Exam 4 Flashcards
In performing a bone image, which of the following views would best demonstrate an abnormality in the calcaneus?
a. lateral views of the patella
b. postvoid image of the pelvis
c. plantar view of the feet
d. anterior view of the distal humerus and radius
c. plantar view of the feet
All of the following statements about four-phase bone imaging are true, except?
a. this study includes both dynamic and static imaging
b. the study may be performed with any blood pool agent
c. the patient is positioned under the camera before tracer administration
d. the third phase is performed 5-6hr after tracer administration
b. the study may be performed with any blood pool agent
Which of the following patients should receive fewer particles than typically administered for lung perfusion imaging?
a. 80-year-old woman with suspected pulmonary embolism
b. 65-year-old man with chronic obstructive pulmonary disease
c. 45-year-old man with right-to-left cardiac shunt
d. 25-year-old woman with asthma
c. 45-year-old man with right-to-left cardiac shunt
Which of the following statements about the wash in/washout method for performing xenon ventilation studies is true
a. the patient rebreathes a mixture of xenon and oxygen during the wash-in phase
b. the patient can be disconnected from the gas-trapping apparatus after the wash-in phase
c. this method is not recommended for comatose patients
d. it is not necessary to introduce oxygen or air into the xenon delivery system
a. the patient rebreathes a mixture of xenon and oxygen during the wash-in phase
After the administration of Tc99m pentetate aerosol with a face mask, radioactive contamination is likely to be found in all the following areas except?
a. on the floor between the patient and nebulizer
b. around the patient’s mouth
c. on the patient’s chest
d. on the technologist’s hands
d. on the technologist’s hands
Thyroid imaging may be performed with which of the following radiopharmaceuticals?
a. Tc99m pertechnetate
b. I123 sodium iodide
c. Tc99m sestamibi
d. Tc99m pertechnetate or I123 sodium iodide
d. Tc99m pertechnetate or I123 sodium iodide
When performing a radioiodine thyroid uptake, nonthyroidal (body) background measurements may be taken over the?
a. lateral skull
b. mediastinum
c. abdomen
d. thigh
d. thigh
Pulse rates may be determined by all of the following methods except?
a. multiplying the respiration rate by 4
b. using a pulse oximeter
c. listening to the heart with a stethoscope
d. analyzing the electrocardiogram
a. multiplying the respiration rate by 4
Which of the following statements regarding the administration of oxygen is false?
a. oxygen is classified as a drug
b. oxygen therapy may be ordered by a physician, nurse, athletic trainer, or respiratory therapist
c. with the consent of a physician or nurse, an oxygen appliance may be removed from the patient if it interferes with the imaging procedure
d. orders for oxygen therapy must include the amount to be delivered, the type of oxygen appliance to be used, and whether administration is to be continuous or intermittent
b. oxygen therapy may be ordered by a physician, nurse, athletic trainer, or respiratory therapist
Treatment of the adverse effects induced by dipyridamole involves the administration of?
a. adenosine
b. aminophylline
c. acetazolamide
d. nitroglycerin
b. aminophylline
Which of the following must be discontinued for at least 24-36hr before the administration of dipyridamole?
a. water
b. aspirin
c. insulin
d. theophylline
d. theophylline
In a normal hepatobiliary study, excretion of the tracer into the intestines should occur a maximum of how long after tracer administration?
a. 5-10mins
b. 20-30mins
c. 45-60mins
d. 1-2hrs
b. 20-30mins
Which of the following agents would be used to perform a gallbladder ejection fraction?
a. sincalide and Tc99m disofenin
b. sincalide and Tc99m sulfur colloid
c. morphine and Tc99m lidofenin
d. morphine and Tc99m mertiatide
a. sincalide and Tc99m disofenin
For which of the following procedures is the radiopharmaceutical administered orally?
a. gastric emptying
b. gastrointestinal bleeding
c. salivary gland imaging
d. vesicoureteral reflux imaging
a. gastric emptying
Patient preparation for functional renal imaging should include which of the following?
a. hydration of the patient
b. discontinuation of all medications
c. fasting for at least 2hr before imaging
d. administration of furosemide 1hr before imaging
a. hydration of the patient
Static renal imaging is performed about how long after the administration of Tc99m succimer?
a. immediately
b. 30min
c. 2hr
d. 8hr
c. 2hr
Patient preparation for Ga67 citrate imaging may include administration of which of the following?
a. diuretics
b. potassium perchlorate
c. Lugol’s solution
d. laxatives
d. laxatives
A normal biodistribution of In111 labeled leukocytes will demonstrate the greatest tracer uptake at 24hr after injection in which of the following sites?
a. bone marrow
b. liver
c. lung
d. spleen
d. spleen
A patient with diabetes who becomes hypoglycemic may exhibit all of the following signs and symptoms except?
a. weakness and shakiness
b. confusion
c. irritability
d. nausea and vomiting
d. nausea and vomiting
Which of the following tracers may be used to confirm brain death?
a. Tc99m exametazime
b. Tc99m oxidronate
c. Tc99m mertiatide
d. Tl201 thallous chloride
a. Tc99m exametazime
Counting cotton gauze that has been placed in a patient’s nose after intrathecal tracer administration is most useful when which of the following conditions is suspected?
a. rhinorrhea
b. hydrocephalus
c. CSF shunt patency
d. blockage of CSF flow
a. rhinorrhea
Colloidal P32 chromic phosphate is administered by which of the following routes?
a. intraperitoneal
b. intravenous
c. subcutaneous
d. inhalation
a. intraperitoneal
A Tc99m medronate image of the region shown would best demonstrate which of the following structures?
I. iliac crest
II. distal femur
III. ischium
IV. thoracic vertebrae 10-12
a. III only
b. I and III only
c. III and IV only
d. I, III, and IV only
a. III only
Which of the following radiation safety measures should be used when performing Sr89 therapy?
a. use of lead vial and syringe shields
b. urinary catherterization for incontinent patients
c. use of absorbent paper in isolation room
d. monitoring patient radiation level weekly
b. urinary catherterization for incontinent patients
On the basis of blood flow, which of the following is visualized as an area of high tracer concentration on a brain image performed with Tc99m exametazime?
a. gray matter
b. white matter
c. pineal body
d. medulla oblongata
a. gray matter
A technologist is performing a lung image on a patient known to have active tuberculosis. The most appropriate personal protective device the technologist should utilize is?
a. latex gloves
b. gown
c. lab coat
d. mask
d. mask
The patency of a LeVeen shunt may be demonstrated with which of the following radiopharmaceuticals?
a. Tc99m disofenin or Tc99m sulfur colloid
b. Tc99m MAA or Tc99m sulfur colloid
c. Tc99m pentetate or Tc99m pertechnetate
d. Tc99m albumin or Tc99m labeled red blood cells
b. Tc99m MAA or Tc99m sulfur colloid
Which of the following is common to imaging gastroesophageal reflux in both adults and children?
a. Tc99m sulfur colloid is the tracer of choice
b. the patient must fast starting at midnight before the test
c. an abdominal binder is used to increase pressure over the abdomen
d. the patient ingests dilute hydrochloric acid with the tracer
a. Tc99m sulfur colloid is the tracer of choice
The following studies are ordered for a patient:
I. ERPF determination
II. total-body bone imaging
III. In111 pentetreotide imaging
In which order should the studies be performed so that they do not interfere with one another and so that they can be accomplished in the shortest amount of time?
a. I, II, III
b. I, III, II
c. II, I, III
d. III, II, I
a. I, II, III
Historically, the function of intrinsic factor administration during a Schilling test was to?
a. increase urine output
b. facilitate the absorption of vitamin B12
c. saturate the body’s vitamin B12 storage sites
d. relieve patient anxiety
b. facilitate the absorption of vitamin B12
The region (s) of interest for detection of a left-to-right cardiac shunt is (are) drawn around which of the following structures?
a. superior vena cava
b. one or both lungs
c. left ventricle
d. right ventricle and great vessels
b. one or both lungs
Which of the following sets of vital signs measurements represent normal values for an adult?
a. 45bpm pulse, 85/45mm Hg blood pressure, 10resp/min, 97 F temp
b. 60bpm pulse, 100/50mm Hg blood pressure, 12resp/min, 98.6 F temp
c. 75bpm pulse, 120/80mm Hg blood pressure, 17resp/min, 98.6 F temp
d. 100bpm pulse, 150/100mm Hg blood pressure, 25resp/min, 102 F temp
c. 75bpm pulse, 120/80mm Hg blood pressure, 17resp/min, 98.6 F temp
A common antecubital vein used for intravenous administration of a radiopharmaceutical is the?
a. cephalic
b. radial
c. brachial
d. ulnar
a. cephalic
The Cr51 red cell sequestration study is performed to identify abnormal destruction of red blood cells by the?
a. bone marrow
b. heart
c. liver
d. spleen
d. spleen
The difference in hematocrit values between the average whole body hematocrit and the venous hematocrit is the result of?
a. the difference in vessel size
b. the variation in red blood cell diameter
c. the increased amount of blood in the extremities
d. plasma leakage
a. the difference in vessel size
On the basis of the following counts per minute obtained from a thyroid uptake test:
Thyroid = 2876
Patient Background = 563
Standard = 10,111
Room Background = 124
the percentage radioiodine uptake is?
a. 3.5%
b. 4.3%
c. 23%
d. 28%
c. 23%
A technologist is asked to check the flow rate on a drip infusion on a patient in the department. An acceptable flow rate is how many drops per minute?
a. 1-5
b. 10-20
c. 40-60
d. 75-100
b. 10-20
The total blood volume may be calculated by dividing the measured red cell volume by the?
a. hematocrit
b. plasmacrit
c. corrected hematocrit
d. corrected plasmacrit
c. corrected hematocrit
The following data were collected for a plasma volume determination:
Net standard counts = 839,621 cpm
Standard dilution factor = 15
Net plasma counts = 2,528 cpm/mL
the calculated plasma volume in milliliters is?
a. 2214
b. 3321
c. 4516
d. 4982
d. 4982
If the concentration of a 1:2,000 dilution is 0.05uCi.mL, what is the tracer concentration of the original solution?
a. 0.00025uCi/mL
b. 10uCi/mL
c. 25uCi/mL
d. 100uCi.mL
d. 100uCi.mL
A patient scheduled for F18 FDG imaging has a measured blood glucose level of 100mg/dL. Which of the following actions should the technologist perform next?
a. reschedule the patient for a later time
b. administer insulin to lower the patient’s blood glucose level
c. administer glucose to raise the patient’s blood glucose level
d. proceed with the examination
d. proceed with the examination
Based on the net counts shown here, what is the percentage gallbladder ejection fraction?
maximum gallbladder counts = 185,632
minimum gallbladder counts = 77,203
a. 71%
b. 58%
c. 41%
d. 29%
b. 58%
After a Mo99/Tc99m generator is eluted, it takes approximately how many hours for the Tc99m activity to build up to a maximum level?
a. 8hr
b. 12hr
c. 24hr
d. the secular generator can be eluted only once
c. 24hr
What is the total activity of 8mL of Tc99m eluate that has a concentration of 2.0MBq/mL?
a. 4 MBq
b. 6 MBq
c. 10 MBq
d. 16 MBq
d. 16 MBq
A wet-column generator is equipped with all of the following parts except a (n)?
a. alumina column
b. lead shield
c. charging port
d. collection port
c. charging port
According to the USP, the maximum allowable aluminum concentration in Tc99m eluate is not to exceed?
a. 0 ug/mL
b. 10 ug/mL
c. 20 ug/mL
d. 10mg/mL
b. 10 ug/mL
Which of the following statements about determining Mo99 concentration in Tc99m eluate using the lead shield method is true?
a. the eluate is assayed only for Mo99
b. the lead shield is used to absorb high-energy Mo99 photons
c. the unshielded eluate is assayed for Mo99 and Tc99m by adjusting the dose calibrator settings
d. the eluate in the lead shield is measured with the dose calibrator set to assay Mo99
d. the eluate in the lead shield is measured with the dose calibrator set to assay Mo99
The test kit used to measure aluminum ion concentration in Tc99m eluate contains specially treated paper and an aluminum solution with a concentration of approximately?
a. 2 ug/mL
b. 5 ug/mL
c. 10 ug/mL
d. 20 ug/mL
c. 10 ug/mL
Which of the following pairs of radiopharmaceuticals may be used to perform lung perfusion and ventilation imaging?
a. Tc99m sulfur colloid and Tc99m pentetate aerosol
b. Tc99m albumin and Xe133 gas
c. Tc99m MAA and Xe133 gas
d. Tc99m bicisate and Tc99m aerosol
c. Tc99m MAA and Xe133 gas
An eluate of Tc99m pertechnetate is assayed for Mo99 contamination at 0600 with the following results:
Mo99 = 15.5uCi Tc99m = 250mCi
at 1000, the eluate is used to prepare a Tc99m labeled compound with a shelf life of 8hr. What is the latest time that the Tc99m compound may be administered to patients?
a. 1400
b. 1500
c. 1700
d. 1800
a. 1400
If the following reagents are available:
Oxidronate kit:
maximum Tc99m activity to be added = 250mCi
reconstituting volume = 1-5mL
Tc99m pertechnetate:
concentration = 35mCi/mL
total volume = 10mL
what is the maximum amount of Tc99m oxidronate (in mCi) that can be prepared from one kit?
a. 35 mCi
b. 175 mCi
c. 250 mCi
d. 350 mCi
b. 175 mCi
Which of the following ingredients in a sulfur colloid kit are combined and heated?
a. Tc99m pertechnetate and thiosulfate mixture
b. thiosulfate mixture and acid
c. Tc99m pertechnetate, thiosulfate mixture, and acid
d. Tc99m pertechnetate, thiosulfate mixture, acid, and buffer
c. Tc99m pertechnetate, thiosulfate mixture, and acid
When preparing to withdraw a unit dose of P32 chromic phosphate, the technologist visually inspects the radiopharmaceutical and notes that it is a blue-green color. The technologist should next?
a. contact the radiopharmaceutical manufacturer
b. reschedule the procedure
c. withdraw the unit dose
d. place the dose in radioactive waste for disposal
c. withdraw the unit dose
What is the concentration of Tc99m succimer if 1.5mL succimer reagent and 30mCi Tc99m pertechnetate (concentration is
18mCi/mL) are mixed to prepare the radiopharmaceutical?
a. 20mCi/mL
b. 17.6mCi/mL
c. 14.3mCi/mL
d. 9.4mCi/mL
d. 9.4mCi/mL
The tagging efficiency of a radiopharmaceutical is determined using the following solvent/support media system:
System 1: 0 Rf for Radiopharmaceutical, 0.9 Rf for free tech, 0 Rf for hydrolyzed reduced Tc99m
System 2: 1 Rf for Radiopharmaceutical, 1 Rf for free tech, 0 Rf for hydrolyzed reduced Tc99m
After a chromatography strip containing a sample of the radiopharmaceutical was developed in each solvent, cut in half, and counted, the following results were obtained:
System 1: 1,716 cpm at solvent front half and 23,706 cpm at origin half
System 2: 21,001 cpm at solvent front half and 1,200 com at origin half
What is the tagging proficiency?
a. 92.8%
b. 87.0%
c. 12.1%
d. 6.7%
b. 87.0%
The label on an unopened vial states that the vial contains 10mL of radiopharmaceutical with a concentration of 55.5MBq/mL. When the technologist assays the vial in a dose calibrator, it measures 9mCi. Which of the following actions should the technologist perform first?
a. check the radionuclide setting on the dose calibrator
b. begin to prepare unit dose from the vial
c. perform an accuracy check on the dose calibrator
d. contact the radiopharmaceutical manufacturer
a. check the radionuclide setting on the dose calibrator
A vial of Ga67 gallium citrate is calibrated to contain 5mCi at 0600, Pacific Standard Time, on March 8. How much activity does the vial contain on March 9 at 1200, eastern standard time?
a. 6.3mCi
b. 4.9mCi
c. 3.9mCi
d. 3.7mCi
c. 3.9mCi
A technologist needs 50uCi Cr51 sodium chromatic at 0800 on March 15. The label on the radiopharmaceutical vial contains the following information:
Total activity = 2mCi
Total volume = 5mL
Assay = 0600 March 18
What volume is required to obtain the necessary activity on March 15?
a. 0.07mL
b. 0.12mL
c. 0.86mL
d. 1.2mL
a. 0.07mL
In labeling red blood cells with Cr51 sodium chromate, which of the following components is first added to the ACD solution?
a. Cr51 sodium chromate
b. blood sample
c. ascorbic acid
d. heparin
b. blood sample
All of the following are advantages of the in vitro method of labeling red blood cells with Tc99m pertechnetate except?
a. the red blood cells can be washed to remove substances from the plasma that may interfere with labeling
b. a commercially manufactured kit that requires no cell separation by centrifugation is available
c. higher labeling efficiencies than with the in vivo method are possible
d. in vitro labeling has the lowest risk of red cell hemolysis
d. in vitro labeling has the lowest risk of red cell hemolysis
Which of the following equipment is needed to verify the size and number of MAA particles in a Tc99m MAA preparation?
a. dose calibrator
b. limulus amebocyte lysate solution
c. chromatography strips, solvent, developing chamber
d. hemocytometer, light microscope
d. hemocytometer, light microscope
According to NRC regulations, records of patient dosage determination must be retained for how long?
a. 3 years
b. 5 years
c. 10 years
d. indefinitely
a. 3 years
During red blood cell labeling with Cr51, the purpose of adding ascorbic acid to the ACD whole blood solution is to?
a. prevent hemolysis of the red blood cells
b. maintain the pH of the mixture
c. prevent clot formation
d. reduce the chromate ion to a lower valence state
d. reduce the chromate ion to a lower valence state
Upon visual inspection, a vial of Tc99m MAA has a white, slightly cloudy appearance, which of the following actions should the technologist perform next?
a. prepare unit dose from the vial
b. prepare another vial of Tc99m MAA
c. filter the preparation
d. adjust the pH of the preparation
a. prepare unit dose from the vial
On the basis of the chromatography results shown here, what is the percentage radiochemical purity of the Tc99m mertiatide preparation?
System 1 = 107.5uCi Tc99m mertiatide + HR-Tc at origin and 9.2uCi Tc99m pertechnetate at the solvent front
System 2 = 8.4uCi HR-Tc at origin and 132.6uCi Tc99m mertiatide + HR-Tc at the solvent front
a. 13.9%
b. 86.1%
c. 92.1%
d. 94%
b. 86.1%
If an MAA kit contains approximately 6 million particles, what reconstituting volume is required to obtain 500,00 particles in 0.4mL?
a. 0.03mL
b. 0.21mL
c. 4.8mL
d. 12mL
When assembling a needle and syringe for an intravenous administration, all of the following areas must remain sterile except the?
a. outer side of the syringe barrel
b. syringe tip
c. needle shaft
d. needle tip
a. outer side of the syringe barrel
The NRC defines an unrestricted area as one in which an individual will receive less than how many millirems in an hour?
a. 2mrem
b. 5mrem
c. 50mrem
d. 100mrem
a. 2mrem
A package containing radioactive material is monitored and found to produce 0.4mR/hr at the surface and no detectable radiation exposure at 1m from the surface. Which DOT label must be affixed to the outside of the package?
a. “Category I”
b. “Category II”
c. “Category III”
d. no DOT label is required
a. “Category I”
The NRC requires that all of the following information be included in unit dosage measurement records except the?
a. date and time of measurement
b. dose calibrator make and model number
c. patient’s name
d. radiopharmaceutical name
b. dose calibrator make and model number
If the distance between a radiation point source and a survey meter is doubled, the measured radiation exposure rate is reduced?
a. to half of the original exposure rate
b. to one-quarter of the original exposure rate
c. to one-eighth of the original exposure rate
d. unpredictably
b. to one-quarter of the original exposure rate
According to NRC regulations, which of the following radiopharmaceutical administration errors must be reported to the NRC?
a. A patient receives 18mCi of Tc99m pertechnetate when 20-25mCi was prescribed
b. a patient scheduled for bone imaging receives 20mCi of Tc99m pertechnetate instead of Tc99m medronate
c. Patient A receives a hepatobiliary scan dosage intended for patient B that results in a 20rem exposure to the liver
d. a patient receives a whole-body scan dosage of I131 instead of I123 for thyroid uptake and scan that exceeds 50rem exposure to the thyroid
d. a patient receives a whole-body scan dosage of I131 instead of I123 for thyroid uptake and scan that exceeds 50rem exposure to the thyroid
According to the NRC, a written directive for the administration of Sr89 chloride must include all of the following information except?
a. route of administration
b. radiopharmaceutical name
c. patient’s social security number
d. signature of an authorized user
c. patient’s social security number
According to the NRC, the radiation dose to the fetus of a declared pregnant worker must not exceed how many rems during pregnancy?
a. 500rem
b. 50rem
c. 5rem
d. 0.5rem
d. 0.5rem
Which of the following monitoring techniques should be employed to rule out internal contamination after handling a radioiodine solution?
a. thyroid uptake 24hr after handling the solution
b. urine counts 2-4hrs after handling the solution
c. plasma counts 24hr after handling the solution
d. pocket dosimeter reading
a. thyroid uptake 24hr after handling the solution
According to the NRC, packages with which of the following DOT labels must be checked for contamination using a wipe test?
a. yellow II only
b. white I and yellow II only
c. yellow II and yellow III only
d. white I, yellow II and yellow III
d. white I, yellow II and yellow III
The first step in decontamination of personnel is to?
a. remove any articles of contaminated personal or protective clothing
b. wash contaminated areas of the skin with soap and water
c. remove the contaminated person from the site of the spill
d. immediately place the contaminated person in a shower
a. remove any articles of contaminated personal or protective clothing
According to NRC regulations, a written directive must be retained?
a. for 1 year
b. for 3 years
c. for 5 years
d. indefinitely
b. for 3 years
According to the NRC, patient dosage records must be retained for how many years?
a. 1 year
b. 3 years
c. 5 years
d. as long as the facility’s license is in effect
b. 3 years
If a technologist stands next to a radioactive source that is producing an exposure rate of 0.5mrem/hr for 20 min, what radiation dose does the technologist receive?
a. 0.17mrem
b. 0.5mrem
c. 10mrem
d. 17mrem
a. 0.17mrem
A wipe test gives a reading of 1,240 cpm with a background count of 410 cpm. If the efficiency of the instrument is 35%, what is the wipe test reading in dpm?
a. 35 dpm
b. 290 dpm
c. 2,371 dpm
d. 3,542 dpm
c. 2,371 dpm
Ten millisieverts is equivalent to how many millirems?
a. 0.1
b. 1
c. 100
d. 1000
d. 1000
If a technologist received dosimeter readings that are nearly equal to the NRC limits, which of the following is the most appropriate action?
a. the technologist must cease working in a radiation area
b. the technologist can work in a radiation area but must limit exposure
c. the RSO must review the technologist’s work habits
d. the RSO must give the technologist a written warning
c. the RSO must review the technologist’s work habits
How often must dose calibrator constancy be performed?
a. annually
b. monthly
c. weekly
d. daily
d. daily
According to the NRC, records of survey meter calibration are retained for how long?
a. 3 years
b. 5 years
c. as long as the instrument is in use
d. as long as the facility license is in effect
a. 3 years
The following are the results of energy-resolution tests for the last four quarters:
January = 9.5% energy resolution
April = 10.3% energy resolution
July 10.9% energy resolution
October 11.1% energy resolution
According to these data, which of the following statements is true?
a. the energy resolution of the instrument is improving
b. the energy resolution of the instrument is worsening
c. the results indicate that the instrument should no longer be used
d. the test should be performed with a different radionuclide
b. the energy resolution of the instrument is worsening
According to the NRC, how often must survey meters be calibrated?
a. daily
b. before each use
c. monthly
d. annually
d. annually
The standard of practice dictates that the center of rotation offset correction be performed how frequently on SPECT cameras?
a. daily
b. weekly
c. monthly
d. quarterly
b. weekly
How often should a uniformity flood be acquired on a scintillation camera?
a. daily
b. weekly
c. monthly
d. quarterly
a. daily
Static frame mode acquisition is the most appropriate type of image acquisition for which of the following procedures?
a. first pass of a three-phase bone scan
b. left ventricular ejection fraction determination
c. thyroid imaging
d. renal function imaging
c. thyroid imaging
Which of the following radionuclide sources is used to acquire a uniformity correction flood?
a. Tc99m point source with collimator removed
b. Co57sheet source with collimator removed
c. Tc99m point source with collimator removed
d. Co57 sheet source with collimator in place
d. Co57 sheet source with collimator in place
It is recommended that high-count uniformity correction flood images be acquired how frequently?
a. daily
b. weekly
c. monthly
d. quarterly
b. weekly
Which of the following will increase the resolution of a “spot view” bone image obtained with a parallel-hole collimator?
a. increasing the pulse-height analyzer window width
b. moving the camera closer to the patient’s body
c. using the high-sensitivity collimator instead of LEAP collimator
d. using fewer shades of gray to display the image
b. moving the camera closer to the patient’s body
If a Butterworth filter is applied to an image and the order of the filter remains constant, which of the following cutoff frequencies (the frequency at which the filter magnitude drops below 0.5) will result in the smoothest image?
a. 0.50cycles/pixel
b. 0.42cycles/pixel
c. 0.33cycles/pixel
d. 0.15cycles/pixel
d. 0.15cycles/pixel
When a high activity of a radionuclide is used for a PET scan, image quality is degraded because?
a. deadtime decreases
b. random events increase
c. attenuation increases
d. noise increases
b. random events increase
If a 20% window test is set around a centerline of 344keV, what energies will be accepted by the pulse-height analyzer?
a. 291-437keV
b. 328-400keV
c. 344-384keV
d. 354-374keV
b. 328-400keV
A technologist changes the collimator on a gamma camera from a low-energy all-purpose collimator to a high-resolution collimator. If the same number of counts is acquired, how will the acquisition time change when the high-resolution collimator is used?
a. the acquisition time will be the same with both collimators
b. the acquisition time will decrease
c. the acquisition time will increase
d. the effect on acquisition time is unpredictable
c. the acquisition time will increase
