-
Compton Equation (Energy)
-
Compton Equation (Wavelength)
-
Capacitor
- Q=CV
-
-
-
Resistance
- R = resistance
- = resistivity
- L = length
- A = cross-sectional area
-
-
T1/T2 images
- T1 = fat bright
- T2 = water/fluids bright
-
Detector Dead Time Correction
- (non-paralyzable)
- (paralyzable)
-
-
Avogadro's number
Na = 6.02x1023 atoms/mol
-
Roentgen to C/kg
R = 2.58x10-4 C/kg
-
Curie to Bq
1 Ci = 3.7x1010 Bq
-
Kerma from attenuation coefficient
-
Bits to Bytes
8 bits = 1 byte
-
Transmission, Attenuation
-
kB, MB, GB, TB
- kB = 210 bytes
- MB = 220 bytes
- GB = 230 bytes
- TB = 240 bytes
-
Radiation Protection Barrier Transmission
-
Film Gamma or Average Gradient
-
Electric Field and Voltage
-
-
-
Radioactive Decay, Half Life
-
-
Dose Equivalent, Effective Dose
-
Average energy of beta decay particle
1/3 of the max energy
-
-
Survival Fraction (Single target, Single hit) (Multiple target, Single hit)
(Single target)
(Multiple Target)
-
Ion Chamber Temperature and Pressure Correction
-
Transient Equilibrium Activity of Daughter
- Note: after about 4 Half-lives, the daughter is approximately in equilibrium with the parent. If branching ratio is 1, then the daughter has a slightly higher activity than the parent.
-
Neutron beam activation saturation activity
-
Temperature Conversions (Celsius to Kelvin, Celsius to Fahrenheit)
- T[K] = T[C] + 273.15
- T[F] = 9/5 T[C] + 32
-
MeV/c2 to amu conversion
1amu = 931.5 MeV/c2
-
Sensitivity and Specificity; ROC Curve
- Sensitivity = TP/(TP+FN)
- Specificity = TN/(TN+FP)
- ROC Curve is Sensitivity vs (1-Specificity)
-
-
Exposure from Gamma Constant
-
Fetal Dose Effects
- During pre-implantation (1st week), the most likely result is death
- During organogenesis (2-8 weeks), the most likely result is growth development and malformations
- During early fetal stage (8-15 weeks), the most likely result is mental retardation
- During mid to late fetal stage (15+ weeks), the most likely result is leukemia and other cancers
- Threshold dose is likely around 10 cGy – 50 cGy
-
What process competes with gamma ray emission?
Internal conversion
-
-
What's the phase difference between the two surfaces of a piezoelectric crystal used in US?
- Quarter-wave matching
- 90-degree phase difference
-
-
Speed of sound in fat and soft tissue?
- In fat: 1450 m/s
- In soft tissue: 1540 m/s
-
Specific heat equation
- Specific heat transfer:
- Fusion (change in state of matter):
-
-
What standard controls patient demography and billing info?
HL7 (Health Level 7)
-
What regulation controls patient anonymization?
HIPAA
-
What is the lower limit for a fringe field for MRI?
5 Gauss = 0.5 mT
-
An emission has only neutrino and characteristic x-ray, what's the decay scheme?
Electron Capture
-
If a gamma emission from a metastable state to stable state is forbidden, what's the alternative decay?
Internal Conversion
-
Focal Spot Blur
Blur = spotsize*OID/SOD
-
Secular equilibrium ratio of daughter to parent
F = 1-(1/2)n where n is number of half lives
-
Relation between HVL and TVL?
TVL = 3.32 HVL
-
Standard deviation values of Gaussian Distribution
- +/-1 sigma = 68%
- +/-2 sigma = 95%
- +/-3 sigma = 99.7%
-
Electron mass and charge
- Mass = 9.1E-31 kg = 0.511MeV/c2
- Charge = 1.6E-19 C
-
According to NCRP 116 and ICRP report, what is the fatal risk of cancer by radiation for whole population for low dose rate and low LET
5% per Sv of whole body
-
According to FDA, the collimator or jaw of linac is required to be how many HVL layer?
0.5% = 0.005 ~ 8HVL
-
An atom that decays by releasing a positron has an excess of .. (neutrons, protons, electrons)
protons
-
Radiation Dose Limits
- Occupational: 50 mSv/year
- Extremities: 500 mSv/year
- Eyes: 150 mSv/year
- Fetus: 5 mSv/year
Population: 1mSv/year
-
Planck's Constant
h = 6.62E-34 m2kg/s
|
|
