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51 Cards in this Set
- Front
- Back
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what is the routine for cardiac thallium imaging
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inject 2-3 mCi
image at 10 min with two windows, 69-87 keV and 167 keV |
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what predictive info does thallium give in MI
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size of thallium infarct predicts income:
>40% of LV = 92% chance of mortality over next 9 months <40% of LV = 7% mortality |
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what is adequate exercise in thallium cardiac stress imaging
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85% of maxiumum HR (220-age) or 250 000 double product
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when do you stop a stress test
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symptoms
arrhythmia 2nd or 3rd degree heart block ST depression over 3 mm systolic BP decrease or HTN > 240/120 |
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how do you tell if there was adequate exercise at imaging
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no liver uptake
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how often do areas of ischemia fill in delayed on standard thallium
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15-35%
*pearl* reinjection reduces this to negligible |
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how is a dipyridamole stress test performed
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give 140 ug/kg/min DP for 4 min
wait 7-9 min and inject thallium wait 5 min and image *pearl* reverse DP with 50-100mg of aminnophylline |
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how do you perform an adenosine stress test
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give 140 ug/kg/min adenosine for 6 min
give thallium at 3 min image 5 minutes later *pearl* adenosine's half-life is seconds, so turn it off to reverse it |
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which type of lymphoma is best seen by gallium
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hodgkin's > non-hodgkin's
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which type of hodgkin's is toughest to see on gallium
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lymphocyte predominant
*pearl* it also has the best prognosis |
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what tumors take up gallium
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melanoma
lung ca head and neck ca sarcoma gynecologic tumors |
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why must gallium be imaged late
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so that kidney, lung and bowel activity is cleared - usually by 24 hours
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ddx: lung uptake with gallium
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Some Causes of Lung Uptake Are Tough to Remember Properly
sarcoid CMV lymphoma UIP (IPF) asbestosis/silicosis TB/fungus radiation/chemotherapy PCP |
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when should you use gallium or indium in infection imaging
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indium for most bone and belly imaging
gallium for spine imaging |
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how do you tell infection with bone scan and gallium imaging together
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it's all relative
gallium > MDP uptake - infection MDP > gallium - no infection |
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how do you image prostheses
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sulfur colloid and gallium - sub out the marrow on SC from the gallium
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on V/Q imaging, what is the drawback of Xe-133 imaging
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low energy (keV = 81)
down scatter from Tc perfusion |
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what are pros and cons of radioaerosols in V/Q
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pro: multiple views because aerosolized particles settle
con: no wash out info |
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what are the minimum requirements for particle size and number in V/Q
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60 000 particles with 10-90 micron size
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how do you perform a sestamibi stress cardiac study
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2 ways to do it:
give 8 mCi image 30 min later for rest 4 hours later give 20 mCi at peak stress image 30 min later if low likelihood of disease: give 30 mCi for stress - if normal: done - if abnormal: redo next day with rest/stress |
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what are the benefits of first pass and MUGA with ventriculography
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first pass:
rapid collection measure at peak exercise RV better measured MUGA: better counts/statistics |
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how is EF calculated with nucs
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(end diastolic counts - end systolic counts)/end diastolic counts
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when is MUGA not good to use
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with afib or if >5-10% PVCs
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what is a normal study for ventriculography
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3 things:
no wall motion abnormality normal chamber size EF increases at least 5% with stress *pearl* a decrease in EF with stress portends a bad prognosis |
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ddx: increased renal uptake of MDP
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NO SCAR
nephrocalcinosis obstruction sulfur colloid/thallium chemo ATN radiation |
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ddx: decreased renal uptake
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renal failure
mets superscan paget's |
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ddx: superscan
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mets
metabolic - hyperparathyroidism - osteomalacia - renal failure myelofibrosis |
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ddx: AVN
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ASEPTICLeG
alcohol/anemia sickle cell/SLE exogenous steroids pancreatitis trauma idiopathic caisson's leukemia/legg-perthes gaucher's |
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in what situations is there a high chance of a solitary bone lesion being cancer
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spine:
- 40-80% malignant - higher if in pedicle/body - lower endplate pediatrics: - 55% malignant |
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how may one image the parathyroid
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3 options:
1. sestamibi - early: uptake in both parathyroid and thyroid - delayed: (4-6 hours) thyroid washes out, parathyroid retains 2. sestamibi minus iodine/pertechnetate 3. thallium minus iodine/pertechnetate - subtracts thyroid - iodine/tech - from thyroid/parathyroid - thal and mibi |
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what drugs cause uptake on lung gallium studies
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BANC
bleomycin amiodarone nitrofurantoin cytoxan |
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ddx: resting cardiac wall-motion abnormality
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contusion
infarct severe ischemia non-ischemic cardiomyopathy valvular heart disease endocarditis abscess |
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what is the appearance of MI on ventriculography
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ventricular dilatation
regional wall-motion abnormality decreased EF *pearl* EF < 35% in setting of MI = high mortality |
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ddx: sulfur colloid uptake in lung
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DIC
EG bone marrow transplant trauma infection serum albumin elevation radiopharmaceutical impurity liver disease malignancy |
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ddx: fatty liver infiltration
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POoR ST. JUDE
pancreatitis obesity reye's syndrome steroids TPN jejunoileal bypass ulcerative colitis DM ETOH |
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ddx: solitary splenic lesion on sulfur colloid
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infarct
abscess hematoma cyst hemangioma fibroma hamartoma lymphoma met |
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ddx: liver hot spot on sulfur colloid
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IVC/SVC obstruction
budd-chiari regenerating nodule FNH |
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ddx: absent perfusion to one lung
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obstructing mass
post pneumonectomy congenital heart disease with shunt procedure sever parenchymal disease massive pulmonary embolism |
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ddx: gallium uptake in kidneys
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Nucs Scans Are Long And Tiring To Read Particularly Post-Chemo
neoplasm sarcoid abscess liver failure amyloid TB/tuberous sclerosis transplant radiation pyelonephritis PAN chemo |
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where is gallium normally seen
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glands (lacrimal, salivary)
nasopharynx bone marrow spleen neutrophils colon thymus minimal liver |
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ddx: delayed gastric emptying
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DM
drugs surgery scleroderma anorexia amyloid high grade obstruction |
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how do you do a CSF leak radionuclide cisternogram
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use In-111 DTPA
inject via LP image at 4,24 and later if necessary include abdomen to see swallowed tracer if leaks into nose/mouth measure pledgets from nose - ratio of counts/gm nose: counts/gm serum - if > 3.1 then positive for leak |
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ddx: meckel's scan uptake
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GI DAMIT
GI tract duplication cyst AVM meckel's diverticulum inflammation (appendicitis) tumor, hypervascular |
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ddx: non-visualized thyroid
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subacute thyroiditis
IV contrast within 6 weeks exogenous iodine PTU, tapazole foods (turnips, cabbage) hypothyroidism ectopic thyroid surgery/radiation infiltration |
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ddx: increased uptake in liver on MDP imaging
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hepatoblastoma
hemangioendothelioma lymphoma hepatoma cholangiocarcinoma mets aluminum breakthru recent sulfur colloid study amyloid |
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ddx: MIBG uptake
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neuroblastoma
pheochromocytoma carcinoid medullary thyroid ca |
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evaluation for right to left shunt
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use MAA, IV
look for uptake in brain and kidney quantify by measuring: - ROI of lungs - ROI systemic (whole body - lung) - divide systemic by systemic + lung - normal = 1-10% |
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ddx: cold thyroid nodule
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carcinoma
adenoma colloid cyst hematoma focal thyroiditis fibrosis parathyroid adenoma lymphoma extrinsic mass |
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ddx: cold defect in vertebral body
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hemangioma
met infarct XRT osteomyelitis brown tumor |
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what is the formula for I-131 treatment of:
- graves - multinodular goitre |
graves:
gland wt x 100/% uptake X 160 ug/g MNG: gland wt x 100/% uptake x 240 ug/g |
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what is I-131 treatment for cancer after:
- partial thyroidectomy - total thyroidectomy |
partial:
60-80 mCI for ablation total: wait 4-6 weeks then 60-100 mci follow thyroglobulin q6mo and retreat if increased |
