SP8:Cardiovascular System Scintigraphy Flashcards Preview

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Flashcards in SP8:Cardiovascular System Scintigraphy Deck (82)
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1
Q

What portion of an ECG wave represents the depolarization of the ventricles?
(a)QRS complex

(b) P wave
(c) ST segment
(d) T wave

A

(a) The QRS complex represents depolarization of the ventricles. The P-wave represents depolarization of the atria. The ST segment is representative of a pause between depolarization and repolarization of the ventricles. The T-wave represents repolarization of the ventricles.

2
Q

A patient is only able to tolerate three images during a 201Tl chloride myocardial perfusion study. From those views listed, which would be the best choice of images to obtain?s
(a)RAO 10°, LAO 45°, and left lateral

(b) Anterior, LAO 25°, and LAO 60°
(c) Anterior, LAO 45°, and LAO 70°
(d) Anterior, LAO 70°, and left lateral

A

(c) In general, the 45° LAO should allow visualization of the septum and the inferoapical and posterolateral sections of the left ventricular wall. The anterior would then show the inferior, apical, and the anterolateral wall sections, and the 70° LAO would allow evaluation of the anterior, apical, inferior, and posterolateral all sections. If the septum is not well resolved on the 45° LAO due to the patient’s anatomy, another angle could be chosen, and the remaining two angles calculated by subtracting 45° for the “anterior” and by adding 25° for the steep lateral oblique.

3
Q

Within what time frame must imaging be initiated following injection of 201Tl chloride in an exercise perfusion study?
(a)Within 5 min

(b) Within 10–15 min
(c) Within 20–30 min
(d) Within 4 h

A

(b) Following injection the patient ideally continues to exercise for 30 s to 1 min to allow localization of the radiopharmaceutical in the myocardium, and imaging begins as soon as possible. Most sources state 10-15 min as the maximum time allowed before imaging is begun. Although 5 min would be better, it is not usually possible to remove the patient from the exercise situation and into imaging position within this time.

4
Q

Of the choices offered, which is the best imaging view for calculating right ventricular ejection fraction, using a first-pass study?
(a)RAO 60°

(b) RAO 30°
(c) Anterior
(d) LAO 10°

A

(b) First-pass studies are used to calculate the ejection fraction of the right ventricle and are generally performed using the 30 RAO position.

5
Q

Of the choices offered, which is the best imaging view for calculating left ejection fraction?
(a)Anterior

(b) LAO 5
(c) LAO 45
(d) Left lateral

A

(c) The 45 LAO is, from the choices listed, the best choice for imaging when calculation of the left ventricular ejection fraction.

6
Q

Given the data below, calculate the left ventricular ejection fraction.
Net ED = 58,219
Net Es = 35,317
(a)16%

(b) 39%
(c) 43%
(d) 60%

A

(b) Ejection fraction is the portion of blood in the ventricle that is pumped out with a single heartbeat. Ejection fraction is calculated as a percentage of the counts at end diastole using the formula:
(End diastolic counts - end systolic counts x 100) / (End diastolic counts - background counts)
Because the counts given in the question are net counts, we do not need to subtract background. Using the formula given, 39% is the ejection fraction.

7
Q

The left ventricular ejection fraction determined is within the normal range.
Net ED = 58,219
Net Es = 35,317
(a)True

(b)False

A

(b) Ejection fraction of the left ventricle is usually considered normal if above 50%, though some sources state 55%. Normal EF for the right ventricle is >40%

8
Q

Figure 1 shows computer-generated time activity curves over a cardiac cycle for two patients. Which curve represents the patient with the higher ejection fraction?

a: ED = 15319 - ES = 7886
b: ED = 24614 - ES = 8148

(a) 1a
(b) 1b

A

(b) Without calculating, it can be seen that there is a greater difference in counts at the end of end diastole vs. end systole (counts at end systole are nearly a third of those at end diastole) in the lower curve than on the upper curve (where end systolic counts are roughly half of end diastolic counts). The ejection fraction calculated for the upper curve is 66%. and the ejection fraction represented by the lower curve is 48%.

9
Q

Which of the following cannot be evaluated by radionuclide ventriculography?
(a)Wall motion

(b) Wall thickness
(c) Aneurysmal flow
(d) Conduction abnormalities

A

(b) The radionuclide ventriculography can be used to assess wall motion but is not ideal for measuring wall thickness because camera resolution and partial volume effects limit the reliability of such measurements. Dyskinetic segments resulting from left ventricular aneurysms can be assessed by creating a paradox image (subtraction of the diastolic frame from the systolic frame) which may show increased activity in this case. Ventricular aneurysm may also cause parts of the wall to contract out of phase with the rest of the ventricle.

10
Q

The images in Fig. 2 represent what type of images?
(Cardiac image > )
(a)Short axis

(b) Vertical long axis
(c) Horizontal long axis
(d) None of the above

A

(b) The vertical long-axis projections have been created during a SPECT 201Tl study. These images logically show the left ventricle from the septum to the lateral wall of the ventricle.

11
Q

During a gated study, 24 images per cardiac cycle are obtained. If the patient’s heart rate is 65 bpm, the length of time per image is:
(a)3.8 ms

(b) 38 ms
(c) 4.1 ms
(d) 41 ms

A

(b) If there are 65 bpm, each cardiac cycle lasts 0.92 s (60/65=0.92). If that cycle is divided into 23 images, each images represents 38 msec (0.92/24 = 0.0384).

12
Q

A right anterior oblique is useful for:
(a)Facilitating calculation of LVEF and RVEF on first pass

(b) Separating ventricles from the stomach on first pass
(c) Visualizing the lateral wall of the left ventricle
(d) Increasing patient comfort and potentially improving image quality

A

(a) First-pass studies are often performed using an RAO of 10-30 in order to allow calculation of ejection fraction for both right and left ventricles. This position also separates ventricular from atrial activity.

13
Q

What will reverse the effects of dipyridamole?
(a)Dobutamine

(b) Cholecystokinin
(c) Aminophylline
(d) Adenosine
(e) Thallium

A

(c) Dipyridamole, adenosine, and dobutamine can be used to produce pharmacologic stress. The side effects of dipyridamole can be reversed by using aminophylline, which should be on hand during, and for 1 h following, dipyridamole administration. Side effects of dipyridamole include angina, dizziness, and headaches and nausea.

14
Q

Which of the following will most negatively affect radionuclide ventriculography?
(a)Sinus tachycardia

(b) Sinus bradycardia
(c) Long Q-T interval
(d) Occasional PVC
(e) Sinus arrhythmia

A

(e) The R-wave signals the start of data collection, but each R-R interval is divided into segments, so if the R-R interval varies, as it does in arrhythmia, the data will be degraded. If this data is filtered out, the exam time will be increased.

15
Q

The vertical long-axis view of the heart is most comparable to a:
(a)Coronal image

(b) Sagittal image
(c) Transverse image

A

(b) Vertical long-axis slices show sections of the left ventricle from the septum to the free wall and are most similar to sagittal images.

16
Q

As an alternative to exercise studies, pharmacologic stress can be achieved through the use of any of the following except:
(a)Dipyridamole

(b) Aminophylline
(c) Dobutamine
(d) Adenosine

A

(b) Aminophylline may be used to reverse the side effects of dipyridamole which is used to create pharmacologic stress, as are adenosine and dobutamine.

17
Q

In multigated analysis of the left ventricle, end systole is best described as:
(a)The frame with the highest number of counts in the ROI around the left ventricle

(b) The frame with the lowest number of counts in the ROI around the right ventricle
(c) The frame with the lowest number of counts in the ROI around the left ventricle, plus the counts from the background ROI
(d) All of the above
(e) None of the above

A

(e) End systole is represented by the frame with the lowest number of counts in the ROI around left ventricle.

18
Q

All of the following will negatively affect a non-gated myocardial study with 201Tl chloride except:
(a)Wrong collimator

(b) Arrhythmia
(c) Incorrect COR
(d) Increased patient to detector distance
(e) None of the above

A

(b) The quality of a non-gated study would not be affected by arrhythmia, but using the wrong collimator, or center of rotation would, as would increased patient to detector distance.

19
Q

Dipyridamole is supplied to a nuclear medicine department in 10-ml vials, each containing 50 mg. If a patient weighs 155 lb, how many milliliters must be injected for him to receive 0.56 mg/kg?
(a)7.9 ml

(b) 8.7 ml
(c) 17.4 ml
(d) 39.5 ml

A

(a) The patient’s weight must first be converted from pounds to kilograms (155 lb divided by 2.2 lb/kg = 70.7) and then multiplied by 0.56 mg to find the required dose (39.5 mg required). Since each ml of dipyridamole contains 5 mg, 39.5 is divided by 5 to find the number of ml to inject 39.5/5 = 7.9).

20
Q

Which of the following does not describe correct preparation for an exercise myocardial perfusion study?
(a)NPO at least 4 h prior to radiopharmaceutical administration

(b) Catheter placement for injection of radiopharmaceutical during exercise
(c) Halt all medication 24 h before study
(d) None of the above

A

(c) Patients should be on NPO for at least 4 h before the exam, although some departments now allow water to drink, and in the case of diabetics, a light meal is often allowed. Caffeinated food and beverages are also often restricted after midnight before the exam, and sometimes for 24 h before it. Medications may or may not be taken before the exam according to the needs of the patient. Intravenous access is always in place before exercise begins to facilitate the administration of the radiopharmaceutical.

21
Q

During an exercise gated study, the ECG pattern suddenly becomes dramatically different, although the patient is responsive, has an unchanged pulse rate, continues to exercise, and has no pain. The technologist should first:
(a)Start CPR

(b) Call a code
(c) Check for a disconnected lead
(d) Call the referring physician
(e) Do nothing

A

(c) In the situation described, the most likely explanation is a disconnected ECG lead and can quickly be confirmed. If this is not the case, medical assistance should be immediately sought.

22
Q

Which of the following radiopharmaceuticals is not used to study the heart?
(a)99mTc sestamibi

(b) 99mTc HSA
(c) 99mTc PYP
(d) 32P chromic phosphate
(e) both (b) and (d)

A

(d) 99mTc sestamibi is used for myocardial perfusion imaging, 99mTc pyrophosphate has been used for myocardial infarct detection, and 99mTc HSA can be used for cardiac blood pool scintigraphy. 32P is a beta emitter and has therapeutic applications.

23
Q

Which of the following is not a critical factor in obtaining a gated first-pass study?
(a)Tracer bolus of small volume

(b) Regular heartbeat
(c) The use of a multi-crystal gamma camera
(d) Positioning the heart in the center of the field of view
(e) Injection of at least 10 mCi of radiotracer

A

(c) The radioactive dose should be administered in as small a volume as possible, in the hope that the bolus will be intact upon entering the heart. Because the first-pass study represents very few heartbeats, it is important that those beats not be rejected. As with all dynamic studies, careful positioning is critical. Hot markers can be used to ascertain that the sternal notch and the xiphoid process are within the FOV, and the detector head should be in an RAO position. A multi-crystal camera is ideal because of the high count rate, but is not strictly necessary. A high-sensitivity collimator is also preferred.

24
Q

The best collimator for use during a first-pass study is:
(a)LEAP

(b) High sensitivity
(c) High resolution
(d) Medium energy

A

(b) A high-sensitivity collimator is also preferred.

25
Q

A neonatal first-pass study is performed, and the time activity curve for the ROI around the left ventricle shows a peak of activity occurring before the activity peak on the lung ROI. This most likely indicates:
(a)Improperly drawn regions of interest

(b) Interventricular shunt
(c) Prolapsed mitral valve
(d) Radiotracer contained in a too high volume

A

(b) If activity is seen in the left ventricle before the lungs are visible, it is very likely that activity has passed from the right to the left side of the heart through an intracardiac shunt.

26
Q

A nuclear medicine physician prefers that static myocardial perfusion images be obtained according to the best septal visualization. If the septum is well visualized on LAO 40, what other views should be obtained?
(a)Anterior, LAO 70

(b) RAO 20, LAO 60
(c) Anterior, LAO 60
(d) RAO 5, LAO 65

A

(d) In general, the 45° LAO should allow visualization of the septum and the inferoapical and posterolateral sections of the left ventricular wall. The anterior would then show the inferior, apical, and the anterolateral wall sections, and the 70° LAO would allow evaluation of the anterior, apical, inferior, and posterolateral all sections. If the septum is not well resolved on the 45° LAO due to the patient’s anatomy, another angle could be chosen, and the remaining two angles calculated by subtracting 45° for the “anterior” and by adding 25° for the steep lateral oblique.

27
Q

Cardiac contraction is initiated in the:
(a)SA node

(b) AV node
(c) Bundle of His
(d) P wave

A

(a) The action potential that causes contraction arises in the sinoatrial (SA) node which is located in the right atria. It then travels to the AV node and through the bundle of His. The bundle of His branches into the right and left bundle branches which end in the Purkinje fibers; these innervate the individual contractile myocardial cells. The P-wave is that part of the ECG that represents the depolarization of the atria.

28
Q

Treadmill exercise tests increase heart rate by:
(a)Increasing the slope of the treadmill

(b) Increasing treadmill speed
(c) Simulating infarct
(d) All of the above
(e) (a) and (b) only

A

(e) A commonly used exercise protocol is the Bruce protocol which gradually increases both the speed and the grade of the treadmill. A false-negative exercise myocardial perfusion study may be the result of insufficient exercise.

29
Q

A high-resolution collimator would be most appropriate for:
(a)Myocardial perfusion study with 201Tl chloride

(b) Myocardial perfusion with 99mTc sestamibi
(c) First-pass study with 99mTc DTPA
(d) Myocardial imaging with 99mTc pyrophosphate

A

(b) The high photon flux involved with 99mTc sestamibi necessitates the use of a high-resolution collimator. It is sufficient to use a low-energy all-purpose collimator (LEAP) for the 201Tl exam (as well as the infarct study with pyrophosphate). High-sensitivity collimation is preferable to a first-pass study.

30
Q

On Monday morning, a technologist receives a telephone request to perform a myocardial study with 99mTc PYP for detection of a myocardial infarct suspected to have taken place that morning at about 8:00 a.m. What should be done?
(a)The patient should be injected, but not scanned until at least 8:00 a.m. on Tuesday.

(b) The study should be delayed until 8:00 a.m. on Tuesday.
(c) The study should be delayed until 8:00 a.m. on Thursday.
(d) The patient should be injected and scanned as soon as possible.

A

(b) Pyrophosphate and other bone agents will bind in sites of myocardial injury because calcium will travel into the damaged cells, but this does not take place until at least 12 h and more often between 24 and 72 h after an infarct has occurred. The scan should not take place before 24 h after the suspected event.

31
Q

Infarct-avid myocardial imaging with 99mTc PYP is usually interpreted by comparing cardiac activity with:
(a)Rib

(b) Sternum
(c) Kidneys
(d) All of the above
(e) (a) and (b) only

A

(e) Uptake in the myocardium is usually compared to the uptake in the ribs and sternum when interpreting infarct studies.

32
Q

If a SPECT myocardial study with 99mTc PYP is performed using 64 views of 20 s each over 360, how long will the study take assuming continuous rotation?
(a)18 min

(b) 21 min
(c) 92 min
(d) 112 min

A

(b) The number of views is multiplied by seconds per view and divided by 60 to obtain the total number of minutes. If this was acquired in step-and-shoot mode, the stepping time would need to be added to find the total acquisition time. Myocardial perfusion SPECT studies are usually performed over 180.

33
Q

Gated equilibrium cardiac blood pool images can be used to reliably determine:
(a)Hibernating myocardium

(b) LVEF
(c) Interventricular shunt
(d) Ischemia
(e) All of the above

A

(b) Gated blood pool imaging of the heart can be analyzed to determine the left ventricular ejection fraction. Hibernating myocardium and ischemia can be assessed using myocardial perfusion imaging, and intracardiac shunt may be determined by a gated first-pass study.

34
Q

Akinesis refers to:
(a)A lack of wall motion

(b) Diminished wall motion
(c) Paradoxical wall motion
(d) Septal motion

A

(a) Akinesis means no wall motion, dyskinesis means paradoxical wall motion, and hypokinesis means diminished wall motion.

35
Q

The R-R interval represents:
(a)Only repolarization.

(b) Arrhythmia filtering.
(c) The length of cardiac cycles
(d) Length of time data is held in a buffer before being accepted or rejected.

A

(c) The R-R interval represents the length of the cardiac cycle. In patients with rhythm disturbances, the R-R interval may vary. Since gated imaging involves division of the interval into equal parts, if the interval is not of constant length, the part of the cycle that is being imaged will vary from cycle to cycle, and the resulting images will be compromised. For this reason, arrhythmia filtering is used; data from cardiac cycles that vary too much in length are rejected.

36
Q

When labeling RBCs with 99mTc for radionuclide ventriculography, the highest labeling efficiency will be obtained by:
(a)The in vivo method

(b) The in vitro method
(c) The modified in vivo/in vitro method
(d) All result in the same labeling efficiency

A

(b) The highest labeling efficiency results from in vitro methods, although the other methods are still considered acceptable for use. The in vivo method results in free technetium localizing in the kidneys, bladder, stomach, thyroid, and salivary glands.

37
Q

In which of the following cases must imaging be initiated as soon as possible after radiopharmaceutical injection?
(a)Gated radionuclide ventriculography with 99mTc-labeled RBCs

(b) Radionuclide ventriculography with 99mTc HSA
(c) Myocardial perfusion imaging with 99mTc sestamibi
(d) Resting myocardial perfusion with 201Tl chloride

A

(b) When labeled HSA is used, the radiopharmaceutical will eventually be taken up by the liver. For this reason, cardiac imaging should begin immediately after injection.

38
Q

A patient has an enlarged left atrium. When drawing an ROI for calculation of LVEF following radionuclide ventriculography, the technologist includes some activity from the left atrium. The resulting ejection fraction will be:
(a)Unchanged

(b) Falsely elevated
(c) Falsely lowered
(d) Cannot be determined from the information given

A

(c) If the ROI drawn around the left ventricle is incorrectly drawn to include some of the left atrium, the resulting ejection fraction will be falsely low.

39
Q

Gated blood pool ventriculography is often used to:
(a)Diagnose arrhythmia

(b) Obtain a baseline measurement of cardiac function in potential radiation therapy patients
(c) Detect hematologic spread of metastases
(d) Determine effect of chemotherapy on cardiac function

A

(d) Gated blood pool ventriculography is useful for determining the effect of chemotherapy on cardiac function. IN general, if the LVEF is less than 45%, the cardiotoxic therapy may be discontinued, or if a change in LVEF is more than 15%, the therapy may be considered to be too dangerous to cardiac function to continue.

40
Q

Setup for a SPECT imaging of myocardial perfusion with 99mTc sestamibi includes all of the following except:
(a)Ensuring that the detector head will not snag IV lines or oxygen tubing

(b) Setting a 10 caudal tilt to differentiate the left atrium from left ventricle
(c) Moving patient’s arm over his or her head
(d) Ensuring that COR correction for high-sensitivity collimator is selected

A

(b) In the case of myocardial perfusion imaging, the separation of the left atrium from the left ventricle is not as important as it is in ventriculography, so the caudal tilt is not important. All of the other items are important for SPECT myocardial imaging with 99mTc sestamibi.

41
Q

A patient who cannot exercise and who has asthma can undergo a stress myocardial perfusion study through the use of:
(a)The Bruce protocol

(b) Dipyridamole
(c) Dobutamine
(d) Adenosine

A

(c) Dipyridamole, adenosine, and dobutamine may all be used to produce pharmacologic stress or as an adjunct to exercise. All of these are associated with side effects, but both dipyridamole and adenosine may cause or worsen bronchospasm and so should not be used in patients with asthma or COPD.

42
Q

A patient will be asked to fast or to eat lightly between stress and redistribution studies with 201Tl chloride because:
(a)Peristalsis will degrade images.

(b) Stomach activity may obscure the myocardium.
(c) Gall bladder contraction will be stimulated.
(d) The patient will experience nausea following the stress test.

A

(b) If the patient eats a heavy meal during the redistribution period, stomach activity may compromise the images obtained later.

43
Q

Which radiopharmaceutical can be used to assess myocardial perfusion, right ventricle ejection fraction, and left ventricle ejection fraction with a single injection?
(a)201Tl chloride

(b) 99mTc PYP
(c) 99mTc-labeled RBCs
(d) 99mTc sestamibi

A

(d) 99mTc has superior imaging characteristics compare to 201 Tl and can be used to image myocardial perfusion at 1-3 h after injection. The disadvantage to 99mTc sestamibi is that two doses need to be injected for imaging of perfusion under stress and at rest. Another alternative is to perform a resting study with 201Tl followed by a stress study using 99mTc sestamibi. In addition, a first-pass study and gated myocardial images can be obtained with 99mTc sestamibi, although radionuclide ventriculography is typically done with labeled erythrocytes or albumin. 99mTc PYP and labeled erythrocytes are not used for assessment of myocardial perfusion.

44
Q

Choose the correct order in which the structures appear during a first-pass study.
(a)Right ventricle, pulmonary artery, lungs, pulmonary veins, left atrium

(b) Right ventricle, pulmonary veins, lungs pulmonary artery, left atrium
(c) Left ventricle, pulmonary artery, lungs, pulmonary veins, right ventricle
(d) Left ventricle, pulmonary veins, lungs, pulmonary artery, right ventricle

A

(a) The tracer first enters the right heart, leaves the right heart via the pulmonary artery, and enters the lungs. The oxygenated blood enters the pulmonary vein and is carried to the left side of the heart.

45
Q

Which of the following is the most likely cause of false anterior or lateral wall defects on myocardial perfusion imaging with 201Tl chloride?
(a)Center of rotation error

(b) Respiratory motion
(c) Too few projections
(d) Attenuation by breast tissue or implant

A

(d) Attenuation from breast tissue or breast implants may create the appearance of defects in the anterior and lateral walls of the heart. If the patient is not positioned in the same way for stress and redistribution studies, this may appear to be at true, reversible defect, so positioning must remain constant.

46
Q

During a 1-day myocardial perfusion study with 99mTc sestamibi including both stress and rest:
(a)Rest images must be obtained before stress images.

(b) The second dose of sestamibi should be higher than the first.
(c) The higher dose of sestamibi is always injected for the stress portion.
(d) The sestamibi doses should be identical for the best comparison of stress and rest.

A

(b) The lower dose is always administered first, no matter if the rest or stress is performed first.

47
Q

Why is it necessary to inject two doses of 99mTc sestamibi for a myocardial perfusion study including both stress and rest conditions?
(a)Because the physical half-life of 99mTc is too short to obtain both image sets from one injection

(b) Because there is no redistribution of 99mTc sestamibi within the myocardium
(c) Because the effective half-life is too short
(d) Because sestamibi is not retained by the myocardium for a sufficient time

A

(b) The second injection of 99mTc sestamibi is required, because unlike 201Tl, there is no redistribution of sestamibi in the myocardium.

48
Q

Soft tissue attenuation is least problematic in:
(a)SPECT myocardial imaging with 99mTc sestamibi than with planar imaging with 99mTc sestamibi

(b) SPECT myocardial imaging with 201 Tl chloride than with planar imaging with 201Tl chloride
(c) Myocardial imaging with 201Tl chloride than wtih 99mTc sestamibi
(d) Myocardial imaging with 99mTc sestamibi than with 201 Tl chloride

A

(d) Because of the higher photon energy of 99mTc relative to 201Tl, attenuation is less of a problem.

49
Q

The bull’s eye display created after myocardial perfusion imaging represents:
(a)Only short axis images

(b) An entire set of stress or rest SPECT images
(c) All part of the myocardial wall except the apex
(d) None of the above
(e) (b) and (c)

A

(b) A bull’s-eye display or polar map is created from the entire set (either stress or rest) of perfusion images, so it includes all walls of the myocardium. It offers a convenient way to compare stress and rest data sets.

50
Q

Differences between myocardial perfusion imaging with 201Tl chloride and 99mTc sestamibi include:
(a)High-resolution collimator can be used with 201Tl.

(b) Less soft tissue attenuation with 201Tl.
(c) Higher photon flux with 99mTc.
(d) Less respiratory motion with 201Tl due to delay after exercise before imaging.

A

(c) The LEAP collimator is used with 201Tl, so (a) is not correct. There is less soft tissue attenuation with 99mTc, so (b) is incorrect. The delay between exercise and imaging is the same for both isotopes, so (d) is also incorrect. There is a higher photon flux from the 99mTc dose.

51
Q

When performing a radionuclide venography to visualize deep venous thrombosis, what should be injected, and where?
(a)99mTc MAA in bilateral pedal veins

(b) 99mTc MAA subcutaneously in either foot
(c) 99mTc pertechnetate in the femoral artery
(d) 99mTc PYP in the left foot

A

(a) The radionuclide venography for deep venous thrombosis involves imaging the deep venous flow from the feet through the lower extremities. 1-1.5 mCi of 99mTc MAA is injected into the pedal vein atop each foot. To prevent clumping, it is important not to withdraw blood into the syringe before injection. (Other radionuclide approaches to DVT are also used.)

52
Q

Following injection of 99mTc sestamibi, during a resting myocardial perfusion study, imaging is delayed for 1 h because:
(a)Respiratory motion will decrease.

(b) Liver and lung activity is too high to allow high-quality images of the myocardium.
(c) Until 1 h after injection, sestamibi has not had sufficient time to be taken up by the myocardium.
(d) The patient should be monitored for adverse reactions during the first hour.

A

(b) Initial uptake of 99mTc sestamibi into the liver and lungs can obscure the myocardium. For this reason, imaging does not begin immediately. A fatty meal or milk may stimulate gallbladder contraction, and some activity may be distributed into the bowel.

53
Q

When performing a dual-isotope myocardial perfusion rest/stress study, which isotope should be injected first?
(a)201Tl.

(b) 99mTc.
(c) It doesn’t matter which is injected first, as long as 99mTc is used for the stress study.
(d) Either can be injected first without any consequence.

A

(a) The lower-energy isotope (201Tl) should be imaged first, to prevent interference from the higher-energy photons. Because attenuation is a bigger problem with 201Tl, the exercise study is best performed with 99mTc.

54
Q

Which of the following technical considerations are applicable for radionuclide venography?
(a)Tourniquets applied about the ankles and just below the knee

(b) Radioactive markers taped atop each patella
(c) Knees elevated with a pillow
(d) All of the above

A

(a) The knees should not be elevated, and any radioactive markers, if used, should be placed next to the joints, rather than atop them. Tourniquets are placed above the ankles and just below the knee to assist deep venous filling.

55
Q

False-negative stress myocardial perfusion studies are usually caused by:
(a)Failure of the myocardium to extract 201Tl chloride form the bloodstream

(b) Electrocardiogram leads
(c) Failure of the patient to reach maximal stress
(d) Thallium contained in a too large volume

A

(c) If the patient fails to reach maximal stress, false negatives may result. The maximal stress is usually defined as 85% of a predicted maximum heart rate (usually 220 - age x.85) but may also be the point that chest pain or significant ECG changes occur, or when the systolic blood pressure multiplied by the heart rate is greater than 25,000.

56
Q

Which of the following should be prepared ahead of a dipyridamole stress myocardial perfusion study?
(a)Dose of dipyridamole

(b) Dose of radiopharmaceutical
(c) Dose of aminophylline
(d) All of the above
(e) (a) and (b) only

A

(d) The dipyridamole (0.56 mg/kg body weight) is injected first, normally over 4 min. The radiopharmaceutical is injected after 7 or 8 min, and the aminophylline should be prepared in advance for injection in case of serious side effects (side effects may include chest pain, dizziness, headaches, and nausea).

57
Q

During a MUGA study, data collection is stopped when:
(a)A preset number of counts have been acquired.

(b) A preset number of cardiac cycles have been reached.
(c) A present time has been reached.
(d) Either a preset number of counts or a preset number of cardiac cycles have been reached
(e) Either a preset number of cardiac cycles or a preset time has been reached.

A

(d) The data collection time may be fixed by setting a count number to be reached or by setting the number of cardiac cycles to image.

58
Q

A technologist injects a patient with 1 mg of unlabeled stannous phosphate. After 20 min, 20 mCi of 99mTc pertechnetate is administered. This is:
(a)An in vitro labeling procedure

(b) An in vivo labeling procedure
(c) A modified in vivo labeling procedure
(d) None of the above

A

(b) In vivo means that the labeling takes place inside an organism. In vitro means that the labeling takes place outside of the organism. The modified in vivo procedure involves injecting the reducing agent into the patient and then withdrawing and labeling the blood in vitro before reinjecting the blood.

59
Q

A disadvantage of using 99mTc HSA for radionuclide ventriculography includes:
(a)High radiation dose

(b) Lung uptake
(c) Liver uptake
(d) Relatively low photon flux
(e) Difficult labeling procedure

A

(c) Although HSA may be used, it will be taken up by the liver, so imaging must begin promptly after injection.

60
Q

Which of the following may have an effect on the time it takes to acquire a cardiac gated blood pool study?
(a)Amount of radiopharmaceutical injected

(b) Heart rate
(c) Use of arrhythmia filtering
(d) All of the above
(e) (a) and (b) only

A

(d) The data collection time may be fixed by setting a count number to be reached or by setting the number of cardiac cycles to image. Depending on what parameters are set for data collection (total counts or cardiac cycles), all of the choices may affect imaging time.

61
Q

Gated cardiac blood pool scintigraphy (MUGA) is used to evaluate:
(a)Ejection fraction

(b) Wall motion and contraction
(c) Myocardial ischemia
(d) All of above
(e) (a) and (b) only

A

(e) MUGA is used to evaluate LV ejection fraction and wall motion/contraction, not myocardial ischemia

62
Q

For gated cardiac blood pool scintigraphy (MUGA), which of the following is not correct:
(a)PYP needs to warm up to room temperature before reconstitution.

(b) A good bolus injection is critical.
(c) Imaging is obtained 20 min or later after tracer injection.
(d) Both LAO and anterior views are required.

A

(b) A good bolus injection is not required (no dynamic imaging during injection is needed) because this study is to evaluate the blood pool activity (thus imaging is obtained 20 min or later after tracer injection).

63
Q

To perform a sestamibi myocardial perfusion study, which of the following is not correct:
(a)NPO overnight or at least 4 h

(b) No coffee or tea at least 12 h prior to the study for Lexiscan test
(c) No coffee or tea at least 12 h prior to the study for Persantine test
(d) No coffee or tea at least 12 h prior to the study for treadmill test

A

(d) Treadmill exercise test can still be performed if the patient had coffee or tea before the study.

64
Q

Coffee or tea is not contraindicated in which of the following studies:
(a)Myocardial perfusion study with Persantine

(b) Myocardial perfusion study with Lexiscan
(c) Myocardial perfusion study with treadmill
(d) FDG-PET study of the brain

A

(c) Coffee and tea are contraindicated in stress test when using Persantine, Adenosine, or Lexiscan. Coffee and tea are stimulant agents to the central nervous system and should be avoided for FDG-PET study of the brain.

65
Q

To perform a sestamibi myocardial perfusion study, which of the following is correct:
(a)Aminophylline is used to treat patient’s symptoms from treadmill exercise.

(b) Aminophylline is used to treat patient’s symptoms from Persantine or dobutamine.
(c) Aminophylline is used to treat patient’s symptoms from Persantine or Lexiscan.
(d) Aminophylline is used before the stress test to avoid any side effect.

A

(c) Aminophylline is used to treat patient’s side effects from Persantine or Lexiscan and should be used 2 min or more after tracer injection.

66
Q

To perform a pharmaceutical sestamibi myocardial perfusion study, which of the following is correct:
(a)Sestamibi should be injected 2 min after Lexiscan administration.

(b) Sestamibi should be injected immediately after Persantine administration.
(c) Sestamibi should be injected immediately after dobutamine administration.
(d) Sestamibi should be injected during Lexiscan administration.
(e) Sestamibi should be injected during dobutamine administration.

A

(e) Sestamibi should be injected during the last minute of dobutamine administration, immediately after Lexiscan administration, or 2 min after Persantine administration.

67
Q

To perform a myocardial perfusion study, which of the following is correct:
(a)Rest and stress tests have to be performed on the same day.

(b) Rest imaging can be followed by stress imaging for treadmill sestamibi test.
(c) Rest imaging can be followed by stress imaging for treadmill thallium test.
(d) Rest imaging can be followed by stress imaging for Lexiscan thallium test.
(e) Rest imaging can be followed by stress imaging for Persantine thallium test.

A

(b) For thallium study, stress test has to be performed first. For sestamibi study, either rest or stress test can be performed first. (???)

68
Q

The advantage of 82Rb PET cardiac perfusion study (vs. SPECT imaging) includes all of the following except:
(a)Better imaging resolution

(b) Less radiation exposure
(c) Ideal for overweight patients
(d) Able to determine myocardial ischemia and viability

A

(d) 82Rb cardiac perfusion study cannot determine myocardial viability.

69
Q

Myocardial viability can be determined by the following studies:
(a)FDG-PET

(b) Sestamibi after Persantine administartion
(c) 201Tl without stress test
(d) 201Tl after Persantine administration
(e) Nitrogen-13 ammonia PET
(f) (a) and (c) only

A

(f) a and c only. Myocardial viability does not need the stress part.

70
Q

To perform an FDG-PET myocardial viability study, patients need to be:
(a)NPO for at least 4 h

(b) Blood sugar should be <200 mg before tracer injection.
(c) Having high-carbohydrate food on the day before the study.
(d) Oral glucose is not allowed before the study.
(e) Both (a) and (c)

A

(e) Both (a) and (c). For FDG-PET myocardial viability study, patient’s blood sugar should be high, and oral glucose may be needed to increase the blood sugar level.

71
Q

82Rb chloride is the daughter of which isotope?
(a)82Sr

(b) Sr85
(c) Rb85
(d) None of the above

A

(a) Rubidium 82 is the daughter of 82Sr.

72
Q

What is the half-life of 82Rb
(a)110 min

(b) 75 s
(c) 75 min
(d) 2 min

A

(b) The half-life of 82Rb is 75 s.

73
Q

How is 82Rb produced?
(a)Nuclear reactor

(b) Generator
(c) Cyclotron

A

(b) 82Rb is generator produced. Given the short half-life of rubidium, a generator must be on-site in order for a study to be performed utilizing 82Rb.

74
Q

What is the usual dose of Rb chloride?
(a)15 mCi for each of the stress and rest doses

(b) 30 mCi total for the stress and rest scans
(c) 30-60 mCi for each of the stress and rest doses
(d) 15 mCi total for the stress and rest scans

A

(c) The usual dose of Rb-Cl is 30-60 mCi for each of the stress and rest scans. This is dependent on camera capabilities. Too high a dose may flood the crystal, making imaging impossible.

75
Q

How does an infarct appear on a PET perfusion scan?
(a)Focal areas of increased uptake.

(b) Diffuse areas of increased uptake.
(c) Focal areas of decreased.low uptake.
(d) There is no visual difference.

A

(c) Infarcted tissue does not perfuse; therefore, you would see areas of low or no uptake.

76
Q

Which of the following is not correct:
(a)To perform FDG-PET/CT and then 82Rb PET/CT on the same day

(b) To perform 82Rb PET/CT and then FDG-PET/CT on the same day
(c) To perform sestamibi SPECT and then FDG-PET/CT on the same day
(d) To perform sestamibi SPECT rest and then 82Rb PET/CT stress on the same day.

A

(a) To perform FDG-PET/CT and then 82Rb PET/CT on the same day

82Rb PET should be performed before FDG-PET, due to its very short half-life.

77
Q

Contraindication(s) to treadmill exercise cardiac stress testing include
(a)Acute MI (within 3-4 days).

(b) Uncontrolled hypertension (SBP >210 mm Hg and/or DBP >110 mm Hg).
(c) Acute illness for any reason.
(d) Patient is on beta-blocker.

A

(d) Beta-blocker is not recommended for exercise stress test but is not an absolute contraindication.

78
Q

For SPECT myocardial perfusion imaging, which of the following is not correct:
(a)With 99mTc sestamibi or 99mTc tetrofosmin, imaging should be begun approximately 45 min after stress testing.

(b) With 201Tl, imaging should be begun approximately 10 min after stress testing.
(c) With 99mTc sestamibi or 99mTc tetrofosmin, imaging acquisition after stress testing can be repeated multiple times when patient motion or other artifacts are suspected.
(d) With 201Tl, imaging acquisition after stress testing can be repeated multiple times when patient motion or other artifacts are suspected.

A

(d) For thallium, imaging should start as soon as possible, ideally within the first 5-10 min of exercise. The quality of repeat imaging is likely compromised due to tracer redistribution in the myocardium. As a result, the benefit of repeating image acquisition is questionable.

79
Q

For sestamibi SPECT myocardial perfusion imaging, a delay in imaging acquisition (approximately 45 min or a little more after stress testing and tracer injection) has the following benefit except for:
(a)To allow more tracer accumulation within the myocardium

(b) To allow the patient to recover from exercise with a more peaceful respiration
(c) To allow heart rate to return to baseline and more regular cardiac rhythm
(d) To minimize interference from hepatic uptake

A

(a) The SPECT myocardial perfusion study tries to evaluate initial tracer distribution as an indication of coronary circulation. Any tracer redistribution (more prominent for 201Tl, minimal for sestamibi) has only adverse effect on imaging quality.

80
Q

Indications for early termination of exercise include:
(a)Moderate to severe angina pectoris

(b) Marked dyspnea or fatigue
(c) Dizziness or near-syncope
(d) Patient’s request to terminated the test
(e) All of the above

A

(e) All of the above

81
Q

For pharmacologic stress tests, which of the following has the shortest half-life:
(a)Adenosine

(b) Dipyridamole
(c) Regadenoson
(d) Dobutamine

A

(a) Adenosine has a half-life of only ~10 s.

82
Q

When performing a MUGA scan to evaluate LV ejection fraction, including the spleen, within the ROI for the background will cause:
(a)Artificially high EF.

(b) Artificially low EF.
(c) Any changes depend on the activity of the LV.
(d) Either b or c.

A

(a) Including the spleen within the ROI for the background will give a higher background activity, and thus higher EF.