RADR 2205 Unit 6 exam

For each description or characteristic below, indicate whether it is associated with "stochastic" or "deterministic" effects.

occur randomly

referred to as "probabilistic"

as exposure increases, the risk of biologic effect increases

late effects

early effects

as dose increases, effects are more severe
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Terms in this set (28)
For each description or characteristic below, indicate whether it is associated with "stochastic" or "deterministic" effects.

occur randomly

referred to as "probabilistic"

as exposure increases, the risk of biologic effect increases

late effects

early effects

as dose increases, effects are more severe
stochastic

stochastic

stochastic

stochastic

deterministic

deterministic
A disadvantage associated with visual grading of normal anatomy is:
bias of the observer
Select all statements below regarding gonadal shielding that are accurate:
Select four
Gonadal shields are intended to provide protection from primary radiation exposure.

For female patients, a flat gonadal contact shield should be placed so that it is centered such that the edges are approximately 2.5 cm (1 inch) medial to each ASIS.

For male patients, the symphysis pubis should be used as a guide to ensure placement of the flat gonadal contact shield over the testes.

Use and placement of such shielding can reduce male gonadal dose by 90-95%.
The two categories of Observer Performance, are based on:
the scope of the clinical role
Which of the following are considered the four requirements that should be included in medical imaging research studies involving optimization?
Select four
Dose reduced, image quality maintained

Image quality necessary established

Ensure patient dose is safe

Reliable and valid methodologies used
Contrast-to-noise ratio is improved with ________ increase (for both radiography and fluoroscopy).
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kV
Match the measurable image characteristic with the appropriate description.

a measure of how accurate the information contained in the image is in comparison to the actual structure

directly impacts the contrast resolution which is essential to a quality diagnostic image

measures how efficiently the x rays received by a detector can be converted into a useful image
MTF

SNR

DQE
Optimization of a digital image encompasses:
Exposure factors and exposure indicator
Select the choice below that accurately states the relationship of SID its affect upon source to skin distance (SSD) and dose.
Shorter SID's decrease SSD, thus increase patient skin dose
Select all of the following possible answers that are equal to the result of doubling the mAs.
2 X mAs = ________
2 X exposure

2 X quantity

2 X dose

an increase in kV by 15%
Select the desirable image quality descriptors below:spatial resolution should be maximized Correct answer detective quantum efficiency (DQE) should be high Correct answer noise should be decreasedThe term "dose-image quality optimization" encompasses which of the following:maintenance of image quality reducing dose adherence to the ALARA PrincipleThe European Guidelines on Quality Criteria require the following criteria for each: Select threediagnostic requirements radiation dose to the patient example of appropriate radiographic techniqueMatch the definition/description with the term that best defines/describes the term. diagnostic need in which the benefit of diagnosis outweighs the risk of the radiation exposure exposure is kept ALARA while maintaining overall image quality measure taken to minimize biologic damageJustification Optimization Dose LimitationTo best ensure understanding of optimization, radiographers should have a firm foundation of: Select twoexposure creep dynamic rangeWhich of the following factors that affect image quality could be impacted by collimation?scatterUse of grids improves __image contrastReduction of patient dose, while maintaining image quality, best describes:dose optimizationto improve a noisy image, an increase in exposure by:4X results in noise reduction by a factor of 2The ICRP principle of optimization involves utilizing _________ to keep radiation dose as low as possible and use of the three __________ . Select two answers below that will accurately fill in the blanks and complete the sentence above.ALARA Cardinal PrinciplesMore sensitive IR detectors require:less exposureOf the following statements, select the ones that are true.kV affects penetration of the x ray beam. Higher kV must be used to penetrate thicker anatomical parts. Digital processing primarily controls contrast. Appropriate kV must be used to ensure an adequate amount of signal (radiation) reaches the IR.Which of the following may NOT potentially occur if the AEC detector is not positioned accurately over the anatomical structure of interest?the anatomy may be clipped due to collimationThe overall goal of dose optimization is to produce an optimum image, while minimizing __________ effects and preventing __________ effects.stochastic / deterministicmatch the description with the appropriate associated response-"low kV technique" or "high kV technique" does not penetrate tissue as well more mAs deposited in tissue higher dose less mAs deposited in tissue lower doselow kV technique low kV technique low kV technique high kV technique high kV techniqueWhich of the following statements regarding the exposure indicator (EI) is NOT accurate. It provides a mechanism for dose optimization.The EI should be used to calculate doseMatch the following types of quality assessment with the appropriate method of assessment: Objective Physical Measures Observer Performance Methodsobjective subjectiveIf the exposure field and the light field are not congruent, which of the following could result?anatomy could be clipped, requiring a repeat exposure