MHP Exam 2 Prep Questions With Correct Answers Guaranteed Pass.

For Linacs, how wide should the Primary Barrier be designed if the maximum field width at the wall is 400cm? - correct answers 460 cm For patient scatter with MV beams: - correct answers the intensity is prop to beam area the mean energy for 90 deg scatter is less than .5 mev production is primarily by compton scattering distribution is considered isotropic about isocenter for leakage rad w mv beams: - correct answers assume .1% at 1 meter unless otherwise specified For 15 MV beams, the TVL in concrete for leakage radiation is approximately twice that for patient scatter radiation (t/f) - correct answers true At 15 MV, the first TVL is ____ the equilibrium TLV for lead and steel for primary photons - correct answers equal to At 15 MV, the first TVL is ______ the equilibrium TLV for lead and steel for leakage photons. - correct answers equal to High energy photons produce neutrons when they hit the concrete walls of the linac room (t/f) - correct answers false Neutrons produce photons when they hit the concrete walls of the linac room (t/f) - correct answers true Fast neutrons are beste moderated by _____ while slow neutrons are best captured by ______. - correct answers polyethylene, boron Neutrons have no charge and therefore do not affect pacemakers (t/f) - correct answers false Gafchromic film can reliably measure doses up to ____ Gy. - correct answers 10 Which detector gives both intensity and location information regarding skin dose? - correct answers gafchromic film Which parameter is the best predictor of possible skin injury from fluoroscopy? - correct answers CAK In early 1982, medical radiation represented 15% of the Effective Dose to individuals in the USA. In 2006, it increased to: - correct answers 48% There is a great concern in the press today regarding cancer risk and CT scans. This risk is thought to be proportional to the: - correct answers DLP Personnel monitoring is required if the worker is likely to receive more than: - correct answers 10% of annual limit The metal filters in a film badge holder are used to estimate the radiation: - correct answers energy To estimate the neutron dose using a CR-39 dosimeter, it is necessary to count the tracks created directlly by: - correct answers alpha particles and protons The NRC recommends that ALARA Level I and ALARA Level II be designated as 10% and 30% of the annual limit, respectively. (t/f) - correct answers true The EDE for fluoroscopy operators wearing a single badge at the collar outside the lead apron is ____ times the badge reading. - correct answers 30% The typical entrance dose rate with fluoroscopy is _______ R/min. - correct answers 5 in general, what is the Tissue Air Ratio to the center of the pelvis from a direct anterior pelvis X-ray? - correct answers 25% of in-air dose What is the minimum distance beyond the field border whereby the radiation dose drops to 5% of the infield entrance dose for a typical anterior pelvis X-ray? - correct answers 5cm For CT scanning, the ratio of the Central to Peripheral Dose for a body scan is: - correct answers 1:2 The CTDI is a function of: - correct answers phantom size A cardiac RF ablation procedure goes on for 70 minutes of fluoroscopy. What is the likely skin dose? - correct answers 350 rem The CTDI100 for a pelvis scan is 20 mGy and the pitch is 0.8. What is the CTDIvol? - correct answers 25 mgy The pelvis scan in Question 7 has DLP of 500 mGy-cm. What was the scan length? - correct answers 20cm The pelvis scan in Question 7 delivered an Effective Dose of 7.5 mGy. Therefore the k factor must have been 0.015 (t/f) - correct answers true The Effective Dose in Question 9 is almost as much as a _____ at the beach. - correct answers decade