MDCB LATEST 2026 EXAM STUDY GUIDE QUESTIONS
AND ANSWERS MARKED A+
✔✔Density of mass in air in thimble chamber increases with... - ✔✔decreasing T
increasing P
✔✔TG report concerning measurements absorbed dose - ✔✔51
✔✔In tx breast, dose at chest-lung interface" - ✔✔80% E = depth x 3
✔✔Ripple in - ✔✔1) ~0%
✔✔1) constant - ✔✔2) 5-10%
✔✔2) three phase 6 pulse - ✔✔3) 4%
✔✔3) three phase 12 pulse - ✔✔Tungsten k edge
✔✔70 KeV - ✔✔increase of mAs of 100% is equal to what increase of kVp
✔✔15% - ✔✔Fluoroscopy x ray tube currents
✔✔1-6 mA - ✔✔Radiography/CT xray tube currents
✔✔~100s mA - ✔✔Focal spot in CR
✔✔Small 0.6 mm Large 1.2 mm - ✔✔Typical anode angle
✔✔15 degrees - ✔✔At what energy are photon and compton equal
✔✔25 keV - ✔✔Screen film needs how many uGy to blacken?
✔✔5 uGy - ✔✔Entrance Air Kerma for 1) chest 2) skull 3) abdomen
✔✔1. 0.1 mGy 2. 1.5 mGy 3. 3 mGy - ✔✔State regualtions for HVL
✔✔>2.5 mm Al at 80 kVp - ✔✔OD of the following values allows what percentage of
light to pass through OD 1 OD 2 OD 3
✔✔1 = 10% 2 = 1% 3 = 0.1% - ✔✔Bucky Factor for mammo
✔✔2:1 - ✔✔Bucky factor for CR
, ✔✔5:1 - ✔✔Grid ratio for mammo
✔✔5:1 - ✔✔Grid ration for normal CR
✔✔10-12:1 - ✔✔Bits in a byte
✔✔8 - ✔✔how many gray levels in 8 bits
✔✔256 - ✔✔How many MB do the following images take up 1) CXR 2) Single Mammo
image 3) Digital photospot 4) MR (single slice)
✔✔1) CXR 10 MB 2) Mammo 24 MB 3) Digital photospot 2 MB 4) MR 1/8th mammo -
✔✔Resolution of 1) Screen/film 2) CR 3) Digital Mammo 4) Conventional Mammo 5)
Fluoro 6) CT 7) MR
✔✔1) Screen film 5 lp/mm 2) Digital CR 3 lp/mm 3) Digital Mammo 7 lp/mm 4) Conv
Mammo 15 lp/mm 5) Fluoro 1 lp/mm 6) CT 0.7 lp/mm 7) MR 0.3 lp/mm -
✔✔Occupational Dose Limit (whole body)
✔✔50 mSv/y - ✔✔Occupational Dose Limit (Skin/extremity/any organ other than eye)
✔✔500 mSv/y - ✔✔Occupational Dose limit (eye)
✔✔150 mSv/y - ✔✔Dose limit to general public
✔✔1 mSv/y - ✔✔Dose limit to fetus
✔✔0.5 mSv/ month or 5 mSv entire pregnancy - ✔✔Doubling dose for hereditary effects
✔✔1 Gy - ✔✔Dose to cause skin erythema
✔✔2 Gy - ✔✔Half life of Tc
✔✔6h - ✔✔LD 50/60 for adults
✔✔~ 3.5 Gy - ✔✔Temporary Epilation
✔✔3 Gy - ✔✔Permanet Epilation
✔✔7 Gy - ✔✔Dose to cause catarct (acute and accumulative) acute 4 Gy accumulative
8 Gy
✔✔Sterility in males (temporary and permanent) - ✔✔2.5 and 5 Gy
AND ANSWERS MARKED A+
✔✔Density of mass in air in thimble chamber increases with... - ✔✔decreasing T
increasing P
✔✔TG report concerning measurements absorbed dose - ✔✔51
✔✔In tx breast, dose at chest-lung interface" - ✔✔80% E = depth x 3
✔✔Ripple in - ✔✔1) ~0%
✔✔1) constant - ✔✔2) 5-10%
✔✔2) three phase 6 pulse - ✔✔3) 4%
✔✔3) three phase 12 pulse - ✔✔Tungsten k edge
✔✔70 KeV - ✔✔increase of mAs of 100% is equal to what increase of kVp
✔✔15% - ✔✔Fluoroscopy x ray tube currents
✔✔1-6 mA - ✔✔Radiography/CT xray tube currents
✔✔~100s mA - ✔✔Focal spot in CR
✔✔Small 0.6 mm Large 1.2 mm - ✔✔Typical anode angle
✔✔15 degrees - ✔✔At what energy are photon and compton equal
✔✔25 keV - ✔✔Screen film needs how many uGy to blacken?
✔✔5 uGy - ✔✔Entrance Air Kerma for 1) chest 2) skull 3) abdomen
✔✔1. 0.1 mGy 2. 1.5 mGy 3. 3 mGy - ✔✔State regualtions for HVL
✔✔>2.5 mm Al at 80 kVp - ✔✔OD of the following values allows what percentage of
light to pass through OD 1 OD 2 OD 3
✔✔1 = 10% 2 = 1% 3 = 0.1% - ✔✔Bucky Factor for mammo
✔✔2:1 - ✔✔Bucky factor for CR
, ✔✔5:1 - ✔✔Grid ratio for mammo
✔✔5:1 - ✔✔Grid ration for normal CR
✔✔10-12:1 - ✔✔Bits in a byte
✔✔8 - ✔✔how many gray levels in 8 bits
✔✔256 - ✔✔How many MB do the following images take up 1) CXR 2) Single Mammo
image 3) Digital photospot 4) MR (single slice)
✔✔1) CXR 10 MB 2) Mammo 24 MB 3) Digital photospot 2 MB 4) MR 1/8th mammo -
✔✔Resolution of 1) Screen/film 2) CR 3) Digital Mammo 4) Conventional Mammo 5)
Fluoro 6) CT 7) MR
✔✔1) Screen film 5 lp/mm 2) Digital CR 3 lp/mm 3) Digital Mammo 7 lp/mm 4) Conv
Mammo 15 lp/mm 5) Fluoro 1 lp/mm 6) CT 0.7 lp/mm 7) MR 0.3 lp/mm -
✔✔Occupational Dose Limit (whole body)
✔✔50 mSv/y - ✔✔Occupational Dose Limit (Skin/extremity/any organ other than eye)
✔✔500 mSv/y - ✔✔Occupational Dose limit (eye)
✔✔150 mSv/y - ✔✔Dose limit to general public
✔✔1 mSv/y - ✔✔Dose limit to fetus
✔✔0.5 mSv/ month or 5 mSv entire pregnancy - ✔✔Doubling dose for hereditary effects
✔✔1 Gy - ✔✔Dose to cause skin erythema
✔✔2 Gy - ✔✔Half life of Tc
✔✔6h - ✔✔LD 50/60 for adults
✔✔~ 3.5 Gy - ✔✔Temporary Epilation
✔✔3 Gy - ✔✔Permanet Epilation
✔✔7 Gy - ✔✔Dose to cause catarct (acute and accumulative) acute 4 Gy accumulative
8 Gy
✔✔Sterility in males (temporary and permanent) - ✔✔2.5 and 5 Gy
