Nukes Flashcards
Normal Gallium-67 uptake
Liver, bone, lacrimal gland, nasopharynx
Gallium-67 half life
78 hours
Gallium-67 critical organ
colon
Imaging time point for Gallium-67
24 hours
Which radiotracer causes increased breast uptake in pregnant/lactating females?
Gallium-67
Radiotracer uptake in Kaposi sarcoma
Ga-67 negative, Tl-201 positive
morphine dose
.04 mg/kg
maximum amount of Mo-99 allowed in Tc-99m
.15 microCi Mo-99 per 1 milliCi Tc-99m
typical tube voltage in chest XR
100 kV
1 Becquerel (Bq)
1 decay/s (DPS)
1 mCi
37 MBq
t 1/2 Ru-82
75 sec
t 1/2 18-F
110 min
t 1/2 Tc-99m
6 hours
4 production methods of radionuclides
- linear accelerator/cyclotron - nuclear reactor (fission) - nuclear reactor (neutron activation) - radionuclide generator
Low energy tracers
Tc-99m, I-123, Xe-133, Tl-201
High energy tracers
I-131, F-18
t 1/2 I-123
13 hr
t 1/2 Ga-68
68 min
Best to worst soft tissue contrast
MRI > CT > digital mammography > computed radiography
artifact seen in adenomyomatosis
comet tail
side lobe artifact results from
radial expansion of piezoelectric crystals
magic angle artifact appears on what kind of sequences
short TE
HVL definition
thickness of material that attenuates xray by 50%
skin entrance dose for early transient erythema
2 Gy
k-edge of Iodine
33.2 keV
transducer type affected by side lobe artifact
linear
false positive sestamibi parathyroid scan
thyroid adenoma, thyroid cancer, parathyroid cancer
photopeak of Xe-133
81 keV
t 1/2 Xe-133
5 days
In-111 t 1/2
67 hours
stripe sign
normal parenchyma interposed between pleura and perfusion defect (insert picture)
major spill > 1 mCi
I-131
major spill > 10 mCi
- Ga-67 - I-123 - In-111
major spill > 100 mCi
- Tc-99m - Tl-201
which brain radiotracers are lipophilic
- Tc99m-exametazime (HMPAO) - Tc99m-bicisate (ECD)
Tl-201 critical organ
kidney
proximal colon is critical organ for what?
- sestamibi - oral sulfur colloid
critical organ for sestamibi
proximal colon
uptake in lacrimal glands
- Gallium-67 - MIBG - free Tc (pertechnetate)
when are images obtained in Dual Phase parathyroid scan?
10 min & 3 hours
liver or splenic uptake on Tc-99m scan
alumina breakthrough
frequency of performing linearity and spatial resolution test on phantom
weekly
duration of flow phase on DTPA and Mag-3 renal scans
1 minute
NRC deep dose equivalent depth
1 cm tissue depth
reports for NRC reportable events must be kept for how long?
5 years
False low EF on MUGA
inclusion of LA counts
False high EF on MUGA
wrong ROI (over spleen)
indication for MUGA
estimation of EF during cancer therapy
what are cardiotoxic drugs
- doxorubicin (Adriamycin) - mitoxantrone (Novantrone) - cyclophosphamide
sealed source leak testing frequency
semi-annual (q 6 mo)
normal time to peak for renal cortical of DTPA and Mag-3
< 5 min
best scan for aortic graft infection
In-111 labeled WBC
best scan for IBD
In-111 labeled WBC
best scan for disciitis/osteomyelitis
Tc-99m MDP + Ga-67
best scan for sinus infection
In-111 labeled WBC
NRC dose rate limit for unrestricted area
< 2 mrem/hr
how long after administration of In-111 labeled leukocytes is lung uptake normal?
6 hours
normal uptake of In-111 labeled leukocytes
spleen, liver (spleen > liver), bone marrow
triple matched defect in lower lung zones PE probability by PIOPED
intermediate
triple matched defect in middle/upper lung zones PE probability by PIOPED
low
stop breast-feeding prior to administration of which radionuclides?
- Ga-67 - I-131
I-131 decays how?
beta emission
for gamma camera, extrinsic spatial resolution test uses what kind of source?
flood source
for gamma camera, intrinsic spatial resolution test uses what kind of source?
point source
what is the difference between gamma camera extrinsic and intrinsic spatial resolution test?
extrinsic - collimator on intrinsic - collimator off
sincalide dose
.02 MICROgm/KG over 60 min
what is ProstaScint?
monoclonal Ab to PMSA
which brain tumors can take up octreoscan?
meningioma astrocytoma medulloblastoma
what % of meckel’s diverticula have gastric mucosa?
25%
which lung cancers are not FDG avid?
- carcinoid - BAC
yellow 2 label
< 50 mrem/hr @ surface, < 1 mrem/hr @ 1 m
white 1 label
- almost no radiation < 0.5 mrem/hr @ surface
yellow 3 label
- high radiation < 200 mrem/hr @ surface, < 10 mrem/hr @ 1 m
fetal absorbed dose above which cancer risk doubles
25 mGy
what is this called and what does it measure?
gamma camera bar phantom
spatial resolution and spatial linearity
how often is uniformity checked in PET?
daily
what source is used for checking uniformity in PET?
Ge-68 or Na-22
Wolff-Chaikoff
exposure to large amt of exogenous iodine (ie contrast) –> inhibition of thyroid hormone synthesis in follicular cells (autoregulatory phenomenon)
what is it?
dose calibrator
dose calibrator constancy is checked how frequently? using what? response should vary by how much?
- daily
- Cs-137
- <5%
dose calibrator linearity is checked how frequently? using what? over how long?
- quarterly
- Tc-99m
- 72 hours
24 hour thyroid uptake in Grave’s
40-70%
method to measure chemical impurity
colorimetry
what is chemical impurity?
Al in Tc-99m MDP
what is radiochemical impurity?
free Tc in Tc-99m MDP
thin layer chromatography measures what?
radiochemical purity
what molecules circulate in Grave’s?
TSIs (thyroid-stimulating immunoglobulins)
TSIs activate which receptors?
thyrotropin
% of cold nodules that are malignant
20%
reportable event
- whole body dose > 50 mSv OR organ dose > 500 mSv
- AND-
- 20% over prescribed dose OR wrong patient OR wrong dose OR wrong route OR wrong pharmaceutical
family member allowable dose after I-131 tx
5 mSv
registration error between PET and CT
1 mm
patient may be released without futher monitoring if less than how much I-131 was administered?
< 33 MILLICi
after > 33 mCi I-131 tx, radiation dose cannot exceed how much?
.07 mSv per hour @ 1 m from patient’s chest
White I
< 0.5 mrem/hr @ surface
Yellow II
< 50 mrem/hr @ surface
< 1 mrem/hr @ 1 m
Yellow III
< 200 mrem/hr @ surface
< 10 mrem/hr @ 1 m
ionization chamber exposure range
0.1 R/hr - 100 R/hr
normal %RAIU of I-131 at 4-6 hr
5-15%
normal %RAIU of I-131 at 24 hr
10-30 %
radioactive waste with t 1/2 less than how much may be disposed via decay-in-storage?
120 days
how frequently are wipe tests performed?
weekly
PET/CT effective radiation dose
15 mSv
energy window (%) used in gamma camera imaging
20%
how long to delay breast feeding after Ga-67
4 weeks
DaT scan radiopharmaceutifcal
I-123 Ioflupane
size range of MAA particle
10-90 microns
Tl-201 t 1/2
73 hours
transient ischemic dilation (TID) meaning and significance
- increased LV volume on stress compared to rest
- multivessel hemodynamically signficant stenosis
Sr-89 t 1/2
50.5 days (14 days in bone)
Sa-153 t 1/2
46 hours
Ra-223 t 1/2
11 days
Y-90 t 1/2
64 hours
most sensitive method of epileptogenic focus localization
ictal perfusion SPECT
I-131 dose requiring a WRITTEN DIRECTIVE
> 30 MICROCi
I-131 dose requiring education on radiation safety prior to release
> 7 MILLICi
I-131 dose requiring EARLY RELEASE CALCULATIONS prior to release
> 33 MILLICI
how far distal to mass should wire be in breast pre-op localization?
1 cm
ambient lighting
25 - 50 lux
minimal luminance for NONmammo display
350 cd/m2
minimal luminance for mammo display
420 cd/m2
time points for Tl-201 imaging
immediate and 24 hours
time points for In-111-DTPA-pentetreotide (Octreoscan)
4 and 24 hours
how long to stop breastfeeding after I-123
2 days
18 hour fast prior to cardiac PET/CT performed for dx of what?
sarcoidosis
size of filtered Tc sulfur colloid particles used in lymphoscintigraphy
100 - 220 nm
by what time should see flow over cerebral convexities on In-111 DTPA NPH study?
12 hours
radiopharmaceutical used for NPH eval
In-111 DTPA
radiopharmaceuticals used for shunt patency
In-111 DTPA
Tc-99m DTPA
normal % gastric retention @ 1 hour
< 90% AND > 30%
normal % gastric retention @ 2 hours
< 60 %
normal % gastric retention @ 4 hours
< 10 %
normal particle number for Tc-99m MAA
200-500 k
Tc-99m particle number for peds
50-150 k
combined Ga-67 + MDP scan: Ga < MDP In bone
NEGATIVE for osteo
combined Ga-67 + MDP scan: Ga > MDP In bone
POSITIVE for osteo
combined Ga-67 + MDP scan: Ga = MDP In bone
equivocal for osteo
how many counts should be in MUGA scan?
2-7 million
dx
cause
- mucosal diaphragm disease (strictures)
- chronic NSAID use
resolution of FDG-PET
4-5 mm
free Tc-99m
Ga-67
I-123 MIBG
I-131 pre and post treatment - this is thyroid stunning
