Comprehensive Flashcards
1
Q
Type of radionuclide: spleen > liver
A
WBC (very low counts)
2
Q
Type of radionuclide: liver = spleen
A
Sulfur colloid
3
Q
Type of radionuclide: spleen
A
Gallium (Also shows bowel)
4
Q
Type of radionuclide: Heart and kidneys seen
A
MIBI
5
Q
Type of radionuclide: liver without kidneys or bones
A
MIBG
6
Q
Type of radionuclide: very hot spleen and kidneys
A
octreotide (has very high counts)
7
Q
Tag for WBCs
A
In-111
8
Q
Type of radionuclide: bones and lacrimal glands visible
A
gallium or free Tc
9
Q
Type of radionuclide: lacrimal glands visible without bones
A
Sulfur colloid, WBCs
10
Q
When to image Tc-WBCs
A
4 hours (too much lung) vs. 24 hours (too much bowel)
11
Q
Tc-WBCs vs. In-WBCs
A
Indium shows no renal or GI
12
Q
MDP dose
A
20 mCi +/- 5
13
Q
Timing for delayed images in MDP
A
2-4 hours
14
Q
MDP mechanism
A
Chemisorption (phosphate binding)
15
Q
HDP is AKA
A
Tc-MDP
16
Q
F-18 vs. FDG with increased bone uptake
A
FDG shows brain activity
17
Q
Skull sutures very bright on MDP
A
renal osteodystrophy
18
Q
Unilateral breast activity on MDP
A
mastitis or cancer
19
Q
Bilateral breast activity on MDP
A
Lactating
20
Q
Very bright renal activity on MDP
A
chemotherapy
21
Q
Liver seen on MDP (3 things)
A
- Aluminum contamination
- Malignancy
- Amyloidosis
22
Q
Spleen on MDP
A
Sickle cell disease
23
Q
Probability that single bright bone lesion on MDP is cancer:
A
15-20%
24
Q
Decreased skeletal uptake on MDP
A
Dose issue or bisphosphonates
25
Flair phenomenon for bony mets (timing)
Starts at 2 weeks, ends at 3 months.
| X-rays show increasing sclerosis.
26
PSA threshold for bone scan
PSA
27
Radionuclide of choice for bone mets in neuroblastoma
MIBG
28
Alternative to MDP for lytic mets
skeletal survey
29
Double density on bone scan
Osteoid osteoma
30
Hot mandible on MDP
Fibrous dysplasia
31
Mature heterotopic ossification on MDP
cold lesion
32
Hot AVN on MDP
repairing (middle phase)
33
Metabolic vs. metastatic superscan
Metabolic = hotter skull and extremities
34
Nuc Med for spine
Gallium
35
Nuc med for bowel
WBC
36
Positive WBC/Sulfur Colloid study
Hot on WBC, cold on colloid
37
Prosthetic loosening (Rule in)
Sulfur Colloid/WBC
38
Prosthetic loosening (rule out)
3 phase bone scan
39
When to do 4th phase bone scan
PAD or diabetes (slower blood pool clearance)
40
Tc-HMPAO WBC over In-WBC
Children
| Small body parts (hands/feet)
41
Xe-133 physical Halflife
5.3 days
42
Xe-133 biological halflife
30 seconds (not absorbed)
43
Xe-133 energy
80 keV
44
In V/Q, which performed first?
Ventilation
45
Size of MAA in VQ
10-100 micrometers (capillary = 10 micrometers)
46
When to halve MAA dose (5 things)
1. Children
2. Pneumonectomy
3. Right to left shunt
4. Pulmonary hypertension
5. Pregnancy
47
Clumped activity on Q portion of VQ
MAA clumped from tech drawing blood into syringe
48
Hepatic activity on Xe-133
Fatty liver (xe is fat soluble)
49
Free Tc on VQ
gastric + thyroid
50
Right to left shunt on VQ
brain +/- gastric or thyroid
51
Unilateral perfusion defect on VQ (3 things)
Mass
Fibrosing mediastinitis
Central PE
52
Gallium mechanism
Iron analogue, bound to lactoferrin (inflammation or rapid cell turnover)
53
Radionuclide of choice for chronic infection
Gallium binds dead neutrophils; more sensitive than WBC
54
Gallium production
cyclotron (Zn68)
55
Ga halflife
78 hours
56
Gallium photopeak
93, 184, 300, 393
57
Gallium imaging
24 hours
58
Gallium critical organ
colon
59
Panda sign (radionuclide and 3 Dx)
Gallium
1. Sarcoid (classic)
2. Sjogren's
3. Treated lymphoma
60
Kaposi Sarcoma (Nuc med results)
```
Gallium = negative
Thallium = Positive
```
61
Which thyroid radionuclide is not organified
Tc (I-123 and I-131 are)
62
Fetal thyroid formation (trimester)
Late first (8-12 weeks)
63
I-131 Half life
8 days
64
I 131 photopeak
364 keV
65
I-123 half life
13 hours
66
I-123 photopeak
159 keV
67
I-131 decay type
beta emission
68
I-123 decay type
electron capture
69
Breast feeding (thyroid imaging; 3 radionuclides)
Rule of thumb - 4 half-lives:
1. I-131 = stop entirely
2. I-123 = 2-3 days
3. Tc = 12-24 hours
70
Normal thyroid uptake (4 hours and 24 hours)
6-18% (4 hours)
| 10-30% (24 hours)
71
Increased thyroid uptake
Graves, hashimotos, medication rebound, I deficiency
72
Decreased thyroid uptake
Renal failure (increased free I pool), medications (anti thyroidals, nitrates, IV contrast, amiodarone), toxicosis
73
Plummer disease
Toxic multinodular goiter
74
Non-toxic multinodular goiter
Background uptake not entirely suppressed
75
Graves antibody
Anti-thyroTROPIN
76
Hashimotos antibodies (2)
Anti-TPO and antithyroGLOBULIN
77
Hashimotos co-morbidity
Primary thyroid lymphoma
78
Hashimotos appearance on thyroid scan
Acute (hyperthyroid) = identical to Graves
| Later = heterogeneous with cold spots
79
Graves vs. De Quervains thyroiditis
DeQuervains = granulomatous thyroiditis
| = Decreased uptake (Graves is increased)
80
Discordant nodule on thyroid scan
Hot on Tc, cold on I123
81
Most common thyroid cancer
papillary
82
Thyroid cancer that does not organify
Medullary (don't give I-131)
83
Medullary thyroid cancer syndromes
MEN 2A and 2B
84
Retreatment dose for I-131 in cancer
150% original dose
85
Medicine associated with I-131 resistant cancer
methimazole
86
Ideal post-surgical thyroid uptake for I-131 treatment
5% will be painful, treat with steroids/NSAIDs)
87
I-131 pre-treatment (2)
1. Stop thyroid hormone
| 2. Give thyrogen (AKA TSH)
88
Initial I-131 cancer dose (3 different doses)
1. Thyroid only = 100
2. Nodal disease = 150
3. Distal disease = 200
Alternative = volumetric
89
I-131 hospital admission rules
NRC: > 7mR/h at 1 meter from chest
| 33 mCi residual activity
90
At increased risk for non-target injury in I-131
Sjogrens (salivary)
91
Home I-131 precaution duration (33 mCi dose)
3 days
92
Abstinence from pregnancy post I131
6-12 months
93
How to identify post-treatment Iodine scan
Activity in the liver
94
Absolute contraindications to I-131 treatment (2)
1. Pregnancy
| 2. Acute or severe thyrotoxicosis
95
I-131 treatment on dialysis (2 considerations)
1. Tubing goes into storage (liquids can get dumped)
| 2. Decrease dose
96
I-131 dose for graves vs. multinodular goiter
```
Graves = 15 mCi
Goiter = 30 mCi
```
97
Thyroid eye disease and I-131
I-131 may worsen
98
Wolff-Chaikoff
Large iodine ingestion followed by decreased hormone production (10 days)
99
False positives on parathyroid sestamibi (4)
Cancer
Lymphadenopathy
Thyroid nodules
Brown fat
100
Hot nodule on sestamibi and Tc
Thyroid nodule
101
Hot nodule on sestamibi, but cold on Tc
Parathyroid adenoma
102
Tc DTPA vs. HMPAO for brain imaging (2)
1. Perfusion imaging only
| 2. Can be repeated (no parenchymal localization) in epilepsy cases
103
Thallium 201 Mechanism
```
Potassium analogue (Na/K)
--Needs living cells to work (viability detector)
```
104
Thallium half life
73 hours
105
Thallium photopeaks
69 and 81 keV
106
Thallium decay
electron capture
107
Thallium brain (infection vs cancer)
Lymphoma positive
| Toxo negative
108
Kaposi on nuclear medicine (2 tests)
```
Thallium positive
Gallium negative (opposite of PJP)
```
109
Thallium brain (recurrent cancer vs. radiation necrosis)
```
Cancer = thallium positive
Necrosis = negative
```
110
Vasovagal pt, poorly responsive to IV fluids (med and dose).
Atropine 0.6-1.0 mg (max dose ~3 mg)
111
Epi dose for severe urticaria (and route).
0.1 - 0.3 ml 1:1000 (IM)
112
Bronchospasm/facial and laryngeal edema/Hypotension treatment algorithm (3 steps)
1. Albuterol
2a. Epi 1:1000 (IM) 0.1-0.3 ml (0.1 - 0.3 mg), up to 1 mg
or
2b. Epi 1:10k (IV) 1-3 ml (0.1 - 0.3 mg), up to 1 mg
If hypotension, add IV fluids
113
Seizure treatment
Diazepam 5 mg vs. midazolam 0.5-1 mg
