Prelim Topic 2

Question 1

Basic process of nucmed

Answer 1

Injection of radiopharmaceutical
Pharmaceutical carries the radionuclide to the
organ being examined.
The target organ is localized.
Radionuclide in the target organ emits gamma
rays.
Gamma camera detects the gamma rays to
create a digital image.

Question 2

Imaging procedures - referred to as

Answer 2

scanning scintigraphy

Question 3

is the nuclear medicine laboratory technique for measuring trace amount of substances in the blood. (substances being measured with RIA are the least 1000 times less)

Answer 3

Radioimmunoassay (RIA)

Question 4

In “ __ “ - in the living subject

Answer 4

Vivo

Question 5

for brain, liver, lung, bone, kidney, heart, thyroid, and other organs for detection of a tumor. Whole body imaging for the detection of metastases.

Answer 5

Imaging studies

Question 6

are thyroid uptake to determine thyroid function, renography for the investigation renal function, and blood volume measurement.

Answer 6

Non-imaging studies

Question 7

Therapeutic Procedure -treatment of

Answer 7

Hyperthyroidism with I-131

Question 8

In “ __ “ - in a glass

Answer 8

Vitro

Question 9

measurement of hormones, enzymes, and other substances.

Answer 9

Radioimmunoassay

Question 10

uses a __ of radioactive material (unsealed source)

Answer 10

small amount

Question 11

Unsealed means?

Answer 11

Open

Question 12

Uniqueness of Nuclear Medicine is that it
evaluates the __ of the organ

Answer 12

function

Question 13

Two classes of nucmed imaging

Answer 13

Single photon imaging, positron imaging

Question 14

includes Single Photon emission Computed tomography (SPECT), Uses radionuclides that decay by gamma emission

Answer 14

Single photon imaging

Question 15

Includes Positron Emission Tomography (PET) Uses radionuclide that decay by positron emission

Answer 15

Positron Imaging

Question 16

Two main categories of detectors

Answer 16

Gas filled detectors, scintillation detectors

Question 17

Those that depend on ionization in which ionization is translated into electric current or impulses.

Answer 17

Gas filled detectors

Question 18

those that depend on excitation.

Answer 18

Scintillation detectors

Question 19

Radiation is sensed by

Answer 19

Detecting ionization of gas

Question 20

The use of an ionization chamber. The generic design concept is a gas-filled chamber with __ and __ electrodes,

Answer 20

positive, negative

Question 21

placed either at opposite sides of the chamber. A __ is created between two electrodes, but __ in the absence of exposure of the chamber to radiation.

Answer 21

potential difference, no current flows

Question 22

3 types of gas filled detectors

Answer 22

Proportional counter, ionization chamber, geiger-muller counter

Question 23

Are very sensitive type of personnel monitoring device Provides an instantaneous reading, but must be recalibrated daily Resembles a fountain pen Inside the dosimeter is an ionization chamber Normally used only in emergency situation immediate reading is necessary

Answer 23

Pocket dosimeter, pen dosimeter

Question 24

Used to determine the amount of radioactivity in syringes or vials, Device that is used to measure, Radioactivity before Injecting to the Patient

Answer 24

Dose calibrator

Question 25

The main difference between a __ and basic ionization chamber is greater applied voltage between electrodes Proportional chambers do not have wide application in clinical nuclear medicine. They are used in research In detection alpha and beta particles. useful is their ability to distinguish between alpha and beta radiation.

Answer 25

Proportional counters

Question 26

an instrument for detecting and measuring the intensity of ionizing radiation Used as a survey meter __ counter is used for contamination control in nuclear medicine laboratories. They are not particularly useful as dosimeters

Answer 26

Geiger-muller

Question 27

When ionizing particles pass through certain crystals, flashes of light or scintillation is emitted. The amount of light emitted is proportional to the amount of energy absorbed by the material. This type of detector is the most commonly used detector in nuclear medicine.

Answer 27

Scintillation detectors

Question 28

The output signal form accumulated charge in radiation detectors is typically quite low

Answer 28

Pre-amplifier

Question 29

1. To amplify, if necessary, small signals from detectors 2. To shape signals for remaining signal processing

Answer 29

main purposes of the preamplifier (or preamp):

Question 30

The output signal form the preamplifier can still be quite low for traditional electronics in signal processing chain

Answer 30

Amplifier

Question 31

1. To amplify, the still relatively small pulses from the preamplifier 2. To reshape the long signals from the preamplifier to minimize pulse-pileup at high count rates and improve SNR

Answer 31

Main purpose of amplifier

Question 32

• Is an electronic device used to determine which portion of the detected spectrum is used to create images. • The PHA can be set to allow only selected energies to be counted, and reduce the number of Compton scatter photons in the image. • The PHA allows the operator either to set the upper and lower energy limits or to set a peak energy level and associated window.

Answer 32

Pulse height analyzer

Question 33

Types of collimator

Answer 33

Pinhole Collimator • Parallel hole Collimator • Converging Multihole Collimator • Diverging Multihole Collimator

Question 34

HIGHEST RESOLUTION, This type of collimator provides the best spatial resolution and the lowest sensitivity of any collimator used in nuclear medicine, USED IN THROID SCANS

Answer 34

Pinhole collimator

Question 35

Spatial Resolution: determined by the collimator

Answer 35

a. Diameter of aperture b. Distance from both of the object c. NaI crystal aperture

Question 36

No magnification occurs with this type of collimator Hole Diameter: 1mm Hole length: 20 mm MOST COMMON TYPE OF COLLIMATOR

Answer 36

Parallel hole collimator

Question 37

Provides both enhanced spatial resolution and improved sensitivity. Used for imaging smaller objects (similar to pinhole) using a camera with a large FOV. Used to achieve magnified image with slightly improved spatial resolution.

Answer 37

Converging collimator

Question 38

3 parts of PMT

Answer 38

photocathode, dynode, anode (collecting anode)