Safety Flashcards
What does reduction of intensity of a radiation beam as it passes through a substance describe?
Attenuation
What does the distance from X ray source to the center of the gantry opening describe?
Focus to isocenter distance
Filtration within the CT xray tube varies between approximately..
6-9mm of Aluminum or equivalent
What is the purpose of beam-shaping or bowtie filters?
they are added to x ray tube to compensate for noncylindrical of most body shapes
what is important when bowtie filter is employed?
positioning pt in the isocenter
when the detector array are not efficient at capturing the x ray, what can occur?
it can increase pt’s dose due to compensating for loss of data
The process of adjusting parameters such as mA/kVp, slice thickness, and pitch for the purpose of achieving lowest dose possible but maintaining image quality is known as
protocol optimization
If mAs is doubled patient dose is…
doubled, direct relationship
section of the patient that is exposed to radiation is called
dose profile
Decreased dose normally means there is an increase in…
Image noise
Image noise is____ related to patient size
directly
Pitch value of greater than one will increase/decrease patient dose?
Decrease
How many ways can Automatic tube current modulation occur?
2, angular and longitudinal
what type of gating is used to reduce patient dose in cardiac scans?
Prospective gating
Quantity of dose received by the patient from series of CT scan is referred to as…
MSAD (Multiple Scan Average Dose)
