NM Flashcards
1
Q
PET –> how does it work?
A
1) radiotracer –> emit positron –> travel small distance in tissue
2) meet electron –> positron & electron annihilate
3) create two 511 keV photons –> travel 180 deg apart
2
Q
PET –> what radiotracer?
A
Fluorine-18 fluorodeoxyglucose (F-18 FDG)
3
Q
PET –> F-18 FDG –> MOA?
A
glucose analog –> GLUT1 & 3 -> transport into cells –> phosphorylated by hexokinase –> trapped in cell
4
Q
F-18 –> half life?
A
110 min
5
Q
standardized uptake value (SUV) –> proportional to what formula?
A
(ROI activity x body wt) / administered activity
6
Q
PET: FDG uptake –> depend on what lab values?
A
serum glucose & insulin levels
7
Q
PET: inc insulin –> what happen to FDG uptake?
A
inc uptake by muscle –> dec sensitivity for mild FGD-avid lesions
8
Q
PET: how long NPO?
A
at least 4hr –> insulin at basal level
9
Q
PET: blood glucose level should be?
A
<200 –> prefer
10
Q
PET: inject F-18 FDG –> rest in quiet room –> how long?
A
1hr
11
Q
PET –> effect of metformin?
A
- inc colonic uptake
- small inc small bowel uptake
12
Q
PET: salivary gland, tonsil, thyroid –> normal uptake?
A
symm –> mild-mod uptake
13
Q
PET: bowel –> normal uptake?
A
diffuse –> mild-mod uptake
14
Q
PET: heart –> normal uptake?
A
variable
15
Q
PET: muscle –> normal uptake?
A
- usu low
- if elevated insulin –> inc uptake
- if recent exercise –> inc uptake
16
Q
PET: brown fat –> normal uptake? exacerbating factor?
A
mild-mod
cold
17
Q
brown fat –> MC location?
A
- supraclavicular
- intercostal
18
Q
PET/CT –> evaluate what type of lung cancer? why?
A
only non-small cell lung cancer
small cell –> considered metastatic at dx
19
Q
LN staging –> gold standard?
A
mediastinoscopy
20
Q
PET –> malig LN –> sens? spec?
A
- very sens
- not spec
21
Q
pulm nodule –> smallest size that can be eval by PET?
A
8 mm
22
Q
solitary pulm nodule –> not FDG avid –> next step?
A
short term f/u
23
Q
solitary pulm nodule –> FDG avid –> next step?
A
- bx
- resect
24
Q
colon CA –> role of PET?
A
- local colon cancer –> limited role
- good for mets eval
25
colon CA --> initial tx --> when can do f/u PET? why?
2mo
peritx period --> inc FDG uptake --> flare phenomenon
26
head/neck CA --> tx --> when can do f/u PET? why?
4mo
chemorad --> alter anatomy, inflamm --> dec specificity for recurrent dz
27
inc thyroglobulin --> whole body radioiodine scan --> neg --> next step?
PET --> look for thyroid CA:
- undiff
- medullary
28
PET --> lymphoma --> inc marrow uptake --> diffuse --> ddx? (3)
- granulocyte colony-stimulating factor (G-CSF)
- ctx --> rebound effect
- malig marrow infiltration
29
esophagus CA --> role of PET?
ID mets --> not surg candidate
30
esophagus CA --> initial neoadjuvant tx --> dec FDG avid by how much --> favorable prognosis?
at least 30%
31
esophagus CA --> initial neoadjuvant tx --> unchanged FDG avid --> indicates what in terms of tx?
ctx ineffective --> stop ctx
32
cancers w limited role for PET? (4)
- HCC
- RCC
- bladder CA
- prostate
33
HCC --> limited role for PET --> why?
high phosphatase --> dephosphorylate FDG --> FDG diffuse out of cells
34
bladder CA --> limited role for PET --> why?
surrounding high urine FDG uptake
35
LV perfusion imaging --> evaluates what?
blood flow to myocardium
36
LV perfusion imaging --> perfusion abnormality --> factors to eval? (5)
- ir/reversible?
- size?
- severity: mild (subendocardial), mod, severe (transmural)?
- coronary A territory?
- assoc abnormalities? --> RV uptake, ischemia dilation, wall motion abnormal?
37
LV perfusion imaging --> stress --> 3 methods?
- physical --> treadmill
- pharmacologic-adrenergic --> dobutamine
- pharmacologic-vasodilatory --> dipyridamole, adenosine
38
myocardial perfusion imaging --> indications? (6)
- eval acute chest pain
- eval hemodynamic significance of coronary stenosis
- risk stratification after MI
- preoperative risk assessmt for noncardiac surg
- eval viability prior to revasc therapy
- eval myocardial revasc s/p CABG
39
risk stratification after MI --> myocardial perfusion imaging --> "high risk" findings? (5)
- sig peri-infarct ischemia
- defect in diff vascular territory --> mult-vessel dz
- sig lung uptake --> LV dysfx
- LV aneurysm
- low EF <40%
40
what is "hibernating" myocardium?
myocardium:
- hypoperfused
- viable
41
myocardial viability imaging --> 2 methods?
- #1 F-18 FDG PET
| - thallium-201 perfusion imaging
42
myocardium --> region of perfusion defect --> FDG uptake --> dx? tx?
viable myocardium --> CABG or percutaneous intervention
43
myocardium --> region of perfusion defect --> no FDG uptake --> dx?
non-viable scar --> medical therapy only
44
radionuclides used in nuclear cardiology? (5)
- thallium-201
- technetium-99m sestamibi (cardiolite)
- rubidium-82
- nitrogen-13 ammonia
- F-18 FDG
45
thallium-201:
- half life?
- decay?
- charact Xray?
- MOA?
- 73hr
- electron capture
- 69-81 keV
- potassium analog --> ATP-dep Na-K transmembrane pump --> into cell --> uptake directly proportional to myocardial perfusion
46
thallium-201 --> myocardial perfusion imaging --> max exercise --> perfusion defect --> at least what % stenosis?
50%
47
thallium-201 --> undergoes redistribution --> T/F?
T
48
technetium-99m sestamibi (cardiolite) --> undergoes redistribution --> T/F?
F
49
technetium-99m sestamibi (cardiolite) --> MOA?
passive diffusion --> into cell --> bind to mitochondrial membrane proteins --> uptake proportional to myocardial perfusion
50
rubidium-82:
- half life?
- decay?
- MOA?
- perfusion vs viability?
- 76 sec
- positron
- potassium analog
- perfusion
51
rubidium-82 --> type of stress --> exercise vs pharmacologic --> why?
pharm only --> very short half life
52
nitrogen-13 ammonia:
- half life?
- decay?
- perfusion vs viability?
- 10min
- positron
- perfusion
53
myocardial imaging --> nitrogen-13 ammonia --> pro (2) vs con (2)?
pro:
- don't travel far in tissue --> high resolution
- short half-life --> can give lrg dose
con:
- short half life --> must be produced by cyclotron on-site
- pharm stress only
54
F-18 FDG:
- half life?
- decay?
- perfusion vs viability?
- 110 min
- positron
- viability only --> must correlate w sestamibi perfusion study
55
myocardial perfusion study:
- NPO how long? why?
- should stop what meds? why?
NPO 6hr --> dec splanchnic blood flow --> reduce liver/bowel uptake
hold CCB/BB --> allow to reach target HR
56
myocardial perfusion study --> stress --> max heart rate? target heart rate?
max HR = 220 bpm - age
target HR = 85% of max HR
57
myocardial perfusion study --> dipyridamole --> MOA?
adenosine deaminase inh --> adenosine accumulate --> vasodilate --> coronary blood flow inc 3-5x
58
myocardial perfusion study --> dipyridamole --> what subst must be held for 24hr prior to study? (2) why?
- theophylline
- caffeine
reverse effects of dipyridamole
59
myocardial perfusion study --> dipyridamole --> antidote?
aminophylline
60
myocardial perfusion study --> differentiate: dipyridamole vs adenosine (3)
adenosine:
- same effect as dipyridamole
- faster effect
- very short half life --> no reversal agent required
61
myocardial perfusion study --> regadenoson --> MOA? pro compared to adenosine?
adenosine receptor agonist --> vasodilate
easier to administer than adenosine
62
myocardial perfusion study --> dobutamine --> MOA?
B1 agonist --> inc myocardial O2 demand
63
myocardial perfusion study --> dobutamine --> indication?
adenosine contraindicated:
- severe asthma
- COPD
- recent caffeine
64
Tc-99m sestamibi perfusion study --> when image after injection (min)? why?
30min after inject --> allow liver activity to clear
65
Tc-99m sestamibi perfusion study --> gated SPECT show wall motion at time of what? perfusion imaging shows perfusion at time of what?
gated SPECT --> wall motion at time of imaging
perfusion imaging --> perfusion at time of inject
66
cardiac imaging --> Tc-99m sestamibi perfusion study vs PET perfusion --> which has grter sens, spec, accuracy?
PET perfusion
67
myocardial imaging --> significant RV uptake --> ddx? (2)
- R heart dz
| - pHTN
68
myocardial imaging --> pulm uptake --> ddx? (1)
LV dysfx
69
myocardial imaging --> stress --> LV dilate --> ddx? (1)
transient ischemic dilation (TID) --> 3-vessel dz (even if no focal defect)
70
myocardial imaging --> what is a small perfusion defect? med? large?
- small: 1-2 segmts
- med: 3-4
- lrg: >5
71
myocardial imaging --> fixed perfusion defect --> ddx? (2)
- myocardial scar
| - hibernating myocardium
72
LV --> vertical vs horizontal long axis --> U-shape point in which direction?
- vertical: U to the left
| - horizontal: U point down
73
I-131:
- half life?
- decay?
- how produced?
- 8day
- beta particles & gamma photon (364 keV)
- generator
74
I-131 --> use?
therapy only:
- thyroid cancer s/p thyroidectomy
- hyperthyroid (Graves, multinodular goiter)
75
I-123:
- half life?
- decay?
- how produced?
- mode of administration?
- 13hr
- electron capture & gamma photon (159 keV)
- cyclotron
- PO
76
I-123 --> use?
thyroid imaging
77
thyroid --> radiotracers? (3)
- I-131
- I-123
- Tc-99m pertechnetate
78
Tc-99m pertechnetate:
- half life?
- decay?
- mode of administration?
- 6hr
- gamma photon (140 keV)
- IV
79
thyroid radiotracers --> ok during pregnancy? why?
no --> cross placenta --> taken up by fetus
80
when can resume breastfeeding?
- I-131
- I-123
- Tc-99m
- I-131: never
- I-123: 2-3 days after administration
- Tc-99m: 12-24hr
81
I-131/I-123 therapy/imaging --> patient pre-procedure prep? why?
non-suppressed TSH (high TSH level):
- stop exogenous thyroid hormone for 4wk
- 2 IM injection of TSH
inc thyroid uptake of radiotracer
82
ectopic thyroid tissue --> 3 types?
- lingual thyroid
- retrosternal thyroid (substernal goiter)
- ovarian teratoma (struma ovarii)
83
ectopic thyroid tissue --> imaging options? (2)
- I-123
| - Tc-99m
84
thyroid nodule --> cytology indeterminate --> next step?
nuclear imaging
85
thyroid nodule --> hyperfxing --> ddx? (1)
benign adenoma
86
thyroid nodule --> cold --> ddx? (2)
- 70-75% benign colloid cyst
| - 20% malig
87
thyroid nodule --> warm --> ddx? (1)
cold nodule --> overlapping thyroid tissue
88
thyroid nodule --> warm --> next step?
oblique view --> still indeterminate --> bx
89
what is discordant thyroid nodule? next step?
- Tc-99m --> hot --> can uptake technetium
- I-123 --> cold --> can't trap iodine
may be malig --> bx
90
thyroid imaging --> normal 6hr uptake? 24hr?
- 6hr --> 6-18%
| - 24hr --> 10-30%
91
Graves dz --> thyroid imaging --> dec/normal/inc?
- 6hr uptake
- 24hr
- 6hr --> elevated
| - 24hr --> elevated
92
thyroid imaging --> how can differentiate if I-123 vs Tc-99m?
Tc-99m --> salivary uptake
93
Graves dz --> how can differentiate if I-123 vs Tc-99m?
often not possible --> thyroid uptake too strong --> salivary glands often not seen
94
Graves dz --> definitive tx? MC?
- #1 I-131
| - surg
95
MC inflamm dz of thyroid?
Hashimoto thyroiditis
96
Hashimoto thyroiditis -> thyroid scan --> appearance?
- diffuse inc activity (like Graves)
| - patchy uptake (like MNG)
97
subacute thyroiditis --> thyroid imaging --> dec/normal/inc?
- 6hr uptake
- 24hr
- 6hr --> dec
| - 24hr --> slight inc
98
thyroid cancer --> thyroidectomy --> 1-2mo later --> I-131 tx --> goal?
image + trt:
- residual dz
- potential mets
99
I-131 --> low dose (<30 mCi) vs high dose (100-200) --> indication?
low risk pt --> low dose:
- <1.5 cm
- no invasion of thyroid capsule
risk high --> high dose
100
thyroid cancer --> s/p I-131 ablation --> monitor?
follow thyroglobulin levels
101
thyroid cancer --> s/p I-131 ablation --> inc thyroglobulin --> next step?
I-123 scan --> assess for dz recurrence/mets
102
thyroid cancer --> s/p I-131 ablation --> inc thyroglobulin --> I-123 scan positive --> next step?
repeat I-131 ablation
103
thyroid cancer --> s/p I-131 ablation --> CI to monitor with thyroglobulin levels?
presence of anti-thyroglobulin Ab
104
Graves dz --> I-131 tx --> CI? (3)
- preg
- lactation
- unable to comply w radiation safety guidelines
105
I-131 tx --> Graves dz vs multinodular goiter --> # of tx?
- Graves --> single dose
| - MNG: mult tx may be required
106
parathyroid imaging --> radiotracer?
Tc-99 sestamibi
107
nuclear imaging --> parathyroid --> indication?
localize suspected parathyroid adenoma
108
nuclear imaging --> parathyroid adenoma --> findings?
- early phase: inc uptake
| - delayed phase: persistent retained activity
109
nuclear imaging --> thyroid adenoma --> findings?
- early phase: inc uptake
| - delayed phase: washout
110
Tc-99m sulfur colloid --> uptake by what tissues?
reticuloendothelial cells:
- #1 liver --> Kupffer cells
- #2 spleen
- #3 BM
111
Tc-99m sulfur colloid:
- Tc-99m physical half life?
- sulfur colloid biologic half life?
- Tc-99m: 6hr
| - sulfur colloid: 2-3min
112
sulfur colloid scan --> what is photopenic defect? MCC?
complete absence of radiotracer
hepatic cyst
113
sulfur colloid scan --> focal dec uptake --> ddx? (3)
most hep mass:
- HCC
- adenoma
- abscess
114
sulfur colloid scan --> focal inc uptake --> ddx? (3)
- focal nodular hyperplasia
- liver cirrhosis --> regenerating nodule
- Budd-Chiari (hep V thrombosis) --> late stage --> inc uptake in caudate lobe
115
sulfur colloid scan --> what is colloid shift? ddx? (1)
spleen & BM --> inc sulfur colloid
liver dysfx --> #1 cirrhosis
116
sulfur colloid scan --> diffuse pulm uptake --> ddx? (4)
nonspecific:
- cirrhosis
- COPD w infx
- Langerhans cell histiocytosis
- high aluminum (antacids, excess Al in colloid preparation)
117
sulfur colloid scan --> focal nodular hyperplasia (FNH) --> appearance? (3)
- normal liver (contain Kupffer cells)
- inc uptake (Kupffer cells + hypervasc)
- photopenic defect (insuff colloid concentration)
118
focal nodular hyperplasia (FNH) --> nuclear imaging options? (2)
- sulfur colloid scan
| - HIDA
119
focal nodular hyperplasia (FNH) --> HIDA finding?
contain bile ductules --> positive on HIDA
120
intra-pancreatic spleen --> nuclear imaging options? (2)
- sulfur colloid scan
| - Tc-99m damaged red cell study
121
GI bleed --> nuclear imaging options? (2)
- Tc-99m labeled RBCs
| - Tc-99m sulfur colloid
122
GI bleed --> Tc-99m sulfur colloid study --> cons? (2)
- sig prep time
| - vasc half-life 2-3min --> rapid blood clearance
123
GI bleed --> Tc-99m labeled RBCs study --> in vitro vs in vivo --> which is more commonly used? why?
#1 in vitro --> 95% labeling efficiency
in vivo --> worse labeling eff --> free pertechnetate --> noisier images
124
GI bleed --> tagged RBC study vs IR angiography --> can detect bleeding rate of?
- tagged RBC: 0.2 ml/min
| - IR angio: 1 ml/min
125
GI bleed --> tagged RBC study --> appearance?
activity --> over time --> peristalsis of intraluminal blood --> change shape & position
126
Tc-99m pertechnetate --> localize to what tissue?
gastric mucosa
127
Meckel diverticulum --> radiotracer?
Tc-99m pertechnetate
128
Meckel diverticulum --> Tc-99m pertechnetate study --> finding?
- RLQ --> focal inc activity
| - lat view --> activity is ant, not post
129
RLQ pain --> suspect Meckel diverticulum --> Tc-99m pertechnetate study --> diffuse regional inc uptake --> ddx? (2)
hyperemia:
- appendicitis
- intussusception
130
Meckel diverticulum --> embryology?
omphalomesenteric duct remnant
131
HIDA scan --> radiotracer?
Tc-99m iminodiacetic acid (IDA)
132
HIDA scan --> disofenin vs mebrofenin:
- max bili level?
- % hep uptake?
disofenin:
- bili 20 mg/dL
- 90% hep uptake
mebrofenin:
- 30
- 98%
133
HIDA scan: NPO how long?
- must have eaten within 24hr
| - NPO 6hr
134
HIDA scan: NPO for >24hr --> next step?
cholecystokinin --> empty GB --> wait 2hr --> HIDA scan
135
HIDA scan --> gallbladder visualized --> dx?
no acute cholecystitis
136
HIDA scan --> 1hr --> gallbladder NOT visualized --> next step? why?
morphine --> contract sphincter of Oddi --> redirect bile into cystic duct
137
HIDA scan --> 1hr --> gallbladder NOT visualized --> can't give morphine in what situation? why?
tracer --> nonvisualized in small bowel
theoretical risk of worsening potential CBD obstruction
138
HIDA scan --> 1hr --> gallbladder NOT visualized --> morphine --> when image again?
30min
139
HIDA scan --> 1hr --> gallbladder NOT visualized --> morphine allergy --> next step?
image for total 4hr
140
HIDA scan --> tracer in small bowel --> indicates?
patent CBD
141
HIDA scan --> 1hr --> gallbladder NOT visualized --> morphine --> 30 min --> gallbladder NOT visualized --> next step?
finished
86-98% sens for acute cholecystitis
142
6% --> false positive HIDA (GB non-visualized WITHOUT acute cholecystits) --> ddx (7)
- recent meal or prolong fasting
- admin CCK immed prior to exam --> persistent sphincter of Oddi relaxation
- total parental nutrition
- pancreatitis --> biliary stasis
- severe illness
- chronic cholecystitis
- cholangioCA of cystic duct
143
HIDA scan: what is rim sign?
inc hep activity surrounding GB fossa:
- hyperemia
- gangrenous cholecystitis
144
very rare --> false negative HIDA (GB non-visualized WITHOUT acute cholecystits) --> ddx (3)
- acalculous cholecystitis w patent cystic duct
- duodenal diverticulum --> simulate GB
- biliary cyst --> simulate GB
145
what is chronic cholecystitis?
GB --> longstanding inflamm:
- loss of GB fx
- inc risk of stone formation
146
chronic cholecystitis --> HIDA MC finding?
normal
147
HIDA scan --> finding suggestive of chronic cholecystitis?
low GB ejection fraction <35%
148
biliary leak --> nuclear imaging option? (1)
HIDA scan
149
biliary leak --> HIDA scan --> what can do to inc detection?
do study in R lat decubitus position --> promote dep pooling of bile
150
severe hepatic dysfx --> HIDA scan --> findings? (2)
- very poor hep uptake
| - delayed blood pool clearance
151
hepatic mass --> HIDA scan --> finding?
focal photopenic defect
152
V/Q scan --> radiotracers? (3)
- Tc-99m-MAA --> perfusion
- Xenon-133 --> vent
- Tc-99m DTPA --> vent
153
V/Q scan --> Tc-99m-MAA --> who should get half dose? (4)
- child
- preg
- mild pHTN
- R-L shunt
154
V/Q scan --> Tc-99m-MAA --> relative CI? (1) why?
severe pHTN
obstruct pulm capillaries --> clinical worsening
155
V/Q scan --> Tc-99m-MAA --> what is clumping of MAA?
MAA --> inadvertently drawn back into syringe --> coagulation w pt blood
156
V/Q scan --> Tc-99m-MAA --> renal uptake --> ddx? (2) how differentiate?
free pertechnetate:
- thyroid uptake
- no brain uptake
R-L shunt:
- no neck uptake
- brain uptake
157
Xenon-133:
- physical half life?
- biological half life?
- decay?
- critical organ?
- physical half life: 5.3day
- biological half life: very short
- decay: gamma photon & beta emitter
- critical organ: trachea
158
preg --> PE --> CTA PE vs V/Q scan --> fetal rad dose?
CTA: similar to slightly higher than VQ
159
PIOPED II --> high probability for PE?
>2 large (>75% segmt) mismatched segmental defect --> no assoc XR abnormality
160
PIOPED II --> intermediate probability for PE? next step?
1 lrg segmtal mismatched perfusion defect
not clinically helpful --> further imaging required
161
VQ scan --> lower lung --> what is triple match? dx?
perfusion defect --> vent defect --> matching abnormality on CXR ==> intermediate probability
162
PIOPED II --> low probability for PE? (3)
- 1 mod-lrg MATCHED defect
- >3 small segmental lesions
- entire lung --> no perfusion
163
PIOPED II --> very low probability for PE? (3)
- nonsegmtal lesion
- stripe sign
- mid-upper lung --> 1 triple match defect
164
VQ scan --> what is stripe sign?
perfusion defect --> thin line of MAA uptake bw defect & pleura --> intervening perfused lung
165
VQ scan --> possible impressions? (5)
- normal
- very low prob
- low prob
- interm
- high
166
bone scan --> radiotracer?
Tc-99m MDP
167
bone scan --> diffuse soft tissue uptake --> ddx? (1)
renal fail
168
bone scan --> 3 phases?
- angiogram (flow): eval blood flow
- blood pool: eval extracellular distribution
- delayed (skeletal)
169
cancer pt --> bone scan --> 1 rib --> focal uptake --> low/high probability of mets?
low (10%)
170
cancer pt --> bone scan --> 2 adj rib --> uptake in similar location--> low/high probability of mets? ddx? (1)
low
trauma
171
cancer pt --> bone scan --> mult adj photopenic lesions --> low/high probability of mets? ddx? (3)
low
- infarction
- avascular necrosis
- sequela of rad tx
172
breast cancer pt --> bone scan --> 1 sternal lesion --> low/high probability of mets?
high
173
cancer pt --> bone scan --> multifocal lesions in nonadj ribs --> low/high probability of mets?
high
174
cancer pt --> bone scan --> 1 photopenic lesion --> low/high probability of mets?
high
175
bone scan --> inc uptake in brain --> ddx? (1)
recent infarct
176
bone scan --> inc uptake in heart --> ddx? (1)
recent infarct
177
soft tissue mets --> positive on bone scan --> ddx? (4)
Ca-containing:
- osteosarcoma
- neuroblastoma
mucin-producing:
- GI
- ovarian
178
inflamm dz --> bone scan --> uptake in soft tissues & muscles --> ddx? (3)
- myositis ossificans
- dermatomyositis
- rhabdomyolysis
179
bone scan --> what is superscan?
diffuse inc osseous uptake
180
bone scan --> superscan --> ddx? (4)
- #1 metastatic prostate Ca
- breast Ca
- lymphoma
- hyperPTH
181
positive bone scan --> which bone tumors? (3)
- osteosarcoma
- Ewing sarcoma
- osteoid osteoma
182
bone scan --> double density sign --> ddx? (3)
- osteoid osetoma
- Brodie abscess
- stress fx
183
fx --> bone scan appearance:
- acute (up to 3-4wk)
- subacute (up to 2-3mo)
- chronic
- acute: 1day after injury --> uptake surrounding fx
- subacute: more focal uptake
- chronic: gradual dec uptake
184
what is medial tibial stress synd (shin splint)?
exercise-induced stress injury that occurs at the medial tibial mid-to-distal shaft
185
medial tibial stress synd (shin splint) --> bone scan appearance?
- blood flow phase: normal
- blood pool phase: normal
- delayed: tibia --> postmed --> linear inc uptake
186
osteoporosis --> sacrum --> insuff fx --> bone scan finding?
"Honda" sign --> sacrum --> H shaped uptake
187
bone scan --> indications? (9)
- bony mets
- bone tumor
- fx
- jt prosthesis --> loose or infx
- osteomyelitis
- hypertrophic pulm osteoarthropathy
- AVN
- Paget
- complex regional pain synd (reflex sympathetic dystrophy)
188
cemented jt prosthesis --> bone scan --> normal appearance?
up to 1yr --> activity around prosthesis
189
non-cemented jt prosthesis --> bone scan --> normal appearance?
up to 2yr --> activity around prosthesis
190
hip prosthesis --> bone scan --> finding suggestive of loosening?
focal activity at lesser trochanter
191
hip prosthesis --> bone scan --> finding suggestive of osteomyelitis?
generalized inc activity
192
hip prosthesis --> bone scan --> grter trochanter/intertrochanteric region --> mild-mod activity --> ddx? (1)
heterotopic ossification
193
normal XR --> bone scan --> positive on all 3 phases --> dx?
osteomyelitis
194
methods to inc specificity for osteomyelitis? (2)
- WBC imaging + Tc-99m sulfur colloid BM scan
| - gallium-67 scan
195
WBC imaging --> radiotracer? (2)
- Indium-111 - WBC
| - Tc-99m - WBC
196
WBC imaging + Tc-99m sulfur colloid BM scan --> indication? (1)
underlying abnormality --> ie fx, prosthesis --> eval for osteomyelitis
197
osteomyelitis --> WBC imaging + Tc-99m sulfur colloid BM scan --> appearance?
focal WBC activity --> no colloid activity
198
osteomyelitis --> gallium-67 scan --> appearance?
area of concern:
- bone scan --> inc activity
- gallium scan --> high inc activity
199
cellulitis --> bone scan findings?
- blood flow phase: inc activity
- soft tissue phase: inc activity
- delayed skeletal phase: normal
200
septic arthritis --> bone scan findings?
jt --> both sides --> positive --> all 3 phases
201
bone scan --> delayed skeletal phase --> inc activity in 2 adj vertebral bodies --> ddx? (1)
discitis
202
what is hypertrophic pulm osteoarthropathy?
pulm dz (ie lung CA) --> long bone --> diaphysis --> periosteal rxn
203
hypertrophic pulm osteoarthropathy --> bone scan finding?
long bone --> cortex --> parallel line --> inc activity
204
avascular necrosis --> bone scan --> finding? (2)
- initial phase --> dec activity
| - hyperemic phase --> inc activity
205
avascular necrosis --> bone scan --> SPECT finding? (1)
- rim of inc activity
| - central photopenia
206
spontaneous osteonecrosis of knee (SONK) --> bone scan finding?
med femoral condyle --> intense inc activity
207
Paget dz --> lytic phase --> XR appearance? bone scan?
- XR: normal
| - bone scan: positive
208
Paget dz --> mixed phase --> XR appearance? bone scan?
- XR: positive
| - bone scan: positive
209
Paget dz --> sclerotic phase --> XR appearance? bone scan?
- XR: positive
| - bone scan: activity subside
210
Paget dz --> bone scan --> persistent cold lesion --> ddx? (1)
malig degeneration --> central necrosis
211
complex regional pain synd (reflex sympathetic dystrophy) --> MCC? ssx?
minor trauma --> persistent pain/tender/swell
212
complex regional pain synd (reflex sympathetic dystrophy) --> bone scan --> appearance?
- blood pool: variable --> usu inc
- soft tissue phase: variable --> usu inc
- skeletal: hand/foot --> mult small jts --> juxta-articular --> diffuse inc activity
213
kidney --> radiotracers? (3)
- Tc-99m DTPA
- Tc-99m MAG3
- Tc-99m DMSA
214
kidney --> Tc-99m DTPA --> what eval?
- eval renal perfusion
| - measure GFR
215
kidney --> Tc-99m MAG3 --> what eval?
- eval renal perfusion
| - estimate renal plasma flow
216
kidney --> Tc-99m DMSA --> what eval?
renal scarring assoc w pyelonephritis
217
kidney --> Tc-99m DTPA --> excreted by?
glomerular filtration
218
kidney --> Tc-99m MAG3 --> excreted by?
tubules
219
kidney --> Tc-99m MAG3 --> better than Tc-99m DMSA --> for which conditions? (2) why?
- renal insuff
- obstruction
higher extraction fraction --> better images for renal insuff/obstruction
220
nuclear renogram --> flow phase --> slow upslope --> suggests?
dec perfusion
221
nuclear renogram --> cortical fx phase --> delayed uptake --> suggests?
dec renal fx
222
nuclear renogram --> clearance phase --> slow/lack of clearance --> suggests?
hydronephrosis
223
renal A stenosis --> nuclear imaging options? (2)
- Tc-99m MAG3
| - Tc-99m DTPA
224
Tc-99m MAG3/DTPA study --> what med is administered for eval renal A stenosis?
ACE-inh
225
renal A stenosis --> Tc-99m MAG3/DTPA study --> appearance?
after ACE-inh --> renogram --> abnormal or more abnormal
226
renal A stenosis --> Tc-99m MAG3 --> findings:
- % uptake at 2-3min
- difference in cortical activity
- time to peak activity
compared to pre-ACE inh):
- <40% uptake
- 20% difference in cortical activity
- >2min delay in time to peak
227
diuretic renogram --> general procedure?
Tc-99m MAG3 --> 20min after --> administer lasix
228
diuretic renogram --> goal?
hydronephrosis --> cause:
- obstruction
- non-obstructive cause
229
diuretic renogram --> clearance half time:
- normal?
- borderline
- obstruction
- <10min --> normal
- 10-20min --> borderline
- >20min --> obstruction
230
diuretic renogram --> false positive? (3)
- dehydration
- distended bladder
- renal fail (dec response to diuretic)
231
Tc-99m DMSA --> normal --> dx?
no acute pyelonephritis
232
pyelonephritis --> Tc-99m DMSA --> appearance? (3)
- focal cortical defect
- multifocal cortical defect
- diffuse dec activity
233
pediatric vesicoureteral reflux --> radionuclide cystography vs voiding cystourethrogram:
- sens
- rad exp
radionuclide cystography:
- no sens
- less rad exp
234
radionuclide cystography --> radiotracers? (3)
- Tc-99m pertechnetate
- Tc-99m DTPA
- Tc-99m sulfur colloid
235
radionuclide cystography --> general procedure?
radiotracer --> retrograde inject into bladder
236
I-123 MIBG --> use? (2)
- adult --> image pheochromocytoma
| - ped --> image neuroblastoma
237
MIBG --> uptake by what conditions? (5)
- pheochromocytoma
- neuroblastoma
- carcinoid
- medullary thryoid CA
- paraganglioma
238
I-131 MIBG --> use? (1)
ped --> tx neuroblastoma
239
I-123 MIBG --> normal distribution?
sympathetic innervation:
- salivary glands
- heart
- thyroid
- liver
- kidney
- bladder
240
I-123 MIBG --> how dec thyroid uptake?
Lugol's soln
241
Indium-111 pentetreotide (Octreoscan) --> indication? (2)
image:
- carcinoid
- islet cell tumor --> gastrinoma
242
Indium-111:
- half life?
- decay?
- production?
- 67hr
- electron capture
- cyclotron
243
Indium-111 pentetreotide (Octreoscan) --> uptake MOA?
octreotide analog --> somatostatin receptor:
- carcinoid
- islet cell tumor
- amine precursor uptake and decarboxylation (APUD) tumor
- head/neck --> glomus tumor (extra-adrenal pheochromocytoma)
244
Indium-111 pentetreotide (Octreoscan) --> normal distribution?
- kidney --> intense uptake
- spleen --> intense uptake
- liver --> less uptake
245
Gallium-67:
- half life?
- decay?
- production?
- 78hr
- electron capture
- cyclotron
246
Gallium-67 --> uptake MOA?
bind to transferrin:
- infx
- inflamm
- neoplasm
247
Gallium-67 --> normal distribution?
- bowel, colon --> high activity
- liver --> less
- skull
- BM
- salivary glands
248
Gallium-67 --> 24hr --> kidney --> activity --> dx?
renal dz
249
Gallium-67 --> lungs --> diffuse uptake --> dx?
infx/inflamm
250
Gallium-67 --> what is panda sign?
inflamm --> inc uptake:
- nasopharynx
- parotid gland
- lacrimal gland
251
Gallium-67 --> panda sign --> ddx? (4)
- classically --> sarcoidosis
- Sjogren
- lymphoma after irrad
- AIDS
252
sarcoidosis --> Gallium-67 study --> signs? (2)
- panda sign
| - lambda sign --> bilat hilar + R paratracheal LAD
253
thallium-201:
- half life?
- decay?
- production?
- 73hr
- electron capture
- cyclotron
254
thallium-201 --> normal distribution?
- kidney
- heart
- liver
- thyroid
- bowel
255
indium-111 oxine leukocytes (WBCs) --> normal distribution?
spleen > liver >> BM
256
indium-111 oxine leukocytes (WBCs) --> pro (1) vs con (3) --> compared to gallium study?
pro:
- no physiologic bowel accumulation --> can eval abd/bowel infx/inflamm
con:
- tedious labeling procedure
- higher rad dose
- less accurate for spinal osteomyeltis
257
gallium study --> liver --> focal uptake --> dx?
HCC
258
gallium + thallium study --> indication? (3)
- Kaposi sarcoma
- TB, atypical myobacteria
- lymphoma
259
Kaposi sarcoma --> gallium + thallium study --> findings?
KaT: Kaposi is Thallium avid
- thallium avid
- no gallium uptake
260
TB, atypical myobacteria --> gallium + thallium study --> findings?
TuG: Tuberculosis is Gallium avid
- gallium avid
- no thallium
261
lymphoma --> gallium + thallium study --> findings?
Lymphoma likes both:
- gallium avid
- thallium avid
262
brain --> radiotracers? (3)
- Tc-99m DTPA
- Tc-99m HMPAO
- Tc-99m ECD
263
brain --> Tc-99m HMPAO vs ECD --> demonstrates what?
- HMPAO: perfusion
| - ECD: living cells
264
brain death scan --> what is hot nose sign?
inc collateral flow --> nonspecific --> abnormal cerebral perfusion --> ie. brain death
265
brain --> acetazolamide challenge --> indication?
eval cerebral perfusion reserve
266
brain --> acetazolamide challenge --> appearance?
after acetazolamide:
- normal brain --> inc perfusion
- areas that have already maxed their autoregulatory mechanisms --> relatively lower activity compared to rest of brain
267
seizure --> Tc-99m HMPAO/ ECD --> appearance?
- ictal imaging (inj during sz or 30 sec after end of sz) --> hypermetabolic
- inter-ictal ---> hypometab
268
dementia --> Tc-99m HMPAO/ ECD --> appearance?
- Alzheimer dz
- Lewy body dementia
- multi-infarct dementia
- Pick dz
symm dec activity:
- Alzheimer --> post temporal + parietal lobes
- Lewy body --> + occipital calcarine cortex
- mult-infarct dementia --> mult asymm foci
- Pick dz --> frontal lobes + ant temporal lobes
269
brain tumor --> recurrence vs radiation necrosis --> nuclear imaging options? (2)
- thallium-201
| - dual phase F-18 FDG PET
270
brain --> malig glioma --> thallium-201 study --> recurrence vs radiation necrosis --> appearance?
- tumor --> uptake
| - granulation tissue --> no uptake
271
what is crossed cerebellar diaschisis?
supratentorial lesion --> ie. tumor, stroke, trauma --> disrupt corticopontine-cerebellar pathway --> contralat cerebellar hemisphere --> dec radiotracer uptake
272
how to recognize MIBG scan?
- no bones
- liver > spleen
- no kidney!
273
high uptake in spleen & kidneys --> what study?
octreotide
274
how to differentiate Tc-WBC scan from In-WBC scan?
- Tc-WBC: kidney & GI uptake
| - In-WBC: no kidney & GI uptake
275
Tc-MDP --> how localize?
phosphate analog --> chemiabsorption --> bind w hydroxyapatite on bone surface
276
F18-FDG --> how localize?
facilitated diffusion
277
I-123 & I-131 --> how localize?
Na/I symporter (NIS) --> into cell --> incorporate into thyroid hormone
278
thallium-201 --> how localize?
potassium analog --> Na/K ATP pump
279
brain death study --> Tc99m HMPAO vs Tc99m ECD --> main difference?
Tc99m ECD --> more rapid clearance from blood pool
280
bone scan --> abnormally low bone uptake --> ddx? (2) how to differentiate?
- poor renal fx --> too much soft tissue noise
| - air in vial/syringe --> poor labeling --> free Tc --> stomach uptake
281
bone scan --> what is flare phenomenon?
bone mets --> ctx --> 2wk-3mo post --> look like inc size & number of lesions --> "pseudo-progression"
282
bone scan --> liver uptake --> ddx? (4)
- Al3+ contaminiation
- cancer --> ie hepatoma, mets
- amyloidosis
- necrosis
283
bone scan --> spleen uptake --> ddx? (1)
sickle cell --> auto-infarcted spleen
284
elderly --> fx --> bone scan --> should be positive at what time point?
1wk
285
bone scan --> tramline sign --> dx? next step?
hypertrophic osteoarthropathy --> CXR or CT chest --> look for lung cancer
286
lytic bone mets --> imaging modality of choice?
skeletal survey
287
blastic/sclerotic bone mets --> imaging modality of choice?
bone scan
288
bone scan --> single lesion --> equivocal --> next step?
XR
289
bone scan --> equivocal single lesion --> normal XR --> next step?
susp for bone met --> MRI
290
vertebral osteomyelitis --> study of choice?
- WBC scan + Gallium-67
| - MRI
291
infx --> when would use Tc-HMPAO WBC over In-WBC? (2)
- peds: Tc99 --> lower absorbed dose, shorter imaging time
| - small parts ie hands/feet
292
In-WBC --> critical organ?
spleen
293
Tc99m MAA --> particle size?
10-100 micrometer
294
Tc99m MAA --> when use fewer particles? (5)
- peds
- only 1 lung
- RtoL shunt
- pHTN
- preg
295
gallium --> critical organ?
colon
296
gallium scan --> panda sign --> ddx? (3)
- sarcoid
- sjogren
- treated lymphoma
297
differentiate: trapping vs organification?
- trapping: iodine tracer transported into thyroid gland
| - organification: iodine incorporated into tyrosyl moiety
298
thyroid scan --> when would use Tc-99m over I-123/I-131?
recent thyroid blocker ie iodinated contrast
299
Tc-99m thyroid scan --> when can resume breastfeed?
24hr
300
I-123 thyroid scan --> when can resume breastfeed?
2-3 day
301
Hashimoto thyroiditis --> potential comp?
1ary thyroid lymphoma
302
I-131 radioiodine therapy --> dose for...
- thyroid only
- thyroid + nodes
- distant mets
- thyroid only: 100
- thyroid + nodes: 150
- distant mets: 200
303
I-131 radioiodine therapy --> pt should be admitted to hospital when how much residual activity?
33 mCi
304
hyperthyroid --> I-131 radioiodine therapy --> dose for...
- Graves
- MNG
- Graves: 15 mCi
| - MNG: 30 mCi
305
parathyroid scan --> radiopharmaceutical?
Tc sestamibi
306
brain --> shunt scan --> radiopharmaceutical?
Tc-DTPA
307
brain --> sz scan --> finding?
- ictal: hot focus
| - interictal: cold
308
Kaposi sarcoma --> uptake on...
- gallium
- thallium
- gallium --> neg
| - thallium --> pos
309
HIDA scan --> CCK --> dose?
0.02 microgram/kg over 60min
310
HIDA scan --> morphine --> dose?
0.02-0.04 mg/kg over 60min
311
infant --> HIDA scan --> phenobarbitol --> dose?
5mg/kg for 5 days
312
sulfur colloid liver scan --> cold or hot?
- hepatic adenoma
- FNH
- cavernous hemangioma
- HCC
- cholangioCA
- mets
- abscess
- focal fat
- FNH --> hot
| - rest are cold
313
sulfur colloid scan --> diffuse lung uptake --> ddx? (1)
Al contaminiation
314
sulfur colloid scan --> kidney uptake --> ddx? (2)
- CHF
| - renal tx --> rejection
315
hemangioma scan --> radiopharmaceutical? findings?
Tc-RBC
- flow phase: no uptake
- pool: no uptake
- delayed: hot
316
which radiotracers are made by generator? (2)
- Tc99
| - rubidium
317
hepatic adenoma
- sulfur colloid
- HIDA
- gallium
- sulfur colloid: photopenic
- HIDA: hot
- gallium: neg
318
thyroid scan --> meds that interfere w thyroid uptake?
- thyroid blockers
- IV contrast
- amiodarone
- nitrates
