CAMRT EXAM QUESTIONS AND ANSWERS GRADED A+

How far away must the operator stand from the xray tube if not covered with lead? - 3 meters 90% of man made radiation to the population is related to? - Medical Radiography and Dental For each peak xray voltage, what lead equivalent is required? 100kV or less (o-100) Between 101kV-149kV 150kV or greater (150+) - 0-100kV = 0.25mm of lead Greater than 100kV but less then 150kV = 0.35mm of lead 150kV or greater = 0.50mm of lead What protective equipment is required during interventional procedures - Full wrap around protective gowns of 0.50mm pb in the front panels and 0.25mm pb in the back panels Thyroid shields with an equivalent of 0.50mm of pb Lead drapes/curtains mounted to II of 0.25mm of pb at 100kv What lead equivalent must protective gloves/ gauntlets possess? - 0.25mm of pb What lead equivalent must ceiling mounted lead screens and moveable shields provide? - 0.50mm of pb What are the annual radiation dose limits for radiation workers? - Whole body= 20mSvLens of eye= 150mSv Skin = 500mSv Hands = 150mSv All other organs = 500mSv For pregnant women an effective dose of 4 mSv must be applied for the remainder of the pregnancy from all sources What are the annual radiation dose limits to members of the public? - Whole body = 1mSv Lens of the eye= 15mSv Skin = 50mSv Hands = 50mSv All other organs = 50mSv *these also apply for students* What are primary protective barriers? Give examples - Primary barriers provide shielding from the direct xray beam. Such as, the walls and floor where the tube can be directed -The wall behind the wall bucky -Floor under the table What are secondary barriers and give examples - Provide shielding against both leakage and scattered radiation. Walls that the primary beam is not directed towards and the ceiling are secondary barriers. The control booth is also a secondary barrier, the primary beam should never be directed towards it. What should the focal spot to skin distance be for:-Mobile equipment -Stationary equipment -Radioscopic equipment -Must not be less than: -Mobile: 30cm -Stationary: 38cm -Radioscopic: 20cm (designed for special procedures that would be impossible at 30cm or 38cm) What are the maximum air kerma rates for radioscopic equipment: -with automatic intensity control -without AIC - Not equipped with AIC: 50mGy/min With AIC: 100mGy/min The air kerma rate must not exceed ___ from scattered radiation of radioscopic equipment - 2 mGy/h HVL of Aluminum for given tube voltages? (70kV-150kV) - 70: 2.5mm 80: 2.9mm 90: 3.2mm 100: 3.6mm 110: 3.9mm 120: 4.3mm 130: 4.7mm 140: 5.0mm 150: 5.4mm