Module 5 Flashcards

1
Q

BD takes advantage of X-ray energy and body composition process by using a blank technique

A

Subtraction

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2
Q

What type of equipment used a water bath to emulate soft tissue during scanning

A

Absorptiometry scanners

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3
Q

How is the value of bmd calculated

A

Determining the BMC and dividing it by the area of bone that was scanned

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4
Q

Refers to the binding energy of the K shell electron which varies for different materials

A

K edge

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5
Q

What type of filter does the GE system use

A

CERIUM

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6
Q

What type of filter does a Norland system use

A

Samarium

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7
Q

What type of energy does hologic use

A

A patent energy switch in system to generate beams with the 2 distinct photo electric pics

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8
Q

Where is the detector

A

The scanner arm that passes over the patient

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9
Q

What are 3 common physics problems that occur with DXA

A

Beam hardening, scintillating detector pillup, and cross over

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10
Q

This problem is from increased absorption shifts the distribution of photons towards high energy x-rays

A

Is beam hardening

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11
Q

This affects K edge filtration systems because they pulse counting detector can only process one photo at a time, if it’s not processed quickly enough and incoming photon can be missed

A

Scintillating detector pile up

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12
Q

This problem occurs because high energy photons can sometimes lose energy when passing through the body and be counted as low energy photons by the detector

A

Crossover

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13
Q

Travels back-and-forth in a rectilnear pattern across the scan area

A

Pencil beam

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14
Q

This scanner has a slit shaped colometer and a multi element detector the scanning motion only moves along one access

A

Is fan beam or fan array

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15
Q

What is a Disadvantage of fan beam technology

A

It can magnify and distort the outer edges of the scan area

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16
Q

This is a process by which the lateral projections of the spine are analyzed and measured, Answer is not VFA

A

Morphometric Absorptiometry

17
Q

The ability of a test to measure the correct value of the thing it’s measuring

18
Q

The likelihood a test can achieve the same result when It is repeated on the same subject and under the same conditions

19
Q

How is the operator’s precision assist through in vivo

A

Scan of 15 patients 3 times or 30 patients 2 times

20
Q

This error is expressed mathematically as a standard deviation with the most common results falling in the middle of a range and the less frequent results to the edge

A

Random error

21
Q

A wide standard deviation indicates

A

Low precision

22
Q

This measures how closely the results of the test match an external reference value

23
Q

What are the 2 factors of in vivo studies

A

The variability of a patient’s anatomy and the skill and attentiveness of the technologist

24
Q

LSC

A

Least significant change is the minimum change in a patient’s measured bone density that reflects a real change in the patient rather than an error by the technologist or scanner

25
The minimum accuracy for the lumbar spine is ____ part technologist with an associated LSC of _____
1.9% and 5.3%
26
The minimum Accuracy for a scan of a total hip is ______ with a LSC of ______
1.8% and 5%
27
The minimum accuracy for a scan of the femoral neck is _____ with an LSC of _____
2.5% and 6.9%
28
What are the 4 speeds of the hologic system
Fast array 30 seconds array 60 seconds high definition a 120 seconds Turbo 10 seconds
29
What modes do GE And Norland have
Thick standard thin and quick view modes
30
Slow shifts in blank are a much greater concern because they can affect many patient scans before being noticed
Accuracy
31
DEXA uses a blank technique that eliminates soft tissue from the scan results
Subtraction
32
K edge filter crossover occurs when high energy photons lose energy passing through the body and are
Registered as photons from the low energy beam
33
What value measures how closely the results of the test match an external reference value
Truness
34
What type of patient is most appropriate for precision testing
One that represents the facility's population
35
DXA equipment calibration effects which values
Precision and truness