HomeStretch CRACK vol 1. NUCS Flashcards
1
Q
Bone scan - relatively hotter kidney = ?
A
hemochromatosis or chemotherapy
2
Q
Timing of “flare phenomenon”
A
aka pseudoprogression
2 weeks to 3 months (some say up to 6 months)
3
Q
Bone scan marked skull suture activity = ?
A
renal osteodystrophy
4
Q
liver uptake on bonescan = ?
A
too much Al+3 chemical contamination in the Tc
Hepatoma or mets
Amyloidosis
Liver necrosis
5
Q
Spleen uptake on a bone scan?
A
Auto-infarcted spleen in SCD
6
Q
Bone scan with muscle uptake?
A
Rhabdo
7
Q
Super hot mandible on bone scan?
A
Fibrous dysplasia
8
Q
Which one is better for spine infection, Indium WBC or Ga scan?
A
GAllIUM is better for the spinal COllUNM
9
Q
Sulfur Colloid Bone Scan & WBC imaging
A
Combined with Tc-Sulfur colloid and WBC study is poistive for infection if there is activity on the WBC scan, without corresponding Tc-sulfur colloid activity on the bone marrow image
10
Q
Cold Lesions on Bone Scan?
A
- Late radiation therapy chages/osteitis
- Early osteonecrosis (AVN)
- Infarction (very early or late)
- Anaplastic tumor (Renal, thyroid, Neuroblastoma, Myeloma)
- Artifact from prosthesis
- Hemangioma (variable)
- Bone cyst (w/o fracture)
- Mature Heterotopic Ossification
11
Q
Osteoid osteoma on boner scan
A
Focal and three phase hot
Double density or hotter spot within a hot area
12
Q
Particle size for MAA
A
MAA = 10-100 micrometers
Sulfur colloid (unfiltered) = 1 micrometer
Ultrafiltered sulfur colloid and DTPA (inhaled portion) = 0.1 micrometers
13
Q
Particle size for DTPA (inhaled)
A
MAA = 10-100 micrometers
Sulfur colloid (unfiltered) = 1 micrometer
Ultrafiltered sulfur colloid and DTPA (inhaled portion) = 0.1 micrometers
14
Q
Particle size for sulfur colloid (filtered)
A
MAA = 10-100 micrometers
Sulfur colloid (unfiltered) = 1 micrometer
Ultrafiltered sulfur colloid and DTPA (inhaled portion) = 0.1 micrometers
15
Q
Particle size for sulfor colloid (unfiltered)
A
MAA = 10-100 micrometers
Sulfur colloid (unfiltered) = 1 micrometer
Ultrafiltered sulfur colloid and DTPA (inhaled portion) = 0.1 micrometers
16
Q
When do you reduce the particle amount in a V/Q scan?
What is the normal amount of particles? what do you reduce it down to?
How about in a neonate?
Will this reduce the dose?
A
- Pregant people
- Right to left shunts
- Pulmonary HTN
- Children
- People with one lung
- Normal particle count = 500,000
- decrease it to 100,000
- down to 10,000-50,000 in a neonate
- Dose will not decrease. . .
17
Q
Gallium, Indium, Thallium
Half-lives and energies
A
- Gallium = 78 hours
- 100, 200, 300, 400
- Indium
- 67 hours
- 175 and 250
- Thallium = 73 hours
- major emissions are via characteristics xrays of its daughter product, Mercury 201
- 69 and 81 KeV
- major emissions are via characteristics xrays of its daughter product, Mercury 201
18
Q
Tc-99m in the thyroid - trapped or organified?
A
trapped and not organified
19
Q
Breastfeeding versus Tc-99m, I-123 and I-131
A
Tc-99m = 12-24 hours
I-123 = 2-3 days
I-131 = contraindicated - pump and dump!
20
Q
Does renal failure increase or decrease Iodine update
A
decrease it (since there is more circulating normal iodine)
21
Q
Iodine uptake test
What dose do you give with I-131? How about I-123?
What is normal uptake at 6 hours? How about 24 hours?
A
I-131 = 5 micro curie
I-123 = 10-20 microcurie
normal uptake is 5-15 (say 10%) at 5 hours and 25 at 24 hours
22
Q
Plummer disease
A
Multi-nodular toxic goiter
23
Q
Dose for Iodine uptake scan? The imaged when?
A
I131 = 5 microCu
123 = 10microCu
4-6 hours (normal = 15% uptake)
24 hours (normal = 30% uptake)
24
Q
I-131 dosing for hyperthyroidism and for cancer therapy
A
- hyperthyroidism
- 10 mCi for graves
- 20 mCi for autonomous hyperfunction nodule
- 30 mCi for multinodular goiter
- Cancer: depends on stage
- 100 for thyroid only
- 150 for thyroid +nodes
- 200 for distal
25
Thyroid scan that will take up Tc but NOT iodine at 24 hours?
Congenital enzyme deficiency that inhibits organification or drug blocking organification (propylthiouricyl)
26
Subacute thyroiditis labs and uptake pattern
Mimics graves but has DECREASED % RAIU
Low TSH and high T3/T4
27
Patient on dialysis needs I131 therapy. What do you do?
Give I131 right after dialysis to maximize the time I131 is on board.
Decrease dose as their is limited excretion until next dialize
Dialysate can go down sewer.
Tubing needs to be stored.
28
Wolf-Chaikoff effect
reduction in thyroid hormone levels caused by ingestion of a large amount of iodine.
29
When do I-131 treated patient's need to be admitted to hospital?
NRC limit is 7mR/h at 1 meter from patient's chest
33mCi of residual activity
30
What are the three renal tracers?
DTPA, MAG3, DMSA, (GH too)
31
Parathyroid adenoma dual phase versus dual tracer technique
Dual phase just uses Tc99m-Sestamibi and both early (10 minutes) and delayed (3 hours) scans are done
Dual tracer are used with two different tracers and then subtraction is done.
* first agent is chosen cuz it goes to both thryoid and parathyroid (options are Tc99m-Sestamibi or 201-thallium chloride)
* 2nd agent is chosen because it only goes to the thyrpid (I123 or pertechnetate)
32
Most common cause of hyperPTH?
hyperfunctioning adenoma
second is multiple gland hyperplasia
third is cancer
33
What are the three agents used in CNS nukes? Which two are similar?
HMPOA and ECD are similar (are extracted and can be used for parenchymal imaging; HMPOA washes out faster while ECD has better blood clearance [better brain to background ratio]).
DTPA: not extracted and can't be used for parenchymal imaging. This has the advantage of being repeated without delay. main utility is for shunt studies, NPH and Brain death
34
FDG PET Brain Dementia Patterns:
1. Normal
2. Alzheimers
3. Parkinsons
4. LBD
5. Picks
6. Multi-infarct
1. "Things look symettric, basal ganglia is 15% more than cortex, cerebellum is 15% \< cortex, Thalamus = cortex
2. Low posterior temporoparietal, cingulate gyrus first place abnormal
3. identical to 3
4. low in lateral occipital cortex (halluicinations!) cingulate island sign (opposite that of 2)
5. “frontotemporal dementia”
6. Scattered areas of decreased activity
35
DTPA
Filtered (GFR)
Good in people with normal renal function
critical organ = bladder
36
Before Tc-99m can be tagged to an RBC (beta chain of the Hg), what must be done first?
Must be reduced using stannous ion (tin)
This is the in vivo, in vivo/vitro and in vitro methods
37
GI Bleed Sensitivity for RBC scan, CTA and Angiogram
RBC scan = 0.1 mL/min
CTA = 0.4 mL/min
Angiogram = 1.0 mL/min
38
Vascular territories for:
* Celiac
* SMA
* IMA
* Celiac: Distal esophagus, Stomach, 1st part of the duodenum
* SMA: 2nd-4th parts of duodenum, the rest of the small bowel and large bowel to the splenic flexure
* IMA: distal ⅓ of transverse colon to the proximal rectum
39
What are you looking for in a GI bleed RBC scan?
1. Tracer outside vascular distribution
2. Tracer that moves like bowel
3. Tracer that increases in intensity overtime
40
Dose of CCK?
Dose of Morpine?
Dose of phenobarb?
Dose of CCK = 0.02 **micro**gram/KG over 60 minutes.
Dose of Morpine = 0.02 **mg**/kg over 60 minutes.
Dose of phenobarb = 5 **mg**/kg x 5 days
41
Gastric Emptying Pharmacology Trivia
* What are the prokinetic drugs and what to do with them?
* What to do about opiates?
* What are some anticholinergic/antisposmodic drugs and what to do with them?
* What do you do with serotonin receptor antagonists (ie Zofran)?
* Prokinetics = metoclopramide (reglan), tegaserod, erythromycin, and domperidone = STOP FOR 2 DAYS PRIOR TO EXAM
* Opiates = STOP FOR 2 DAYS BEFORE EXAM
* Anticholinergic drugs = Donnatal, Bentyl, Robinul, Levsin = STOP FOR 2 DAYS PRIOR TO EXAM
* Can keep taking zofran!
42
Meckels scan:
* False Positives:
* False negatives:
* False Positives: Bowel irritation \*ie recent scope or laxatives
* False negatives: Recent in vivo labeling of RBCs, recent barium study (attenuated)
43
What medications can you use to make a meckel's scan better?
Pentagastric = enhances uptake of pertechnetate by gastric mucosa
H2 blockers = Cimetidine and Ranitidine = block secretion of the pertechentate out of gastric cells making it stick around for longer
Glucagon = slows gastric motility
44
In a HIDA scan, what medications can cause prompt uptake with delayed biliary excretion?
Erythromycin, Estrogen (contraceptives), Anabolic steroids, chlorpromazine, sometimes statins
45
HIDA scan: medications that cause prompt hepatic uptake with delated biliary excretion?
* Erythromycin
* Birth Control (Estrogens)
* Anabolic steroids
* Chlorpromazine
* Sometimes statins
46
HIDA SCAN BLITZ!
No bowel activity + persistent blood pool = ?
No bowel activity + blood pool goes away normally = ?
No gallballder activity x 4 hours (or 1 hour + morphine) = ?
Abnormal GB emptying (EF \< 20%) = ?
Hepatic dysfunction (hepatitis)
CBD obstruction
Acute chole
Chronic chole
47
Suspected renal artery stenosis renogram:
Normal scan?
What does the MAG3 graph look like?
What does it DTPA graph look like?
Normal scan = pre and post captoprils looks the same!
MAG3 = marked tracer retention (kind of looks like obstruction graph)
DTPA = decreased flow and uptake
48
Diffuse pulmonary activity on a sulfur colloid scan = ?
excess aluminium in the colloid
49
renal activity on sulfur colloid = ?
CHF
Alternatively in renal transplant can indicate rejectoins
other rare causes = coxsackie b virus, DIC and TTP
50
MAG 3
secreted (threecreated) (ERPF)
concentrated better in poor kidney function
critical organ is bladder
51
DMSA
binds to renal cortex
critical organ = kidney
52
How does a kidney with renal artery stenosis look when using MAG3? How about DTPA?
MAG 3 = the sick kidney holds on the the tracer
DTPA = the sick kidney has decreased uptake and flow.
53
Renal transplant nucs renogram - ATN versus rejection
both will have delayed excretion, but ATN has preserved flow and rejection has decreased flow
54
Meningiomas can be hot on what scans?
Hot on Octreotide and MDP
55
What medications interfere with the workings of MIBG?
Kids with neuroblastoma don't need TLC or cocaine!
TCA's, labetalol, Ca channel blockers and cocaine
56
MIBG versus Octreotide
MI**B**G is superior for neuroBlastoma and non-malignant (adrenal) pheos
o**C**treotide = superior for Carcinoid and malignant (extra-adrenal) pheos
57
What is the dose for MDP scan? How long do you wait until you scan?
15-25 mCi
2-4 hours
58
Critical organs for:
Indium prostascint (PMSA)
Indium WBC
Indium octreotide
* Indium prostascint (PMSA) = Liver
* Indium WBC = Spleen
* Indium octreotide = Spleen!
59
What is the best view for a MUGA scan?
left anterior oblique
60
What gives a false low EF on MUGA?
Screwed up view with overlap of LV by the RV or great vessels
61
What gives a false high EF on MUGA?
Wrong (high) background ROI (over the spleen)
62
What is the only pet agent made with a generator? half life?
Rb-82; super short half life
63
Cardiac scan artifacts
Breast tissue
left hemidiaphragm
LBBB
Breast tissue = anterior wall
left hemidiaphragm = inferior wall
LBBB = septal defect sparing apex
64
Dipyridamole
vasodilator - inhibits breakdown of adenosine, lower side effect profile
no caffeine
65
adenosine
vasodilator, no caffeine, worse side-effects relative to dipyridamole
66
Tumors that are PET COLD
* Low grade lung adenoCA
* Carcinoid/Neuroendocrine
* RCC
* HCC
* Peritoneal Bowel / Liver Implants
* Anythin mucinous
* Prostate
* Extranodal marginal zone lymphomas (such as marginal zone lymphoma or MALT)
67
Not cancer but PET HOT
* Infection
* Inflammation
* Ovaries in follicular phase
* Muscles
* Brown fat (help this with propranalol, reserpine or diazepam)
* Thymus
68
SUV Calculation
SUV = FDG concentration at time “T” / (Dose/Body Weight)
69
Indium critical organ trivia:
* Indium prostascint =
* Indium WBC =
* Indium octreotide =
* Indium prostascint = Liver
* Indium WBC = Spleen
* Indium octreotide = Spleen
70
Sestamibi versus tetrofosmin?
Tetrofosmin is cleared from liver more rapidly and therefore decreases the chance of a hepatic uptake artifact
71
Ragedenoson
vasodilator (selective A2a)
fewer side effects
no caffeine
72
Dobutamine
Beta 1 agonist
better in patients with COPD or Asthma
avoid with LBBB
73
aminophyline
antidote for adenosine
half-life shorter than dipryidaomele
74
What are the three agents used for treatment of boner pain?
Strotium 89
Samarium 153
Radium 223 Xofigo
75
Sr89
AKA Metastron
Works by complexing with hydroxyappetite where bone turnover is high
Pure beta emitter
Most boner marrow toxicity (longest recovery)
renal excretion
76
Sm153
AKA Quadramet
Works by complexing with hydroxyappetite where bone turnover is high
steeper drop but faster recovery of plt and WBC from preinjection relative to Sr
Unlike Sr89, 28% of the decay is via gamma rays (103 kEv)
Beta emmitter with some immageable gamma rays
less boner marrow toxicity
renal excretion
77
Ra223
AKA Xofigo
Behaves similar to Ca++ and is absorbed nto the bone matrix
alpha emmitter
least bone marrow toxicity (because alpha particles have a shorter range)
1 study showed one trial of survival benefit in prostate CA
Non-hematologic side-effects are more common than hematologic (ie dirrhea, fatigue, nausea, vomiting and bone pain make the list)
GI excretion
improved survival for prostate mets
Long half life of 11.4 days
78
Yttrium-90
pure betta emmiter, maximum tissue penetration = 1 cm
particle size = 20-40 microns
dose typically is 100-1000 Gy
can image it's 175 and 185 keV emissions
half-life = 64 hours
79
What is radioimmune therapy?
- first line or refractory treatment for NH-lymphoma
- basically bind Y-90 to a mab
- the Ab binds to the CD20 B-cell receptior
- first give rituximab to block the CD20 receptors of circulating B-cells, then check with Indium-111 taged to the MAB (zevalin) to check for altered distribution, if you suspect that get a delayed, if altered = don't treat, if okay, then blast them!
- dont give with plt under 100K (most common side effect is
- can send home after treatment, just give them a hand out with precautions
80
Three scenarios for SPECT at the level of the kidneys
1. Aorta/IVC present = ?
2. No Aorta/IVC present = ?
3. Hot Kidneys = ?
1. RBC Scan → Hemangioma
2. Sulfur Colloid Scan → FNH
3. Octreotide Scan → Neuroendocrine tumor
81
MIBG can be tagged to both I123 or I131. How may one tell the difference?
MIBG-I123 has more cardiac activity
Normal adrenals are usually not seen, but you can have feint uptake in the adrenals in about 75% of the time with MIBG-I123 (as apposed to 15% of the time with I131).
82
Just like MIBG can be labeled with either I-123 or I-131, you can label WBCs with Tc or Indium
How to tell the difference?
Tc-WBC at 4 hours and 24 hours lung versus bowel uptake
Both will have hot spleens; Tc is a higher count study and cleaner
4 hours: Can see lung uptake
24 hours: lungs clearing up but you start to get some bowel uptake
83
Wolf-Chaikoff effect
reduction in thyroid hormone levels caused by ingestion of a large amount of iodine.
84
Tc HMPOA and ECD
Both agents pass through BBB and stick to gray matter proportional to CBF
HMPOA washes out faster (best imaged 15 min - 2hr post injection and uptake facors frontal lobe, thalamus and cerebellum)
ECD washout is slower, has better background clearance, and does not demonstrate intracerebral redistribution (best imaged 15 - 30 min post injection and uptake prefers occipitoparietal lobes).
85
Tc-99m-DTPA brain imaging utility
Shunt studies, NPH and Brain Death
86
High yield Thallium Generalizations / Uses
Toxo infection is thallium negative (don't have human Na/K ATPase)
Lymphoma is thallium positive
Kaposi sarcoma is thallium positive (Ga negative)
Tumor is thallium positive while necrosis is gallium negative)
87
Suspected renal artery stenosis renogram:
Normal scan?
What does the MAG3 graph look like?
What does it DTPA graph look like?
Normal scan = pre and post captoprils looks the same!
MAG3 = marked tracer retention (kind of looks like obstruction graph)
DTPA = decreased flow and uptake
88
Absolute contraindications for Sr and Sm?
Pregnancy
Breastfeeding
renal failure
