Instrumentation Final Review

An Instrument that detects radiation using a crystal, or other material that fluoresces when ionizing radiation strikes it is called a:

a) Geiger-Muller Detector

b) Scintillation Counter

c) Photomultiplier Tube

d) Gamma Camera

B

Quality Control tests are performed to assess all the characteristics of dose calibrators EXCEPT:

a) Accuracy

b) Linearity

c) Geometry

d) Predictability

e) Constancy

D

Which paring of dose calibrator characteristics and how often it needs to be tested is correct?

a) Accuracy : Once a year

b) Linearity : Once per month

c) Geometry : Once every three months

d) Predictability : once per day

A

Quality Control procedures that must be performed on scintillation detectors include all of the following EXCEPT:

a) Linearity

b) Constancy

c) Calibration

d) Chi-square

e) Energy Resolution

A

Testing of surgical gamma probes, used in surgical procedures to detect malignant tissue that has been labeled with radiopharmaceuticals, requires which of the following?

a) A sample of cobalt-57 as a radioactive source

b) Radiation activity range of 10 to 50microcuries (uCi)

c) Radiation frequency range of 1020 to 1022 hertz (Hz)

d) None of the above

A

A collimator built with relatively thin septa between the holes should be used with a radionuclide such as:

a) Technetium-99

b) Indium-111

c) Phosphorus-32

d) Fluorine-18

C

Which of the following must be done performed before a package containing radioactive materials can be returned to the vendor:

a) Confirm that the exposure rate does not exceed background levels

b) Perform a wipe test to assure there is no surface contamination

c) Cover each individual vial with a waterproof covering

d) Notify the NRC that a shipment is being made

e) Performing a calibration check on the dose calibrator

B

According to the NRC, the NRC and the final delivery carrier must be notified if exposure rate at the surface of the package containing radioactive materials exceeds:

a) 100 mR/hr

b) 2,000 mR/hr

c) 1,000 mR/hr

d) 200 mR/hr

e) 10 mR/hr

D

What energies will be accepted by a 15% window placed around a centerline of 159 keV:

a) 135-183 keV

b) 144-174 keV

c) 151-167 keV

d) 141-171 keV

e) 159-189 keV

D

Using a 125uCi source, 30,500 cpm were collected during a camera sensitivity determination. If the background count is 1200 cpm, what is the sensitivity of the instrument?

a) 234 cpm/uCi

b) 244 cpm/uCi

c) 29,300 cpm/uCi

d) 3,662,500 cpm

e) 30,500 cpm

A

If a PLES transmission phantom is used, how many images must be acquired assess linearity over the entire field of view of the scintillation camera?

a) 1

b) 3

c) 2

d) 5

e) 4

C

According to the NRC regulations, personnel radiation exposure records must be maintained:

a) For 3 years

b) Indefinately

c) For 5 years

d) For 6 years

e) For 7 years

B

Based on the graph shown, the Full Width Half Max (FWHM) is:

a) 2500 cpm

b) 680 keV

c) 7500 cpm

d) 50keV

e) 500cpm

B

The scintillation camera quality control images produced was obtained with what transmission phantom?

a) 4-quadrant bar

b) Orthogonal hole

c) Moire phantom

d) Parallel-line equal-space (PLES)

e) Hine-Duley

B

The use of elliptical and/or body contour orbits in SPECT imaging should result in improved:

a) Temporal Resolution

b) Spatial Resolution

c) Reconstruction Times

d) Acquisition times

e) Patient Comfort

B

At what distance is the exposure rate (in mR/hr) indicated by a package's transport index measured?

a) At the surface

b) At 1 meter from the surface

c) At 3 meters from the surface

d) At 6 meters from the surface

e) Transport index does not have anything to do with exposure, all packages, radioactive or not, have a T.I.

B

According to the NRC, an unrestricted area is one in which a person would receive a radiation dose of less than:

a) 2 mrem/hr

b) 5 mrem/hr

c) 10 mrem/hr

d) 20 mrem/hr

e) 50 mrem/hr

A

What does ALARA stand for:

a) Linear no-threshold hypothesis

b) As long as reasonably achievable

c) As long as unreasonably achievable

d) As low as reasonably achievable

e) As long as Ray allows

D

What is the measured exposure rate shown on the diagram of the G-M meter shown?

a) 0.1 mR/hr

b) 1 mR/hr

c) 100 mR/hr

d) 10 mR/hr

e) 0.001 mR/hr

D

According to the NRC, areas where therapeutic radiopharmaceuticals are prepared or administered must be surveyed:

a) Weekly

b) Monthly

c) Quarterly

d) After each therapeutic dose is prepared or administeded

e) At the end of each day a therapeutic doseage is prepared or administered

E

If a 20% window is set around a centerline of 364 keV, what energies will be accepted by the pulse-height analyzer:

a) 291-437 keV

b) 328-440 keV

c) 344-384 keV

d) 354-374 keV

e) 364-384 keV

B

According to the NRC, survey meters must be calibrated __________ and following any repairs.

a) Semiannually (twice a year)

b) Biannually (every other year)

c) Monthly (once a month)

d) Yearly (once a year)

e) Quarterly (four times a year)

D

The difference between a direct radiation survey and a wipe check radiation survey is that:

a) There is none

b) One is qualitative and one is not

c) One is quantitative and one is not

d) One breaks bonds and the other does not

e) One gives an instant reading and one does not

E

An occupational worker has received 14,000mRem of exposure to the eyes in a 1 year period on their dosimeter, which course of action would be appropriate?

a) Recommend eye chelation

b) Review ALARA standards to reduce exposure because s/he is close to exceeding their annual eye dose limit

c) Review ALARA standards to reduce exposure because s/he has exceeded his/her annual eye dose limit

d) Recommend s/he use leaded eyeglasses to reduce exposure

e) Recommend s/he use thyroid shields

B

If a G-M meter has a scale of 1-5mR/hr. If a deflection on the meter reads 4.5 and the meter is set

on the x 0.1 setting, what is the reading?

a) 40.5 mR/hr

b) 4.5 mR/hr

c) 0.45 mR/hr

d) 0.045 mR/hr

e) 45 mR/hr

C

In operating a G-M meter on a daily basis, what is the first thing you should always do?

a) Use a check source to make sure the meter is working correctly

b) Set it to the most sensitive scale/.setting

c) Insert the batteries

d) Check the batteries

e) Set it to the least-sensitive scale/setting

D

The average energy required to create an ion pair in air is__________.

a) 60 eV

b) 34 eV

c) 5 eV

d) 30 keV

e) 50 eV

B

The ionization of the entire fixed volume of a gas due to secondary ionization is know as

the______________.

a) Geiger effect

b) Townsend avalanche

c) Proportional effect

d) Internal amplification

e) Inverse gain

A

How do sizes of the pulses produced by the collection of ions in the proportional region compare to those produced by an instrument that operates in the ionization region of the gas curve for radiation detectors?

a) The pulses are in resonance

b) The pulses are smaller

c) The pulses are the same size

d) The pulses are larger

e) The pulses are affected by pulse pile-up

D

Gas amplification is a phenomenon associated with instruments that operate in which region of the gas curve for radiation detectors?

a) recombination

b) ionization

c) proportional

d) Continuous discharge

e) G-M

C

The output pulse height of a gaseous detector is, in most cases, dependent upon what?

a) The quality of radiation that passes through the gas

b) Numbers of ions produced in the gas

c) Volume of gas in the detector

d) Pressure of the gas in the tube

e) Type of gas in the tube

B

Which of the following is used for SPECT system performance?

a) High count flood

b) COR offset measurement

c) PLES phantom

d) Jaszczak phantom

e) 3D or 4D operation

D

Full width at half maximum (FWHM) is often used as a measure of:

a) Uniformity

b) Sensitivity

c) Intensity

d) Resolution

e) Dead Time

D

Uncorrected flood field non-uniformities cause __________ artifacts in tomographic reconstruction.

a) Irregular

b) Dropout

c) Ring

d) Undulating

e) Linear

C

According to national standards, how often should the activity linearity of a dose calibrator be

measured?

a) Each day of use

b) Weekly

c) Monthly

d) Quarterly

e) Annually

D

According to the NRC, records of surveys should be retained for how long?

a) 1 year

b) 3 years

c) 5 years

d) 10 years

e) Indefinitely

B

For a parallel-hole collimator, the best resolution is at:

a) The collimator surface

b) 10 cm

c) 15 cm

d) 20 cm

e) The focal distance

A

How often should the COR check be performed?

a) Each day that SPECT scans will be performed

b) At least weekly

c) Biweekly

d) At least monthly

e) Every 6 months

B

If a 15% window is set around a centerline of 364 keV, what energies will be accepted by the pulse height analyzer?

a) 309-419 keV

b) 328-400 keV

c) 337-391 keV

d) 346-382 keV

e) 360-368 keV

C

To obtain high resolution resolution images of a small organ, gland or joint which

collimator would be most useful?

a) Diverging

b) Flat Field

c) High Energy Diverging

d) Low-Energy Diverging

e) Pinhole

E

If a technologist wishes to evaluate the intrinsic uniformity of a camera used for planar imaging

and is preparing a dose of technetium-99, how much activity is sufficient for the image?

a) 10 mCi

b) 1 mCi

c) 200 uCi

d) 2 mCi

e) 20 mCi

C

Of the following, the two most important quality assurance measurements of a scintillation camera imaging system are:

a) Focus, Astigmatism

b) Energy resolution, Counting efficiancy

c) Field uniformity, Spatial resolution

d) Deadtime, revolving time

e) Astigmatism, revolving time

C

The amount of light generated by a sodium iodide crystal is directly related to the:

a) Photon energy absorbed in the crystal

b) Diameter of the crystal

c) Thickness of the crystal

d) Age of the crystal

e) Material of the crystal

A

The basic function of all collimators is to:

a) Increase resolution of the instrument

b) Increase efficiency of the instrument

c) Limit scatter radiation

d) Limit access of the photons to the instrument

e) Purple triangle

D

All of the following are gas detectors EXCEPT:

a) Gamma Camera

b) Cutie Pie survey meter

c) Dose Calibrator

d) Geiger-Mueller Detector

e) Ion Chamber

A

Dose Calibrators are examples of a(n):

a) Ionization Chamber

b) Solid Scintilation System

c) Liquid Scintilation System

d) G-M Meter

e) Ion Chamber

A

If a noticeable change in field uniformity of a gamma camera occurs, a technologist should first check the:

a) Temperature

b) Photo Peaking

c) Collimator

d) System for Contamination

e) PLES phantom

B

The sensitivity of the dose calibrator chamber to different source configurations is measured by:

a) Accuracy

b) Linearity

c) Geometry

d) Constancy

e) Precision

C

You are returning a shipment of radioactive material to the pharmacy. You have 11 mCi of Tl-201 and 1.6 mCi of Cs-137. What is the total activity you are allowed to ship back as a limited quantity shipment.

a) 11 mCi

b) 1.6 mCi

c) 1.4 mCi

d) 110 mCi

B