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Final
RDTC 236
Question | Answer |
---|---|
Xrays are only produced when button pressed (T/F)? | True - Dead man's switch |
Leakage MAX of Protective Housing? | 1 mGy/hr (100 mR/hr) @ 1 meter |
Acceptable SID Variance? | 2% |
Collimation & PBL accurate within __% of __? | 2% of SID |
Minimum Filtration Half Value Layer? | HVL 2.5 mm Al Equiv @ 80 kVp |
Acceptable Reproducibility Variance? | 5% mR/mAs |
Acceptable Linearity Variance? | 10% mR/mAs |
Handswitch placed permanently BEHIND protective barrier (T/F)? | True |
Mobile system exposure switch on __ cord? | 2 meter (6.5') |
Minimum Source-to-Skin Distance for Stationary Fluoro? | 38 cm (15") |
Minimum Source-to-Skin Distance for mobile C-arm? | 30 cm (12") |
Primary Protective Barrier | |
Legal Filtration Standard? | Minimum HVL 2.5mm AL Eq @ 80 kV |
Minimum shielding for Bucky Slot Cover? Is it Automatically activated? | .25 Pb (Lead Equiv), Auto |
Minimum shielding for Protective Curtain btwn Patient & Rad? | .25 Pb |
Entrance Skin Exposure in fluoro is measured at __ or __? | Table top or 30 cm from IR |
MAX Entrance Skin Exposure WITHOUT high level boost? | 10 R/min |
MAX Entrance Skin Exposure IN high level boost? | 20 R/min |
Primary Barrier is for surfaces Primary Beam is routinely directed at (T/F)? | True |
Primary Barrier is for surfaces that intersect Scatter, Secondary, & Leakage radiation (T/F)? | False - Secondary |
Barrier protection uses what size Lead-Backed drywall? | 1/16" (1.6 mm) or 1/32" (.8 mm) |
Scatter 1 meter from patient is __% of INTENSITY of radiation entering patient? | 1/1000 (.1%) |
Calculating Barrier Thickness - W=? | Workload in mA min/wk |
Calculating Barrier Thickness - U=? | Use Factor |
Calculating Barrier Thickness - T=? | Occupancy (time of) |
How do you find the mA minutes for the workload (WUT)? | mAs รท 60 |
WUT is calculated & __ are used to find required lead thickness? | Tables from NCRP Report #49 |
Secondary Barriers are only required to be __ high? | 7' |
Barrier Thickness Limits for Controlled Areas? | 100 mrem/ wk |
Barrier Thickness Limits for Uncontrolled (public) Areas? | 2 mrem/wk |
__ radiation detectors measure the release of electrons in gas and are used as Survey & Calibration instruments? | Ionization Chamber |
__ radiation detectors are used to locate smallest potential spills or Radionuclides? | Geiger-Muller Detector |
Any ionization releases multiple electrons due to Cascade Effect caused by Higher Voltage in chamber, used in __ rad detectors? | Geiger-Muller |
__ radiation detectors used in labs to detect Alpha & Beta radiation? | Proportional Counter |
__ radiation detectors used in Gamma Cameras & some CT scanners? | Scintillation Detectors |
For Scintillation Detectors, the electron pulse output of the PMT is proportional to __? | Energy absorbed by Scintillation Crystal |
Scintillation Crystals emit __ when struck by __? | Light (from) Radiation |
PMT has Photocathode that emits __ when struck by __? | PMT- Electrons (from) Light |