Nuc Med Flashcards
What is I-123 MIBG scan used for?
to find/confirm presence of neuroendocrine tumor (pheochromocytoma, neuroblastoma, paraganglioma)
What is patient pre-treated with prior to I-123 MIBG scan? Why?
saturated solution of potassium iodide (SSKI, Lugol’s)
decrease thyroid uptake of I-123
What is pre-treatment for Meckel diverticulum scintigraphy? Why?
Cimetidine (histamine H2 blocker) –> inhibit acid secretion by parietal cells
limit release of pertechnetate by gastric mucosal cells
What radiopharmaceutical is used to assess glomerular filtration?
Tc-99m DPTA
What radiopharmaceutical is used to assess effective renal plasma flow?
Tc-99m MAG3
What radiopharmaceutical is used to assess renal cortical integrity?
Tc-99m DMSA
What is renal cortical imaging test used for?
differentiate: renal scar vs pyelonephritis
What is Ga-68 DOTATATE imaging used for?
detects somatostatin receptors –> find neuroendocrine tumors
What is the normal biodistribution of Ga-68 DOTATATE?
- high spleen
- medium liver
- renal excretion
What radiopharmaceutical is a lipophilic brain perfusion agent used for planar and SPECT brain scintigraphy?
Tc-99m HMPAO
Tc-99m heat-damaged red blood cells –> used for what?
ID spleen tissue
What is Rb-82 used for?
myocardial perfusion imaging
What is the mechanism of Rb-82 localization to myocytes?
Na+/K+/ATPase pump incorporates Rb-82 into myocardium
What type of radiation is detected by PET scan?
positron –> 2 photons detected in coincidence
instant thin layer chromatography is used to test what parameter of radiopharmaceutical quality assurance?
radiochemical purity
MIBG scan –> positive in what conditions? (6)
- neuroblastoma
- carcinoid tumor
- paraganglioma –> pheochromocytoma
- medullary thyroid carcinoma
- ganglioneuroma
- ganglioneuroblastoma
MIBG scan –> what pharmaceutical? what radioisotope?
- MIBG (norepinephrine analog)
- Iodine-123 or I-131
what is required prior to 90Y ibritumomab tiuxetan (Zevalin) radioimmunotherapy? why?
pretreatment infusion with unlabeled monoclonal Ab (rituximab) –> bind extra-tumoral binding sites ie. circulating lymphocytes –> zevalin –> higher % of binding to tumor
If hallway gets contaminated with radioactivity –> ok to remove cordon around the area –> below what level of radioactivity?
2x background
bone scintigraphy –> what are the 3 phases? what does each phase demonstrate?
1) flow phase: demonstrates perfusion
2) blood pool: demonstrates blood pool (balance bw plasma & interstitium)
3) delayed: degree of uptake depends on blood flow and rate of new bone formation
heterotopic ossification –> mature –> bone scan findings
- normal flow
- normal blood pool
- normal uptake on delayed
thallium-201 –> used for what study?
myocardial perfusion imaging
what is the critical organ for myocardial perfusion imaging using Tl-201 chloride?
kidneys
what is I-131 used for?
thyroid ablation s/p post-thyroidectomy for thyroid cancer
what is Tc-99m sestamibi used for?
- parathyroid scan
- myocardial perfusion scintigraphy
breastfeeding patient –> Tc-99m - sestamibi –> how long should stop breastfeed?
not need to stop breastfeeding
breastfeeding patient –> radiopharmaceutical –> child dose limit?
1mSv
breastfeeding patient –> 18F FDG –> how long should stop breastfeed?
12hr
breastfeeding patient –> Tc-99m MDP –> how long should stop breastfeed?
not need to stop breastfeeding
breastfeeding patient –> I-131 –> how long should stop breastfeed?
complete cessation recommended
bone scan –> what is the mechanism of uptake of MDP?
chemiabsorption
Indium-111 –> used in what kind of study?
In-111 leukocyte scinitigraphy –> localize infection/inflamm
In-111 –> half life?
67 hr
Gallium-67 –> half life?
78 hr
Iodine-123 –> half life?
13 hr
Iodine-131 –> half life?
8 days
Technetium-99m –> half life?
6 hr
Thallium-201 –> half life?
73 hr
Xenon-133 –> half life?
5 days
Gallium-67 –> used for what kind of study?
Gallium-67 scinitgraphy –> sites of inflamm –> esp spinal infection, esp discitis
V/Q scan –> perfusion scintigraphy –> focal areas of increased tracer uptake –> what does it mean?
focal areas of aggregated MAA particles d/t:
- blood in syringe during injection
- particles not properly suspended
gastric emptying pattern:
- liquid?
- solid?
liquid: exponential
solid: linear
I-123 MIBG –> what medication should be d/c prior to scan? why?
TCA –> interfere with I-123 MIBG uptake
suspect spinal osteomyelitis –> best scan?
combined Tc-99m MDP & gallium-67 citrate scans
yttrium-90 ibritumomab –> used to treat what malignancy?
non-Hodgkins lymphoma
HIDA scan –> rim sign:
- what is rim sign?
- dx?
- nonvisualization of gallbladder
- increased pericholecystic hepatic uptake
==> gangrenous cholecystitis
gastric emptying study –> what radiopharmaceutical?
Tc-99m sulfur colloid
gastric emptying study –> liquid –> used for which situtations? (2)
- feeding tube
- peds –> feeding difficulty/failure to thrive
QC –> which parameters are checked…
- daily?
- wkly?
- qtrly?
- uniformity –> daily
- linearity –> wkly
- center of rotation –> qtrly
QC for the following are checked how often?
- Geometry
- Constancy
- Linearity
- Accuracy
- Geometry –> once
- Constancy –> daily
- Linearity –> qtrly
- Accuracy –> yrly
According to the Nuclear Regulatory Commission (NRC) Agreement State Program, regulatory
authority over radioactive source material and by-products is transferred to a state via an
agreement signed by the NRC Chairman and who else?
governor of state
what is the annual whole-body total effective dose equivalent limit?
5 rem (50 mSv)
dementia with Lewy bodies –> hallmark finding of hypometabolism in what struct?
occipital lobe –> visual cortex
What is the MOST commonly cited threshold for the diagnosis of malignancy using standardized uptake value (SUV) on PET imaging for a solitary pulmonary nodule
2.5
which med is the MOST appropriate pharmacologic stress agent for patients undergoing myocardial perfusion imaging who have severe bronchospasm?
dobutamine
empiric treatment of Plummer disease (autonomously functioning thyroid nodule) or multinodular goiter –> I-131 dose?
30 mCi
bone scan –> focal decreased uptake –> bone mets of what primary cancer? (4)
“cold” mets:
- lung
- breast
- renal
- thyroid
thyroid cancer –> regional neck metastasis –> I-131 dose?
100 - 150 mCi
thyroid cancer –> lung and bone metastasis –> I-131 dose?
175-200 mCi
What is the mechanism of localization of F18 - FDG
Uptake via surface transport receptors
what is purpose of 60 minute sincalide (CCK analog) infusion during hepatobiliary imaging?
Decrease gallbladder ejection fraction variability
cardiac study –> what is maximum acceptable percent of aberrant beats permitting accurate assessment of regional wall motion and left ventricular ejection fraction?
10%
A Tc-99m sulfur colloid scan performed in a 25-year-old woman reveals an incidental round, hyperintense area of activity within the liver. What is the MOST likely etiology for this finding?
focal nodular hyperplasia
What finding on an In-111 Zevalin® scan would constitute a CONTRAINDICATION to radioimmunotherapy with Y-90 Zevalin
Lung activity greater than liver activity
stress myocardial perfusion imaging in patients with left bundle branch block –> Exercise treadmill testing –> false positive rate –> dec/same/inc?
inc
C-14 urea breath test for the detection of Helicobacter pylori (H. pylori) infection –> abx will affect the results –> T/F?
T
C-14 urea breath test for the detection of Helicobacter pylori (H. pylori) infection –> bismuth will affect the results –> T/F?
T
C-14 urea breath test for the detection of Helicobacter pylori (H. pylori) infection –> PPI will affect the results –> T/F?
T
C-14 urea breath test for the detection of Helicobacter pylori (H. pylori) infection –> antacid will affect the results –> T/F?
F
center of rotation offset error in SPECT imaging –> produce what artifact?
ring artifact
In nuclear medicine, what is the primary benefit for the use of a narrow energy window?
Reduces scatter radiation in image
