physics 2nd sem. 25/30 Flashcards

1
Q

storing images for reference

A

image archiving

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2
Q

image analysis includes:

A

traditional image quality factors such as:

density/image receptor exposure

contrast

recorded detail

distortion

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3
Q

when some factors act upon each other and cause issues

A

the pyramid problem

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4
Q

what are the 5 factors that can determine whether or not an image is acceptable

A

tech factor selection

subject density

contrast

pathology

film processing

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5
Q

what are the 4 major steps to the diagnostic problem-solving strategy

A

narrow the field by finding any suspicious areas

use info found to form a hypothesis

information seeking-test hypothesis

evaluate hypothesis…. solution??

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6
Q

important facts about ACCEPTANCE LIMIT CURVES

A

overexposure Errors are more acceptable than under because they can be corrected more easily via adding brightness or extracting info digitally

narrow limit = ⬆️ repeat rate

acceptance limits can vary by radiologists

wide limits make us careless

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7
Q

why can’t DIAGNOSTIC IMAGE Quality be defined?

A

too many variables

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8
Q

what is the primary purpose of an image?

A

to provide information about a medical condition

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9
Q

what are the three steps to the image critique method?

A

classify the image - is it within dx acceptance limits?

determine cause of the problem- if not acceptable determine if it is because tech factors, procedure, equipment

recommend Corrective action

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10
Q

if the image critique determines the cause is a technical factor problem …..what does this mean?

A

either you can’t see detail ( 1 ) or there is not enough detail ( geometric- definition, sharpness, resolution)

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11
Q

geometric problems are further classified as ….

A

recorded detail or distortion

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12
Q

problems with recorded detail are caused by:

A

focal spot size, SID, OID, IR used and pt motion

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13
Q

problems with distortion are categorized as

A

size ( Sid. OID) or shape distortion ( improper tube/part/IR alignment

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14
Q

image acquisition is _________ to each imaging modality.

A

unique

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15
Q

if the problem is a procedural factor it is caused by….

A

pt positioning or preparation

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16
Q

if the problem is determined to be an equipment malfunction it is caused by …..

A

quality control

17
Q

incomplete plate erasure in the CR system or extreme over exposure can cause

A

phantom or ghost images

18
Q

dust or material on an IR can cause …

A

light spots

19
Q

what causes a white line along the length of travel on the image?

A

dust

20
Q

reductions in resolution overall or in a specific area which tend to be accompanied by contrast scale reductions are called…

A

dropout artifacts

21
Q

what causes drop out artifacts?

A

A build up of dust in the CR or laser unit on the light gate, mirror or reflective surface

22
Q

what causes fogging in the digital system

A

background radiation due to sensitivity

23
Q

what is another word for quantum mottle?

A

reticulation

24
Q

when the manufacturer sets up a system they have certain settings to avoid these

A

algorithm artifacts

25
Q

uneven scanning or transfer of film through and imaging system can cause…

A

laser film transport artifact

26
Q

improper collimation , improper technique, beam alignment, scatter and extreme density differences can cause this

A

histogram analysis

27
Q

what causes nonparallel collimation ?

A

when edges are not parallel to the sides of the imaging plate

28
Q

poor grid alignment can cause these two things to occur

A

grid lines or poor image quality