15% Rule

SID50 mAs @ 40" SID; ____ mAs @ 20" SID

_12.5_ mAs @ 20" SID

____ mR @ 20" SID; 75mR @ 40" SID

_300 mR @ 20" SID

100 mAs @ 40" SID; ____mAs @ 72" SID

_324_mAs @ 72" SID

____mAs @ 60" SID; 200 mAs @ 40" SID

_450_mAs @ 60" SID

The exposure intensity is 200 mR at 40" SID. What will the intensity be at 60" SID?

88.89 mR

An exposure was made at 150 mA and produced 75mAs. What is the exposure time?

0.5 sec

A chest radiograph was obtained upright at 72" using a technique of 4 mAs @ 100 kVp. A second film is to be obtained supine at 36". What will the mAs need to be to maintain density?

1

A portable knee film was obtained in the recovery room using 4 mAs at 65 kVp at 40" distance. A second film was requested in the patient's room later. Due to space constraints only 20 inch distance could be obtained what would the new mAs be to maintain density?

1

A film was obtained at 75 kVp and 200 mA @ .25 sec. What is the mAs of the original exposure and what would the new kVp be to double the exposure?

86.25 kVp

An acceptable radiograph was obtained using 60 kVp and 20 mAs. To maintain density at 69 kVp what will the new mAs need to be?

10 mAs

Maintain density using the 15% Rule. 25 mAs, 100 KVp: 12.5 mAs, ____KVp.

115

A Radiograph was obtained using 50 mR at 40 inches. What would the new exposure be at 72 inches?

15.43

400 mAs @ 40" SID; ____ mAs @ 80" SID

1600_ mAs @ 80" SID

An acceptable radiograph was obtained at 40" distance using 300 mA @ .25sec and 75 kVp. What will the new mAs need to be at 72" distance?

243 mAs

An acceptable radiograph was obtained using 20 mAs and 70kVp at 40" distance. What must the new distance be to double the density on the film?

28.28

Given and exposure of 200 mA at .20 sec. What is the mAs?

40 mAs

200 mR @ 40" SID; 400 mR @ ____ SID

400mR @ _28.28_ SID

Maintain density using the 15% Rule. 75 mAs, 50 KVp: 150 mAs, ____KVp.

42.5

A radiograph was obtained at 40 inches with an exposure at 70 KVp and 25 mR. A second radiograph is requested and only 30 inch distance can be obtained. What will the new exposure be?

44.45

Maintain density using the 15% Rule. 100 mAs, 60 KVp; 200 mAs, ____ KVp.

51

An acceptable radiograph was obtained at 40" FFD using 65 kVp and 25 mAs. A second radiograph was requested at 60" FFD. What mAs should be used for the exposure at 60"?

56.25 mAs

Maintain density using the 15% Rule. 32 mAs, 55 KVp: 16 mAs, ____ KVp.

62.25

Maintain density using the 15% Rule. 200 mAs, 75 KVp: 400 mAs, ____KVp. .

63.75

150 mAs @ 40" SID; _____ mAs @ 60" SID

66.67_mAs @ 60" SID

Original film technique: 80 KVp, 30 mAs. What will the KVp need to be to reduce the density by half?

68 kVp

Maintain density using the 15% Rule. 50 mAs, 60 KVp: 25 mAs, ____ KVp.

69

A radiograph was obtained which was too light with a technique of 60 KVp and 25 mAs. To double the density what will the new KVp be to accomplish this?

69 kVp

75 mR @ ____ SID; 300 mR @ 20" SID

75 mR @ _40_ SID

Maintain density: original film: 100 mAs, 100 KVp. Second Film: 200 mAs, ______ KVp.

85 kVp