Block 1-3 Review

Question 1

Answer 1

Know how to label

Question 2

What is a PM Tube

Answer 2

A light sensitive device which converts light into measurable electronic pulses.

Question 3

What does a dynode do?

Answer 3

It helps produce secondary electrons

Question 4

What does the anode do?

Answer 4

Collects the electron pulse from the last dynode

Question 5

The intensity of scintillating on the NaI crystal is proportional to:

Answer 5

The amount of energy deposited by ionized electrons

Question 6

What is the makeup of the reflective coating of the crystal

Answer 6

Titanium or magnesium

Question 7

Why is the crystal hermetically sealed

Answer 7

Moisture

Question 8

The strength/brightness of the scintillation in the NaI crystal is due to

Answer 8

The number of free electrons created by the incident photon

Question 9

The PM Tube is magnetically shielded to prevent

Answer 9

Influence from outside electrical noise

Question 10

A change in temperature no more than _____ can crack the NaI crystal.

Answer 10

10°/hour

Question 11

The photo peak of the spectrum is comprised mostly of this type of atokic interaction where all of the energy of the incident photon…

Answer 11

Photoelectric effect

Question 12

The electron multiplication factor depends on

Answer 12

Energy of photoelectron

Question 13

Which is NOT an advantage of the naI crystal

Answer 13

Can easily detect beta radiation

Question 14

The percent of light created in NaI crystals that reaches the photocathode

Answer 14

15%

Question 15

Coincidence loss is more likely to occur when

Answer 15

Pulses arrive too close together

Question 16

Pulse height represents

Answer 16

Energy of the pulse in KeV

Question 17

When working on the efficiency of a camera the activity used to determine the efficiency must be converted to DPM by multiplying

Answer 17

2.22 x 10^6 DPM/uCi

Question 18

Process in which a photon deposits all of its energy when colliding with an orbital electron

Answer 18

Photoelectric effect

Question 19

Am electrons ____ energy must be overcome before it can be ejected from its orbital shell

Answer 19

Binding

Question 20

Know how to label photo peak. Where is it on a graph?

Answer 20

The topmost point of the curve

Question 21

One current (ci) equal?

Answer 21

3.7 x 10^4 DPS

Question 22

Difference between x-rays and gamma rays

Answer 22

Their origins

Question 23

Formula for detector efficiency

Answer 23

Efficiency = CPM/DPM

Question 24

To ensure highest energy detection efficiency during imaging with a NaI crystal detector system, the radionuclide used should be between

Answer 24

0.100 & 0.500 MeV

Question 25

What are the two different types of efficiency that must be considered when designing/choosing a scintillation detector

Answer 25

Geometric and Intrinsic

Question 26

The concept of the signal leaving the pre-amplifier and that same signal leaving the amplifier is known as

Answer 26

Linear fashion

Question 27

What does this graph show

Answer 27

Baseline shift

Question 28

What does this graph show

Answer 28

Pulse pileup

Question 29

The signal received by the pre-amplifier is measured in

Answer 29

Milivolts

Question 30

The pre-amplifier is close to the PM. Tube in order to

Answer 30

Maximize the signal to noise ratio

Question 31

Because of the pulse shaping by the amplifier the detectors counting efficiency is increased by a factor of

Answer 31

6

Question 32

Geometric efficiency of camera when imaging whole body bone scans

Answer 32

50%

Question 33

Term that described a detectors ability to absorb incident radiation and convert that energy into a potentially....

Answer 33

Intrinsic efficiency

Question 34

Solid detector components in order beginning with part that would collect photons from patient

Answer 34

1. Crystal 2. Photocathode 3. Dynode 4. Anode 5. Preamp 6. Amplifier 7. Pulse height analyzer

Question 35

137- Cs is a good calibration source for radionuclide counting equipment because

Answer 35

It has one distinct photo peak and higher energy photo peaks have better resolution

Question 36

The window used for acquiring nuclear medicine images is usually _____ than the window used for HV calibration

Answer 36

Wider

Question 37

Energy resolution value for 137-Cs on a solid detector system

Answer 37

8-12% 10% on quiz

Question 38

Energy resolution got a gamma camera

Answer 38

10%

Question 39

Type of counting that only uses one discriminator and counts above the discriminator setting

Answer 39

Integral

Question 40

Allows detector to count more than one window at a time

Answer 40

Multi channel analyzer

Question 41

Know the room Calc formula

Answer 41

Question 42

Xe room Calc w0 ft 25 ft 12 ft

Answer 42

1.53 x 10^7 ml/min

Question 43

When should the air concentration and room ventilation rate calculations be done

Answer 43

Semi-annually

Question 44

Exhaust flow rate for scan room 872

Answer 44

Department should change to aerosol studies

Question 45

If exhaust is less than supple

Answer 45

Change to aerosol studies

Question 46

Limist for maximum airborne concentrations of radioactive aerosols established by

Answer 46

Nuclear Regulatory Comission

Question 47

Value of A when solving spilled gas clearance time equation

Answer 47

Highest activity in a single container in uCi

Question 48

Maximum permissible derived air concentration DAC for a restricted room where Xe is used

Answer 48

1.0 x 10^-4 uCi/ml

Question 49

Xenon uses what type of system

Answer 49

Delivery/ trap system

Question 50

Xenon collection system checks performed

Answer 50

Monthly

Question 51

According to the procedure for monitoring or checking... a test in which 59 cpm bag and 25 cpm background ...

Answer 51

Xe trap should be replaced

Question 52

Xe trap component that prevents Co2 from returning to patient

Answer 52

Soda lime

Question 53

Independent window with a LL setting of 180 & a window setting of 40 KeV. Equivalent UL setting?

Answer 53

220

Question 54

Energy resolution if our FWHM was 20 KeV and we're using Tc99m

Answer 54

14.28%

Question 55

On a counting device configured with independent windows, if the LL is on 450 and a 30Ke: window is desired what would the UL be set on

Answer 55

490

Question 56

If a room has a supply of 525 CFM and a exhaust of 400 CFM then the room would have a positive or negative pressure by how much?

Answer 56

125 CFM positive

Question 57

If a 20% window centered around the 159- Kev I-123 peak is desired what would the LLP and ULD settings be

Answer 57

143 KeV - 175 KeV

Question 58

Know % energy resolution formula

Answer 58

Question 59

The _____ the bell curve of the energy spectrum the better the energy resolution

Answer 59

Narrower

Question 60

What is the FWHM

Answer 60

20 KeV

Question 61

What is the % energy resolution

Answer 61

14%

Question 62

What effect does increasing the width of the window have on resolution and count rate

Answer 62

When resolution decreases count rate increases

Question 63

Changing calibration settings

Answer 63

The count rate decreases since the photopeak will be shifted to the left

Question 64

Calibration of HV on scintillation detectors is performed

Answer 64

Daily

Question 65

An anti coincidence circuit will ____ a pulse if it receives a pulse from LLD and ULD

Answer 65

Reject

Question 66

Collimator for liver spleen LFOV camera

Answer 66

LEAP

Question 67

SFOV camera biliary scan collimator

Answer 67

Diverging

Question 68

When is spatial resolution performed

Answer 68

Weekly

Question 69

What is used for an intrinsic uniformity test

Answer 69

A Tc99m point source

Question 70

Disadvantage of a Liquid source

Answer 70

Less convenient

Question 71

What DOESNT affect intrinsic resolution

Answer 71

Geometry of collimator holes

Question 72

What collimator will not distort image

Answer 72

GAP

Question 73

Diameter of hole _____ sensitivity of collimator

Answer 73

Increases

Question 74

Best collimator construction

Answer 74

Increase Hole length DECREASE hole diameter

Question 75

Septal penetration is...

Answer 75

Reduced by thickening the septa

Question 76

Variables not utilized in calculation of collimator septa thickness

Answer 76

Thickness of crystal

Question 77

Pin hole collimator: the closer the object is to the pinhole

Answer 77

The larger the image, smaller FOV

Question 78

What is the collimator septa

Answer 78

The region between the holes

Question 79

What is NOT considered when designing/choosing collimator

Answer 79

Activity of source

Question 80

SFOV camera diverging collimator organ scan

Answer 80

Lungs

Question 81

Pin hole collimator: 33 cm 54 diameter

Answer 81

FOV: 12.67

Question 82

Detector 11in 3cm thickness

Answer 82

38.32 cm

Question 83

Extrinsic flood source

Answer 83

Co 58 sheet source

Question 84

When do you do uniformity floods

Answer 84

Daily before patients

Question 85

Pin hole collimator: 30 cm object 5cm

Answer 85

6.0 x magnified

Question 86

Detector 11 in 5 cm thick

Answer 86

39.9 cm

Question 87

Answer 87

Multi Window Registration Error

Question 88

Answer 88

Edgepacking and crystal hydration

Question 89

Answer 89

PM Tube out

Question 90

Answer 90

Contamination

Question 91

Answer 91

Gain shift

Question 92

Answer 92

Cracked crystal

Question 93

Answer 93

PHA set offpeal

Question 94

Answer 94

Hine dully Ples Four quadrant Orthogonal UB

Question 95

Answer 95

Improper mixing

Question 96

Answer 96

Moire artifact

Question 97

Answer 97

Air bubbles

Question 98

What happens to the image when we use continuous acquisition and step and shoot

Answer 98

Continuous causes blurring and step and shoot increases acquisition time