PET/CT EXAM WITH CORRECT
QUESTIONS AND ANSWERS 100%
CORRECT
4 things you need to know before getting started - ANSWER-1. Correct patient with 2
identifiers
2. Medical History
3.Protocol Ordered
4.Reason for the exam
What are the 4 main components of a PET/CT scan? - ANSWER-1. FDG amount
2. Injection site
3. Uptake period
4. Imaging protocol
The amount needed for optimal images mostly depends on the type of __________
________ in the scanner. - ANSWER-detector material
3 Options based on PATIENT SIZE (FDG Amount) - ANSWER-1. Same dose, vary
imaging time
2. Dose ranges based on patient weight
3. Calculate dose for each patient
FDG is injected... - ANSWER-Intravenously (IV) or Port (20+ mL flush)
Choice of injection site depends on... (3 things) - ANSWER-1. Quality of patient's veins
2. Indication of the scan
3. Central line or Port
3 things to consider during uptake period - ANSWER-1. Patient should be resting
2. Patient should be warm
3. Little to no talking or movement
higher energy photons are needed to penetrate large bones therefore higher
_________ setting is required - ANSWER-kVp
kVp setting defines - ANSWER-the fraction of photons that will successfully reach the
detectors of the scanner, because higher energy photons are less attenuated by the
body
As energy of photons increase (3) - ANSWER-1. more photons reach the detectors
,2. less noise in the image
3. radiation exposure to the patient increases
3 Advantages to using a higher kVp - ANSWER-1.greater penetration through the body
2. decrease in noise
3. reduction in beam hardening artifacts
2 Disadvantages of using a higher kVp - ANSWER-1. higher dose to patient
2. reduction in tissue density difference
Considerations for uptake time period (3) - ANSWER-1. 2hr half life (therefore the
longer the delay before imaging, the fewer the counts in the images or longer scan time)
2. FDG uptake in tumors rises over time
3. The longer the delay, the higher the target-to-background ratio
(45-60 min uptake period)
Imaging protocol is chosen on the___________ __________. - ANSWER-clinical
question
skull- base to mid thigh imaging protocol is used for - ANSWER-most typical for cancer
imaging
head to toe imaging protocol is used for - ANSWER-melanoma, multiple myeloma
brain imaging is used for - ANSWER-recurrent brain tumors, seizure focus, dementia
Why are brain mets difficult to see? - ANSWER-high level of glucose metabolism
(needle in a haystack)
head and neck imaging protocol is used for - ANSWER-usually performed magnified,
longer duration image of head and neck along with scan through body to mid-thigh
arms up or down imaging protocol - ANSWER-depends on area(s) of interest and
patient ability
The CT must line up with the PET image for the image to _________ and for the
____________________ _________________ of the PET images. - ANSWER-fusion
attenuation correction
The CT portion time span - ANSWER-20-60 seconds
PET portion of exam is done using what method? - ANSWER-step and shoot (moving
every 2-3 minutes)
2 Reasons CT is important! - ANSWER-1. Fusion
, 2. Attenuation Correction
CT Basics: Define X-ray Tube - ANSWER-evacuated container comprised of the anode
and cathode in which x-rays are produced and surrounded by the tube housing, which
provided electrical safety and radiation protection from leakage x-rays
CT basics: Define Anode - ANSWER-The Target--> the positively charged electrode
that attracts free electrons to subsequently produce x-rays; fixed anodes and rotating
disk designs are common
CT Basics: Define Cathode - ANSWER-The Source--> the negatively charged
electrode, typically comprised of a filament, that produces free electrons
kVp (kilovolt peak) - ANSWER-the peak voltage that is applied between the cathode
and anode
mA (milliampere) - ANSWER-the unit of electric current that describes the flow of
charge per second
pitch - ANSWER-the ratio of table movement per resolution over the collimated slice
thickness of one row of a multislice CT detector (spiral). Also known as the table
movement through the scanner
Other Risk Factors to Consider - ANSWER-anxiety, multiple myeloma, sickle cell
anemia, thyroid cancer/condition
Premeditation for Allergic and At-Risk Patients - ANSWER-Corticosteroid and Benadryl
When injecting IV contrast, what is an important precaution to take? - ANSWER-Ensure
that the vein or port can withstand the flow rate required.
2 Possible Problems with Contrast Injection - ANSWER-Extravastion and Air Embolism
Mild Reactions - ANSWER-Signs and symptoms are self-limited without evidence of
progression
Moderate Reactions - ANSWER-Signs and symptoms are more pronounced and
commonly require medical management. Some of these reactions have the potential to
become severe if not treated
voltage and current - ANSWER-the 2 primary settings that can be adjusted in the x-ray
tube
mAs - ANSWER-current per second
Energy variation for PET/CT - ANSWER-80-140kVp
QUESTIONS AND ANSWERS 100%
CORRECT
4 things you need to know before getting started - ANSWER-1. Correct patient with 2
identifiers
2. Medical History
3.Protocol Ordered
4.Reason for the exam
What are the 4 main components of a PET/CT scan? - ANSWER-1. FDG amount
2. Injection site
3. Uptake period
4. Imaging protocol
The amount needed for optimal images mostly depends on the type of __________
________ in the scanner. - ANSWER-detector material
3 Options based on PATIENT SIZE (FDG Amount) - ANSWER-1. Same dose, vary
imaging time
2. Dose ranges based on patient weight
3. Calculate dose for each patient
FDG is injected... - ANSWER-Intravenously (IV) or Port (20+ mL flush)
Choice of injection site depends on... (3 things) - ANSWER-1. Quality of patient's veins
2. Indication of the scan
3. Central line or Port
3 things to consider during uptake period - ANSWER-1. Patient should be resting
2. Patient should be warm
3. Little to no talking or movement
higher energy photons are needed to penetrate large bones therefore higher
_________ setting is required - ANSWER-kVp
kVp setting defines - ANSWER-the fraction of photons that will successfully reach the
detectors of the scanner, because higher energy photons are less attenuated by the
body
As energy of photons increase (3) - ANSWER-1. more photons reach the detectors
,2. less noise in the image
3. radiation exposure to the patient increases
3 Advantages to using a higher kVp - ANSWER-1.greater penetration through the body
2. decrease in noise
3. reduction in beam hardening artifacts
2 Disadvantages of using a higher kVp - ANSWER-1. higher dose to patient
2. reduction in tissue density difference
Considerations for uptake time period (3) - ANSWER-1. 2hr half life (therefore the
longer the delay before imaging, the fewer the counts in the images or longer scan time)
2. FDG uptake in tumors rises over time
3. The longer the delay, the higher the target-to-background ratio
(45-60 min uptake period)
Imaging protocol is chosen on the___________ __________. - ANSWER-clinical
question
skull- base to mid thigh imaging protocol is used for - ANSWER-most typical for cancer
imaging
head to toe imaging protocol is used for - ANSWER-melanoma, multiple myeloma
brain imaging is used for - ANSWER-recurrent brain tumors, seizure focus, dementia
Why are brain mets difficult to see? - ANSWER-high level of glucose metabolism
(needle in a haystack)
head and neck imaging protocol is used for - ANSWER-usually performed magnified,
longer duration image of head and neck along with scan through body to mid-thigh
arms up or down imaging protocol - ANSWER-depends on area(s) of interest and
patient ability
The CT must line up with the PET image for the image to _________ and for the
____________________ _________________ of the PET images. - ANSWER-fusion
attenuation correction
The CT portion time span - ANSWER-20-60 seconds
PET portion of exam is done using what method? - ANSWER-step and shoot (moving
every 2-3 minutes)
2 Reasons CT is important! - ANSWER-1. Fusion
, 2. Attenuation Correction
CT Basics: Define X-ray Tube - ANSWER-evacuated container comprised of the anode
and cathode in which x-rays are produced and surrounded by the tube housing, which
provided electrical safety and radiation protection from leakage x-rays
CT basics: Define Anode - ANSWER-The Target--> the positively charged electrode
that attracts free electrons to subsequently produce x-rays; fixed anodes and rotating
disk designs are common
CT Basics: Define Cathode - ANSWER-The Source--> the negatively charged
electrode, typically comprised of a filament, that produces free electrons
kVp (kilovolt peak) - ANSWER-the peak voltage that is applied between the cathode
and anode
mA (milliampere) - ANSWER-the unit of electric current that describes the flow of
charge per second
pitch - ANSWER-the ratio of table movement per resolution over the collimated slice
thickness of one row of a multislice CT detector (spiral). Also known as the table
movement through the scanner
Other Risk Factors to Consider - ANSWER-anxiety, multiple myeloma, sickle cell
anemia, thyroid cancer/condition
Premeditation for Allergic and At-Risk Patients - ANSWER-Corticosteroid and Benadryl
When injecting IV contrast, what is an important precaution to take? - ANSWER-Ensure
that the vein or port can withstand the flow rate required.
2 Possible Problems with Contrast Injection - ANSWER-Extravastion and Air Embolism
Mild Reactions - ANSWER-Signs and symptoms are self-limited without evidence of
progression
Moderate Reactions - ANSWER-Signs and symptoms are more pronounced and
commonly require medical management. Some of these reactions have the potential to
become severe if not treated
voltage and current - ANSWER-the 2 primary settings that can be adjusted in the x-ray
tube
mAs - ANSWER-current per second
Energy variation for PET/CT - ANSWER-80-140kVp
