NUCLEAR MEDICINE UPDATED EXAMINATION SET
QUESTIONS AND SOLUTIONS GUARANTEE A+
✔✔Common indication for V/Q scans - ✔✔Suspected PE. Preoperative estimates of
lung function. To evaluate right-to-left shunts. Serial assessment of inflammatory lung
disease.
✔✔When should a V/Q scan be ordered over CTA? - ✔✔Low clinical probability.
Normal CXR is normal. Pregnant patient. Contraindication to iodinated contrast.
✔✔Normal ventilation scans - ✔✔Homogeneous radiopharmaceutical distribution
throughout both lungs on all three phases: Initial breath. Equilibrium. Washout.
✔✔Retention (trapping) of xenon in the lungs in a focal or diffuse pattern is an indication
of - ✔✔Obstructive lung disease.
✔✔Normal perfusion scans - ✔✔Well-defined margins of both lungs on all views.
Sharply defined costophrenic angles.
✔✔Hampton hump - ✔✔Wedge-shaped, pleural-based infarct on CXR.
✔✔Westermark sign - ✔✔Wedge-shaped area of oligemia.
✔✔Most common but nonspecific CXR finding of PE - ✔✔Atelectasis or opacities in the
region of emboli. Elevated diaphragm, small pleural effusion, and/or prominent hilum
are also frequently seen.
✔✔Two moderate (25-50%) or four small (<25%) perfusion defects are equivalent to -
✔✔Full-segment defect.
✔✔Perfusion defect that demonstrates normal ventilation is termed a - ✔✔Mismatched
defect.
✔✔Perfusion defects that match ventilation and CXR abnormalities in size and location
are called - ✔✔Triple match defects.
✔✔Stripe sign. - ✔✔Central perfusion defects with a rim or stripe of increased activity
around them. Less than 10% probability of PE.
✔✔V/Q scan PIOPED categories? - ✔✔High (2 or more mismatched perfusion
segments). Intermediate. Low. Very low. Normal.
✔✔Ventilation scan signs in COPD? - ✔✔Delayed wash-in and delayed washout.
, ✔✔Perfusion defects that are significantly larger than the CXR abnormality are -
✔✔Higher probability for PE.
✔✔Three principle coronary artery distributions of the LV - ✔✔Left anterior descending
artery (LAD). Left circumflex artery (LCX). Posterior descending artery (PDA).
✔✔Pharmocologic stress agents in myocardial perfusion imaging? - ✔✔Adenosine.
Dipyridamole (if bronchospasm may give dobutamine).
✔✔At what percent stenosis can pharmocologic agents not dilate effectively? - ✔✔>
50% stenosis.
✔✔Tc-99m Sestamibi is taken up by perfused myocardium by - ✔✔Passive diffusion.
Bound in myocyte, mostly within myocardial mitochondria.
✔✔Hibernating Myocardium - ✔✔Severe ischemia with high-grade stenosis may be
slow to reverse on Tl-201 rest imaging after stress. Respond to revascularization
procedures. Perfusion-metabolism mismatch.
✔✔Stunned Myocardium - ✔✔Temporarily damaged cells around infarct. Generally is
hypokinetic or akinetic. Will not uptake Tl-201 until recovery several weeks later. Normal
perfusion.
✔✔Solitary palpable thyroid nodules are best evaluated initially - ✔✔FNA.
✔✔Discordant thyroid nodule - ✔✔Increased Tc-99m-O4 uptake but decreased I-123
uptake (lost ability to organify iodine). Increased risk of malignancy.
✔✔Measurement of the RAIU is usually indicated for one of three reasons: -
✔✔Differentiation of Graves disease (uptake high, usually >35% at 24 hours) from
subacute or factitious hyperthyroidism (uptake usually < 2%). Calculation of radioactive
iodine dose for treatment of Graves disease. Assessment of suspected toxic
multinodular goiters.
✔✔Lingual thyroid pediatric patients are at high risk of developing - ✔✔Hypothyroidism,
with an estimated risk of ~30%.
✔✔Hyperthyroidism causes? - ✔✔Graves disease (diffuse toxic goiter) is most
common. Subacute or painless thyroiditis. Toxic nodular goiter. Factitious
hyperthyroidism.
✔✔Substernal goiter imaging? - ✔✔I-123. Due to large blood pool, Tc-99m-O4 is not
useful with substernal goiters.
QUESTIONS AND SOLUTIONS GUARANTEE A+
✔✔Common indication for V/Q scans - ✔✔Suspected PE. Preoperative estimates of
lung function. To evaluate right-to-left shunts. Serial assessment of inflammatory lung
disease.
✔✔When should a V/Q scan be ordered over CTA? - ✔✔Low clinical probability.
Normal CXR is normal. Pregnant patient. Contraindication to iodinated contrast.
✔✔Normal ventilation scans - ✔✔Homogeneous radiopharmaceutical distribution
throughout both lungs on all three phases: Initial breath. Equilibrium. Washout.
✔✔Retention (trapping) of xenon in the lungs in a focal or diffuse pattern is an indication
of - ✔✔Obstructive lung disease.
✔✔Normal perfusion scans - ✔✔Well-defined margins of both lungs on all views.
Sharply defined costophrenic angles.
✔✔Hampton hump - ✔✔Wedge-shaped, pleural-based infarct on CXR.
✔✔Westermark sign - ✔✔Wedge-shaped area of oligemia.
✔✔Most common but nonspecific CXR finding of PE - ✔✔Atelectasis or opacities in the
region of emboli. Elevated diaphragm, small pleural effusion, and/or prominent hilum
are also frequently seen.
✔✔Two moderate (25-50%) or four small (<25%) perfusion defects are equivalent to -
✔✔Full-segment defect.
✔✔Perfusion defect that demonstrates normal ventilation is termed a - ✔✔Mismatched
defect.
✔✔Perfusion defects that match ventilation and CXR abnormalities in size and location
are called - ✔✔Triple match defects.
✔✔Stripe sign. - ✔✔Central perfusion defects with a rim or stripe of increased activity
around them. Less than 10% probability of PE.
✔✔V/Q scan PIOPED categories? - ✔✔High (2 or more mismatched perfusion
segments). Intermediate. Low. Very low. Normal.
✔✔Ventilation scan signs in COPD? - ✔✔Delayed wash-in and delayed washout.
, ✔✔Perfusion defects that are significantly larger than the CXR abnormality are -
✔✔Higher probability for PE.
✔✔Three principle coronary artery distributions of the LV - ✔✔Left anterior descending
artery (LAD). Left circumflex artery (LCX). Posterior descending artery (PDA).
✔✔Pharmocologic stress agents in myocardial perfusion imaging? - ✔✔Adenosine.
Dipyridamole (if bronchospasm may give dobutamine).
✔✔At what percent stenosis can pharmocologic agents not dilate effectively? - ✔✔>
50% stenosis.
✔✔Tc-99m Sestamibi is taken up by perfused myocardium by - ✔✔Passive diffusion.
Bound in myocyte, mostly within myocardial mitochondria.
✔✔Hibernating Myocardium - ✔✔Severe ischemia with high-grade stenosis may be
slow to reverse on Tl-201 rest imaging after stress. Respond to revascularization
procedures. Perfusion-metabolism mismatch.
✔✔Stunned Myocardium - ✔✔Temporarily damaged cells around infarct. Generally is
hypokinetic or akinetic. Will not uptake Tl-201 until recovery several weeks later. Normal
perfusion.
✔✔Solitary palpable thyroid nodules are best evaluated initially - ✔✔FNA.
✔✔Discordant thyroid nodule - ✔✔Increased Tc-99m-O4 uptake but decreased I-123
uptake (lost ability to organify iodine). Increased risk of malignancy.
✔✔Measurement of the RAIU is usually indicated for one of three reasons: -
✔✔Differentiation of Graves disease (uptake high, usually >35% at 24 hours) from
subacute or factitious hyperthyroidism (uptake usually < 2%). Calculation of radioactive
iodine dose for treatment of Graves disease. Assessment of suspected toxic
multinodular goiters.
✔✔Lingual thyroid pediatric patients are at high risk of developing - ✔✔Hypothyroidism,
with an estimated risk of ~30%.
✔✔Hyperthyroidism causes? - ✔✔Graves disease (diffuse toxic goiter) is most
common. Subacute or painless thyroiditis. Toxic nodular goiter. Factitious
hyperthyroidism.
✔✔Substernal goiter imaging? - ✔✔I-123. Due to large blood pool, Tc-99m-O4 is not
useful with substernal goiters.
