Test 3 Intro to Nuclear Imaging Flashcards
1
Q
What are the main types of anatomical imaging?
A
- MRI
- CT
2
Q
What does anatomical imaging do?
A
- provides information about morphology of tissues
- looking at bone structure, primary tumors
3
Q
computed tomography
A
- multiple xray exposure that are combined into a 3D image
- measure transmission of xray via radiodensity
- resolution: < 1mm
- fast acquisition
- cam be used with metallic implants
- radiation dose: about 3 yrs of background radiation
- relatively low costs
- good for hard tissue
4
Q
What is the difference of CT scan with and without contrast?
A
- without contrast: looking at hard tissue, gives high resolution, high radiodensity
- with contrast: can see embolism in arteries, etc
5
Q
magnetic resonance imaging
A
- uses powerful magnetic fields to measure elemental radiofrequency energy in a tissue
- measures nuclear spin energy in a tissue
- resolution: <1 mm
- takes about 40-60 min to obtain
- cost is twice as much at CT
- good for soft tissue
6
Q
nuclear imaging
A
- use of radioactive substances to diagnose a disease
- radiation source is internal
7
Q
SPECT
A
- Single Photon Emission Computed Tomography
- patient inject with radio-labeled probe -> cameras measure gamma rays emitted
- radiotracers are chelated to the targeted moiety
- resolution: 1cm
- radiation dose: 1-3 years of background radiation
- takes about 40 min
- cost is relatively low
8
Q
PET
A
- Positron Emission Tomography
-uses positron
patient injected by radiolabled probe - resolution: 2mm
- radiation: 8 years of background radiation
- 30 min acquisition time
- cost is twice as much as CT
9
Q
What is attenuation?
A
the lower energy your photons is, the less it can transmit through your tissue
10
Q
half value layer
A
thickness of the material at which the intensity of radiation entering it is reduced by one half
11
Q
describe the relationship between photon keV and HVL
A
↑ photon keV = ↑ HVL
12
Q
(99m)Technetium Radionuclide
A
- keV: 140
- half life: 6 Hours
- modality: SPECT
13
Q
(18)Fluorine
A
- keV: 511
- half life: 109 Min
- modality: PET
14
Q
What is the energy for positrometers?
A
511 keV
15
Q
What are the three forms of imaging?
A
- anatomical imaging
- physiological imaging
- molecular imaging
