Critique review PET/CT

True or false: do positrons have short half lives

true

how can you tell the difference between a malignant and benign single pulmonary nodule

malignant will have more uptake on a F-18 FDG scan

what is the half live of C11

20 min

what is the half live of N13

9 min

what is the half live of O15

2.1 min

what is the half live of F18

110 min

what is the half live of Rb82

75 sec

what is the half live of Ga 68

68 min

what is the half live of Cu-64

12 hours

Numerous malignant tumors have an affinity for what

glucose

What happens to F-18 FDG when it is trapped in a cell

dose not re-cross the cell membrane = no redistribution

what is the name of F-18 FDG

Flurodeoxyglucose

FDG is tagged to what

F-18

what is the half life of F-18

109 minutes

F-18 emits what

two 511keV 180 degrees apart

what happens to F-18 when it decays

emits positron that annihilate and release photon energy

what is a true coincidence

simultaneous detection of two emissions resulting form a single decay event

what is scatter coincidence

one or both photons from a dingle event are scattered and both are detected

what is random coincidence

simultaneous detection of emission from more than one decay event

what is 2d acquisition mode for PET

with septa (collimated)

Still a 3D image

what is 3D acquisition

no septa (non-collimated)

what doee no septa lead to

increase in sensitivity and photons from a larger number of incident angles are accepted

what do newer PET scanner have

septa can be retracted and placed in the detector in 3D mode

What is the patient prep

NPO 4 hours

What is involved in the patient interview

identify the patient

patient height/weight

NPO 4 hours

Diabetic status

measure glucose

allergies if using CT contrast

What is the glucose range for PET/CT

< 160 > assess continuing

what is the adult dose for FDG

5-20mCi

most institution give 10mCi or 12mCi

what is the pediatric dose range

0.1-0.14mCi/kg

when is imaging performed for FDG after injection

60-90 minutes

True or false: FDG dose can be weight based

true

what is the patient procedure for FDG

patient voids

imaging starts 60-90 minutes after injection

select appropriate PET/CT procedure

place patient on imaging pallet/table

scout CT (FOV)

non diagnostic CT decrease dose ( transmission scan and attenuation values

PET scan (emission scan)

analyze study

where are we scanning from for a whole-body PET scan

base of brain to pelvis (mid thigh)

90cm scan length

what is scanned first for a whole-body PET scan

pelvis to head

how many bed positions are there for a whole-body scan

5-7 bed positions

how long dose a whole body scan take

30-1hour

what are we scanning form for a total body PET

head to legs

how long does a total body PET scan take

30mins-1 hour

what is the indication for a total body PET scan

malignant melanomas

how many bed positions are there for a total body PET

10

what should be done if there is cancer in the pelvis

catheterize to reduce bladder activity and saline flushes

what can be used to promote FDG excretion for patients that have cancer in the pelvis

diuretic

what is normal distribution of FDG (most common and constant sites of intense uptake)

brain

liver (moderate)

Kidneys (calyces and pelvis)

bladder

what is variable activity of normal distribution of FDG

salivary glands

thyroid

heart and vessels

spleen

stomach

bowel

bone marrow

muscles

testicles

muscle uptake can result from

exercise or weight lifting the day before a PET exam

how can muscle uptake be avoid

patient should be instructed to refrain form strenuous activity the day before the scan

how many scans must a radiologists have under their belt in order to become familiar with normal variations for FDG

100

CT-PET-fused

is the normal PET/CT scan

yes

what view is the left image

transverse

what view is the middle image

sagittal

what view is the right image

coronal

what is CT used for in a PET scan

anatomy overlay and attenuation correction

is the top row attenuation corrected (AC) or nonattenuation corrected (NAC)

attenuation corrected (AC)

is the bottom row attenuation corrected AC or nonattenuation corrected NAC

nonattenuation corrected

what does this image show

melanoma (diffuse) whole body

what does this image show

melanoma (scale area)

what does this image show

malignant single pulmonary nodule

what does this image show

benign single pulmonary nodule

what are standard uptake values used for

measure tumor metabolic function

uptake on a scan (ROI) can be converted to what for a SUV

number or ratio

what are the parameter needed for a SUV

dose injected

imaging time post injection

absolute activity calibration QC

reconstruction algorithms used

what does this image show if the chest x-ray demonstrated a nodule in the right lung

increased metabolic activity indicative of malignancy

single pulmonary nodule (SPN)

what are the two different lymphoma

Hodgkin’s (HL) and non-Hodgkin’s lymphomas (NHL

how can PET be used for lymphoma

staging of the disease

how are pre and post therapy scan helpful for lymphoma

evaluating response to therapy

the image on the left is pre or post therapy for lymphoma

pre therapy

the image on the right is pre or post therapy for lymphoma

post therapy

colon cancer can lead to what

bowel cancer

multiple metastatic sites for colon cancer suggest what

widespread disease

where can colon cancer spread to

liver and lung

this image shows what

colon cancer

this image shows pre and post breast cancer monitoring (pre and post chemotherapy)

the image on the left is initial, 3 months or 5 months

initial

this image shows pre and post breast cancer monitoring (pre and post chemotherapy)

the image in the middle is initial, 3 months or 5 months

3 months

this image shows pre and post breast cancer monitoring (pre and post chemotherapy)

the image on the right is initial, 3 months or 5 months

5 months

ovarian cancer with extensive METS to where

peritoneal cavity

what does this image show

ovarian cancer

CT left and PET right

this scan shows what

abnormal distribution in the right lung = lung cancer

what is the protocol for a brain scan with FDG

interview the patient

take glucose

place IV

make patient comfortable, dim the lights, allow them to rest with eyes closed

no talking/music

after 10 minutes inject

scan 30 minutes after injection

scan takes 10 min

for a brain FGD how long after injection does imaging begin

30 minutes

how long does a FDG brain scan take

10 min

this image is an example of 

F-18 FDG brain

what view is this image

transverse or axial

top to bottom

what view is this image

coronal

front to back

what view is this image

sagittal side to side

this image is an example of axial PET, CT or fused

axial PET

this image is an example of axial PET, CT or fused

CT axial

this image is an example of axial PET, CT or fused

axial fused

what view of the brain is this

coronal

what view of the brain is this

sagittal

what is the part of the brain called where the seizure starts

seizure focus

what is it called during or immediately a seizure

ictal

True or false: blood flow is increased to the seizure focus during a seizure

true

when the focus area is not causing a seizure is called

hypometabolic

when the focus area is hypometabolic that means

decreased blood flow and uses less glucose

when focus returns to the hypometabolic/hypoperfusion state it is called 

interictal

what is the organ of this image

brain

what is view of this image

transaxial (transverse) slice

what are the results of the scan

brain metastases

what are some symptoms Alzheimer disease

cognitive impairment

speech problems

confusion

aggression

impaired muscle coordination

what can plaques and tangles cause

neuron degeneration

what causes Alzheimer disease

build up of amyloid plaques in the brain and neurofibrillary tangles