radiology Flashcards
reduction of the exposure time will increase the motion unsharpness?
False
what is the role of a collimator?
setting the size of the x-ray beam
KW is an exposure factor, true of false?
False
to maintain the same exposure, if increasing the MAs you have to elevate the KVp too?
False
What is the normal tube voltage range in small animal radiography?
40-100 KVp
the use of a grid improves the image contrast?
True
what is not a normal component of an indirect digital system (CR)?
X-ray film
the elementary unit of the X-ray beam is the electron?
FALSE
Fluroscopy can be digital or analog, true or false?
True
Fluroscopy is also called “C-arm”
true
electromagnetic radiation with higher frequency has more penetrating power through space and matter?
True
What is the direction of travel of electrons in the X-ray tube?
from the cathode to the anode
how do we increase the penetrating power of X-rays?
increase the KVp
increasing the film-object distance will what?
distort the image
1% of the energy produced by the anode is in the form of What?
X-rays
the temperature of the filament within the cathode is controlled by what?
time setting
The intensity of X-rays increases as SID (source-image-distance) decreases?
True
How is the potential difference measured between the anode and the cathode?
kilovolts
thinner body parts do what to the radiographic density?
increase it
what is the main factor controling the scatter radiation?
the collimator setting
what do grids contain?
Lead
where is a grid located?
Between the patient and cassette
to prevent magnification and distortion of the object being radiographed, the patient must be??
As parallel and close to the film as possible
how should the animal be positioned when radiograph is taken over laterally positioned animal?
head should face the viewers left with its spine at the top of the image
any body part exceeding this measurement requires the use of a grid?
10cm
when using a grid the dose of radiation should be reduced?
true
the scattered beam is negligible concerning safety of staff?
False
the X-ray penetrates the body without losing energy?
False
what is the purpose of a grid?
to improve the image contrast
the X-ray consists of charged particles?
False
what is not a normal component of the digital radiographic technology:
X-ray tube
Intensifying screen
Grid
Collimator
Intensifying screen
the attenuation of the x-ray beam does not rely on which parameter?
the optical density
what component is different between conventional and digital radiography ?
detector
what is the main source of exposure of the personnel?
secondary beam from the patient
Fat is more radiopaque than fluids?
False
increased distance between the the object and detector can cause an unsharp image?
False
Distortion can be prevented by centralisation?
true
CR systems are cheaper, DR systems are more expensive?
True
what exposure factor can be used in small animal radiography?
5-11mAs
scatter radiation is mainly bases on mAs?
False
longer exposure time is needed for a chest X-ray?
False
what exposure factors cause the same blackening on the detector as 60KV/8mAs?
80Kv/ 2mAs
magnification is an image parameter?
False
An under exposed image will be too bright?
True
an under exposed image will be too bright?
True
Digital systems require much higher doses than anolog?
False
dose equivaent is a protection against ionising radiation?
False
what does the personal dose meter record?
the effective dose
Sochastic effects may result from diagnostic radiology?
true
what is an especially sensitive tissue for the ionising radiation?
Bone marrow
deterministic effects are proportionate to what ?
severity is proportionate to the dose
Radon is produced by what?
the x-ray
the X-ray photons in the body are not normally …..?
transmitted
why can a structure be more radiopaque than others?
it consists of elements of higher atomic number and has the same diameter
what if the object is not in the centre of the detector plate?
the resulting image will be unsharp
what does aqusition mean in digital imaging?
the creation of a picture from the electric sign
DICOM files are preferred by the owners?
true
