ST:6

Question 1

If someone is receiving 20 mRem/hr exposure at a distance of 3 m from a source, at what distance would they receive 500 mRem/hr exposure?
(a)0.36 cm

(b) 0.36 m
(c) 60 cm
(d) 0.60 cm
(e) 3.6 cm

Answer 1

(c) The inverse square law is represented by the equation I1(D1)^2, with I equaling intensity in mR/hr and D equaling distance. 20 mR/hr represents the I1 value, while 3m will be the D1 value. 500 mR/hr is the D2 value and the I2 value can be found by plugging in all the given information to the Inverse Square Law equation and solving for the missing variable.
20 mR/hr (3 m)^2 = 500 mR/hr (I2)^2
(I2)^2 = 20 mR/hr (9m) = 0.36 m
500mR/hr
Take the square root of both sides to get I2 = 0.60m
How many cm = 0.60 m x 100 cm/1 m = 60 cm?

Question 2

If an area survey reveals an ambient radiation level of 7 mRem/hr, which of the following radioactive signs would be the best choice to display on the door leading to this area?
(a)”Caution: Radioactive Materials”

(b) “Caution: Radiation Area”
(c) “Caution: High Radiation Area”
(d) “Grave Danger: Very High Radiation Area”
(e) “Caution: Very High Radiation Area”

Answer 2

(b) The “Caution: Radioactive Materials” sign is used in any area where certain quantities of radioactive materials are used or stored. The “Caution: Radiation Area” sign is used in areas where an individual could receive more than 5 mRem (0.05 mSv) in 1 hr at 30 cm from a radioactive source. The “Caution: High Radiation Area” signs are used where an individual could receive more than 100 mRem/hr (1 mSv) in 1 hr at 30 cm from a radioactive source. Since the ambient radiation exposure is between 5 mRem/hr and 100 mRem/hr, the appropriate caution sign would be “Caution: Radiation Area.”

Question 3

An ionization chamber is left in integral mode for 10 min and records a total dose of 3 mRem. Which of the following area posting signs should be used on the door leading into this area?
(a)”Caution: Radiation Area”

(b) “Caution: Radioactive Materials”
(c) “Caution: High Radiation Area”
(d) “Grave Danger: Very High Radiation Area”
(e) “Caution: Very High Radiation Area”

Answer 3

(a) The “Caution: Radioactive Materials” sign is used in any area where certain quantities of radioactive materials are used or stored. The “Caution: Radiation Area” sign is used in areas where an individual could receive more than 5 mRem (0.05 mSv) in 1 hr at 30 cm from a radioactive source. The “Caution: High Radiation Area” signs are used where an individual could receive more than 100 mRem/hr (1 mSv) in 1 hr at 30 cm from a radioactive source. Since the integral dose in 10 min is 3 min, this implies that the total dose for 1 hr is 6 times this amount or 18 mRem/hr. Therefore, the radiation exposure is between 5 mRem/hr and 100 mRem/hr, and the appropriate caution sign would be “Caution: Radiation Area.”

Question 4

Which of the following area posting signs would NOT normally be found in a hospital?
(a)”Grave Danger: Very High Radiation Area”

(b) “Caution: Radiation Area”
(c) “Caution: High Radiation Area”
(d) “Caution: Radioactive Materials”
(e) “Caution: Very High Radiation Area”

Answer 4

(a) In areas where personnel would receive life-threatening doses of radiation such as levels over 500 R/hr, the sign “Grave Danger: Very High Radiation Area” would be used. It is unlikely that materials with an activity of lethal dose levels would be stored on the premises of a hospital.

Question 5

Which of the following type of survey instruments would be best to use to survey a spill for removable contamination in a hot lab area where radioisotopes are being stored?
(a)G-M detector

(b) personal pocket dosimeter
(c) well counter with a wipe test
(d) dose calibrator with a wipe test
(e) cutie pie

Answer 5

(c) G-M detectors are used to survey large areas for contamination that may not always be removable. Pocket dosimeters are used to measure personnel exposure. Dose calibrators are used to measure activity in patient doses. Scintillation probes can be used to detect removable and non-removable contamination at a higher efficiency than G-M detectors because of its use of a sodium iodide-thallium crystal. Most often, wipe tests with a well counter are used to check for removable contamination.

Question 6

Four HVLs reduce the amount of incident radiation exposure to what?
(a)6.5%

(b) 12.25%
(c) 3.125%
(d) 25%
(e) 50%

Answer 6

(a) The half-value layer (HVL) is the amount of material needed to reduce radiation intensity by half. Following this logic, 4 HVLs reduce the amount of incident radiation to a transmission factor of 0.0625 or 6.25%.

Question 7

Which of the following is NOT required to be included in the records of a radioactive package receipt check-in process?
(a)name of radioisotope

(b) name of patient
(c) amount of activity
(d) external wipe check
(e) internal wipe check

Answer 7

(b) When packages are received, they are inventoried by recording the name of the radioisotope, amount of activity, and results of wipe checks as mandated by NRC regulations. Patient name is not relevant at this point because you are simply taking inventory.

Question 8

If a package is reading 2 mRem/hr at a distance of 2 m, what is the appropriate DOT label for this package?
(a)No labeling is required.

(b) DOT I
(c) DOT III
(d) DOT II
(e) DOT IV

Answer 8

(c) The DOT I transport index or exposure rate at 1 m from the package is mandated to be zero. The DOT II transport index is mandated to be more than 0 but less than 1 mR/hr at 1 m. DOT III is mandated to be more than 1 mR/hr but less than 10mR/hr at 1 m. This package would fall under the DOT III.
DOT I (white)
At contact, not more than 0.5 mR/hr
At 3 feet (1 m), no detectable radiation (NDR)
DOT II (yellow)
At contact, not more than 50 mR/hr
At 3 feet (1 m), not more than 1 mR/hr
DOT III (yellow)
At contact, not more than 200 mR/hr
At 3 feet (1 m), not more than 10 mR/hr

Question 9

The purpose of the transport index is to:
(a)indicate the highest activity of the contents at 1 m from the surface

(b) list the final destination of the package
(c) not to give emergency personnel information about the contents of the package in an accident
(d) not to list the radioisotopes in the package
(e) document wipe check information

Answer 9

(a) The transport index indicates to all handlers the degree of care that should be taken when handling the package. This index is quantified by an exposure reading taken 1 m from the package or source.

Question 10

If a patient who is having a bone scan urinates on the floor next to a camera, what would be the best course of action to reduce radiation exposure?
(a)Remove the spill with some absorbent material and cover any residual activity with a lead plate or lead apron.

(b) Move the camera away from the spill.
(c) Let the radioactive urine decay to background.
(d) Notify the referring physician of a medical event.
(e) Notify the NRC of a medical event.

Answer 10

(a) When decontaminating a liquid spill that can include potentially radioactive biologic waste (urine, emesis, etc) expelled from a patient, the spill can be cleaned up with absorbent material. When contamination cannot be completely removed with thorough cleaning, lead plates or aprons can be used to cover the area of the spill.

Question 11

Which DOT radioactive labeling is entirely white?
(a)DOT III

(b) DOT II
(c) DOT I
(d) DOT IV
(e) DOT V

Answer 11

(c) According to the Department of Transportation, the radioactive label designated as totally white is DOT I. DOT I denotes packages with less than 0.5 mR/hr exposure rate at the surface and with no detectable radiation (NDR) at 1 m.

Question 12

Which absorber would be the best to use to shield strontium-89?
(a)cardboard

(b) No shielding is required.
(c) lead
(d) plexiglas
(e) paraffin

Answer 12

(d) Strontium-89 is a pure beta emitter. Lead shielding cannot be used to block beta particles because of the production of bremsstrahlung radiation caused by the interaction of beta particles with dense materials such as lead. Cardboard is not dense enough to stop the torturous path of beta particle. Plexiglass is ideal because of its density since bremsstrahlung reactions would be kept to a minimum.

Question 13

Which of the following indicates the AMOUNT of radioactive substance in a sample or source?
(a)total effective dose

(b) exposure
(c) absorbed dose
(d) dose equivalent
(e) activity

Answer 13

(e) Exposure is specifically defined as the amount of charge in the air from interactions with X or gamma radiation, 0 to 3 MeV. The unit of exposure is the roentgen: 1 R = 2.58 x 10^-4 c/kg. However, activity indicates the amount of radioactive substance in a sample or source. The units are the curie or becquerel.

Question 14

If the exposure rate is 25 mRem/hr and the person being exposed is present for 25 min, what is his/her total exposure?
(a)24 mRem

(b) 10.4 mRem
(c) 12.5 mRem
(d) 5.2 mRem
(e) 27 mRem

Answer 14

(b) 25 mRem/hr (1 hr/60 min) x 25 min = 10.4 mRem

Question 15

What is 120 Sv in millirads (Quality Factor [QF] = 1)?
(a)8.3 x 10^-8 mrad

(b) 12 million mrad
(c) 1.2 million mrad
(d) 120,000 mrad
(e) 12,000 mrad

Answer 15

(b) 1 Sv = 1 Gray = 100 rad
1 Sv = 100 Rem
120 Sv = (100)120 rad
120 Sv = 12,000 rad = 12,000,000 mrad

Question 16

An alpha particle is simliar to what?
(a)an electron

(b) a proton
(c) a hydrogen atom minus its neutron
(d) a helium atom minus its neutrons
(e) a helium atom minus its electrons

Answer 16

(e) When an alpha particle decays, it loses the two electrons it originally had. Helium nuclei consist of the same number of protons and neutrons.

Question 17

A higher or lower sensitivity is affected by all of the following EXCEPT:
(a)properly set Pulse Height Analyzer (PHA) and window width

(b) collimator design
(c) thickness of camera crystal
(d) instrument deadtime
(e) improperly set Pulse Height Analyzer (PHA) and window width

Answer 17

(a) The thickness of the crystal, collimator design, and instrument deadtime all affect sensitivity and can cause it to be higher or lower from day to day. However, a properly set pulse height analyzer with a proper window around the main peak will not affect the sensitivity and make it higher or lower from day to day.

Question 18

Geometric variation, on a dose calibrator, should be performed:
(a)hourly

(b) at installation and yearly
(c) quarterly
(d) daily
(e) at installation and after repair

Answer 18

(e) Geometric calibration is performed at installation, whenever a change is made in the type of vial or syringe used in radiopharmaceutical processing, and after the chamber is repaired.

Question 19

Photomultiplier tube drift is associated with which of the following:
(a)auto-voltage stabilization

(b) inverse gain
(c) energy correction
(d) linearity correction
(e) auto-gain stabilization

Answer 19

(e) The amplifications of electrons in photomultiplier tubes (PMTs) and, therefore, PMT output, are affected by many factors: temperature, PMT age, and Earth’s magnetic field or unshielded MRIs. Automatic gain stabilization, if not correct, can cause tube drift to occur.

Question 20

A paralyzable counting system will:
(a)exhibit a nonlinear threshold response

(b) never plateau and never obtain a peak count
(c) plateau with no decrease in countrate as activity increases, which is the peak count
(d) not exhibit any countrate difference
(e) decrease in count rate after some peak in countrate is obtained

Answer 20

(e) In a paralyzable system, as the activity increases, the count rate increases to a maximum valve and then actually starts decreasing at higher activity levels.

Question 21

Sources of intrinsic non-uniformity include all of the following EXCEPT:
(a)”mistuned” PMTs

(b) regional variations in Z-pulse amplitude
(c) spatial distortion
(d) linearity
(e) mapping malfunction

Answer 21

(d) The three main sources of non-uniformity are “mistuned” PMTs, regional variations in Z-pulse amplitude (spatial distortion), and edge packing. Linearity is a separate issue and not a part of uniformity assessment itself.

Question 22

What is added to NaI crystals to allow them to scintillate at room temperature?
(a)Tl

(b) Xe
(c) Ce
(d) Ag
(e) BGO

Answer 22

(a) NaI (Tl) scintillation camera systems will have a 8% and 12% energy resolution. Thallium functions as an actuator that allows the creation of additional “energy states” within the crystal. Crystals are very sensitive to thermal and mechanical shocks.

Question 23

What maximum percentage difference is acceptable for most regulatory agencies for all four dose-calibrator QC checks?
(a)+-5%

(b) +-10%
(c) +-7%
(d) +-15%
(e) +-20%

Answer 23

(b) The limit for % difference is +- 10%, according to the NRC regulations. However, it may be +- 5% per manufacturer recommendations, which the NRC also says must be adhered to.

Question 24

Extrinsic quality control on a camera means quality control is done:
(a)automatically overnight

(b) without the collimator on
(c) inside the camera
(d) outside the camera
(e) with the collimator on

Answer 24

(e) Extrinsic testing allows evaluation of the total system as it is used clinically, including the collimator. When a collimator is used during assessment, a source having a uniform radionuclide distribution is placed on the collimator.

Question 25

Linearity correction involves: (a)diagonal lines (b) horizontal lines (c) horizontal and vertical lines (d) vertical lines (e) diagonal and vertical lines

Answer 25

(c) Correction involving evaluating the straightness of both horizontal and vertical lines while using a phantom.

Question 26

Dose-calibrator constancy should be performed: (a)monthly (b) daily (c) weekly (d) quarterly (e) hourly

Answer 26

(b) Constancy of a dose calibrator is performed every day that it is used. This is usually done using a long-lived radioisotope and comparing daily values to previously measured values.

Question 27

Which of the following quantitative renal techniques require(s) the calculation of kidney depth? I. Schlegel technique II. Gates' method III. Two-compartment effective renal plasma flow (ERPF) determination IV. Russell's glomerular filtration rate (GFR) method (a)I (b) II and III (c) III and IV (d) II and IV (e) I and II

Answer 27

(e) Schlegel, et al., Brodkey, et al., and Gates described non-invasive isotopic methods for the estimation of GFR and ERPF without blood or urine sampling. These methods allow determination of these parameters separately for each kidney and derive values for global renal function.

Question 28

Which of the following functional images represents the magnitude of ventricular contraction? (a)non-phase image (b) paradox image (c) phase image (d) stroke-volume image (e) amplitude image

Answer 28

(e) The amplitude image is superior to the simple stroke volume image because it shows the actual volume of blood ejected from each region of the heart.

Question 29

The background ROI used in determining percentage gastroesophageal (GE) reflux is placed over the: (a)lower left lung (b) small intestine (c) right hepatic lobe (d) upper esophagus (e) lower esophagus

Answer 29

(a) Background subtraction is used to enhance image quality and increase statistical reliability for quantitative studies such as gastroesophageal reflux studies. The lower left lung servers as an appropriate background region of interest close to but not within the field of view of imaging the esophagus and stomach.

Question 30

Geometric mean is sometimes used in quantization because it corrects for: (a)the size and shape of the organ (b) background activity (c) radioactive half-life (d) radioactive decay (e) attenuation and organ depth

Answer 30

(e) The geometric mean calculation and use in quantitative studies allow for a sense of organ depth and where in an organ any possible attenuation is occurring. This could be due to contrast media, which could be in a part of the colon but not the entire colon.

Question 31

Given a heart rate of 85 bpm, if a 24-frame gated heart study is acquired, the length of each frame in milliseconds is: (a)0.06 msec (b) 0.3 msec (c) 705 msec (d) 29 msec (e) 0.03 msec

Answer 31

(d) With the patient heart rate at 85 bpm, each beat is 0.7058 sec (60 sec/85 beats = 0.7058 sec). Divide this by 25 frames to get 0.029 sec and then convert to msec by multiplying by 1000 to get 29 msec.

Question 32

Concentric ring artifacts in a reconstructed SPECT image may be caused by: (a)improper collimation (b) inadequate uniformity (c) correction of large statistical fluctuations in the projection data (d) too few angles of reconstruction (e) too many angles of reconstruction

Answer 32

(b) Extrinsic flood field uniformity correction is performed to prevent ring artifacts.

Question 33

In processing a myocardial perfusion study, a slice from which body axis is used to identify the degree to which the heart points to the left and to construct slices in the three opposing cardiac planes? (a)horizontal long axis (b) transaxial (c) vertical long axis (d) short axis (e) horizontal short axis

Answer 33

(b) For automatic reorientation of the heart, identify the left ventricle in the transaxial images using a threshold-based approach.

Question 34

The MOST important purpose of center of rotation offset correction is to: (a)eliminate the effects of detector tilt in the reconstructed images (b) minimize count sensitivity variations from one area of the crystal to another (c) ensure that all pixels are uniformly sized over the entire field of view (d) align the center of the computer matrix with the mechanical axis of rotation (e) maximize count sensitivity variations from one area of the crystal to another

Answer 34

(d) The center of rotation (COR) offset correction makes certain that the COR of the camera matrix corresponds to the COR of the camera heads.

Question 35

The x- and y-axes of a circumferential profile curve are, respectively: (a)x-axis-bull's eye quadrant, y-axis: % maximum counts (b) x-axis-time, y-axis: activity (c) x-axis-segment of the myocardium, y-axis: maximum counts (d) x-axis-rest, y-axis: stress (e) x-axis-maximum counts, y-axis: segment of the myocardium

Answer 35

(c) In a circumferential profile curve, segments of the myocardium are listed on the x-axis and the maximum counts related to these segments are plotted on the y-axis.

Question 36

Diaphragmatic attenuation may be reduced by: (a)360 acquisition (b) supine acquisition (c) delayed imaging (d) prone acquisition (e) giving a bolus injection

Answer 36

(d) Imaging in the prone position minimizes attenuation artifacts in myocardial imaging where the inferior wall of the heart may be shadowed by breast tissue or the diaphragm.

Question 37

Which of the following is a definition of sensitivity of a diagnostic test? (a)how good the test is at detecting a true negative (b) how good the test is at detecting a true positive (c) how good the test is at detecting the difference between a true negative and a true positive (d) how good the test is at detecting something (e) how good the test is an detecting idiopathic conditions

Answer 37

(b) Sensitivity is the percentage or fraction of ill patients who have a positive test. Thus, sensitivity is how good a test is at detecting a true positive. Specificity is how good a test is at detecting a true negative.

Question 38

In a patient with pulmonary embolism, the perfusion and xenon ventilation lung images will demonstrate the following findings: Perfusion - Ventilation (a)Normal - Normal (b) Normal - Abnormal tracer retention (c) Normal - Ventilation defects (d) Perfusion defects - Abnormal tracer retention (e) Perfusion defects - Normal

Answer 38

(e) Ventilation study usually presents as normal (uniform and symmetrical uptake and wash-out in all three phases) in cases of pulmonary embolism (PE). Mismatching areas of activity (usually two or more segmental defects) in the perfusion study are indicators for PE.

Question 39

Of the following, the biggest disadvantage of 133Xe (xenon gas) for performing lung ventilation studies is its: (a)rapid lung clearance (b) surface contamination (c) high cost (d) unavailability (e) trapping and shielding requirement

Answer 39

(e) Pricing and availability have forced 133Xe into prominence. The more straightforward wash-in/wash-out method is preferred and can be used even on comatose patients.

Question 40

Which of the following statements about radiolabeled aerosols used for lung ventilation imaging is TRUE? (a)The particles are deposited in ventilated areas of the lungs. (b) It is necessary to trap any radiolabeled particles exhaled by the patient. (c) Particle sizes range form 30 to 90 um in diameter. (d) Deposition of particles in the central airway is never a problem with lung aerosol studies. (e) Contamination concerns are not warranted.

Answer 40

(a) Aerosols are deposited in the bronchial tree in relation to particle size, air flow rates, and turbulence. The delivery tubing effectively filters out larger particles 10-15 um in diameter. Smaller particles are deposited in the larger airways during both inspiration and expiration. Particles less than 2 um can reach the alveoli and be deposited there, while even smaller particles, less than 0.1 um, probably escape in the expired air.

Question 41

An uptake probe is what type of detector? (a)Geiger-Muller counter (b) proportional counter (c) ionization chamber (d) scintillation detector (e) cutie pie

Answer 41

(d) To count radioactivity in a person, a probe system is often used. The probe consists of a sodium iodide crystal with PMT, electronics, and collimator.

Question 42

The purpose of a charcoal filter in a xenon administration unit is to absorb: (a)bacteria (b) carbon dioxide (c) moisture (d) pyrogens (e) xenon

Answer 42

(e) Commercial ventilation units employ xenon traps that use activated charcoal to prevent the release of radioactive xenon during the washout phase of a study.

Question 43

The concentration of 133Xe gas in the lungs is increasing in which phase of a xenon ventilation study? (a)There is no phase of increasing activity. (b) equilibrium (c) washout (d) wash-in (e) trapping

Answer 43

(d) In the wash-in phase, 10-20 mCi of 133Xe diluted in 2 L of oxygen are re-breathed from a simple re-breathing apparatus for approximately 3 min while a static image is taken.

Question 44

What is the range of particle size, in micrometers, of the majority of particles in [99mTc]macroaggregated albumin (MAA)? (a)150-250 um (b) 100-150 um (c) 10-90 um (d) 1-40 um (e) 100-250 um

Answer 44

(c) Particles formed have diameters of 10-90 um, with the majority between 10 and 40 um.

Question 45

Following administration of a bone imaging tracer, the patient is instructed to drink fluids to: (a)decrease radiation exposure to the bones (b) enhance visualization of the kidneys and bladder (c) clear excess tracer from the blood (d) remove tracer from normal bone tissue (e) determine if kidney stones are present

Answer 45

(c) Unless contraindicated, patients should be hydrated to aid clearance of the radiopharmaceutical from the body. This aids in increasing the target:non-target ratio.

Question 46

Radioxenon ventilation studies should be performed in rooms whose air pressure is: (a)higher than adjacent areas (b) positive (c) equal to adjacent areas (d) neither higher or lower than adjacent areas (e) lower than adjacent areas

Answer 46

(e) A negative-pressure room is required for xenon ventilation studies to maintain ALARA for staff members and patients in the event of a leak during the study.

Question 47

The clinical indication for a diagnostic test is: (a)a list of the patient's symptoms (b) the patient's diagnosis (c) the question the referring physician needs answered (d) a summary of the patient's clinical history (e) the differential diagnosis

Answer 47

(c) The clinical indication is usually associated with the chief complaint and is a question the referring physician needs answered. This involves ruling in or ruling out something that s/he is unable to ascertain just by a patient history.

Question 48

In a xenon administration unit, the purpose of soda lime is to absorb: (a)bacteria (b) carbon dioxide (c) moisture (d) xenon (e) pyrogens

Answer 48

(b) Carbon dioxide is absorbed in the closed system by soda lime crystals, while moisture is removed by calcium sulfate or cobalt chloride crystals.

Question 49

If visualized, the gallbladder fossa may be seen on what view(s) of a liver/spleen image? (a)anterior and posterior (b) right lateral only (c) anterior only (d) anterior and right lateral (e) left lateral only

Answer 49

(d) Views in the anterior are normal while the anterior oblique or right lateral projection may be useful for separating the gallbladder and common bile duct from the duodenum and underlying structures such as the kidneys.

Question 50

When performing Meckel's diverticulum imaging, which of the following would be visualized in a positive study? (a)malignant thyroid tissue (b) ectopic stomach mucosa (c) stomach mucosa (d) ectopic endometrial tissue (e) ectopic uterine lining

Answer 50

(b) Meckel's diverticulum is based on the visualization of the ectopic mucosa with intravenously administered [99mTc]pertechnetate.

Question 51

Which of the following studies requires radiolabeled red blood cells? (a)infection imaging (b) renal scan (c) liver/spleen scan (d) MUGA scan (e) gastric emptying

Answer 51

(d) The multigated blood pool acquisition (MUGA) study requires radiolabeled red blood cells that are compartmentalized in the heart to assess ejection fraction and stroke volume.

Question 52

Over what area are 24 hour images sometimes performed to demonstrate gastroesophageal reflux? (a)lower esophagus (b) lung fields (c) stomach (d) upper small intestine (e) lower small intestine

Answer 52

(b) Delayed images of the thorax can be obtained up to 24 hr post-administration of the radiopharmaceutical to detect reflux leading to pulmonary aspiration.

Question 53

The clinical indication for performing a 14C urea breath test is to: (a)rule out excess urea in the blood (b) detect the presence of HELICOBACTER PYLORI bacteria (c) determine the cause of gastric reflux (d) diagnose possible causes of abnormal gastric emptying (e) determine the cause of esophageal reflux

Answer 53

(b) HELICOBACTER PYLORI produces a significant amount of the enzyme urease, which is not present in normal human tissue. When 14C-labeled urea is administered orally to the patient and urease activity is present in the stomach, 14C urea is split into ammonia and 14CO2, which is absorbed into the blood and exhaled through the lungs. The 14C activity is trapped in an alkaline solution and measured.

Question 54

Images acquired during a gastric-emptying study are primarily used for: (a)demonstrating exit of the tracer from the stomach (b) assessing normal biodistribution of the tracer (c) drawing regions of interest (d) measuring the size of the stomach (e) determination of an effective gastric plasma flow

Answer 54

(c) Although conventional gastric emptying is a simple procedure that measures the transit of a standardized radiolabeled test meal through the stomach, the images themselves are not utilized alone. Quantitative information is determined by drawing regions of interest and letting the computer algorithm(s) determine transit times, curves, and graphs.

Question 55

When imaging to determine LeVeen shunt patency, the camera initially is positioned anteriorly over the abdomen, and delayed images can be done: (a)over the brain (b) over the chest or abdomen (c) over the sacroiliac area (d) over the lung or liver fields (e) over the bladder

Answer 55

(d) The last part of the procedure is to obtain 2-4-hr delayed images if no lung or liver visualization occurs within 60 min. Under abnormal results, no lung activity after 4-hr delays using [99mTc]MAA indicates an obstruction. An obstruction is also indicated if no activity in the liver is seen after 4-hr delays using [99mTc]sodium chloride.

Question 56

In a red cell volume determination, it is necessary to add ascorbic acid to the labeled red cells to: (a)determine whether the patient is anemic (b) remove the 51Cr not tagged to red cells (c) suspend the cells homogeneously (d) prevent coagulation of the whole blood sample (e) prevent additional tagging once the cells are re-injected into the patient

Answer 56

(e) Ascorbic acid is added after incubation to reduce the free chromate to chromic ions, which immediately stops the tagging procedure by keeping the chromic ions from penetrating the red blood cell membrane.

Question 57

Morphine is administered during hepatobiliary imaging to cause the: (a)cystic duct to open (b) gallbladder to empty completely (c) sphincter of Oddi to contract (d) tracer to be diverted to the common bile duct (e) tracer to be diverted into the spleen

Answer 57

(c) Morphine sulfate contracts the sphincter of Oddi and generates an increase in pressure in the common bile duct and cystic duct.

Question 58

Which of the following is the reason that it is important to have a standardized meal size and composition in a gastric-emptying scan? (a)It can affect the radiation dose to the patient. (b) It can affect the ability to have gastric emptying. (c) It can affect the rate of gastric emptying. (d) It has no effect and is not necessary. (e) It can affect the cause of the gastric issue.

Answer 58

(c) Gastric emptying is a complex process affected by the physical and chemical composition of the ingested meal. The rate of gastric emptying is determined by many factors including with volume, physical state, caloric content, caloric density, concentration of nutrients, meal distribution, salinity, acidity, and viscosity of the test meal used.

Question 59

Which of the following is/are not indicators of renal function? (a)blood, urea nitrogen (BUN) level (b) CBC (c) creatinine clearance (d) peak transit time (e) ERPF

Answer 59

(b) BUN is the blood-urea-nitrogen level. Greater than 100 mg/dl indicates serious impairment of renal function. Creatinine is entirely excreted by the kidneys, as is BUN. A level greater than 4 mg/dl indicates serious impairment of renal function. The peak transit time is an indicator of radiopharmaceutical clearance when performing renal scans. CBC is the complete blood count, which is a standard blood test to determine the number of red blood cells, white blood cells, platelets, hemoglobin, and hematocrit.

Question 60

If 99mTc radioactivity in the circulation from a previous nuclear medicine test occurs in a renal scan in the plasma draw: (a)the ERPF will be higher than it should (b) it is impossible to predict what will happen to the ERPF (c) the ERPF will not be affected (d) the ERPF will be lower than it should (e) the ERPF cannot be determined

Answer 60

(d) Since the effective renal plasma flow (ERPF) calculation consists of counts of the dose injected divided by counts within a plasma sample taken at approximately 45 min post-injection, a higher amount of counts in the plasma sample would result in an erroneously lower ERPF value.

Question 61

Static renal parenchyma imaging would be best performed with which of the following radiopharmaceuticals? (a)[99mTc]succimer (b) [99mTc]pentetate (c) [99mTc]mertiatide (d) [99mTc]gluceptate (e) [99mTc]medronate

Answer 61

(A) [99mTc]succimer (DMSA) or succimer injection is indicated for kidney imaging for evaluation of renal parenchymal disorders. [99mTc]gluceptate is no longer commercially available, but is best for renal cortex imaging.

Question 62

In a normal kidney, the maximum amount of tracer should be concentrated in the kidney how many minutes after administration of [99mTc]mertiatide? (a)3-5 min (b) 1-2 min (c) 8-10 min (d) 30-35 min (e) 44-47 min

Answer 62

(a) The time activity curve of a renogram from a normal MAG-3 study shows prompt uptake of tracer 3-5 min post-injection.

Question 63

If the tracer for an ERPF determination using the blood sampling method is administered at 0900, at what time should the blood sample be collected? (a)0915 (b) 0944 (c) 0935 (d) 1000 (e) 1015

Answer 63

(b) In approximately 44-45 min, there will have been a maximum amount of tracer uptake and washing out in the kidneys. The residual plasma level can then be assessed for an ERPF by drawing a blood sample.

Question 64

When using the camera method for a GFR, compare the kidney counts to what? (a)dynamic image ROI counts (b) injection site (c) post-injection injection site counts (d) plasma counts (e) pre-injection syringe counts

Answer 64

(e) Right and left kidney counts are compared to the pre- and post-injection syringe counts.

Question 65

Perfusion of the ventricular septum in the heart is provided primarily by which coronary artery? (a)right coronary (b) left circumflex (c) left anterior descending (d) left coronary (e) right circumflex

Answer 65

(c) The myocardium receives oxygenated blood from its two major coronary arteries, the left main and right main coronary arteries. They branch and encircle the heart to provide blood to all portions of the myocardium. The left main coronary artery branches into the left anterior descending (LAD) and left circumflex arteries. however, the LAD branch supplies blood to the anterior wall and over 90% of the ventricular septum.

Question 66

When performing a left ventricular function examination with 99mTc-labeled red blood cells, which of these angles should be adjusted to visually separate the ventricles from one another? (a)the anterior (b) the left lateral (c) the left anterior oblique (d) both the anterior and LAO (e) and left posterior oblique

Answer 66

(d) Because of the position of the heart and the fact that it turns slightly to the left, positioning the camera anteriorly-typically anterior and left anterior oblique (LAO) (35-60 degrees) - will allow for the best septal wall separation for ejection fraction calculation and processing.

Question 67

Tachycardia is demonstrated on a EKG strip as: (a)a large P-R interval (b) an increased heart rate (c) a normal QRS heart rhythm (d) a decreased heart rate (e) a flat line

Answer 67

(b) A normal heart rate is 60-90 bpm in an adult. An increased heart rate is greater than 100 bpm, while a decreased heart rate is less than 60 bpm. Tachycardia is a general symptomatic term that does not describe the cause of the rapid rate.

Question 68

Adenosine is contraindicated for patients with which of the following conditions? (a)chronic obstructive pulmonary disease (b) stress-induced myocardial ischemia (c) diabetes (d) peripheral vascular disease (e) stroke

Answer 68

(a) This is a contraindication if the patient has a history of reactive airway disease. The patient must have bronchodilator therapy and resuscitative measures available. Dobutamine or Lexiscan would be a more reasonable pharmaceutical.

Question 69

Consumption of a fatty meal may have the same effect on the hepatobiliary system as which of the following compounds? (a)cimetidine (b) furosemide (c) morphine (d) sincalide (e) aspirin

Answer 69

(d) To assess the gallbladder ejection fraction (GBEF) and/or the sphincter of Oddi response to cholecystokinin (CCK), the c-terminal octapetide portion of CCK, sincalide (Kinevac) is given intravenously at a concentration of 0.02 ug/kg in normal saline over a period of 3-30 min.

Question 70

Delayed improvement of perfusion after coronary artery revascularization is referred to as: (a)hibernating myocardium (b) infarcted myocardium (c) stunned myocardium (d) necrosed myocardium (e) myocarditis

Answer 70

(c) Areas of stunned myocardium usually present with normal or near-normal perfusion but with absent or diminished contractility. Since the underlying myocardial cells are still viable, stunning generally spontaneously subsides over several weeks once blood flow has been restored.

Question 71

``` The percentage ejection fraction calculated from these data: Diastole: 2750 cpm Systole: 1775 cpm is: (a)61 ``` (b) 55 (c) 22 (d) 35 (e) 12

Answer 71

(d) Ejection fraction (EF) is the fraction of blood ejected by the left ventricle (LV) during the contraction or ejection phase of the cardiac cycle or systole. Before the start of systole, the LV is filled with blood to the capacity known as end diastolic volume (EDV) during the filling phase or diastole. During systole, the LV contracts and ejects blood until it reaches its minimum capacity, known as end systolic volume (ESV); it does not empty completely. Clearly, the EF is dependent on the ventricular EDV, which may vary with ventricular disease associated with ventricular dilatation. Ejection fraction (EF) = (EDV - ESV) x 100% / (EDV) EF = (2750 cpm - 1775 cpm) x 100% / (2750 cpm) EF = 980 cpm x 100% /2750 cpm EF = ~35%

Question 72

Which wave of the ECG is used to trigger the scintillation camera to acquire counts? (a)P (b) R (c) T (d) U (e) V

Answer 72

(b) A standard or small FOV camera equipped with a high-resolution parallel-hole collimator is used to perform gated studies. Using the R wave of the ECG to trigger data collection, hundreds of cardiac cycles are collected and stored in a computer. Depending on the computer software, the interval between R waves is divided into frames, most often 16. Typically each frame is acquired in a 64 x 64 matrix; 200,000-400,000 counts per frame are obtained for a total of about 3-6 million counts for the entire 16-frame study.

Question 73

Which of the following would NOT be a characteristic of an ideal myocardial perfusion agent? (a)high first-pass myocardial extraction proportional to blood flow (b) adequate imaging window (c) high target:non-target ratio (d) ability to complete both rest and stress imaging in 2 days (e) half-life sufficient to complete the heart study

Answer 73

(d) Ideal characteristics of a myocardial perfusion agent include high first-pass myocardial extraction proportional to blood flow, high target:non-target ratio, adequate imaging window, and ability to complete both rest and stress imaging on the same day in as short a time as possible.

Question 74

All of the following are advantages of the first-pass method for performing cardiac function imaging EXCEPT: (a)short acquisition time (b) low background activity (c) choice of radiopharmaceuticals (d) dose that can visualize the right side of the heart (e) multiple views with one tracer

Answer 74

(e) The first-pass method for performing cardiac function imaging has a short acquisition time - usually about 30 sec. The first-pass method has a low background activity. Any non-particulate radiopharmaceutical in a volume of 0.3-0.5 mL can be used.

Question 75

In the 1 day protocol for myocardial perfusion imaging performed with a 99mTc-labeled tracer, the larger amount of activity is administered: (a)for the rest study (b) for the study performed second (c) for the study performed first (d) for the stress study (e) for the study performed third

Answer 75

(b) When a 1-day protocol for myocardial perfusion imaging is performed with a 99mTc-labeled tracer, the smaller dose is administered for the first imaging study and a higher dose is administered for the second study.

Question 76

Which of the following is most likely to interfere with performing a left ventricular ejection fraction using the gated equilibrium technique? (a)doxorubicin toxicity (b) coronary artery disease (c) cardiomyopathy (d) cardiac arrhythmia (e) stroke

Answer 76

(d) To be valid for systolic and diastolic analysis, MUGA requires a constant regular heart rate and R-R interval. The more arrhythmic the heart rate, the less accurate the representation of diastolic function.

Question 77

An advantage of [201Tl]thallium chloride is that it: (a)has a high photon flux at a high-energy window (b) is a calcium analog (c) has a short half-life (d) redistributes (e) has a high first pass extraction rate and stays fixed in the myocardium

Answer 77

(d) Thallium-201 redistributes, which means rest and stress images can be obtained with one injection. It has a low-energy photopeak and low-photon flux. It is a potassium analog. It has a relative long half-life of 73.1 hr.

Question 78

A cardiac shunt would be best demonstrated with which of the following nuclear medicine techniques? (a)first-pass radionuclide angiography (b) equilibrium-gated ventriculogram (c) myocardial infarct imaging (d) myocardial perfusion imaging (e) LeVeen shunt study

Answer 78

(a) First-pass radionuclide angiography is used to detect and evaluate intracardiac shunts (when blood flow follows any pattern other than going from systemic circulation to the right atrium, right ventricle, lungs, left atrium, left ventricle, and then back to the systemic circulation).

Question 79

Functional cardiac studies may be performed to evaluate wall-motion abnormalities caused by all of the following EXCEPT: (a)aneurysm (b) myocardial infarction (c) myocardial perfusion patency (d) myocardial ischemia (e) myocarditis

Answer 79

(c) Functional cardiac studies may be performed to evaluate wall motion abnormalities caused by aneurysm (dykinesia), myocardial infarction, and myocardial ischemia.

Question 80

One advantage of the in vivo method of 99mTc red cell tagging is that: (a)All the circulating red cells are labeled with tracer. (b) No incubation times are required at any step in the process. (c) Smaller amounts of stannous chloride are required. (d) Only a small number of cells are tagged. (e) No manipulation of blood samples outside the body is required.

Answer 80

(e) The in vivo method of 99mTc red cell tagging is the easiest for the technologist, with no handling or manipulation of blood products or risk of inadvertent cross-transfusion.

Question 81

In preparation for a stress test, patients are instructed to fast to: (a)prevent gastrointestinal upsets during exercise (b) clear the body of nicotine (c) enhance myocardial tracer uptake (d) standardize test conditions among patients (e) minimize tracer uptake in the GI tract

Answer 81

(e) In preparation for a stress test, patients are instructed to fast to reduce tracer uptake in the GI tract.

Question 82

Given the decay factor (DF) of a radioisotope is 0.254 for 1 hr and 30 mCi/mL concentration is available at 0700, how much total activity will remain in the vial at 1100 if a total volume of 5 mL was used to make up the kit? (a)312 uCi (b) 125 uCi (c) 452 uCi (d) 754 uCi (e) 624 uCi

Answer 82

(e) The total amount of activity equals 5 mL x 30 mCi/mL = 150 mCi at 0700. A 4-hr decay factor would be (0.254)^4 = 0.00416. A decay factor (DF) of 0.00416 x 150 mCi = 0.624 mCi at 1100 am. ? uCi = 0.624 mCi x 1000 uCi/1 mCi = 624 uCi

Question 83

Which of the following statements is TRUE when transient equilibrium occurs between 99Mo and 99mTc? (a)The 99Mo and 99mTc activities are equal. (b) The maximum amount of 99mTc activity is present. (c) The ratio of the 99Mo and 99mTc activities remains constant. (d) 99mTc and 99Mo have the same decay constant. (e) The maximum amount of 99Mo activity is present.

Answer 83

(c) Transient equilibrium hold true when (T1/2)p and (T1/2)d differ by a factor of about 10 to 50. The daughter activity grows owing to the decay of the parent radionuclide, reaches a maximum followed by equilibrium, and then decays with a half-life of the parent.

Question 84

The concentration of [99mTc]pertechnetate is required to be 60 mCi/mL. If approximately 1,200 mCi [99mTc]pertechnetate will be eluted from a wet column generator, which size evacuated vial should be used to collect the eluate? (a)20 mL (b) 10 mL (c) 15 mL (d) 5 mL (e) 25 mL

Answer 84

``` (a) Concentration [ ] equals total activity over total volume: [ ] = total activity/total volume 60 mCi/mL = 1200 mCi/X X = 1200 mCi/60 mCi/mL X = 20 mL ```

Question 85

The average recommended number of MAA particles recommended to be administered is: (a)100,000 (b) 150,000 (c) 350,000 (d) 1,000,000 (e) 50,000

Answer 85

(c) MAA particle averages about 30-40 um in diameter and, because of this size, become impacted (trapped) in the terminal arterioles and capillaries after they pass through the pulmonary artery. If the recommended dose of particulate material is about 350,000 particles, fewer than 1 in 1000 pulmonary arterioles are actually blocked. The recommended number of particles per single injection is 200,000 to 700,000, with the suggested number being approximately 350,000.

Question 86

``` What approximate volume of [99mTc]pertechnetate should be added to the medronate kit to prepare 180 mCi of [99mTc]medronate? Medronate Kit Maximum activity to be added: 300 mCi Reconstituting volume: 1-8 mL [99mTc]Pertechnetate Concentration: 28.7 mCi/mL Total volume: 7.5 mL (a)0.6 mL ``` (b) 10.4 mL (c) 7.5 mL (d) 6.3 mL (e) 12.5 mL

Answer 86

(d) volume = 180 mCi / 28.7 mCi/mL | volume = 6.3 mL

Question 87

Bioavailability refers to what concerning pharmacology? (a)access to medication across the world (b) fraction of drug that is excreted from the body (c) fraction of drug that is delivered to body on the basis of weight (d) fraction of drug that reaches the heart (e) fraction of drug that reaches systemic circulation after a particular route of administration

Answer 87

(e) Bioavailability describes the fraction of an administered dose of unchanged drug that reaches the systemic circulation.

Question 88

Which of the following is NOT a factor in generator yields: (a)time since last elution (b) column cracks (c) air leaks (d) amount of 99Mo on the column (e) amount of aluminum on the column

Answer 88

(e) Yield may be reduced by a column defect. Time since last elution is a contributing factor since it will determine how much buildup of 99mTc is available on the column. Amount of aluminum on the column does not affect generator yield.

Question 89

Radiopharmaceutical kits reconstituted with 99mTc pertechnetate are prepared in nitrogen- or argon-purged vials to prevent: (a)bacterial growth (b) hydrolysis (c) radiolysis (d) oxidation (e) pyrogens

Answer 89

(d) Introducing nitrogen gas through a sterile filter allows kit contents to be stable for longer periods of time and oxidative processes to no longer affect the labeling yield.

Question 90

Which of the following is NOT part of a 99mTc radiopharmaceutical kit: (a)pyrogenocidal agent (b) ascorbic acid or stannous ion (c) reducing agent (d) lyophilized compound (e) preservative-free saline

Answer 90

(a)An ascorbic acid or stannous ion compound, a lyophilized compound, and a reducing agent are all components of the 99mTc radiopharmaceutical kit. There is no additive that can prevent pyrogens. The presence of pyrogens is tested for as a quality-control measure by the manufacturere of the kit.

Question 91

Hydrolysis of reduced 99mTc during kit preparation is demonstrated on clinical images by radioactivity concentrated in the: (a)kidneys (b) thyroid (c) lungs (d) liver (e) heart

Answer 91

(d) Weak chelates that undergo in vivo hydrolysis are expected to deposit tin in the reticuloendothelial system (RES). The RES is located in the liver, spleen, and bone marrow.

Question 92

When labeling 99mTc (VII), in what state is the 99mTc changed to make it more reactive? (a)99mTc (VIII) (b) 99mTc (VI) (c) 99mTc (IV) (d) 99mTc (V) (e) 99mTc (III)

Answer 92

(c)99mTc7+ is reduced to 99mTc4+ in a reaction that occurs during the reduction of technetium by stannous chloride in an acidic medium.

Question 93

Radiochemical impurities can change: (a)radionuclidic purity (b) generator yields (c) PET blank scans (d) center of rotation (e) target:non-target ratios

Answer 93

(e) The presence of radiochemical impurities in a radiopharmaceutical can result in poor-quality images due to high background from the surrounding tissues in the blood, which is a result of undesirable radionuclides in the dose. This will affect the target:non-target ratio.

Question 94

ITLC refers to: (a)instant transverse light chromatography (b) instant thin layer chromatography (c) instant tomographic layer chromatography (d) instant thin light chromatography (e) instant tomographic light chromatography

Answer 94

(b) ITLC stands for instant thin layer chromatography.

Question 95

Possible radiochromatography artifacts include all of the following EXCEPT: (a)using tweezers to pick up the chromatography paper (b) the strip touching the side of the developing chamber (c) the solvent evaporating before chromatography is completed (d) using the wrong solvent (e) too much solvent in the bottom of the chamber

Answer 95

(a) Grease from fingerprints can alter migration patterns during the development phase of radiochromatography; therefore, using tweezers to pick up the chromatography paper would not cause a radiochromatography artifact.

Question 96

An MAA kit has 3 million total particles. If a 5 mCi dose is needed at 1000 and the following information is provided: 25 mCi/mL in 5 mL total volume at 0700 what approximate number of particles will be given to the patient? (a)600,000 (b) 169,635 (c) 120,000 (d) 134,831 (e) 97,623

Answer 96

(b) activity at 1000 = 25 mCi (0.05)^0.5 activity = 17.68 mCi/mL volume needed = 5 mL / 17.68 mCi/mL volume needed = 0.28 mL 3,000,000 particles / 5 mL = 600,000 particles/mL number of particles = 0.28 mL x 600,000 particles / 1 mL number of particles = 169,635

Question 97

A 20 uCi 123I dose is needed on Monday morning, at 0800 CST, what amount of 123I should be sent from Atlanta at 0800 the previous Friday morning for the right amount to be available Monday morning? (a)925 uCi (b) 878 uCi (c) 988 uCi (d) 1288 uCi (e) 1067 uCi

Answer 97

(a) The time difference between Atlanta, which is on Eastern time, and Central time is 1 hr. Factoring this difference into the elapsed time between 0700 CST on August 12 to 0800 CST on August 15 results in 73 hr. The decay factor for 123I for 73 hr is 0.0216279. The pre-calibration factor is the reciprocal of the decay factor, or 1 divided by 0.0216279, which equals 46.23. 46. 23 x 20 uCi needed = 924.73 uCi or ~925 uCi

Question 98

A 25 mCi dose in a volume of 2 mL is added to 50 mL and a one-sixth serial dilution is performed. What amount of total activity is present in a 5 mL sample of tube no. 33? (a)15.12 x 10^-25 mCi (b) 6.04 x 10^-25 mCi (c) 9.08 x 10^-25 mCi (d) 12.12 x 10^-25 mCi (e) 3.02 x 10^-25 mCi

Answer 98

(e) Original dilution x (dilution factor)^(no. of tubes -1) = dilution factor 25 mCi / 52 mL = 0.48 mCi/mL (1/6 dilution)^(33-1) = 6.03 x 10^-26 mCi/mL in tube 33 5 mL x 6.03 x 10^-26 mCi/mL = 3.02 x 10^-25 mCi in tube 33 of serial dilution

Question 99

A pharmacokinectic profile of a drug depends on what? (a)mode of administration (b) mode of excretion (c) time to excretion (d) time to administration (e) mode of delivery

Answer 99

(a) The mode of administration will determine the other factors concerning the pharmacokinetic profile of a drug, which include the process by which a drug is absorbed, distributed, metabolized, and eliminated by the body.

Question 100

Which of the following may be used to reduce the allergic effects of contrast media? (a)acetaminophen (b) diphenhydramine (c) air (d) water (e) saline

Answer 100

(b) Diphenhydramine, which is an antihistamine, can be given to reduce the symptoms if an allergic reaction occurs due to administration of contrast media.