Med Rad 2 Flashcards
(33 cards)
How to calculate Intensity after passing through a material?
I(x)=(Io)e^-ux
Io=The initial intensity before passing through matter
x=Thickness of material
I=Intensity after going through material
u=How much radiation is weakened as it passes through a material
How to calculate Probability of PE
Probability of PE=density (Z^3)/E^3
How to calcualte Probability of compton scatter
Probability of compton scatter=Density/Energy
How to calculate KE of photoelectron
KE of photoelectron=Incident x-ray photon E (or planck’s constant)-BE of electron
How to calculate E of initial photon with PE
E of initial photon with PE=EBE (binding E) +EKE (photoelectron kinetic E)
How to calculate E of initial photon with CS
E of initial photon with CS=ES+EBE+EKE
How to calculate TMAC
TMAC=u/density
How to calculate PEMAC
PEMAC=t/p
CS unit=o (sigma)
PE unit=t
Density unit=p
How to calculate CEMAC
CEMAC=o/p
How to calculate Probability of PE when using PEMAC
Probability of PE when using PEMAC=t/p (z^3)/E^3)
How to calcultae Probability of CS when using CEMAC
Probability of CS when using CEMAC=o/p (p/E)
How to calculte u
u= -ln(Ix/Io)/x OR -ln(0.5)/HVL
How to calcuate HVL
HVL=I(x)/Io
How to calculate TVL
TVL=2.303/u
How to calculat PMT gain
PMT gain=g^n
g=dynode gain
n=number of dynodes
Flux gain
Flux gain= # of output light photons/ # of input x ray photons
Brightness gain
Brightness gain=Flux gain x minification gain
Minification gain
Minification gain=d1^2/do^2
the ratio of the input phosphor area to the output phosphor area, resulting in a brighter image due to the concentration of electrons on a smaller surface
d1=Diameter of the IP
do=Diameter of the OP
Electronic magnification factor
Electronic magnification factor=IP new size/old IP size
Patient dose factor
Patient dose factor=(IP old size/IP new size)^2
Read Logarithms:
Logb(X)=Y
b^y=X
Acoustic velocity
Acoustic velocity or c=f x λ
Intensity
Intensity= 1/distance^2
Coulomb’s law:
Coulomb’s law: F=K(q1q2)/d^2
k=9x10^9
q=Charge