mAs + keVs of studies Flashcards
regular diagnostic XR (range of parameters)
mA 200-800
kVp 50-120
fluoro
mA 0-5
kVp 50-120
focal spot general XR
1.0 -1.2 mm
focal spot IR
0.3 -0.6 mm
chest XR :
kVp,
mAs,
grid
thickness of body part
kVp 120
mAs 5
yes grid
21 cm
foot XR :
kVp,
mAs,
grid
thickness of body part
kVp 60
mAs 2
NO grid
9 cm
abdominal XR :
kVp,
mAs,
grid
thickness of body part
kVp 80
mAs 20
yes grid
20 cm
CT:
mA
kVp
mA is super HIGH up to 1000
kvp 80-120
CT focal spot
0.6-1.2 mm
In fluoro, best kVp to use with IV contrast?
60-80 kVp
fluoro Air kerma limit (the one for obese people)
176 mGy/min (20R/min)
fluoro Air kerma limit (the normal one)
87 mGy/min (10R/min)
target/filter combo for HUGE breasts
Rh/rh
Mo/Al (dense breasts)
W/Ag
target filter combo for “intermediate” densities breasts
Mo/Rh
Mammo:
kVp
mA
kVp 25-35 (low Energy)
mA 100 (low tube current)
low-low
mammo tube window
Beryllium
general radiography tube window
pyrex glass
Receptor Air Kerma for mammo vs General Radiology
mammo Air Kerma 100uGy
gen XR Air Kerma 5uGy
mammo grid ratio
5:1
Gen radiology grid ratio
10-1
grids are used above what thickness of tissue
10 cm
contact mammo focal spot size
0.3 mm
magnification mammo focal spot size
0.1 mm
mA for magnification mammo
25 mA
have to drop mA from 100 to 25 due to heat loading from focal size of 0.1mm. Also…have to increase exposure time from 1s to 3 s.
digital display pixels for general Xray
3 Mega pixels
digital display pixels for mammo
5 Mega pixels
Spatial resolution (lp/mm)
Screen film mammo
15 lp/mm
spatial resolution (lp/mm)
Digital mammo
7 lp/mm
spatial resolution (lp/mm)
digital radiograph
3 lp/mm
CT lp/mm
0.7 lp/mm
MRI lp/mm
0.3 lp/mm
Bucky factor for general radiography
4-8 depending on grid ratio
bucky factor for mammo
2
(grid ratio 4:1)
kVp in a pediatric CT
`70 kVp
do kVp modulation in kids
