices & _____ Dose.
  3. What is important to remember about Narrow Collimation & Image Quality?
A
  1. WIDE = THICK SLICES & INCREASED DOSE
  2. NARROW = THIN SLICES & DECREASE DOSE
  3. Narrow = Thin Slices which can have images with increase nouse, so mA increase may be needed to decrease noise
35
Q
  1. AEC Stands for:
  2. What is AEC Based off of?
  3. Function of AEC?
A
  1. Automatic exposure control (AEC)
  2. Optimizes the radiation dose that a patient receives based upon their size and the different densities of the tissues being imaged.
  3. Minimum dose necessary to obtain quality images is utilized.
36
Q
  1. What can AEC Adjust?
    - Is this done post processing or during the scan?
  2. The denser the object being imaged is, the ______ the calculated dose.
  3. What does ever CT scanner have to ensures optimal image quality is consistently obtained & optimizing patient dose?
A
  1. mA and kV in the x, y, and z-axis of the patient
    - real-time.
  2. DENSER = HIGH DOSE
  3. Present range of mA & kV
37
Q
  1. In AEC, mA is adjusted based on:
  2. In AEC, Proper mA & kV is calculated from where / when?
  3. Why is it crucial artifacts / objects are removed from patient (when possible) PRIOR to CT?
A
  1. The density of the object that is being imaged during that specific moment of the acquisition
  2. from the scout images that obtained prior to the acquisition
  3. Artifacts on scout images will be used to calculate patient’s technical parameters / Can increase their dose
38
Q
  1. When is ECG Gating typically used?
  2. How is it beneficial?
  3. What does ECG monitor?
    - How?
A
  1. Cardiacs / Thoracic Aorta Exams
  2. Can be utilized to reduce a patient’s radiation dose
  3. ECG leads hooked up PRIOR to exam
    - Monitoring HR through exam
39
Q
  1. In CT Cardiac exams, ECG Gating allows for what?
  2. What is perspective gating?
  3. What is retrospective Gating?
A
  1. Allows image acquisition to occur during desired phase of cardiac cycle only
  2. ECG gating that allows image acquisition to occur during desired phase of cardiac cycle only
  3. ECG gating also allows for acquisitions to occur throughout the entire cardiac cycle. Images can be reconstructed once the acquisition has been completed to display only the desired phase of the cardiac cycle.
40
Q
  1. What is term for ECG gating that allows image acquisition to occur during desired phase of cardiac cycle only
  2. What is term for ECG gating when Images can be reconstructed once the acquisition has been completed to display only the desired phase of the cardiac cycle.
  3. Which above results in INCREASED patient dose?
A
  1. Prospective Gating
  2. Retrospective Gating
  3. Retrospective / #2
41
Q
  1. Prospective vs Retrospective Gating:
  2. What do IR Algorithms allow?

3.What does IR Algorithm Stand For?

A
  1. Pro = Acq. occur only desired phase
    - Retro = Acq. Entire cardiac cycle / Images Reconstructed / Inc. Dose
  2. May allow for less radiation used during acquisition w/o quality of exam suffering.
  3. Iterative Reconstructions
42
Q
  1. __________ algorithms can help to overcome the noise that is present in images that are acquired with lower radiation doses.
  2. What is “Exposure”
    - Reported In?
  3. What is “Absorbed Dose”
    - Reported In?
A
  1. Iterative Reconstruction Algorithms
  2. Exposure = ionization of air.
    - Roentgens, or miliroentgens.
  3. Absorbed = amount of energy absorbed per unit of mass of material.
    - gray or milligray.
43
Q
  1. What is “Effective Dose”
    - Reported In?
  2. What does Effective dose consider?

3.

A
  1. Effective Dose = quantifies an equivalent whole-body radiation dose from a partial body exposure.
    - sievert or the millisievert
  2. The radiosensitivity of different tissues within the patient and each tissue is assigned a weighting factor. WEIGHTED AVERAGE

3.

44
Q
  1. Radiation Dose Measurements:
    - Differences?
  2. Which Dose Uses Weighting Factors?
  3. Which Dose is reported in Sieverts?
A
  1. Exposure = Ionization Air / Roentgen
    - Absorbed = Amount Energy Absorbed PER Unit / Gray
    - Effective = Quantifies whole-body dose from partial body exposure
  2. EFFECTIVE
  3. EXPOSURE & EFFECTIVE
45
Q
  1. What do structured dose reports document?
    - Are they required?
  2. What information from an exam does Structured Dose Reports use?
  3. What are the two metrics displayed in Structured Dose Reports that quantify patient dose?
A
  1. Document patient’s total radiation exposure for that particular exam.
    - YES / REQUIRED
  2. kV
    mA
    SFOV
    Pitch
    Detector collimation
    Scan length
  3. CT Dose Index (CTDI)
    Dose-Length Product (DLP)
46
Q
  1. CT Dose Index (CTDI) & Dose-Length Product (DLP) quantify what?
  2. What is CTDI?
  3. How is CTDI Determined?
A
  1. Patients radiation dose for particular exam
  2. The measure of dose received in a single slice within an acquisition.
  3. Through the use of phantoms to calculate the approximate dose a patient would receive
47
Q
  1. What dose CTDI stand for?
    - DLP?
  2. CTDI can only be calculated if acquisition is ______A___ & does not contain ______B___.
  3. What is CTTDI100
A
  1. CT Dose Index (CTDI)
    Dose-Length Product (DLP)
  2. A. Contiguous
    - B. gaps or overlapping slices
  3. CTDI100 is a measurement taken with a 100mm long pencil ionization chamber.
48
Q
  1. What is CTDIW?
  2. How is CTDIW Calculated?
  3. What is CTDI measured WITH?
A
  1. Accounts for the variations in the density of an object being imaged.
  2. Calculated by summing exposure recorded at the periphery of the field with the exposure at the central portion of the field.
  3. Ionization Chamber
49
Q
  1. What is Calculated by summing exposure recorded at the periphery of the field with the exposure at the central portion of the field.
  2. What is the measure of dose received in a single slice within an acquisition.
  3. How does CTDIW calculate?
    - What isnt accounted for?
A
  1. CTDIW
  2. CTDI
  3. Weights the exposure and creates a more accurate dose approximation.
    - does not account for the effects of spiral or helical scanning
50
Q
  1. What is CTDIVOL
  2. Is CTDIW more or less accurate?
  3. CTDIVOL doesn’t take in account:
A
  1. Measures the radiation dose obtained during a helical scan and accounts for dose in the x, y, and z axis.
  2. MORE
    - But doesn’t account for spiral / helical scan
  3. CTDIVol does not take into consideration the scan range, and is only an estimation of radiation dose within a given slice.
    - DOESNT ACCOUNT PATIENT SIZE
51
Q
  1. CTDIW doesn’t account for:
  2. Is CTDIVOL exact?
    - Why/Why not?
  3. What is DLP?
A
  1. Helical / Spiral scan
  2. Only estimate
    - Doesn’t account patient size or scan range
  3. Dose Length Product
    - total amount of exposure for an exam, with consideration of the scan length.
52
Q
  1. What is the total amount of exposure for an exam, with consideration of the scan length?
  2. Scan length is ________ to radiation dose.
  3. DLP does not account for _______.
A
  1. DLP / Dose Length Product
  2. The scan length is proportional to the radiation dose.
  3. DLP does not account for patient size.
53
Q
  1. Which dose measurement accounts for patient size?
    - Which does not?
  2. When do dose alerts appear?
  3. What is needed when alert appears?
    - Is this required?
A
  1. DOES = CTDIW
    - DOES NOT= CTDIVOL & DLP
  2. when the exam will exceed pre-determined radiation dose.
  3. Can put why exceeding (ex: pt habitus)
    - NOTE WHY REQUIRED
54
Q
  1. When & Why do dose alerts appear on CT scanners?
    - What is required?
  2. Are pediatric absorbed doses higher or lower than older patients?
    - Why?
  3. How can techs reduce pediatric dose?
A
  1. When dose will exceed pre determined dose
    - intent to ensure patient is receiving minimum dose possible.
    - REASON / NOTE WHY REQUIRED
  2. HIGHER
    - Radiation dose remain constant as it enters and exits the patient.
  3. Eliminating multiphase imaging
    - Reducing kV and mA
    - Ensuring clinical appropriateness
55
Q
  1. Pediatric _______ dose is typically higher than older patients because _____________.
  2. What was created to increase the awareness of dose optimization for pediatric patients?
    - How?
  3. What was created to emphasize the importance of dose optimization for the adult population undergoing imaging?
A
  1. Absorbed
    - Radiation tend remain constant as it enters & exits PEDS
  2. Image Gently
    - places an emphasis on reducing technical factors, eliminating multiphase scanning, and imaging only the area of interest to reduce the radiation dose.
  3. Image Wisely
56
Q
  1. Image Gently vs Image Wisely?
  2. mA is ____A____ proportional to dose, if the mA doubles, the dose ____B_____.
  3. kV is _____C_____ to dose, if the kV increases, the dose ___D______.
A
  1. GENTLY = PEDS
    - WISELY = OLDER
  2. mA is directly proportional to dose, if the mA doubles, the dose doubles.
  3. kV is proportional to dose, if the kV increases, the dose increases.
57
Q
  1. As pitch increases, dose ____A____ (all other factors remaining the same)
  2. Failure to iso-center the patient in the gantry can result in:
  3. Increase dose = ___A____ noise
    Improve spatial resolution = ___B___ dose
    Decrease slice thickness = __C___ dose
    Decrease pixel size = ___D____ dose
A
  1. DECREASES
  2. Either an over or underestimation of required dose for an exam.
  3. Increase dose = decrease noise
    Improve spatial resolution = increase dose
    Decrease slice thickness = increase dose
    Decrease pixel size = increase dose
58
Q
  1. Increased dose results from
    - _______ spatial resolution
    - ________ slice thickness
    - ________ pixel size
  2. What does increased dose result IN?
A
  1. Increase dose = decrease noise
    - IMPROVED SR
    - Decreased slice thickness
    - Decreased pixel size
  2. Decreased noise & improved SR
59
Q
  1. During which period of gestation is fetus most sensitive?
  2. WHICH OF FOLLOWING WOULD HAVE GREATEST IMAPCT ON PATIENT DOSE?
    A. Detector Configutation B. Matrix Size. C. kV. D. DFOV
  3. WHOLE-BODY DOSE FROM PARTIAL BODY EXPOSURE IS QUANTIFIED BY:
    A. CTDI B. Effective Dose C. Absorbed Dose D. Exposure
A
  1. FIRST
  2. kV
  3. effective
60
Q
  1. STRUCTURED DOSE REPORT WILL INCLUDE:
  2. ATCM FUNCTION?
  3. BEAM IN MDCT:
A
  1. mA, kV, SFOV, Pitch, Detector, Collimation & Scan Length
  2. FORM OF AEC IN CT, REDUCE PATIENT DOSE
  3. CONE / COVER ALL DETECTORS
61
Q
  1. THIN SLICES CAN RESULT IN HIGHER DOSE BECAUSE:
  2. DLP RELATION TO SCAN LENGTH & DOSE?
  3. CTDI ACQUISITION MUST BE:
    A. AXIAL. B. OVERLAPPING. C. CONTAINS GAPS. D. CONTIGUOUS
A
  1. mA IS INCREASED TO COMPENSATE FOR NOISE
  2. PROPORTIONAL
  3. D. CONTIGIOUS (NO GAPS AND NO OVERLAPPING)

CT (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions