Nuclear Cardiology dx tests and procedures/protocols/artifacts

Question 1

Which of the following is an indication for performing pharm stress in lieu of a treadmill test for SPECT MPI?
a. severe symptomatic PAD
b. chronotropic incompetence
c. LBBB
d. neurologic and MSK disorders
e. all of above

Answer 1

E.

Question 2

Which of the following is not a contraindication to performing a pharm stress test with adenosine?
a. pentoxifylline
b. caffeinated food or bev <12 hrs prior to stress
c. severe COPD w/ ongoing wheeze
d. Dipyridamole or aminophylline <24 hrs prior to stress
E. 2nd or 3rd deg AV block or sick sinus syndrome w/o PPM

Answer 2

A.
adenosine is a nonselective agonist that causes coronary vasodilation when it activates the A2A receptor. A1, A2B, and A3 when activated produce most of side effects including chest pain, bronchiolar constriction, mast cell degranulation (flushing), and neg chronotropic, inotropic, and dromotropic effects.
Caffeine and aminophyline bind to adenosine receptors w/o stimulations. aminophylline should be held 24-48hrs prior to testing. dipyridamole should be held for 24-48hrs. Pts with severe COPD and active wheeze should NOT undergo adenosine/dipyridamole stress due to A2B/A3 receptors causing constriction. OK for albuterol before.

Question 3

In which of the pts w/ an STEMI is there an approp, role for SPECT MPI?
a. stable pts who have undergone cor angio and PCI
b. decomp CHF pts w/ life-threatening arrhythmias and hemodynamic instability
c. stable pts who have undergone successful reperfusion and cor angiography
d. stable pts scheduled for coronary angio
e. stable pts prior to d/c who are not scheduled to undergo cardaic cath

Answer 3

E. is a class I indication. looking for inducible ischemia would change the treatment plan

Question 4

49 yo woman is being evaluated for atypical chest pain. She had an MI 2 yrs ago and received a BMS to the mid LAD> After consulting her pcp she is concerned about the spect mpi. which of the following regarding spect mpi in women is/are correct?
a. women have smaller hearts, which improves image quality and accuracy
b. breast attenuation is not reduced by using tech-99m radiopharm
c. spect diagnostic specificity in women is above 90%
d. best use of the test is in women wiht intermediate to high pretest likelihood for CAD
e. PET has the same diagnostic accuracy as spect in women

Answer 4

D.
Small LV chamber size adversely affects image quality and diagnostic accuracy esp if using thall 201. Women have smaller hearts than men, which diminishes accuracy.
breast attenation can produce anterior wall defects that may mimic LAD infarct. tech-99m agents with ecg gating have less attenuation and give better gated images than thall 201, improves accuracy by improving specificity.
specificity for dx CAD is reduced to 65-70% due to breast tissue artifact but can be improved to 85-90% when integrating rotating projections, wall motion, and attenuation correction.
PET has higher dx accuracy than spect in women with improved accuracy by more successfully addressing breast attenuation, obesity, and small heart

Question 5

An elderly female pt with renal impairment and chest pain is referred for spect mpi. Which of the following statements is true?
a. more severe renal dysfunction, the lower the likelihood of an abnormal spect
b. mortality is increased in pts with a normal MPI and moderate to severe renal dysfunction
c. thall 201 spect stress testing is not effective in renal-impaired pts for predicting high risk of a major cardiac event
d. pts who undergo spect imaging prior to transplant are found to have ischemia in up to 10% and they have a high adverse cardiac event rate

Answer 5

D. Presence of CKD predisposes to accelerated atherogenesis and increased CV risk. Mortality almost doubles in pts with moderate or seveere CKD in presence of abnormal stress spect mpi; the more severe ckd higher the probability of having an abnormal spect study, and more severe ischemia.

Question 6

Tech-99m labeled perfusion tracers are most commonly used to assess resting adn stress myocaridal perfusion. studies have shown admin of nitrates prior to the resting injection images results in which of the following?
a. improve readers ability to detect viable myocardium in severely hypoperfused segments
b. improves overall delivery of tracer to myocardium and therefore improves the quality of images
c. interferes with interpretation of the stress images
d. is of no value, since tech-99m labeled agents do not redistribute
e. none of above

Answer 6

A.
use of nitrates in conjunction wiht rest tech-99m spect mpi has been shown to improve detection of viable myocardium. Compared iwht resting tech-99m studies alone, nitrate enhanced spect has greater ability to predict improvement of regional fxn after revascularization and to provide important prognostic infor.

Question 7

which of the following statements regarding the general sensitivity and specificity for detection of CAD of various cardiac stress testing image methods is true?
a. pet is more sensitive but least specific
b. spect mpi is more sensitive and specific compared to exercise ecg
c. stress echo is more sensitive but less specific than spect
d. sensitivity and specificity of all tests are independent of the population studied

Answer 7

B.
Cardiac pet has the highest sensitivity and specificity of currently available noninvasive modalities. spect has a higher sensitivity and lower specificity in comparison to stress echo. stress ecg vs spect, speect has higher sensitivity and specificity.

Question 8

Exercise spect mpi is the best initial test in which of the following situations?
a. 27 year old female pt with sharp chest pain, no risk factors, normal resting ecg and able to exercise
b. 72 yo male with atypical cp, dm, and htn, lvh and able to exercise
c. 69 yo with atypical cp, new af, an ecg with 2mm st depression and unable to exercise
d. a symptomatic 76 yo female with intreasing typical cp, 3vessel cabg 2 yrs ago, normal ecg, and able to exercise

Answer 8

B.
in female pt with low pretest probability for cad who has a normal baseline ecg and capable of exercising, spect mpi is not indicated and a stress ecg is best. pt with intermediate probability of cad and lvh on baseline ecg is best candidate for exercise stress spect. the ecg alone would not be diagnostic and imaging is required.

Question 9

Failure to achieve 85% of the max age predicted heart rate during spect imaging may reduce the diagnostic performance by which of the following?
a. reducing the size and severity of the perfusion defects
b. interfering with the acquisition of ecg-gated images
c. not allowing enough time for trace uptake
d. lowering the normalcy rate of the test

Question 10

which of the following is an advantage of dual isotope spect mpi?
a. flexibility of performing 1 day stress/rest, rest/stress or 2 day sequence
b. existence of validated attenuation correction algorithms for thallium-20 but not tech-99
c. improved efficiency in the nuclear card lab
d. easier interpretation of artifacts

Question 11

Which of the following variables in sot part of the Duke TReadmill Score?
a. anginal cp
b. chronotropic incompetence
c. magnitude of st segment changes
d. exercise time

Answer 11

B.
chronotropic incompetence is predictive of future cardiac events

Question 12

Which of the following is not a contraindication for spect stress MPI?
a. decompensated chf
b. unstable angina
c. stable post-MI
d. critical valvular disease

Answer 12

C.

Question 13

Relative to a treadmill exercise ecg testing in women, spect mpi does which of the following?
a. is comparable in sensitivity and specificity
b. improves specificity
c. improves the specificity but compromises the sensitivity
d. improves the sensitivity but compromises the specificity

Answer 13

B.
spect improves specificity without compromising sensitivity in the detection of CAD in women compared to exercise ecg stress testing alone

Question 14

Which of the following does not result in poor SPECT quality or creation of artifacts?
a. body size and habitus
b. LVH
c. patient gender
d. patient position relative to the camera

Answer 14

B.
SPECT MPI w/o attenuation correction is adversely influenced by the presece of different tissue densities and the distance between the heart and gamma camera. Camera distance from the patient, ie obesity or poor positioning, results in lower counts and poor quality studies. breast size, density, and position and diaphragmatic position and thickness all cause attenuation resulting in low counts in the covered portions of the myocardium and the appearance of less tracer uptake in the presence of normal blood flow. LVH may improve counts which results in better-quality images with the risk of hiding small areas of ischemia.

Question 15

In a male patient undergoing spect mpi, which of the following is least likely to cause an artifact?
a. abdominal protuberance
b. anterior chest attenuation related to obesity
c. shifting breast artifact
d. elevated diaphragm

Answer 15

C. Abdominal protuberance due to obesity or ascites can cause elevation of the diaphragm and greater inferior wall attenuation and the need to position the gamma camera head further from the patient, which will lower total counts and give poor image quality. chest wall obesity also requires positioning the gamma camera head further from the pt, and mal pts may have substantial gynecomastia. The breast tissue is unlikely to shift between rest and stress images.

Question 16

Breast attenuation is likely to create spect artifacts resulting in which of the following?
a. decreased sensitivity in the rca territory
b. decreased specificaty in the rca territory
c. decresed sensitivity in the lad
d. decreased specificity in LAD

Answer 16

D.
breast artifacts are seen in 40% of myocardial perfusion images in women often present in the anterior wall leading to a lower specificity to correctly diagnose CAD in LAD.

Question 17

All of the following are measures employed to limit or recognize attenuation artifacts in spect mpi except:
a. utilizing higher-energy pharmaceutical
b. reviewing rotating projection images
c. performing quantitative analysis
d. using pharmacologic in place of exercise stress

Answer 17

D.
use of tech-99 radiolabeled perfusion agents results in less attenuation and scatter and gives higher-quality images than thall-201. Review of the rotating projection images in cine format allows identification of the position of the diaphragm and breasts and estimation of the movement of the heart in vertical and horizontal planes. Using gender-matched normal files for quantitative analysis helps to eliminate attenuation artifact. Type of stress does NOT influence attenuation while the higher background usually seen with pharm stress results in poor image quality.

Question 18

Quantitative analysis of SPECT MPI has been used to help differentiate attenuation artifacts from true perfusion defects. Comparison of a given patient to which of the following normal databases gives the best specificity?
a. age matched
b. gender matched
c. weight matched
d. risk factor matched

Answer 18

B.
Normal databases are usually matched for type of protocol, form of stress, adn the type of agent. Gender-matched normal files improve specificity most by accounting for differences in amount of breast attenuation.

Question 19

Prone imaging improves spect mpi accuracy b/c it allows recognition of which of the following?
a. diaphragmatic attenuation
b. patient motion
c. breast attenuation
d. residual liver activity

Answer 19

A.
Prone imaging provides greater separation between heart and diaphragm, so there is less inferior wall attenuation in comparison to a suine image. Pts are usually imaged both prone and supine and a comparison is made. Most available normal files are for supine imaging. Pt motion, breast attenuation, and residual liver activity can be seen on both prone and supine.

Question 20

Which of the following is a true statement about gated spect mpi?
a. it has a very high spatial and temporal resolution compared to echocardiographic methods.
b. it is generated from the best cardiac cycles during image acquisition
c. it improves specificity and reader confidence in the spect interpretation
d. EF measurements can help in the dx of diastolic dysfunction

Answer 20

C.
Traditional gated spect has a low spatial and temporal resolution compared to echo methods. Spatial resolution varies from 14-16mm and the temporal resolution is restricted to 8 or at most 16 time frames for the RR interval. Greater temporal resolution is limitied by the resulting low counts in each time interval. ECG gated SPECt is generated from all teh cardiac cycles throughout the acquisition process. Gated images can help differentiate perfusion defects due to scar, which do not move or thicken, and attenuation defects that move and thicken. The EF is a measure of systolic function.

Question 21

Which of the following maneuvers is most likely to eliminate liver retention with tech-99 radiotracers and improve image quality?
a. having ptient drink two 8oz glasses of water and imaging immediately after pharm stress
b. having patient drink 4oz glasses of a carbonated drink and imaging immediately after pharm stress
c. waiting 45 mins before imaging following pharm stress
d. switching the patient from exercise to pharm stress

Answer 21

C.
Both tech-99 sestamibi and tetrofosmin are cleared from the liver in a time dependent manner. Having the patietn drink large amounts of water or small amounts of a carbonated liquid which will release gas, will not enhance liver clearance and the recommended imaging time after pharm stress or rest is 30-60mins. Imaging immediately after pharm stress will result in significant liver retention. Delaying image acquisition and adding exercise to the stress tests can lead to better clearance and therefore lower liver and GI counts.

Question 22

which of the following is/are the most appropriate reasons for using pharm stress testing?
a. PAD limiting exertion
b. presence of LBBB or PPM
c. failure to achieve target HR with dynamic exercise
d. all of above

Answer 22

D.
w/ a LBBB or V paced rhythm septal defect may be observed with exercise stress and decreased when using pharm stress

Question 23

Although vasodilators are generally preferred for pharm stress spect mpi, in which of the following situations is dobutamine the most appropriate stress agent?
a. pt taking BB
b. pt who are in AF
c. Pt in whom higher-sensitivity spect study is desired
d. pt who are being treated with theophylline

Answer 23

D.
Dobutamine is a stress inotropic agent that can be used for pharm stress testing in pts with active airway disease or in patients being treated with theophylline. In such patients dipyridamole, adenosine, or regadenoson may cause further airway decompensation by stimulation of adenosine a2b or a3 receptors that mediate bronchospasm. Theophylline blocks the adenosine receptors and is used to treat side effects induced by vasodilators.

Question 24

Which of the following is the most appropriate explanation for why dipyridamole, regadenoson, and adenosine are effective pharm spect stress agents?
a. ability to increase coronary blood flow 2.4-4.5x above baseline
b. Increase in HR and BP
C. Dilation of epicardial coronary vessels
d. dilation of critically stenosed coronary vessels

Answer 24

A.
all of these agents act as direct or indirect vasodilators of the resistance arterioles varying from 2.4-4.5x above baseline blood depending on the agent. Regadenoson gives a more physiologic increase in blood flow relative to adenosine and dipyridamole, which give a greater response.

Question 25

Which adenosine receptor induces coronary vasodilation when activated?
a. a1
b. a2a
c. a2b
d. a3

Answer 25

B

Question 26

Which of the following is a CV effect of adenosine?
a. vasoconstriction
b. vagal mediated bradycardia
c. increased adrenergic activation
d. bradycardia and AV block

Answer 26

D.
CV effects of adenosine include:
potent vasodilator, vagal inhibition at low doses leading to increase in HR, bradycardia and AV block at high doses, reduced adrenergic activity

Question 27

Which of the following is a biologic effect of dipyridamole?
a taken up rapidly by RBCs and endothelial cells
b. biologic 1/2 life of dipyridamole is 30-45s
c. it is primarily metabolized in the liver
d. due to its short 1/2 life, it is not used in PET imaging

Answer 27

C. Dipyridamole is primarily metabolized in the liver and should be used cautiously in patients with hepatic dysfxn. The biologic 1/2 of dipyridamole is 30-45mins. Adenosine but not dipyridamole is rapidly taken up by RBCs and endothelial cells, and this explains the short biologic 1/2 life of adenosine. The longer 1/2 life makes it good agent for pet imaging as it doesn’t need to be given as a continuous infusion over an extended period of time

Question 28

The side effects reported with adenosine and dipyridamole are due to which of the following?
a. stimulation of a2a receptors
b. stimulation of a1, a2b, and a3 receptors
c. generation of metabolites
d. paradoxical coronary vasoconstriction

Answer 28

B
stimulation of a2a receptors on arterial smooth muscle cells is what leads to coronary vasodilation. a1 a2b and a3 receptors are responsible for undesirable side effects

Question 29

Which of the following is a feature of regadenoson?
a. shorter 1/2 life then adenosine
b. selective activation of a2a
c. longer administration time
d. weight adjusted dosing

Answer 29

B.
Regadenoson selective a2a receptor agonist and approved in 2008. Following a fixed bolus injection of 400mcg over 10 seconds, it produces hyperemia of 2.5x the baseline blood flow with rapid onset for ~2-5mins.

Question 30

Relative to adenosine, pts receiving regadenoson are more likely to have which of the following?
a. Headaches
b. perfusion defects
c. lower poststress EF
d. higher incidence of dyspnea flushing and chest pain

Answer 30

A.
Regadenoson has more HAs

Question 31

Which of the following patients should not receive dipyridamole, adenosine, or regadenoson for spect mpi pharm stress?
a. taking oral dipyridamole
b. known sick sinus syndrome
c. known high-degree AV block
d. taking aggrenox
e. all of above

Answer 31

E.
dipyridamole is an ingredient in aggrenox and leads to prolonged half life of adenosine

Question 32

Coronary steal is sometimes described in pts undergoing vasodilator pharm spect and pet stress tests. When this phenomenon occurs, it is usually:
a. clinically silent
b. assoc with st changes and/or symptoms
c. related to adequate flow in the collateral circulation
d. only seen in pts who had prior bypass coronary surgery

Answer 32

B.
Vasodilators do not significantly increase cardiac work or increase 02 demands but may cause a coronary steal by dilating vessels with noncritical stenoses that are supplying collaterals to areas with high-grade stenosis. This may result in an intracoronary steal due to inadequate flow through the collaterals resulting in an endocardial to subepicardial steal. It is usually assoc with clinical symptoms and ischemic ST changes.

Question 33

Simultaneous low-level exercise is often used during vasodilator spect pharm stress testing. The main advantage of low-level exercise is:
a. increased coronary vasodilation
b. achieving maximal predicted HR
c. inducing true ischemia
d. reducing side effects

Answer 33

D.
Vasodilators used in pharm spect stress protocols produce a fourfold increase in coronary blood flow in normal coronaries, which is greater than that achieved with exercise or dobutamine stress. Ischemia is not a requirement to detect heterogeneity in coronary blood flow on the spect images. Pts usually undergo a low level exercise without achieving target HR in order to minimize the side effects of vasodilators and facilitate the clearance of tracer activity from the liver and gut, which results in better image quality

Question 34

When using vasodilators for pharm spect or pet stress testing, which of the following statements is true?
a. BB, CCB, and nitrates have no impact on the sensitivity of the test and can be continued
b. BB, CCB, and nitrates can decrease the sensitivity of the test and should be discontinued if possible 24 hrs before test
c. only nitrates can decrease the sensitivity of the test
d. only CCB can decrease the sensitivity of the test

Answer 34

B. Pts undergoing spect or pet mpi on maximal BB, CCB, and nitrates can have normal perfusion studies or a significant reduction in the amount of detected ischemia in comparison to studies performed while off these meds. Thus, they should be held for 24-48hrs prior to testing.

Question 35

In pts w/ CKD undergoing pharm spect stress testing, the following statement is true:
a. the annual death rate with a normal scan is <1%/year
b. ischemia but not scar is a predictor of mortality
c. scar but not ischemia is a predictor of mortality
d. both scar and ischemia are predictors of events

Answer 35

D.
W/ a normal SPECT scan, the annual cardiac death rate is 2.7% when CKD is present: w/ no CKD and a normal test, the annual cardiac death rate was significantly lower 0.8%. Pts w/ CKD and scar have an annual event rate of 5.7%. Pts w/ CKD and ischemia have an annual event rate of 11%.

Question 36

which of the following is the most appropriate indication for performing spect mpi?
a. low likelihood of CAD, interpretable ecg, and able to exercise
b. CP w/ ST elevation
c. high pretest likelihood of disease
d. intermediate pretest probability of CAD.

Answer 36

D

Question 37

A 37 yo male presents for a general health checkup. He has no symptoms or risk factors for cad, but he is very concerned b/c his exercise parthner had a stress spect study and was found to have ischemia and multivessel CAD. Is a stress spect mpi an appropriate test?
a. He is at intermediate risk and a stress spect is appropriate
b. he is at high risk for cad and coronary angio is appropriate
c. he is low risk and stress spect stress test is inappropriate
d. spect stress test followed by a CT calcium score is appropriate

Answer 37

C.
This is an asymptomatic pt with very low Framingham risk score. Stress SPECT study is considered inappropriate as is a coronary angiogram.

Question 38

A 57yo male pt is seen in a preventive cardiology setting. He has a bmi of 29 and hypertensive. He is known to have abnormal cholesterol but tells you that his cholesterol now is normal on simvastatin. He has no symptoms and exercises 3x/week when he is off duty from his job as a pilot. His baseline eCG shows normal sinus and 1mm of st depression inferolaterally. Based on his presentation:
a. recommend aggressive risk factor modification
b. recommend aggressive risk factor modification and stress spect MPI
c. Recommend a pharm spect and aggressive risk factor modification
d. He is asymptomatic and therefore no further risk assessment is needed

Answer 38

B.
This is an intermediate - risk score and high-risk occupation. He is able to exercise but has a potentially nondiagnostic baseline ECG. A stress test with an imaging modality is recommended.

Question 39

63 yo female patient has a family hx of CAD, prior tobacco use, htn, and dm. She had a normal spect mpi 1.4 yrs earlier and was told to get a yearly spect for follow up. She apologizes for missing her appt, at 1 yaer to hae the stress done, but tells you that she brought her running shoes and she is fasting and ready to stress today. She is overall asymptomatic and participates in a walking club with yoga 5 days/wk after work. Base on her presentation, you recommend:
a. proceed with stress spect study
b. only a stress ecg w/o imaging
c. coronary Ca score followed by a stress spect
d. No stress is needed, cont aggressive risk factor modifications

Answer 39

D.
This is an asymptomatic pt w/ a prior normal stress test w/in 2 years. No further testing is indicated.

Question 40

A 47 yo female premenopausal pt who presents for preop risk assessment prior to lap chole. She has a hx of htn that is treated with low dose diuretic and is otherwise “healthy”. She power walks 5x/wk w/o any sx’s. Her baseline ecg shows normal sinus w/ infrequent premature beats and otherwise is unremarkable. The anesthesiologist recommended a stress test prior to the gallbladder surgery. Your rec was:
a. proceed with surgery pt is at acceptable risk
b. stress ecg for further risk assessment
c. stress spect mpi given the baseline ecg
d. stress echo given the baseline ecg and to avoid radiation exposure

Answer 40

A.
This is a low risk asymptomatic pt undergoing a low-risk surgery. She can exercise >4 METS w/o difficulty. Preop stress testing is not indicated and will not alter her risk or management.

Question 41

Which of the following patients is at the highest risk for serious hypotension in pt’s receiving regadenoson for spect mpi?
a. female pts
b. male pts
c. patients w/ autonomic dysfxn
d. patient with PAD

Answer 41

C.
Pts w/ autonomic dysfxn. The risk of serious hypotension may be higher in pts with autonomic dysfxn, hypovolemia, left main CAD, stenotic valvular HD, pericarditis, or pericardial effusions, or stenotic CAD. Gender and PAD do not increase the risks of hypotension

Question 42

For symptoms occurring in >5% of patient receiving regadenoson for spect mpi, which of the followign side effects last longest?
a. dyspnea
b. HA
c. chest pain/discomfort
d. dizziness

Answer 42

B.
Most common adverse reactions >/=5% to regadenoson are dyspnea, HA, Flushing, CP, angina or st segment depression, dizziness, chest discomfort, nausea, abdominal discomfort, dysgeusia, and feeling hot. Most reaction start soon after administration and resolve in <15mins except HA ~30mins

Question 43

In patient who received an initial adenosine study and were then randomized ot receive either a repeat adenosine or a regadenoson, what was the interobserver agreement rate between adenosine vs adenosine and adenosine vs regadenoson?
a. 85-90%
b. 30-35%
c. 60-65%
d. 50%

Answer 43

C.
The interobserver agreement rate was very similar for adenosine-adenosine and adenosine-regadenoson for 3 independent blinded readers and varied from 61-64%; there was no difference between serial adenosine and adenosine-regadenoson.