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CORE Nucs > Nukes CORE - Sheet1 > Flashcards

Nukes CORE - Sheet1 Flashcards

1
Q

Tc-99m: energy and half life

A

“low”, 140, 6h

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2
Q

I-123: energy and half life

A

“low”, 159, 13h

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3
Q

Xe-133: energy and half life

A

“low”, 81, 125h (biologic t 1/2 30sec)

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4
Q

Thallium-201: energy and half life

A

“low”, 135 + 167, 73h

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5
Q

Indium-111: energy and half life

A

“medium”, 173 + 247, 67h

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6
Q

Gallium-67: energy and half life

A

multiple, 93 + 184 + 300 + 393, 78h

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7
Q

I-131: energy and half life

A

“high”, 365, 8d

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8
Q

Fluorine-18: energy and half life

A

“high”, 511, 110min

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9
Q

Strontium 89 t 1/2

A

50.5 days (14 in bone)

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10
Q

Samarium 153 t 1/2

A

46h

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11
Q

Yttrium 90 t 1/2

A

64h

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12
Q

Tc-99 DTPA vs. Xe-133

A

DTPA - multiple projections + tends to clump in airways

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13
Q

Tc-99 WBC vs. In-111 WBC

A

Tc Renal + GI, In-111 No renal or GI

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14
Q

Tc-99 WBC 4 vs. 24 hrs

A

4 hrs - lung uptake, 24 hrs - lungs clear, start to get bowel

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15
Q

Tc MDP vs F-18 bone scan (organ with higher dose)

A

Tc MDP - Bone, F-18 - bladder

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16
Q

3 agents for bone met therapy

A

Sr-89, Sm-153, Ra-223

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17
Q

6 cancers that are PET-negative

A

BAC, carcinoid, RCC, Peritoneal/bowel implants, anything mucinous, prostate

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18
Q

6 things that are not cancer but PET-hot

A

infection, inflammation, ovaries in follicular phase, muscles, brown fat, thymus

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19
Q

Alzheimer PET findings

A

low posterior temporoparietal cortical activity

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20
Q

Dementia with Lewy Bodies PET findings

A

low in lateral occipital cortex

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21
Q

cingulate island sign

A

preservation of the mid posterior cingulate gyrus in dementia with lewy bodies

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22
Q

Picks/frontotemporal PET findings

A

low frontal lobe

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23
Q

Huntingtons PET findings

A

low activity in caudate nucleus and putamen

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24
Q

Uptake: Graves vs. multi-nodular goiter

A

Graves: uptake high (70s), Multi-nodular goiter: uptake medium (40s)

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25
Q

hot clumps of signal in the lungs on liver spleen SC scan

A

too much Al in Tc

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26
Q

HOT spleen

A

WBC or octreotide (SC is warm spleen)

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27
Q

bone scan with hot skull sutures

A

renal osteodystrophy

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28
Q

bone scan with focal breast uptake

A

breast CA

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29
Q

bone scan with renal cortex activity

A

hemochromatosis

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30
Q

bone scan with diffusely decreased bone uptake

A
  1. free Tc or 2. bisphosphonate therapy
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31
Q

tramline along periosteum of long bones

A

lung CA

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32
Q

super hot mandible in adult

A

fibrous dysplasia

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33
Q

super hot mandible in kid

A

caffey’s

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34
Q

periarticular uptake of delayed scan

A

RSD

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35
Q

focal uptake along the lesser trochanter

A

prosthesis loosening

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36
Q

tracer in the brain on a VQ scan

A

shunt

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37
Q

tracer over the liver on ventilation with xenon

A

fatty liver

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38
Q

gallium negative, thallium positive

A

Kaposi

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39
Q

high T3, high T4, low TSH, low thyroid uptake

A

quervains/granulomatous thyroiditis

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40
Q

persistent tracer in the lateral ventricles > 24hrs

A

NPH

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41
Q

renal uptake on sulfur colloid

A

CHF

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42
Q

renal transplant uptake on sulfur colloid

A

rejection

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43
Q

filtered renal agent

A

DTPA (or GH whatever that is)

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44
Q

secreted renal agent

A

MAG-3

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45
Q

PET with increased muscle uptake

A

insulin

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46
Q

diffuse FDG uptake in thryoid on PET

A

hashimoto

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47
Q

I see the skeleton on MIBG

A

diffuse neuroblastoma bone mets

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48
Q

cardiac tissue taking up FDG more intense than normal myocardium

A

hibernating myocardium

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49
Q

made with generator

A

Tc-99 and Rubidium

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50
Q

max dose of geiger mueller counter

A

100 mR/h

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51
Q

Tc-99 major spill

A

> 100 mCi

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52
Q

Tl-201 major spill

A

> 100 mCi

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53
Q

In-111 major spill

A

> 10 mCi

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54
Q

Ga-67 major spill

A

> 10 mCi

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55
Q

I-131 major spill

A

> 1 mCi

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56
Q

annual dose limit to the public

A

100 mrem

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57
Q

hourly dose limit to the public

A

2 mrem/hr

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58
Q

body dose limit for workers yearly

A

5 rem

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59
Q

ocular dose limit for workers yearly

A

15 rem

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60
Q

extremity dose limit for workers yearly

A

50 rem

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61
Q

embryo/fetus dose limit for workers yearly

A

0.5 rem

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62
Q

allowable amount of Mo per 1 mCi of Tc

A

0.15 mCi of Mo per 1 mCi of Tc (at time of administration)

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63
Q

how do we check chemical purity?

A

pH paper (Al in Tc)

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64
Q

how do we check radiochemical purity?

A

thin layer chromatography (free Tc)

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65
Q

allowable amount of Al

A

<10 micrograms

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66
Q

what causes free Tc

A

lack of stannous ions or accidental air injection (which oxidizes)

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67
Q

prostate cancer bone mets are uncommon below what PSA?

A

10 mg/ml

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68
Q

flair phenomenon timing

A

2 weeks - 3 months after therapy

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69
Q

skeletal survey: lytic vs. blastic

A

better for lytic

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70
Q

AVN: early, middle, late findings

A

early + late: COLD, middle (repairing): HOT

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71
Q

particle size for VQ scan

A

10-100 um

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72
Q

what is done first in a VQ scan

A

Xenon

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73
Q

classic thyroid uptake blocker

A

amiodarone

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74
Q

hasimotos increases risk for what malignancy

A

lymphoma

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75
Q

major side effect of methimazole

A

neutropenia

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76
Q

what drug treatment (even years prior) makes I-131 treatment more difficult?

A

methimazole

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77
Q

thyroid blocker of choice in pregnancy

A

PTU

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78
Q

how long to wait after chemo or radiation to do a PET?

A

2-3 weeks for chemo and 8-12 weeks for radiation

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79
Q

In-111 pentetreotide

A

somatostatin receptor imaging - carcinoid tumors

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80
Q

random benign tumor that takes up ocretotide

A

mengiomas

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81
Q

prior to MIBG, you need to give the patient…

A

lugols iodine or perchlorate

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82
Q

what EKG finding causes false positive septal defect

A

LBBB

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83
Q

pulmonary uptake of thallium indicates what heart abnormality

A

LV dysfunction

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84
Q

MIBG analog

A

norepinephrine (actively transported)

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85
Q

MDP analog

A

phosphate (chemisorption)

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86
Q

sulfur colloid mechanism

A

particles are phagocytized by RES

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87
Q

how to pick out octreotide scan?

A

no bones + liver + DARK SPLEEN + dark kidneys

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88
Q

what’s hot with free Tc

A

salivary gland, thyroid, stomach

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89
Q

bone scan with diffuse renal uptake

A

chemotherapy or urinary obstruction

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90
Q

bone scan with liver uptake (4 things)

A

too much Al in Tc, cancer (hepatoma or mets), amyloidosis, liver necrosis

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91
Q

bone scan with splenic uptake

A

auto-infarcted spleen 2/2 sickle

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92
Q

honda sign

A

sacral insufficiency fracture

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93
Q

when to do a bone scan in old people

A

1 week post injury

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94
Q

what is flair phenomenon?

A

good response to tx mimicking bad response (increased uptake)

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95
Q

solitary sternal lesion on bone scan

A

breast CA

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96
Q

MIBG detects what cancer

A

neuroblastoma

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97
Q

“tramline”

A

hypertrophic osteoarthropathy (chronic hypoxia + lung cancer)

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98
Q

classic Pagets presentations

A

super hot enlarged femur, super hot enlarged pelvis, super hot skull, expanded hot “entire” vertebral body, metabolic superscan

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99
Q

double density sign

A

osteoid osteoma

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100
Q

most common metabolic superscan

A

hyper PTH (hot skull)

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101
Q

bone uptake is always abnormal on these 3

A

MIBI, I-131, or ocretotide

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102
Q

preferred for osteomyeltitis in the spine

A

gallium

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103
Q

downside to Tc99 HMPAO WBC

A

GI + gb activity

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104
Q

3 reasons to reduce particle amount in Tc99 MAA

A
  1. fewer capillaries (kids, one lung) 2. right to left shunt 3. pulmonary HTN
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105
Q

multiple focal hot spots on Tc99 MAA

A

tech draws blood into syringe prior to injection

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106
Q

persistent pulmonary activity during washout

A

COPD

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107
Q

most common cause of unilateral whole lung perfusion defect with normal ventilation

A

lung CA

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108
Q

positive PE study

A

normal ventilation + multiple areas of abnormal perfusion

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109
Q

CXR within ? hours of VQ

A

24 hours

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110
Q

gallium analog

A

Fe +3 (gets bound via lactoferrin to area of inflammation and rapid cell turnover)

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111
Q

target organ for gallium

A

colon

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112
Q

lambda sign

A

Ga-67, Sarcoid (uptake in bilateral hila and right paratracheal node)

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113
Q

panda sign

A

prominent uptake in the nasopharynx, parotids, and lacrimal glands - Sjogren’s + treated lymphoma

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114
Q

hot lungs in PCP

A

Ga-67

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115
Q

organification

A

I-123 and I-131, oxidized by thyroid peroxidase and bound to tyrosyl moiety

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116
Q

trapping

A

transported into thryoid gland (I-123, !-131, and Tc-99)

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117
Q

Tc-99m and breast-feeding

A

resume in 12-24 hours

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118
Q

I-123 and breast feeding

A

resume in 2-3 days

119
Q

I-131 and breast feeding

A

NEVER

120
Q

diffuse homogenous uptake on thyroid scan

A

Graves

121
Q

most common cause of goitrous hypothyroid

A

hashimoto

122
Q

most common thyroid cancer subtype

A

papillary (papillary is popular)

123
Q

does medullary thyroid CA light up on I-131?

A

NO + doesn’t respond to I-131 treatment

124
Q

what scans are + with medullary thryoid CA?

A

MIBG + octreotide (~10%), cold on I-131

125
Q

ideal TSH for I-131 treatment

A

50 (>30 at least)

126
Q

how do you decide on I-131 dosing (for cancer)?

A

100 for thyroid only, 150 for thyroid + nodes, 200 for distal

127
Q

when do I-131 patients need to be admitted to hospital?

A

33 mCi of residual activity or 5-7 mR/h

128
Q

side effect of I-131 if lung mets

A

pulmonary fibrosis

129
Q

main route of elimination for I-131

A

urine (also sweat, tears, saliva, breast milk)

130
Q

when can I get pregnant after I-131?

A

6-12 months

131
Q

absolute contraindications to I-131 (2)

A

severe uncontrolled thyrotoxicosis and pregnancy

132
Q

when to give I-131 to HD patients?

A

immediate following dialysis (tubing stays in storage)

133
Q

how do you decide on I-131 dosing (for hyperthyroid)?

A

15 mCi for Graves, 30 mCi for multinodular

134
Q

Wolff-Chaikoff Effect

A

reduction in thyroid hormone levels caused by ingestion of large amount of iodine

135
Q

sestamibi likes things with

A

lots of blood flow and mitochondria

136
Q

Tracers with brain binding

A

Tc HMPAO and Tc ECD

137
Q

blood flow tracer

A

Tc DTPA

138
Q

seizures: hot vs. cold

A

HOT: during seizure, COLD: interictal

139
Q

Thallium analog

A

potassium (Na/K pump) gotta be alive to work

140
Q

Crossed Cerebellar Diaschisis

A

Depressed blood flow and metabolism affecting the cerebellar hemisphere after a contralateral supratentorial insult

141
Q

what is “tinning”

A

mixing RBCs with Tin (stannous) to reduce hemoglobin before tagging with Tc99

142
Q

timing of NPH diagnosis

A

at 48 hours there should be no activity in the lateral ventricles and there should be activity over the entire convexities

143
Q

how much activity is allowed in stomach at 4 hrs?

A

at 4 hours 10% or less of initial activity should remain in the stomach

144
Q

drug you give to help differentiate biliary atresia vs. neonatal hepatitis

A

phenobarbital

145
Q

what results in falsely elevated LVEF?

A

high background

146
Q

what do you do if you see lung activity following a treatment dose of I-131?

A

Non-contrast CT of chest

147
Q

hyperthyroid patient with low 24-hour uptake and diminished uptake in the thyroid scan

A

hashimoto

148
Q

what do you treat Hashimoto with?

A

NSAIDs

149
Q

what the heck is a salivagram for?

A

determine aspiration of pharyngeal contents (don’t confuse with salivary gland scintigraphy)

150
Q

most common cause of hyperparathyroidism?

A
  1. hyperfunctional adenoma (85%) 2. multiple gland hyperplasia (12%) 3. cancer (3%)
151
Q

4 false positives in sestamibi

A
  1. thyroid nodules 2. h&n cancers 3. lymphadenopathy 4. brown fat
152
Q

“hot nose sign”

A

2/2 perfusion through external carotid to maxillary branches (2/2 sign of brain death)

153
Q

what drug can you give to evaluate for TIAs?

A

acetazolamide (diamox) = vasodilator + perfusion tracer –> expect 3-4 x increase, but TIAs will be hypointense

154
Q

most common tracer for CSF imaging?

A

In-111-DTPA given intrathecal by LP

155
Q

abnormal CSF imaging (2)

A
  1. tracer in the lateral ventricles 2. failure to clear from cisterns and localize over convexities by 24 hours
156
Q

how to tell between NPH vs. non-obstructive hydrocephalus?

A

NPH will have normal opening pressure on LP

157
Q

how long is “delayed” to diagnose partial distal obstruction in CSF shunt?

A

> 10 min to see flow into peritoneum

158
Q

how long do you fast before a GI emptying study

A

4 hrs

159
Q

more sensitive for emptying study: solids vs. liquids

A

solids are more sensitive

160
Q

curves in emptying studying: solids vs. liquids

A

solids have a “lag phase” to get ground up, liquids don’t

161
Q

2 things that can cause failure of in vivo RBC tagging

A

heparinized tubing or recent IV contrast

162
Q

tracer used for Meckel scan

A

pertechnetate (taken up by gastric mucosal cells)

163
Q

do a Meckel scan when patient is actively bleeding or not?

A

NOT - otherwise do a bleeding scan

164
Q

3 drugs that can enhance a Meckel scan

A
  1. Pentagastrin 2. H2 blockers 3. glucagon
165
Q

false positive Meckel scan can be from

A

bowel irritation (recent scope, laxative use)

166
Q

false negative meckel scan

A
  1. recent in vivo RBC labeling 2. recent barium study (attenuation)
167
Q

if the patient has hyperbilirubinemia, do you need higher or lower dose for HIDA scan?

A

higher doses of tracer

168
Q

how long to fast for HIDA?

A

4 hours, but have eaten something in 24 hours (so your gb isn’t totally full)

169
Q

if you haven’t eaten in over 24 hours (gb is super full!), what drug can you give for a HIDA scan?

A

CCK

170
Q

“hot rim sign”

A

hyperemia in gb fossa - suggests a more angry gallbladder

171
Q

“cystic duct sign”

A

nub of activity in cystic duct, rest is obstructed = acute cholecystitis

172
Q

2 ways of showing chronic cholecystitis

A
  1. delayed filling of gb (not at 1 hr, but at 4) 2. low EF (<30%) with CCK
173
Q

dose of CCK

A

0.02 ug/kg over 60 min (micrograms!)

174
Q

dose of morphine in HIDA

A

0.02-0.04 mg/kg over 30-60 min (milligrams!)

175
Q

HIDA: No Bowel Activity , Persistent Blood Pool

A

Hepatocyte Dysfunction (Hepatitis)

176
Q

HIDA: No Bowel Activity, Blood Pool Goes Away Normally

A

common duct obstruction

177
Q

HIDA: No Gallbladder Activity x 4 hours (or 1 hour + morphine)

A

Acute Cholecystitis

178
Q

HIDA: Abnormal GB emptying (EF < 30%)

A

Chronic Cholecystitis

179
Q

2 drugs that can cause prompt HIDA tracer uptake and delayed clearance

A

dilantin (chlorpromazine) + birth control pills - mimics biliary obstruction

180
Q

what drug do you give babies in biliary atresia vs. hepatitis?

A

phenobarbital

181
Q

“reappearing liver sign”

A

BILE LEAK - liver starts to empty into bowel, then liver gets dark again b/c of leak

182
Q

what liver lesion is HOT on sulfur colloid?

A

FNH (actually only 40% hot)

183
Q

“colloid shift”

A

normally 85% of SC is taken up by liver, in cirrhosis this shifts to spleen and bone marrow (also in diffuse liver mets, diabetes, blunt splenic trauma)

184
Q

sulfur colloid + diffuse pulmonary activity

A

NOT normal - 1. excess Al in colloid 2. diffuse lung disease

185
Q

sulfur colloid + renal activity

A
  1. CHF 2. renal tx rejection
186
Q

what’s a hemangioma scan

A

Tc-RBCs - want marked HOT on delays, with no hot on immediate flow/pool

187
Q

critical organ: DTPA

A

bladder

188
Q

critical organ: Mag3

A

bladder

189
Q

renal tracer best for poor renal function

A

MAG-3

190
Q

what 3 abnormalities will all be NORMAL on perfusion/flow

A

ATN, interstitial nephritis, cyclosporin toxicity

191
Q

phases for basic renal scan

A

flow (20 sec), cortical/parenchymal (1 min), clearance/excretory (half peak by 7-10 min)

192
Q

20/3 or 20/peak ratio (renal scan)

A

peak count at 20 min/peak count at 3 min (normal < 0.8) or /peak count (normal 0.3)

193
Q

when to give lasix in suspected obstruction?

A

wait 30 min after clearance

194
Q

“dilated but not obstructed” (renal)

A

washout of 50% of tracer within 10-20 min of lasix

195
Q

“reservoir effect” (renal)

A

very dilated renal pelvis, delays transit time

196
Q

“back pressure effects” (renal)

A

full or neurogenic bladder generates back pressure, not allowing kidneys to empty

197
Q

2 reasons for poor response to lasix (besides obstruction)

A
  1. bad renal function 2. dehydration
198
Q

appearance of RAS on DTPA

A

decreased uptake and flow (loss of perfusion pressure)

199
Q

appearance of RAS on MAG-3

A

marked tracer retention (secreted tracer)

200
Q

when to stop ace-inhibitor before RAS scan

A

3-5 days if its captopril, NPO for 6 hrs (for PO ACE inhibitors)

201
Q

when does ATN occur s/p tx?

A

immediate post-op (3-4 days)

202
Q

when does cylosporin toxicity occur s/p tx?

A

long standing

203
Q

perfusion in ATN vs. cyclosporin tox vs. acute rejection

A

ATN + cyclosporin tox will have normal perfusion - acute rejection will have POOR perfusion

204
Q

excretion in ATN vs. cyclosporin tox vs. acute rejection

A

delayed in all 3

205
Q

fluid collection s/p renal tx: timing

A

urinoma/hematoma - first 2 weeks, lymphocele - 4-8 weeks delay

206
Q

fluid collection s/p renal tx: appearance

A

urinoma - tracer between bladder and tx kidney, hematoma + lymphocele - photopenia

207
Q

critical organ: DMSA

A

kidney

208
Q

why is DMSA preferred for cortical imaging in peds?

A

lower dose to gonads (compared with glucoheptonate, whatever that is)

209
Q

DMSA study: 3 appearances of acute pyelo

A
  1. focal area of decreased uptake 2. MF areas of decreased uptake 3. diffuse decreased uptake
210
Q

DMSA study: column of bertin vs. mass

A

mass is COLD, bertin takes up tracer, cause it’s normal

211
Q

DMSA study: acute vs. chronic

A

acute defect = pyelo, chronic defect = scar/mass

212
Q

FDG enters cells via what transporter

A

GLUT-1

213
Q

FDG is phosphorylated by what enzyme

A

hexokinase to FDG-6Phosphate

214
Q

2 ways to decrease brown fat uptake

A
  1. warm room 2. benzodiazepines or beta blocker
215
Q

6 classic PET COLD tumors

A
  1. BAC 2. carcinoid 3. RCC 4. peritoneal bowel/liver implants 5. anything mucinous 6. prostate
216
Q

what is the effect of high glucose (>150-200) on SUV?

A

artificially lowers SUV (increase competition for FDG)

217
Q

what is the effect of insulin on PET?

A

diffuse muscle uptake

218
Q

what is the effect of being a fat person on SUV?

A

HIGHER SUV b/c fat takes up less glucose

219
Q

if you see the RV on PET?

A

think about RVH

220
Q

PET: diffuse thyroid uptake

A

autoimmune/hashimoto thyroiditis

221
Q

PET: RCC vs. oncocytoma

A

RCC is COLD, oncocytoma is HOT

222
Q

why is HCC often cold on PET?

A

variable glucose-6-phosphatase and can’t trap the FDG

223
Q

random fact: meningiomas are hot on

A

octreotide and Tc-MDP

224
Q

most common agent for somatostatin receptor imaging

A

In-111 pentetreotide

225
Q

4 tumors showing I-131 MIBG uptake

A
  1. paraganglioma 2. pheochromocytoma 3. carcinoid 4. medullary thyroid
226
Q

I-123 vs. I-131 basics

A

I-123 better imaging quality, I-131 cheaper + longer half life allows for delayed imaging

227
Q

meds that need to be held for MIBG

A

Ca-channel blockers, labetalol specifically, reserpine, TCAs, sympathomimetics

228
Q

MIBG vs. MBP bone scan for neuroblastoma mets?

A

MIBG is superior

229
Q

Prostascint = In-111 + ?

A

antibody capromab to PSA + pendetide chelating agent

230
Q

when do you use prostascint?

A

rising PSA and negative bone scan (localized to soft tissue mets, not bone mets)

231
Q

agent used for sentinel node detection

A

10-50nm Tc99m sulfur colloid.

232
Q

what lesion depth do we use sentinel node detection for in melanoma

A

1-4mm deep - intradermal injection in 4 spots around the lesion

233
Q

what % of time does breast cancer go to internal mammary chain nodes?

A

3%

234
Q

particle size for lymphoscintigraphy

A

< 0.2 microns (<200 nm)

235
Q

particle size for liver/spleen

A

“unfiltered”

236
Q

how is the agent administered in BSGI?

A

20-30 mCi of Tc99 Sestamibi in the contralateral arm then image 20 mins later.

237
Q

what if you want to image both breasts in BSGI?

A

give sestamibi in the foot instead of contralateral arm

238
Q

when is background mibi-activity lowest?

A

mid-cycle in premenopausal women

239
Q

3 false positives in BSGI

A
  1. fibroadenoma 2. fibrocystic change 3. inflammation (how is the test useful??)
240
Q

2 false negatives in BSGI

A
  1. small <1 cm lesions 2. located in medial breast and/or overlapping the heart activity
241
Q

what if you see lymph nodes on a BSGI scan?

A

NOT normal - concerning for mets

242
Q

cardiac imaging: sestamibi vs. tetrofosmin

A

Tetrofosmin is cleared from the liver more rapidly and decreases the chance or a hepatic uptake artifact.

243
Q

how to sestamibi and tetrofosmin enter the cells?

A

passive diffusion (localized in mitochondria)

244
Q

redistribution: cardaic imaging agents

A

thallium - redistributes; sestamibi + tetrofosmin - does NOT redistribute (better flexibility)

245
Q

timing of imaging: cardiac imaging agents

A

thallium - immediately after injection; sestamibi + tetrofosmin - 30-90 min after injection to allow for background to clear

246
Q

thallium: lung/heart ratio

A

If there is more uptake in the lungs, this correlates with multi-vessel disease or high grade LAD or LCX lesions.

247
Q

what % stenosis do you need to see a defect with stress imaging?

A

50%

248
Q

what % stenosis do you need to see a defect with rest imaging?

A

90%

249
Q

meds that interfere with cardiac imaging

A

beta-blockers, Ca-channel blockers, long-acting nitrates (stop for 24 hours)

250
Q

how long NPO for cardiac imaging

A

4 hours (decreased GI blood flow)

251
Q

dose: rest vs. stress

A

low for rest, high for stress

252
Q

cardiac imaging: fixed defect

A

scar (prior infarct)

253
Q

cardiac imaging: reversible defect

A

ischemia

254
Q

cardiac imaging: fixed defect with surrounding reversible defect

A

infarct with peri-infarct ischemia

255
Q

cardiac imaging: transient ischemic dilation (LV bigger on stress)

A

apparent cavity dilation from diffuse subendocardial hypoperfusion (high risk dz - left main or 3 vessel)

256
Q

cardiac imaging: fixed cavity dilation

A

dilated cardiomyopathy

257
Q

cardiac imaging: Right Ventricular Activity on Rest

A

RVH

258
Q

cardiac imaging: Lots of splanchnic (liver and bowel) activity

A

not exercising hard enough! more stress needed!

259
Q

cardiac imaging: stunned myocardium

A

This is the result of ischemia and reperfusion injury. Normal perfusion, but contractility will be crap.

260
Q

cardiac imaging: hibernating myocardium

A

Won’t take up tracer on rest or stress (it’s not dead, just asleep - like a bad soap opera plot). The difference between hibernating muscle and scar is that the hibernating muscle will take up FDG and redistribute thallium.

261
Q

what agent is used for MUGA

A

Tc 99 RBCs

262
Q

photopenic halo around cardiac blood pool on MUGA

A

pericardial effusion

263
Q

regional wall motion abnormality on MUGA

A

usually infarct (less likely stunned or hibernating)

264
Q

how to get false low EF on MUGA

A

Screwed up LAO view can cause overlap of LV with LA or RV or even great vessels

265
Q

how to get false high EF on MUGA

A

Wrong background ROI (over the spleen), will cause over-subtraction of background and elevate the EF.

266
Q

only PET agent made in a generator

A

Rb-82 (half life 75 seconds!)

267
Q

cardiac artifacts: breast tissue

A

anterior wall decreased attenuation, may need to repeat in prone position

268
Q

cardiac artifacts: left hemidiaphragm

A

decreased activity in inferior wall

269
Q

cardiac artifacts: subdiaphragmatic radiotracer activity

A

increased activity in inferior wall, can mask true defect - exercise to reduce GI blood flow

270
Q

cardiac artifacts: patient motion/breathing

A

repeat b/c tracer is fixed for 2 hours

271
Q

cardiac artifacts: LBBB

A

reversible or fixed septal defects - seen more in exercise or dobutamine stress vs. vasodilators

272
Q

cardiac artifacts: normal apical thinning

A

normal variant, fixed “defect” with preserved wall motion

273
Q

mechanism: dipyridamole

A

inhibits breakdown of adenosine (potent vasodilator) - basically an indirect way of giving adenosine

274
Q

mechanism: adenosine

A

vasodilator (worse side effects than dipyramidole, incld AV block)

275
Q

mechanism: regadenoson

A

selective A2A - causes less side effects

276
Q

mechanism: dobutamine

A

B-1 agonist - acts like exercise by increasing HR and contraction

277
Q

mechanism: aminophylline

A

antidote for adenosine

278
Q

patients who should get dobutamine

A

those who can’t have adenosine/dipyramidole - COPD or ashtma or have taken caffeine in 12 hrs

279
Q

3 agents that treat bone pain

A

(I) Sr89-Chloride, (2) Sm153 EDTMP, and (3) Ra223-dichloride.

280
Q

(I) Sr89-Chloride vs (2) Sm153 EDTMP for bone pain

A

Sr-89 is oldest and worst, pure beta emitter - Sm153 (“samarium is a good samaritan”) is a beta decayer

281
Q

major bad side effects of (I) Sr89-Chloride vs (2) Sm153 EDTMP for bone pain

A

myelosuppression - Sr89 takes longer to recover than Sm153

282
Q

why is Ra-223 the “best” agent for bone pain

A
  1. alpha emitter - less heme tox 2. one trial showed a survival benefit in prostate ca 3. long t1/2 (11.4 days), allows for easy shipping
283
Q

Y-90 mechanism

A

pure beta emitter - penetration of 10mm (sparing most normal liver)

284
Q

ideally the lung shunt fraction for Y-90 treatment is

A

<10% (need decreased dose for 10-20% and can’t do if >20%) - measured with 99mTc MAA

285
Q

optimal particle size for Y-90

A

20-40 um

286
Q

Y-90 emissions for imaging

A

175 + 185 keV

287
Q

In-111 ibritumomab (zevalin) for non-Hodgkin lymphoma binds to what receptors

A

CD-20 receptors on B-cells

288
Q

contraindication to In-111 ibritumomab (zevalin)

A

patients with platelets less than 100K

289
Q

common side effects In-111 ibritumomab (zevalin)

A

Thrombocytopenia and neutropenia (about 90% of cases).

290
Q

liver or spleen: hotter on SC liver/spleen scan

A

liver > spleen (except in severe liver dysfunction)

291
Q

liver or spleen: hotter on In111 WBC

A

spleen > liver

292
Q

bone scan w/hot lungs + kidneys + stomach

A

hyperparathyroidsim - metastatic calcification

293
Q

timing of SC scan

A

very rapid uptake - 20-30 min scan

CORE Nucs (3 decks)

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