finals Flashcards
(34 cards)
- most commonly used radionuclide
- readily available
- favorable dosimetry with lack of primary particulate radiations
- favorable energy of its principal gamma photon (___keV)
- ideal half life (___) for many clinical imaging studies
Tc-99m
140keV
6 hours
Tc-99 half life
211k years
product of uranium-235 undergone fission
Tc-99 ?
electrons of excited atom are in higher energy state thus must emit the excess energy in order to go to a lower energy state. the time it takes for that to happen is ___
10^-8 secs
if the time it takes is much longer ___. it is said to be metastable
10^-3 secs
radiation safety procedures
- wear laboratory coats in area where radioactive materials are present
- wear disposable gloves when handling radioactive materials
- monitor hands and body for radioactive contamination before leaving the area
- use syringe and vial shields as necessary
- do not eat, drink, smoke, apply cosmetics, or store food in any area where radioactive material is stored or used
administered tagged compounds localized in abnormal areas
increased uptake or hot areas like in bone or brain scanning
localized in the normal tissue of an organ with abnormal areas
areas of absent activity or cold areas. e.g. thyroid scanning, liver scanning
gamma photons emitted by the patient may be acquired in various forms:
- static
- dynamic
- gated
used to collect images of different regions of the body or differently angled (oblique) views of a particular region of interest
static image acquisition
- if the distribution of nuclide in the organ is changing rapidly and its important to record this change
- 60 second renal flow study
dynamic imaging
- continuous images are obtained of a moving organ (generally the heart) and data are coordinated with the rate of heart beat
gated imaging
nuclear medicine tomographic imaging technique using gamma rays
Single-photon emission computed tomography (SPECT)
- very similar to conventional nucmed planar imaging using a gamma camera. however, it is able to provide tru 3D information
- info is presented as cross-sectional slices thru the patient, but can be freely reformatted
SPECT
SPECT utilizes single photons by gamma emitting radionuclides such as
Tc-99m
Ga-67
In-111
I-123
SPECT camera is constructed so that the head can rotate either ___ or ___ about the patient to acquire multiple view site
stepwise or continuously
introduced transaxial imaging in 1963
David Kuhl
year first practical SPECT system was constructed were the detector was first rotate around the patient rather than the patient rotating in front of the detector
1977
represents an image of the attenuation of the external x-ray source rotated about the patient and is basically a map of the distribution of densities
Transmission Computed Tomography (TCT)
map of radiopharmaceutical distribution modified by the attenuating effect of the body
Emission Computed Tomography (ECT)
concept of emission and transmission tomography was introduced by ____ and ____ in the ____ at the university of Pennsylvania
David E. Kuhl and Roy Edwards
late 1950s
_____ at the Brookhaven National laboratory was the first to describe the synthesis of 18-F FDG
1970s Tatsuo Ido
most commonly used PET scanning isotope carrier
18-F FDG
is the simultaneous emissions resulting from a single nuclear transformation
True Coincidence (true event)
